chore(release): 0.0.9

.opencode/package-lock.json

@@ -1,52 +0,0 @@
-{
-  "name": "opencode-multi-model-tools",
-  "lockfileVersion": 3,
-  "requires": true,
-  "packages": {
-    "": {
-      "name": "opencode-multi-model-tools",
-      "dependencies": {
-        "@opencode-ai/plugin": "1.2.24"
-      },
-      "devDependencies": {
-        "@types/node": "^25.5.0"
-      }
-    },
-    "node_modules/@opencode-ai/plugin": {
-      "version": "1.2.24",
-      "license": "MIT",
-      "dependencies": {
-        "@opencode-ai/sdk": "1.2.24",
-        "zod": "4.1.8"
-      }
-    },
-    "node_modules/@opencode-ai/sdk": {
-      "version": "1.2.24",
-      "license": "MIT"
-    },
-    "node_modules/@types/node": {
-      "version": "25.5.0",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-25.5.0.tgz",
-      "integrity": "sha512-jp2P3tQMSxWugkCUKLRPVUpGaL5MVFwF8RDuSRztfwgN1wmqJeMSbKlnEtQqU8UrhTmzEmZdu2I6v2dpp7XIxw==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "undici-types": "~7.18.0"
-      }
-    },
-    "node_modules/undici-types": {
-      "version": "7.18.2",
-      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.18.2.tgz",
-      "integrity": "sha512-AsuCzffGHJybSaRrmr5eHr81mwJU3kjw6M+uprWvCXiNeN9SOGwQ3Jn8jb8m3Z6izVgknn1R0FTCEAP2QrLY/w==",
-      "dev": true,
-      "license": "MIT"
-    },
-    "node_modules/zod": {
-      "version": "4.1.8",
-      "license": "MIT",
-      "funding": {
-        "url": "https://github.com/sponsors/colinhacks"
-      }
-    }
-  }
-}

.vscode/launch.json

@@ -0,0 +1,25 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "type": "node",
+      "request": "launch",
+      "name": "Open Multi-Model Session",
+      "runtimeExecutable": "bun",
+      "program": "${workspaceFolder}/src/cli.ts",
+      "args": ["open", "test/session1", "--models", "openai/gpt-5.2"],
+      "cwd": "${workspaceFolder}",
+      "console": "integratedTerminal"
+    },
+    {
+      "type": "node",
+      "request": "launch",
+      "name": "Close Multi-Model Session",
+      "runtimeExecutable": "bun",
+      "program": "${workspaceFolder}/src/cli.ts",
+      "args": ["close", "test/session1"],
+      "cwd": "${workspaceFolder}",
+      "console": "integratedTerminal"
+    }
+  ]
+}

.vscode/settings.json

@@ -0,0 +1,16 @@
+{
+  // The path to the `bun` executable.
+  "bun.runtime": "/path/to/bun",
+
+  // If support for Bun should be added to the default "JavaScript Debug Terminal".
+  "bun.debugTerminal.enabled": true,
+
+  // If the debugger should stop on the first line of the program.
+  "bun.debugTerminal.stopOnEntry": false,
+
+  // Glob pattern to find test files. Defaults to the value shown below.
+  "bun.test.filePattern": "**/*{.test.,.spec.,_test_,_spec_}{js,ts,tsx,jsx,mts,cts,cjs,mjs}",
+
+  // The custom script to call for testing instead of `bun test`
+  "bun.test.customScript": "bun test",
+}

README.md

@@ -13,7 +13,7 @@ Add to your OpenCode config (`opencode.json`):
 
 ```json
 {
-  "plugin": ["@username/opencode-multi-model"]
+  "plugin": ["opencode-multi-model"]
 }
 ```
 
@@ -21,10 +21,10 @@ Add to your OpenCode config (`opencode.json`):
 
 ```bash
 # Using bunx (no install)
-bunx @username/opencode-multi-model open my-session -m openai/gpt-5.2 anthropic/claude-3-5-sonnet
+bunx opencode-multi-model open my-session -m openai/gpt-5.2 anthropic/claude-3-5-sonnet
 
 # Or install globally
-bun install -g @username/opencode-multi-model
+bun install -g opencode-multi-model
 opencode-multi-model open my-session -m openai/gpt-5.2
 ```
 
@@ -34,7 +34,7 @@ If you installed it via bun and want to use it as a project tool, import it from
 
 ```typescript
 // .opencode/tools/multi-model.ts
-import { openTool as open, closeTool as close } from "@username/opencode-multi-model"
+import { openTool as open, closeTool as close } from "opencode-multi-model"
 export { open, close }
 ```
 
@@ -118,6 +118,79 @@ opencode-multi-model open my-session -m openai/gpt-5.2 -b kilo
 
 Priority: CLI flag > Environment variable > Default ("opencode")
 
+## CLI Reference
+
+### `open` - Create a new multi-model tmux session
+
+```bash
+opencode-multi-model open <session-name> [options]
+```
+
+**Arguments:**
+- `<session-name>` - Name for the tmux session (required)
+
+**Options:**
+| Option | Description |
+|--------|-------------|
+| `-m, --models <models...>` | Model IDs to launch (space-separated) |
+| `-b, --binary <binary>` | Binary to use (opencode or kilo). Defaults to env var `OPENCODE_MULTI_MODEL_BINARY` or 'opencode' |
+
+### `close` - Close a multi-model tmux session
+
+```bash
+opencode-multi-model close <session-name> [options]
+```
+
+**Arguments:**
+- `<session-name>` - Name of the tmux session to close (required)
+
+**Options:**
+| Option | Description |
+|--------|-------------|
+| `--keep-worktrees` | Do not remove worktrees and delete branches |
+| `--no-tags` | Do not create archive tags before deleting branches |
+| `-f, --force` | Skip confirmation prompts |
+
+### Global Options
+
+| Option | Description |
+|--------|-------------|
+| `-h, --help` | Display help information |
+| `-V, --version` | Display version number |
+
+## How it works
+
+### `open` command
+
+The `open` command performs the following steps:
+
+1. **Validation**: Checks that session name andmodels are provided, no duplicate models exist, and verifies git repo, tmux, and binary are available
+
+2. **Model verification**: Validates models against `opencode models` output to ensure only valid model IDs are used
+
+3. **Git worktree creation**: For each model, creates:
+   - A git worktree at `~/.local/share/opencode/multi-model/<session>/<model>/`
+   - A branch named `opencode/<session>/<model>`
+
+4. **Tmux session**: Creates a tmux session with one window per model, each window's working directory set to its corresponding worktree
+
+5. **Launch**: Sends the launch command to each window to start the binary with the specified model
+
+### `close` command
+
+The `close` command performs the following steps:
+
+1. **Kill tmux session**: Terminates the tmux session if it exists
+
+2. **Worktree discovery**: Finds all worktrees under `~/.local/share/opencode/multi-model/<session>/`
+
+3. **Worktree cleanup** (unless `--keep-worktrees`):
+   - Removes each gitworktree
+   - Creates an archive tag (unless `--no-tags`): `archive/<branch>-<timestamp>` for recovery
+   - Deletes the associated branches
+
+4. **Directory cleanup**: Removes the base session directory
+
 ## Requirements
 
 - tmux
@@ -153,7 +226,7 @@ bun dist/cli.js close test-session
 │   ├── types.ts               # Shared TypeScript types
 │   ├── core/
 │   │   ├── index.ts           # Core exports
-│   │   ├── launch.ts          # Launch session logic
+│   │   ├── open.ts            # Launch session logic
 │   │   ├── close.ts           # Close session logic
 │   │   └── utils.ts           # Helper functions
 │   └── tools/
@@ -166,6 +239,19 @@ bun dist/cli.js close test-session
 └── README.md
 ```
 
+## Local code coverage
+
+The test suite can generate a coverage report locally.
+
+```bash
+# Run tests with coverage (HTML report generated in ./coverage)
+  npm run coverage   # or: bun run coverage
+# Open the HTML report
+ open coverage/index.html   # macOS
+```
+
+The `coverage` directory is ignored by Git but can be inspected to see which lines are exercised.
+
 ## License
 
 MIT

bun.lock

@@ -6,6 +6,7 @@
       "name": "@username/opencode-multi-model",
       "dependencies": {
         "@opencode-ai/plugin": "^1.2.27",
+        "chalk": "^5.3.0",
         "commander": "^12.0.0",
       },
       "devDependencies": {
@@ -25,6 +26,8 @@
 
     "bun-types": ["bun-types@1.3.11", "", { "dependencies": { "@types/node": "*" } }, "sha512-1KGPpoxQWl9f6wcZh57LvrPIInQMn2TQ7jsgxqpRzg+l0QPOFvJVH7HmvHo/AiPgwXy+/Thf6Ov3EdVn1vOabg=="],
 
+    "chalk": ["chalk@5.6.2", "", {}, "sha512-7NzBL0rN6fMUW+f7A6Io4h40qQlG+xGmtMxfbnH/K7TAtt8JQWVQK+6g0UXKMeVJoyV5EkkNsErQ8pVD3bLHbA=="],
+
     "commander": ["commander@12.1.0", "", {}, "sha512-Vw8qHK3bZM9y/P10u3Vib8o/DdkvA2OtPtZvD871QKjy74Wj1WSKFILMPRPSdUSx5RFK1arlJzEtA4PkFgnbuA=="],
 
     "undici-types": ["undici-types@7.18.2", "", {}, "sha512-AsuCzffGHJybSaRrmr5eHr81mwJU3kjw6M+uprWvCXiNeN9SOGwQ3Jn8jb8m3Z6izVgknn1R0FTCEAP2QrLY/w=="],

package.json

@@ -1,11 +1,11 @@
 {
-  "name": "@username/opencode-multi-model",
+  "name": "opencode-multi-model",
-  "version": "1.0.0",
+  "version": "0.0.9",
   "description": "Launch multiple AI models in tmux sessions - OpenCode Plugin, CLI, and Project Tool",
   "type": "module",
   "main": "./dist/index.js",
   "bin": {
-    "opencode-multi-model": "./dist/cli.js"
+    "opencode-multi-model": "dist/cli.js"
   },
   "exports": {
     ".": "./dist/index.js",
@@ -19,9 +19,12 @@
   "scripts": {
     "build": "bun build src/index.ts src/cli.ts --outdir dist --target bun --format esm",
     "test": "bun test",
-    "prepublishOnly": "bun run build"
+    "coverage": "bun test --coverage",
+    "prepublishOnly": "bun run build",
+    "release": "bash ./scripts/release.sh"
   },
   "dependencies": {
+    "chalk": "^5.3.0",
     "@opencode-ai/plugin": "^1.2.27",
     "commander": "^12.0.0"
   },

scripts/release.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+set -e
+
+# Prompt for version bump type
+read -p "Select version bump (major/minor/patch): " bump
+if [[ ! "$bump" =~ ^(major|minor|patch)$ ]]; then
+  echo "Invalid choice. Must be 'major', 'minor', or 'patch'."
+  exit 1
+fi
+
+# Run tests
+echo "Running test suite..."
+npm test
+
+# Build the project
+echo "Building the project..."
+npm run build
+
+# Bump version
+echo "Bumping version ($bump)..."
+npm version "$bump" -m "chore(release): %s"
+
+# Show git status
+git status
+
+# Confirm publishing
+read -p "Proceed with npm publish? (y/N): " confirm
+if [[ "$confirm" != "y" && "$confirm" != "Y" ]]; then
+  echo "Publish aborted."
+  exit 0
+fi
+
+# Publish to npm
+npm publish
+
+# Push git commits and tags
+git push && git push --tags
+
+echo "Release completed successfully."

src/cli.ts

@@ -1,6 +1,6 @@
 #!/usr/bin/env bun
 import { Command } from "commander";
-import { launchMultiModel } from "./core/launch";
+import { openMultiModel } from "./core/open";
 import { closeMultiModel } from "./core/close";
 import { getBinaryName } from "./core/utils";
 
@@ -21,7 +21,7 @@ program
     try {
       const binaryName = options.binary || getBinaryName();
 
-      const result = await launchMultiModel({
+      const result = await openMultiModel({
         sessionName,
         models: options.models,
         binaryName,
@@ -44,30 +44,20 @@ program
   .command("close")
   .description("Close a multi-model tmux session")
   .argument("<session-name>", "Name of the tmux session to close")
-  .option("-c, --cleanup-worktrees", "Remove worktrees and delete branches", true)
+  .option("--keep-worktrees", "Do not remove worktrees and delete branches", false)
+  .option("--no-tags", "Create archive tags before deleting branches")
   .option("-f, --force", "Skip confirmation prompts", false)
-  .action(async (sessionName: string, options: { cleanupWorktrees: boolean; force: boolean }) => {
+  .action(async (sessionName: string, options: { keepWorktrees: boolean; force: boolean; tags: boolean }) => {
     try {
       const result = await closeMultiModel({
         sessionName,
-        cleanupWorktrees: options.cleanupWorktrees,
+        cleanupWorktrees: !options.keepWorktrees,
         force: options.force,
+        createArchiveTags: options.tags,
       });
 
-      if (result.success) {
+if (result.success) {
-        console.log(`Closed session: ${result.sessionName}`);
+          console.log(result.instructions);
-        if (result.cleanupPerformed) {
-          console.log(`  Removed ${result.worktreesRemoved?.length || 0} worktrees`);
-          if (result.tagsCreated && result.tagsCreated.length > 0) {
-            console.log(`  Created backup tags: ${result.tagsCreated.join(", ")}`);
-          }
-          if (result.warnings && result.warnings.length > 0) {
-            console.log(`  Warnings: ${result.warnings.join("; ")}`);
-          }
-          if (result.branchesDeleted && result.branchesDeleted.length > 0) {
-            console.log(`  Deleted ${result.branchesDeleted.length} branches`);
-          }
-        }
         } else {
         console.error(`Failed: ${result.error}`);
         process.exit(1);

src/core/close.ts

@@ -1,6 +1,7 @@
 import * as readline from "node:readline";
+import chalk from 'chalk'; // removed console usage
 import type { CloseSessionOptions, CloseSessionResult } from "../types";
-import { runCommand, getSessionPath, getWorktreesForSession } from "./utils";
+import { runCommand, getSessionPath, getWorktreesForSession, sanitizeName } from "./utils";
 
 /**
  * Prompts the user for input on the terminal.
@@ -45,10 +46,12 @@ async function promptUser(question: string): Promise<string> {
  */
 export async function closeMultiModel(options: CloseSessionOptions): Promise<CloseSessionResult> {
   const worktreesRemoved: string[] = [];
+  const instructionsArr: string[] = [];
   const branchesDeleted: string[] = [];
   const tagsCreated: string[] = [];
-  const warnings: string[] = [];
 
+
+  const safeSessionName = sanitizeName(options.sessionName);
   try {
     // Check if session exists
     const { ok: sessionExists } = await runCommand(["tmux", "has-session", "-t", options.sessionName]);
@@ -56,22 +59,29 @@ export async function closeMultiModel(options: CloseSessionOptions): Promise<Clo
     // Kill tmux session if it exists
     if (sessionExists) {
       await runCommand(["tmux", "kill-session", "-t", options.sessionName]);
+      instructionsArr.push(chalk.green(`Closed session '${options.sessionName}'`));
+    } else {
+      instructionsArr.push(chalk.yellow(`Session '${options.sessionName}' does not exist`));
     }
 
     // Get list of worktrees for this session before killing tmux
-    const worktrees = await getWorktreesForSession(options.sessionName);
+    const worktrees = await getWorktreesForSession(safeSessionName);
 
     // If cleanup requested and not forced, ask for confirmation
     if (options.cleanupWorktrees && !options.force && worktrees.length > 0) {
-      console.log(`\nThe following worktrees and branches will be removed:`);
+      console.log(chalk.red('The following worktrees and branches will be removed:'));
-      worktrees.forEach((wt) => console.log(`  - ${wt.path} (branch: ${wt.branch})`));
+      worktrees.forEach((wt) => {
+        const msg = `  - ${wt.path} (branch: ${wt.branch})`;
+        console.log(msg.trim());
+      });
 
-      const answer = await promptUser("\nDo you want to proceed? (y/N): ");
+      const answer = await promptUser(chalk.bold("\nDo you want to proceed? (y/N): "));
       if (answer.toLowerCase() !== "y" && answer.toLowerCase() !== "yes") {
         return {
           success: false,
-          sessionName: options.sessionName,
+          sessionName: safeSessionName,
           error: "Cleanup cancelled by user",
+          instructions: instructionsArr.join("\n"),
         };
       }
     }
@@ -86,7 +96,8 @@ export async function closeMultiModel(options: CloseSessionOptions): Promise<Clo
           await runCommand(["git", "worktree", "remove", "-f", worktree.path]);
           worktreesRemoved.push(worktree.path);
 
-          // Create an archive tag before deleting the branch for safe recovery
+// Optionally create an archive tag before deleting the branch for safe recovery
+           if (options.createArchiveTags !== false) {
              const timestamp = new Date().toISOString().replace(/[:.]/g, "-");
              const archiveTag = `archive/${worktree.branch}-${timestamp}`;
              const tagResult = await runCommand(["git", "tag", archiveTag, worktree.branch]);
@@ -94,20 +105,20 @@ export async function closeMultiModel(options: CloseSessionOptions): Promise<Clo
              if (tagResult.ok) {
                tagsCreated.push(archiveTag);
              } else {
-            const warningMsg = `Failed to create tag ${archiveTag} for branch ${worktree.branch}.`;
+               const warningMsg = chalk.red(`Warning: Failed to create tag ${archiveTag} for branch ${worktree.branch}.`);
-            warnings.push(warningMsg);
+               instructionsArr.push(warningMsg);
-            console.warn(`Warning: ${warningMsg}`);
+             }
            }
 
           await runCommand(["git", "branch", "-D", worktree.branch]);
           branchesDeleted.push(worktree.branch);
         } catch (err) {
-          console.warn(`Warning: Failed to cleanup worktree ${worktree.path}: ${err}`);
+            instructionsArr.push(chalk.red(`Failed to cleanup worktree ${worktree.path}: ${err}`));
         }
       }
 
       // Also remove the base directory
-      const worktreeBase = getSessionPath(options.sessionName);
+      const worktreeBase = getSessionPath(safeSessionName);
       try {
         await runCommand(["rm", "-rf", worktreeBase]);
       } catch {
@@ -115,26 +126,32 @@ export async function closeMultiModel(options: CloseSessionOptions): Promise<Clo
       }
 
       cleanupPerformed = worktreesRemoved.length > 0;
+      if (cleanupPerformed) {
+        instructionsArr.push(chalk.dim(`Removed ${worktreesRemoved.length} worktrees, alongwith their branches.`));
+        if (tagsCreated.length > 0) {
+          instructionsArr.push(chalk.dim(`Created archive tags: ${tagsCreated.join(", ")}.`));
+        }
+      }
     }
 
-    return {
+return {
        success: true,
-      sessionName: options.sessionName,
+       sessionName: safeSessionName,
        cleanupPerformed,
        worktreesRemoved,
        branchesDeleted,
        tagsCreated,
-      warnings,
+       instructions: instructionsArr.join("\n"),
      };
   } catch (error) {
-    return {
+return {
         success: false,
-      sessionName: options.sessionName,
+        sessionName: safeSessionName,
         error: String(error),
         worktreesRemoved,
         branchesDeleted,
         tagsCreated,
-      warnings,
+        instructions: instructionsArr.join("\n"),
       };
   }
 }

src/core/index.ts

@@ -1,3 +1,3 @@
-export { launchMultiModel } from "./launch";
+export { openMultiModel } from "./open";
 export { closeMultiModel } from "./close";
 export * from "./utils";

src/core/open.ts

@@ -1,4 +1,5 @@
 import * as fs from "node:fs";
+import chalk from 'chalk';
 import type { MultiModelOptions, MultiModelResult } from "../types";
 import {
   runCommand,
@@ -24,7 +25,7 @@ import {
  *
  * @example
  * ```ts
- * const result = await launchMultiModel({
+ * const result = await openMultiModel({
  *   sessionName: "compare",
  *   models: ["openai/gpt-5.2", "anthropic/claude-3-5-sonnet"],
  *   binaryName: "opencode",
@@ -34,7 +35,7 @@ import {
  * }
  * ```
  */
-export async function launchMultiModel(options: MultiModelOptions): Promise<MultiModelResult> {
+export async function openMultiModel(options: MultiModelOptions): Promise<MultiModelResult> {
   const sessionName = options.sessionName.trim();
   const safeSessionName = sanitizeName(sessionName);
   const models = normalizeModels(options.models);
@@ -153,7 +154,9 @@ export async function launchMultiModel(options: MultiModelOptions): Promise<Mult
       if (!sessionCreateResult.ok) {
         const undoErrors = await undoWorktree(worktreePath, branchName);
         let errorMsg = `Error: Failed to create tmux session '${sessionName}'.${sessionCreateResult.stderr ? ` ${sessionCreateResult.stderr}` : ""}`;
-        if (undoErrors.length > 0) errorMsg += ` Cleanup errors: ${undoErrors.join(", ")}`;
+        if (undoErrors.length > 0) {
+          errorMsg += ` Cleanup errors: ${undoErrors.join(", ")}`;
+        }
         return { success: false, sessionName, error: errorMsg };
       }
     } else {
@@ -172,7 +175,9 @@ export async function launchMultiModel(options: MultiModelOptions): Promise<Mult
       if (!windowCreateResult.ok) {
         failedModels.push(`${plan.model} (${windowCreateResult.stderr || "failed to create window"})`);
         const undoErrors = await undoWorktree(worktreePath, branchName);
-        if (undoErrors.length > 0) failedModels.push(`cleanup failed for ${plan.model}: ${undoErrors.join(", ")}`);
+        if (undoErrors.length > 0) {
+          failedModels.push(`cleanup failed for ${plan.model}: ${undoErrors.join(", ")}`);
+        }
         continue;
       }
     }
@@ -201,13 +206,17 @@ export async function launchMultiModel(options: MultiModelOptions): Promise<Mult
       sessionName,
       windows: windowNames,
       instructions: [
-        `Error: Created tmux session '${sessionName}', but some model launches failed.`,
+        chalk.red(`Error: Created tmux session '${sessionName}', but some model launches failed.`),
-        `Succeeded: ${succeededModels.length > 0 ? succeededModels.join(", ") : "none"}.`,
+        chalk.red(`Failed: ${failedModels.join(", ")}.`),
-        `Failed: ${failedModels.join(", ")}.`,
+        chalk.dim(`Succeeded: ${succeededModels.length > 0 ? succeededModels.join(", ") : "none"}.`),
-        `Attach with \`${attachCommand}\` to inspect the session.`,
+        "",
-        `Cleanup when done using either:`,
+        chalk.bold(`Attach with \`${attachCommand}\` to inspect the session.`),
-        `1. ${primaryCleanup}`,
+        "",
-        `2. Or run manually: \`${cleanupCommand}\``,
+        chalk.dim(`When finished, clean up using:`),
+        primaryCleanup,
+        "",
+        chalk.dim(`Alternate manual cleanup - `),
+        chalk.dim(cleanupCommand)
       ].join("\n"),
     };
   }
@@ -217,10 +226,13 @@ export async function launchMultiModel(options: MultiModelOptions): Promise<Mult
     sessionName,
     windows: windowNames,
     instructions: [
-      `Use \`${attachCommand}\` to join session.`,
+      chalk.bold(`Use \`${attachCommand}\` to join session.`),
-      `When finished, clean up using either:`,
+      "",
-      `1. ${primaryCleanup}`,
+      chalk.dim(`When finished, clean up using:`),
-      `2. Or run manually: \`${cleanupCommand}\``,
+      primaryCleanup,
+      "",
+      chalk.dim(`Alternate manual cleanup - `),
+      chalk.dim(cleanupCommand)
     ].join("\n"),
   };
 }

src/core/utils.ts

@@ -332,7 +332,7 @@ export async function getWorktreesForSession(sessionName: string): Promise<Workt
   const { stdout } = await runCommand(["git", "worktree", "list", "--porcelain"]);
   const worktrees: WorktreeInfo[] = [];
 
-  const sessionPath = getSessionPath(sessionName);
+  const sessionPath = getSessionPath(sanitizeName(sessionName));
 
   let currentWorktree: Partial<WorktreeInfo> = {};
 

src/tools/close.ts

@@ -12,12 +12,14 @@ export const closeTool = tool({
   args: {
     sessionName: tool.schema.string().min(1).describe("tmux session name to close"),
     cleanupWorktrees: tool.schema.boolean().default(true).describe("whether to remove worktrees and delete branches (default: true)"),
+      createArchiveTags: tool.schema.boolean().default(true).describe("whether to create archive tags before deleting branches (default: true)"),
   },
   async execute(args, context) {
     // In plugin mode, we skip confirmation (force=true) since there's no interactive terminal
     const result = await closeMultiModel({
       sessionName: args.sessionName,
       cleanupWorktrees: args.cleanupWorktrees,
+      createArchiveTags: args.createArchiveTags,
       force: true,
     });
 
@@ -25,17 +27,6 @@ export const closeTool = tool({
       return result.error!;
     }
 
-    let details = "";
+    return result.instructions;
-    if (result.cleanupPerformed) {
-      details += ` Removed ${result.worktreesRemoved?.length || 0} worktrees.`;
-      if (result.tagsCreated && result.tagsCreated.length > 0) {
-        details += ` Created backup tags: ${result.tagsCreated.join(", ")}.`;
-      }
-      if (result.warnings && result.warnings.length > 0) {
-        details += ` Warnings: ${result.warnings.join("; ")}.`;
-      }
-    }
-
-    return `Session "${result.sessionName}" has been closed.${details}`;
   },
 });

src/tools/open.ts

@@ -1,5 +1,5 @@
 import { tool } from "@opencode-ai/plugin";
-import { launchMultiModel } from "../core/launch";
+import { openMultiModel } from "../core/open";
 import { getBinaryName } from "../core/utils";
 
 /**
@@ -20,7 +20,7 @@ export const openTool = tool({
   async execute(args, context) {
     const binaryName = getBinaryName();
 
-    const result = await launchMultiModel({
+    const result = await openMultiModel({
       sessionName: args.sessionName,
       models: args.models,
       binaryName,

src/types.ts

@@ -32,6 +32,8 @@ export interface MultiModelResult {
  * Options for closing a multi-model tmux session.
  */
 export interface CloseSessionOptions {
+  /** Whether to create archive tags before deleting branches. */
+  createArchiveTags?: boolean;
   /** Name of the tmux session to close. */
   sessionName: string;
   /** Whether to remove worktrees and delete branches. */
@@ -44,6 +46,8 @@ export interface CloseSessionOptions {
  * Result returned after attempting to close a multi-model session.
  */
 export interface CloseSessionResult {
+  /** Console messages and instructions. */
+  instructions: string;
   /** Whether the close succeeded. */
   success: boolean;
   /** The session name that was closed. */
@@ -58,8 +62,7 @@ export interface CloseSessionResult {
   branchesDeleted?: string[];
   /** Archive tags that were created before branch deletion. */
   tagsCreated?: string[];
-  /** Warning messages. */
+
-  warnings?: string[];
 }
 
 /**

tests/close.test.ts

@@ -0,0 +1,261 @@
+import { expect, test, mock, spyOn, beforeEach, afterEach, describe } from "bun:test";
+import * as os from "node:os";
+import * as readline from "node:readline";
+import { closeMultiModel } from "../src/core/close";
+
+let originalBun$: typeof Bun.$ = (globalThis as any).Bun?.$;
+let mockCommandResponses: Record<string, { ok: boolean; stdout: string; stderr: string }> = {};
+let executedCommands: string[] = [];
+
+function setupMockBun$() {
+  const mockFn = mock((strings: TemplateStringsArray, ...values: any[]) => {
+    const parts = values[0] as string[];
+    const commandSignature = parts.join(" ");
+    executedCommands.push(commandSignature);
+    const response = mockCommandResponses[commandSignature] ?? { ok: true, stdout: "", stderr: "" };
+    return {
+      quiet: () => ({
+        nothrow: async () => ({
+          exitCode: response.ok ? 0 : 1,
+          stdout: { toString: () => response.stdout },
+          stderr: { toString: () => response.stderr },
+        }),
+      }),
+    };
+  });
+  (globalThis as any).Bun.$ = mockFn;
+  return mockFn;
+}
+
+function restoreOriginalBun$() {
+  (globalThis as any).Bun.$ = originalBun$;
+}
+
+describe("closeMultiModel", () => {
+  let bunMock: ReturnType<typeof setupMockBun$>;
+
+  beforeEach(() => {
+    spyOn(os, "homedir").mockReturnValue("/home/user");
+    bunMock = setupMockBun$();
+    executedCommands = [];
+    mockCommandResponses = {};
+  });
+
+  afterEach(() => {
+    restoreOriginalBun$();
+  });
+
+  test("kills existing session without cleanup", async () => {
+    mockCommandResponses["tmux has-session -t test-session"] = { ok: true, stdout: "", stderr: "" };
+    mockCommandResponses["tmux kill-session -t test-session"] = { ok: true, stdout: "", stderr: "" };
+    // No worktrees
+    mockCommandResponses["git worktree list --porcelain"] = { ok: true, stdout: "", stderr: "" };
+
+    const result = await closeMultiModel({ sessionName: "test-session", cleanupWorktrees: false, force: false });
+    expect(result.success).toBe(true);
+    expect(result.cleanupPerformed).toBe(false);
+    expect(result.worktreesRemoved).toEqual([]);
+    expect(executedCommands).toContain("tmux has-session -t test-session");
+    expect(executedCommands).toContain("tmux kill-session -t test-session");
+  });
+
+  test("no session exists, no cleanup", async () => {
+    mockCommandResponses["tmux has-session -t test-session"] = { ok: false, stdout: "", stderr: "" };
+    mockCommandResponses["git worktree list --porcelain"] = { ok: true, stdout: "", stderr: "" };
+
+    const result = await closeMultiModel({ sessionName: "test-session", cleanupWorktrees: false, force: false });
+    expect(result.success).toBe(true);
+    expect(result.cleanupPerformed).toBe(false);
+    expect(result.worktreesRemoved).toEqual([]);
+    expect(executedCommands).toContain("tmux has-session -t test-session");
+    // No kill-session should be issued
+    expect(executedCommands.some(c => c.startsWith("tmux kill-session"))).toBe(false);
+  });
+
+  test("cleanup works with worktrees and force, all succeeds", async () => {
+    mockCommandResponses["tmux has-session -t test-session"] = { ok: false, stdout: "", stderr: "" };
+    const worktreePath = "/home/user/.local/share/opencode/multi-model/test-session/model";
+    const worktreeListOutput = `worktree ${worktreePath}\nbranch refs/heads/opencode/test-session/model`;
+    mockCommandResponses["git worktree list --porcelain"] = { ok: true, stdout: worktreeListOutput, stderr: "" };
+    mockCommandResponses[`git worktree remove -f ${worktreePath}`] = { ok: true, stdout: "", stderr: "" };
+    mockCommandResponses["git branch -D opencode/test-session/model"] = { ok: true, stdout: "", stderr: "" };
+    // Tag command will default to ok:true via fallback
+    mockCommandResponses["rm -rf /home/user/.local/share/opencode/multi-model/test-session"] = { ok: true, stdout: "", stderr: "" };
+
+    // Freeze timestamp for deterministic tag name
+    const fixedDate = new Date("2023-01-01T00:00:00.000Z");
+    const OriginalDate = Date;
+    // @ts-ignore
+    global.Date = class extends OriginalDate { constructor() { super(); return fixedDate; } toISOString() { return "2023-01-01T00:00:00.000Z"; } } as any;
+
+    const result = await closeMultiModel({ sessionName: "test-session", cleanupWorktrees: true, force: true });
+    // Restore Date
+    // @ts-ignore
+    global.Date = OriginalDate;
+
+    expect(result.success).toBe(true);
+    expect(result.cleanupPerformed).toBe(true);
+    expect(result.worktreesRemoved).toEqual([worktreePath]);
+    expect(result.branchesDeleted).toEqual(["opencode/test-session/model"]);
+    expect(result.tagsCreated?.length).toBe(1);
+    
+    // Ensure removal commands were executed
+    expect(executedCommands).toContain(`git worktree remove -f ${worktreePath}`);
+    expect(executedCommands).toContain(`git branch -D opencode/test-session/model`);
+  });
+
+  test("user cancels cleanup when not forced", async () => {
+    mockCommandResponses["tmux has-session -t test-session"] = { ok: false, stdout: "", stderr: "" };
+    const worktreePath = "/home/user/.local/share/opencode/multi-model/test-session/model";
+    const worktreeListOutput = `worktree ${worktreePath}\nbranch refs/heads/opencode/test-session/model`;
+    mockCommandResponses["git worktree list --porcelain"] = { ok: true, stdout: worktreeListOutput, stderr: "" };
+
+    // Stub readline to return "n"
+    const mockInterface = {
+      question: (q: string, cb: (a: string) => void) => cb("n"),
+      close: () => {},
+    } as any;
+    spyOn(readline, "createInterface").mockImplementation(() => mockInterface);
+
+    const result = await closeMultiModel({ sessionName: "test-session", cleanupWorktrees: true, force: false });
+    expect(result.success).toBe(false);
+    expect(result.error).toBe("Cleanup cancelled by user");
+  });
+
+  test("user confirms cleanup when not forced", async () => {
+    mockCommandResponses["tmux has-session -t test-session"] = { ok: false, stdout: "", stderr: "" };
+    const worktreePath = "/home/user/.local/share/opencode/multi-model/test-session/model";
+    const worktreeListOutput = `worktree ${worktreePath}\nbranch refs/heads/opencode/test-session/model`;
+    mockCommandResponses["git worktree list --porcelain"] = { ok: true, stdout: worktreeListOutput, stderr: "" };
+
+    // Stub readline to simulate user confirming cleanup (answers "y")
+    const mockInterface = {
+      question: (q: string, cb: (a: string) => void) => cb("y"),
+      close: () => {},
+    } as any;
+    spyOn(readline, "createInterface").mockImplementation(() => mockInterface);
+
+    // Freeze timestamp for deterministic tag name
+    const fixedDate = new Date("2023-01-01T00:00:00.000Z");
+    const OriginalDate = Date;
+    // @ts-ignore
+    global.Date = class extends OriginalDate { constructor() { super(); return fixedDate; } toISOString() { return "2023-01-01T00:00:00.000Z"; } } as any;
+
+    const result = await closeMultiModel({ sessionName: "test-session", cleanupWorktrees: true, force: false });
+
+    // Restore Date after invocation
+    // @ts-ignore
+    global.Date = OriginalDate;
+
+    // Verify result indicates successful cleanup
+    expect(result.success).toBe(true);
+    expect(result.cleanupPerformed).toBe(true);
+    expect(result.worktreesRemoved).toEqual([worktreePath]);
+    expect(result.branchesDeleted).toEqual(["opencode/test-session/model"]);
+    expect(result.tagsCreated?.length).toBe(1);
+    
+
+    // Verify the expected git commands were executed
+    expect(executedCommands).toContain(`git worktree remove -f ${worktreePath}`);
+    expect(executedCommands).toContain(`git branch -D opencode/test-session/model`);
+    const expectedTagCmd = `git tag archive/opencode/test-session/model-2023-01-01T00-00-00-000Z opencode/test-session/model`;
+    expect(executedCommands).toContain(expectedTagCmd);
+  });
+
+  test("warning when tag creation fails", async () => {
+    mockCommandResponses["tmux has-session -t test-session"] = { ok: false, stdout: "", stderr: "" };
+    const worktreePath = "/home/user/.local/share/opencode/multi-model/test-session/model";
+    const worktreeListOutput = `worktree ${worktreePath}\nbranch refs/heads/opencode/test-session/model`;
+    mockCommandResponses["git worktree list --porcelain"] = { ok: true, stdout: worktreeListOutput, stderr: "" };
+    mockCommandResponses[`git worktree remove -f ${worktreePath}`] = { ok: true, stdout: "", stderr: "" };
+    mockCommandResponses["git branch -D opencode/test-session/model"] = { ok: true, stdout: "", stderr: "" };
+    // Tag command will fail
+    const fixedDate = new Date("2023-01-01T00:00:00.000Z");
+    const OriginalDate = Date;
+    // @ts-ignore
+    global.Date = class extends OriginalDate { constructor() { super(); return fixedDate; } toISOString() { return "2023-01-01T00:00:00.000Z"; } } as any;
+    const tagCommand = `git tag archive/opencode/test-session/model-2023-01-01T00-00-00-000Z opencode/test-session/model`;
+    mockCommandResponses[tagCommand] = { ok: false, stdout: "", stderr: "tag error" };
+
+    const result = await closeMultiModel({ sessionName: "test-session", cleanupWorktrees: true, force: true });
+    // Restore Date
+    // @ts-ignore
+    global.Date = OriginalDate;
+
+    expect(result.success).toBe(true);
+    // Expect the warning message to be captured in instructions
+    expect(result.instructions.includes('Failed to create tag')).toBe(true);
+    expect(result.tagsCreated).toEqual([]);
+  });
+
+  test("cleanup works with unsanitized session name", async () => {
+    const unsanitized = "test session!";
+    const sanitized = "test-session"; // result of sanitizeName
+    // tmux lookup uses unsanitized name
+    mockCommandResponses[`tmux has-session -t ${unsanitized}`] = { ok: false, stdout: "", stderr: "" };
+    const worktreePath = `/home/user/.local/share/opencode/multi-model/${sanitized}/model`;
+    const worktreeListOutput = `worktree ${worktreePath}\nbranch refs/heads/opencode/${sanitized}/model`;
+    mockCommandResponses["git worktree list --porcelain"] = { ok: true, stdout: worktreeListOutput, stderr: "" };
+    mockCommandResponses[`git worktree remove -f ${worktreePath}`] = { ok: true, stdout: "", stderr: "" };
+    mockCommandResponses[`git branch -D opencode/${sanitized}/model`] = { ok: true, stdout: "", stderr: "" };
+    mockCommandResponses[`rm -rf /home/user/.local/share/opencode/multi-model/${sanitized}`] = { ok: true, stdout: "", stderr: "" };
+
+    // Freeze timestamp for deterministic tag name
+    const fixedDate = new Date("2023-01-01T00:00:00.000Z");
+    const OriginalDate = Date;
+    // @ts-ignore
+    global.Date = class extends OriginalDate { constructor() { super(); return fixedDate; } toISOString() { return "2023-01-01T00:00:00.000Z"; } } as any;
+
+    const result = await closeMultiModel({ sessionName: unsanitized, cleanupWorktrees: true, force: true });
+    // Restore Date
+    // @ts-ignore
+    global.Date = OriginalDate;
+
+    expect(result.success).toBe(true);
+    expect(result.cleanupPerformed).toBe(true);
+    expect(result.worktreesRemoved).toEqual([worktreePath]);
+    expect(result.branchesDeleted).toEqual([`opencode/${sanitized}/model`]);
+    expect(result.tagsCreated?.length).toBe(1);
+    // Verify that the commands used the sanitized paths for worktree removal and branch deletion
+    expect(executedCommands).toContain(`git worktree remove -f ${worktreePath}`);
+    expect(executedCommands).toContain(`git branch -D opencode/${sanitized}/model`);
+  });
+
+  test("tmux commands use sessionName, not safeSessionName", async () => {
+    const unsanitized = "my session!";
+    const sanitized = "my-session";
+    mockCommandResponses[`tmux has-session -t ${unsanitized}`] = { ok: true, stdout: "", stderr: "" };
+    mockCommandResponses[`tmux kill-session -t ${unsanitized}`] = { ok: true, stdout: "", stderr: "" };
+    // No worktrees
+    mockCommandResponses["git worktree list --porcelain"] = { ok: true, stdout: "", stderr: "" };
+
+    const result = await closeMultiModel({ sessionName: unsanitized, cleanupWorktrees: false, force: false });
+    expect(result.success).toBe(true);
+    // Verify tmux commands used unsanitized name
+    expect(executedCommands).toContain(`tmux has-session -t ${unsanitized}`);
+    expect(executedCommands).toContain(`tmux kill-session -t ${unsanitized}`);
+    // Ensure sanitized name not used in tmux commands
+    expect(executedCommands.some(c => c.includes(`-t ${sanitized}`))).toBe(false);
+  });
+
+  test("skip archive tags when flag disabled", async () => {
+    mockCommandResponses["tmux has-session -t test-session"] = { ok: false, stdout: "", stderr: "" };
+    const worktreePath = "/home/user/.local/share/opencode/multi-model/test-session/model";
+    const worktreeListOutput = `worktree ${worktreePath}\nbranch refs/heads/opencode/test-session/model`;
+    mockCommandResponses["git worktree list --porcelain"] = { ok: true, stdout: worktreeListOutput, stderr: "" };
+    mockCommandResponses[`git worktree remove -f ${worktreePath}`] = { ok: true, stdout: "", stderr: "" };
+    mockCommandResponses["git branch -D opencode/test-session/model"] = { ok: true, stdout: "", stderr: "" };
+    mockCommandResponses["rm -rf /home/user/.local/share/opencode/multi-model/test-session"] = { ok: true, stdout: "", stderr: "" };
+
+    const result = await closeMultiModel({ sessionName: "test-session", cleanupWorktrees: true, force: true, createArchiveTags: false });
+
+    expect(result.success).toBe(true);
+    expect(result.cleanupPerformed).toBe(true);
+    expect(result.worktreesRemoved).toEqual([worktreePath]);
+    expect(result.branchesDeleted).toEqual(["opencode/test-session/model"]);
+    expect(result.tagsCreated?.length ?? 0).toBe(0);
+    // Ensure no tag command was executed
+    expect(executedCommands.some(cmd => cmd.startsWith("git tag"))).toBe(false);
+  });
+});
+

tests/close_error.test.ts

@@ -0,0 +1,53 @@
+import { expect, test, mock, beforeEach, afterEach, describe, spyOn } from "bun:test";
+import * as os from "node:os";
+import { closeMultiModel } from "../src/core/close";
+
+let originalBun$: typeof Bun.$ = (globalThis as any).Bun?.$;
+let mockCommandResponses: Record<string, { ok: boolean; stdout: string; stderr: string }> = {};
+let executedCommands: string[] = [];
+
+function setupMockBun$() {
+  const mockFn = mock((strings: TemplateStringsArray, ...values: any[]) => {
+    const parts = values[0] as string[];
+    const cmd = parts.join(" ");
+    executedCommands.push(cmd);
+    // Simulate throwing error for a specific command
+    if (cmd === "git worktree list --porcelain") {
+      throw new Error("unexpected error");
+    }
+    const response = mockCommandResponses[cmd] ?? { ok: true, stdout: "", stderr: "" };
+    return {
+      quiet: () => ({
+        nothrow: async () => ({
+          exitCode: response.ok ? 0 : 1,
+          stdout: { toString: () => response.stdout },
+          stderr: { toString: () => response.stderr },
+        }),
+      }),
+    };
+  });
+  (globalThis as any).Bun.$ = mockFn;
+  return mockFn;
+}
+
+function restoreOriginalBun$() {
+  (globalThis as any).Bun.$ = originalBun$;
+}
+
+describe("closeMultiModel unexpected error handling", () => {
+  beforeEach(() => {
+    spyOn(os, "homedir").mockReturnValue("/home/user");
+    mockCommandResponses = {};
+    executedCommands = [];
+    setupMockBun$();
+  });
+  afterEach(() => {
+    restoreOriginalBun$();
+  });
+
+  test("catches thrown error and returns failure", async () => {
+    const result = await closeMultiModel({ sessionName: "any-session", cleanupWorktrees: false, force: false });
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("unexpected error");
+  });
+});

tests/open.test.ts

@@ -0,0 +1,382 @@
+import { expect, test, mock, spyOn, beforeEach, afterEach, describe } from "bun:test";
+import * as fs from "node:fs";
+import * as os from "node:os";
+import { openMultiModel } from "../src/core/open";
+import {
+  shellQuote,
+  normalizeModels,
+  findDuplicates,
+  createWindowBaseName,
+  createWindowPlans,
+  levenshtein,
+  suggestModels,
+  formatInvalidModelError,
+  sanitizeName,
+  runCommand,
+  getWorktreePath,
+  getSessionPath,
+  undoWorktree,
+  launchModelInWindow,
+  getWorktreesForSession,
+  getBinaryName,
+} from "../src/core/utils";
+
+let originalBun$: typeof Bun.$ = (globalThis as any).Bun?.$;
+let mockCommandResponses: Record<string, { ok: boolean; stdout: string; stderr: string }> = {};
+let executedCommands: string[] = [];
+
+function setupMockBun$() {
+  const mockFn = mock((strings: TemplateStringsArray, ...values: any[]) => {
+    const parts = values[0] as string[];
+    const commandSignature = parts.join(" ");
+
+    executedCommands.push(commandSignature);
+
+    return {
+      quiet: () => ({
+        nothrow: async () => {
+          const response = mockCommandResponses[commandSignature] ?? { ok: true, stdout: "", stderr: "" };
+          return {
+            exitCode: response.ok ? 0 : 1,
+            stdout: { toString: () => response.stdout },
+            stderr: { toString: () => response.stderr },
+          };
+        },
+      }),
+    };
+  });
+
+  (globalThis as any).Bun.$ = mockFn;
+  return mockFn;
+}
+
+function restoreOriginalBun$() {
+  (globalThis as any).Bun.$ = originalBun$;
+}
+
+describe("multi-model launch", () => {
+  let existsSyncMock: ReturnType<typeof spyOn>;
+  let bunMock: ReturnType<typeof setupMockBun$>;
+
+  beforeEach(() => {
+    spyOn(os, "homedir").mockReturnValue("/mock/home");
+    existsSyncMock = spyOn(fs, "existsSync").mockReturnValue(false);
+    bunMock = setupMockBun$();
+    executedCommands = [];
+
+    mockCommandResponses = {
+      "git rev-parse --is-inside-work-tree": { ok: true, stdout: "true", stderr: "" },
+      "command -v tmux": { ok: true, stdout: "/usr/bin/tmux", stderr: "" },
+      "command -v opencode": { ok: true, stdout: "/usr/bin/opencode", stderr: "" },
+      "opencode models": { ok: true, stdout: "openai/gpt-5.2\nanthropic/claude-3-5-sonnet", stderr: "" },
+      "tmux has-session -t test-session": { ok: false, stdout: "", stderr: "session not found" },
+      "git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2": { ok: false, stdout: "", stderr: "" },
+    };
+  });
+
+  afterEach(() => {
+    restoreOriginalBun$();
+  });
+
+  test("fails if session name is empty", async () => {
+    const result = await openMultiModel({
+      sessionName: "",
+      models: ["openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Error: `sessionName` must not be empty.");
+    expect(executedCommands).toEqual([]);
+  });
+
+  test("fails if no models are provided", async () => {
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: [],
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Error: Model names must not be empty.");
+    expect(executedCommands).toEqual([]);
+  });
+
+  test("fails if duplicate models are provided", async () => {
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["openai/gpt-5.2", "openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Duplicate model names are not allowed");
+    expect(executedCommands).toEqual([]);
+  });
+
+  test("fails if not inside a git repository", async () => {
+    mockCommandResponses["git rev-parse --is-inside-work-tree"] = { ok: false, stdout: "", stderr: "not a git repo" };
+
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Error: `multi-model` requires a git repository.");
+    expect(executedCommands).toEqual(["git rev-parse --is-inside-work-tree"]);
+  });
+
+  test("fails if tmux is not installed", async () => {
+    mockCommandResponses["command -v tmux"] = { ok: false, stdout: "", stderr: "" };
+
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Error: `tmux` is not installed or not on `PATH`.");
+    expect(executedCommands).toEqual([
+      "git rev-parse --is-inside-work-tree",
+      "command -v tmux",
+    ]);
+  });
+
+  test("fails if opencode is not installed", async () => {
+    mockCommandResponses["command -v opencode"] = { ok: false, stdout: "", stderr: "" };
+
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Error: `opencode` is not installed or not on `PATH`.");
+    expect(executedCommands).toEqual([
+      "git rev-parse --is-inside-work-tree",
+      "command -v tmux",
+      "command -v opencode",
+    ]);
+  });
+
+  test("fails if model name is not in allowlist", async () => {
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["invalid/model"],
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Error: Model name 'invalid/model' not found");
+    expect(executedCommands).toEqual([
+      "git rev-parse --is-inside-work-tree",
+      "command -v tmux",
+      "command -v opencode",
+      "opencode models",
+    ]);
+  });
+
+  test("fails if session already exists", async () => {
+    mockCommandResponses["tmux has-session -t test-session"] = { ok: true, stdout: "", stderr: "" };
+
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Error: Session already exists");
+    expect(executedCommands).toEqual([
+      "git rev-parse --is-inside-work-tree",
+      "command -v tmux",
+      "command -v opencode",
+      "opencode models",
+      "tmux has-session -t test-session",
+    ]);
+  });
+
+  test("successfully plans and executes tmux launch with single model", async () => {
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(true);
+    expect(result.instructions).toContain("Use `tmux attach -t test-session` to join session");
+    expect(executedCommands.some(c => c.startsWith("tmux new-session -d -s test-session -n gpt-5-2"))).toBe(true);
+    expect(executedCommands.some(c => c.startsWith("tmux send-keys -t test-session:gpt-5-2"))).toBe(true);
+  });
+
+  test("successfully launches multiple models", async () => {
+    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/claude-3-5-sonnet"] = { ok: false, stdout: "", stderr: "" };
+
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["openai/gpt-5.2", "anthropic/claude-3-5-sonnet"],
+    });
+
+    expect(result.success).toBe(true);
+    expect(result.instructions).toContain("Use `tmux attach -t test-session` to join session");
+    expect(executedCommands.some(c => c.startsWith("tmux new-session -d -s test-session -n gpt-5-2"))).toBe(true);
+    expect(executedCommands.some(c => c.startsWith("tmux new-window -d -t test-session -n claude-3-5-sonnet"))).toBe(true);
+  });
+
+  test("sanitizes session name", async () => {
+    mockCommandResponses["tmux has-session -t test session!"] = { ok: false, stdout: "", stderr: "" };
+    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2"] = { ok: false, stdout: "", stderr: "" };
+
+    const result = await openMultiModel({
+      sessionName: "test session!",
+      models: ["openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(true);
+    expect(result.instructions).toContain("Use `tmux attach -t test session!` to join session");
+    expect(executedCommands.some(c => c.startsWith("git worktree add -b opencode/test-session/gpt-5-2"))).toBe(true);
+  });
+
+  test("uses sessionName for tmux commands, not safeSessionName", async () => {
+    const unsanitized = "my awesome session!!";
+    const sanitized = "my-awesome-session";
+    mockCommandResponses[`tmux has-session -t ${unsanitized}`] = { ok: false, stdout: "", stderr: "" };
+    mockCommandResponses[`git show-ref --verify --quiet refs/heads/opencode/${sanitized}/gpt-5-2`] = { ok: false, stdout: "", stderr: "" };
+    mockCommandResponses[`git worktree add -b opencode/${sanitized}/gpt-5-2 /mock/home/.local/share/opencode/multi-model/${sanitized}/gpt-5-2`] = { ok: true, stdout: "", stderr: "" };
+    mockCommandResponses[`tmux new-session -d -s ${unsanitized} -n gpt-5-2 -c /mock/home/.local/share/opencode/multi-model/${sanitized}/gpt-5-2`] = { ok: true, stdout: "", stderr: "" };
+    mockCommandResponses[`tmux send-keys -t ${unsanitized}:gpt-5-2 opencode --model 'openai/gpt-5.2' C-m`] = { ok: true, stdout: "", stderr: "" };
+
+    const result = await openMultiModel({
+      sessionName: unsanitized,
+      models: ["openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(true);
+    // tmux commands should use unsanitized name
+    expect(executedCommands.some(c => c.startsWith(`tmux has-session -t ${unsanitized}`))).toBe(true);
+    expect(executedCommands.some(c => c.startsWith(`tmux new-session -d -s ${unsanitized}`))).toBe(true);
+    expect(executedCommands.some(c => c.startsWith(`tmux send-keys -t ${unsanitized}:`))).toBe(true);
+    // sanitized name should NOT appear in tmux commands
+    expect(executedCommands.some(c => c.includes(`-t ${sanitized}`))).toBe(false);
+    // git branches and paths should use sanitized name
+    expect(executedCommands.some(c => c.startsWith(`git worktree add -b opencode/${sanitized}/gpt-5-2`))).toBe(true);
+  });
+
+  test("fails if tmux new-session fails for the first model and triggers undo", async () => {
+    mockCommandResponses["tmux new-session -d -s test-session -n gpt-5-2 -c /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2"] = { ok: false, stdout: "", stderr: "tmux error" };
+    mockCommandResponses["git worktree remove -f /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2"] = { ok: true, stdout: "", stderr: "" };
+    mockCommandResponses["git branch -D opencode/test-session/gpt-5-2"] = { ok: true, stdout: "", stderr: "" };
+
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Failed to create tmux session");
+    expect(executedCommands).toEqual([
+      "git rev-parse --is-inside-work-tree",
+      "command -v tmux",
+      "command -v opencode",
+      "opencode models",
+      "tmux has-session -t test-session",
+      "git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2",
+      "git worktree add -b opencode/test-session/gpt-5-2 /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2",
+      "tmux new-session -d -s test-session -n gpt-5-2 -c /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2",
+      "git worktree remove -f /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2",
+      "git branch -D opencode/test-session/gpt-5-2",
+    ]);
+  });
+
+  test("fails if worktree path exists for first model", async () => {
+    existsSyncMock.mockImplementation((path: string) => {
+      return path.includes("test-session/gpt-5-2");
+    });
+
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Worktree path already exists");
+    expect(executedCommands).toEqual([
+      "git rev-parse --is-inside-work-tree",
+      "command -v tmux",
+      "command -v opencode",
+      "opencode models",
+      "tmux has-session -t test-session",
+    ]);
+  });
+
+  test("fails if git branch exists for first model", async () => {
+    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2"] = { ok: true, stdout: "", stderr: "" };
+
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Branch 'opencode/test-session/gpt-5-2' already exists");
+    expect(executedCommands).toEqual([
+      "git rev-parse --is-inside-work-tree",
+      "command -v tmux",
+      "command -v opencode",
+      "opencode models",
+      "tmux has-session -t test-session",
+      "git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2",
+    ]);
+  });
+
+  test("fails if git worktree add fails for first model", async () => {
+    mockCommandResponses["git worktree add -b opencode/test-session/gpt-5-2 /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2"] = { ok: false, stdout: "", stderr: "git error" };
+
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["openai/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Failed to create worktree");
+    expect(executedCommands).toEqual([
+      "git rev-parse --is-inside-work-tree",
+      "command -v tmux",
+      "command -v opencode",
+      "opencode models",
+      "tmux has-session -t test-session",
+      "git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2",
+      "git worktree add -b opencode/test-session/gpt-5-2 /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2",
+    ]);
+  });
+
+  test("model name collision creates unique window names", async () => {
+    mockCommandResponses["opencode models"] = { ok: true, stdout: "openai/gpt-5.2\nanthropic/gpt-5.2", stderr: "" };
+    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2"] = { ok: false, stdout: "", stderr: "" };
+    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2-2"] = { ok: false, stdout: "", stderr: "" };
+
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: ["openai/gpt-5.2", "anthropic/gpt-5.2"],
+    });
+
+    expect(result.success).toBe(true);
+    expect(result.instructions).toContain("Use `tmux attach -t test-session` to join session");
+    expect(executedCommands.some(c => c.startsWith("tmux new-session -d -s test-session -n gpt-5-2"))).toBe(true);
+    expect(executedCommands.some(c => c.startsWith("tmux new-window -d -t test-session -n gpt-5-2-2"))).toBe(true);
+  });
+
+  test("long model name is truncated in window name", async () => {
+    const longModel = "verylongmodelfrontexampleprovider";
+    mockCommandResponses["opencode models"] = { ok: true, stdout: longModel, stderr: "" };
+    mockCommandResponses[`git show-ref --verify --quiet refs/heads/opencode/test-session/${longModel.slice(0, 24)}`] = { ok: false, stdout: "", stderr: "" };
+
+    const result = await openMultiModel({
+      sessionName: "test-session",
+      models: [longModel],
+    });
+
+    expect(result.success).toBe(true);
+    expect(result.instructions).toContain("Use `tmux attach -t test-session` to join session");
+    const windowName = executedCommands.find(c => c.includes("tmux new-session"))?.match(/-n (\S+)/)?.[1];
+    expect(windowName?.length).toBeLessThanOrEqual(24);
+  });
+});
+
+// ----------
+// Core utils tests remain in a separate file.

tests/open_error.test.ts

@@ -0,0 +1,236 @@
+import { expect, test, mock, beforeEach, afterEach, describe, spyOn } from "bun:test";
+import * as os from "node:os";
+import * as fs from "node:fs";
+import { openMultiModel } from "../src/core/open";
+
+let originalBun$: typeof Bun.$ = (globalThis as any).Bun?.$;
+let mockCommandResponses: Record<string, { ok: boolean; stdout: string; stderr: string }> = {};
+let executedCommands: string[] = [];
+
+function setupMockBun$() {
+  const mockFn = mock((strings: TemplateStringsArray, ...values: any[]) => {
+    const parts = values[0] as string[];
+    const cmd = parts.join(" ");
+    executedCommands.push(cmd);
+    const response = mockCommandResponses[cmd] ?? { ok: true, stdout: "", stderr: "" };
+    return {
+      quiet: () => ({
+        nothrow: async () => ({
+          exitCode: response.ok ? 0 : 1,
+          stdout: { toString: () => response.stdout },
+          stderr: { toString: () => response.stderr },
+        }),
+      }),
+    };
+  });
+  (globalThis as any).Bun.$ = mockFn;
+  return mockFn;
+}
+
+function restoreOriginalBun$() {
+  (globalThis as any).Bun.$ = originalBun$;
+}
+
+describe("openMultiModel error paths", () => {
+  beforeEach(() => {
+    spyOn(os, "homedir").mockReturnValue("/mock/home");
+    mockCommandResponses = {};
+    executedCommands = [];
+    setupMockBun$();
+  });
+  afterEach(() => {
+    restoreOriginalBun$();
+  });
+
+  test("fails when model list command fails", async () => {
+    const session = "sess";
+    mockCommandResponses["git rev-parse --is-inside-work-tree"] = { ok: true, stdout: "true", stderr: "" };
+    mockCommandResponses["command -v tmux"] = { ok: true, stdout: "tmux", stderr: "" };
+    mockCommandResponses["command -v opencode"] = { ok: true, stdout: "opencode", stderr: "" };
+    mockCommandResponses["opencode models"] = { ok: false, stdout: "", stderr: "model error" };
+
+    const result = await openMultiModel({ sessionName: session, models: ["openai/gpt-5.2"], binaryName: "opencode", mode: "cli" });
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Failed to load valid models");
+  });
+
+  test("fails when duplicate models provided", async () => {
+    const session = "dup";
+    mockCommandResponses["git rev-parse --is-inside-work-tree"] = { ok: true, stdout: "true", stderr: "" };
+    mockCommandResponses["command -v tmux"] = { ok: true, stdout: "tmux", stderr: "" };
+    mockCommandResponses["command -v opencode"] = { ok: true, stdout: "opencode", stderr: "" };
+    mockCommandResponses["opencode models"] = { ok: true, stdout: "openai/gpt-5.2", stderr: "" };
+
+    const result = await openMultiModel({ sessionName: session, models: ["openai/gpt-5.2", "openai/gpt-5.2"], binaryName: "opencode", mode: "cli" });
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Duplicate model names are not allowed");
+  });
+
+  test("fails when session already exists", async () => {
+    const session = "existing";
+    mockCommandResponses["git rev-parse --is-inside-work-tree"] = { ok: true, stdout: "true", stderr: "" };
+    mockCommandResponses["command -v tmux"] = { ok: true, stdout: "tmux", stderr: "" };
+    mockCommandResponses["command -v opencode"] = { ok: true, stdout: "opencode", stderr: "" };
+    mockCommandResponses["opencode models"] = { ok: true, stdout: "openai/gpt-5.2", stderr: "" };
+    mockCommandResponses[`tmux has-session -t ${session}`] = { ok: true, stdout: "", stderr: "" };
+
+    const result = await openMultiModel({ sessionName: session, models: ["openai/gpt-5.2"], binaryName: "opencode", mode: "cli" });
+    expect(result.success).toBe(false);
+    expect(result.error).toContain("Session already exists");
+  });
+
+    test("second model fails because branch already exists", async () => {
+      const session = "sess-add";
+      const binary = "opencode";
+      const models = ["openai/gpt-5.2", "anthropic/gpt-5-2"];
+      // common mocks
+      mockCommandResponses["git rev-parse --is-inside-work-tree"] = { ok: true, stdout: "true", stderr: "" };
+      mockCommandResponses["command -v tmux"] = { ok: true, stdout: "tmux", stderr: "" };
+      mockCommandResponses["command -v opencode"] = { ok: true, stdout: "opencode", stderr: "" };
+      mockCommandResponses["opencode models"] = { ok: true, stdout: models.join("\n"), stderr: "" };
+      mockCommandResponses[`tmux has-session -t ${session}`] = { ok: false, stdout: "", stderr: "" };
+      // first model success
+      const firstBranch = `opencode/${session}/gpt-5-2`;
+      const firstPath = `/mock/home/.local/share/opencode/multi-model/${session}/gpt-5-2`;
+      mockCommandResponses[`git show-ref --verify --quiet refs/heads/${firstBranch}`] = { ok: false, stdout: "", stderr: "" };
+      mockCommandResponses[`git worktree add -b ${firstBranch} ${firstPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux new-session -d -s ${session} -n gpt-5-2 -c ${firstPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux send-keys -t ${session}:gpt-5-2 ${binary} --model 'openai/gpt-5.2' C-m`] = { ok: true, stdout: "", stderr: "" };
+      // second model branch exists
+      const secondBranch = `opencode/${session}/gpt-5-2-2`;
+      mockCommandResponses[`git show-ref --verify --quiet refs/heads/${secondBranch}`] = { ok: true, stdout: "", stderr: "" };
+      const result = await openMultiModel({ sessionName: session, models, binaryName: binary, mode: "cli" });
+      expect(result.success).toBe(true);
+      expect(result.instructions).toContain("Failed: anthropic/gpt-5-2 (Branch");
+      expect(result.windows).toContain("gpt-5-2");
+      expect(result.windows).toContain("gpt-5-2-2");
+    });
+
+    test("second model worktree creation fails", async () => {
+      const session = "sess-wt";
+      const binary = "opencode";
+      const models = ["openai/gpt-5.2", "anthropic/gpt-5-2"];
+      mockCommandResponses["git rev-parse --is-inside-work-tree"] = { ok: true, stdout: "true", stderr: "" };
+      mockCommandResponses["command -v tmux"] = { ok: true, stdout: "tmux", stderr: "" };
+      mockCommandResponses["command -v opencode"] = { ok: true, stdout: "opencode", stderr: "" };
+      mockCommandResponses["opencode models"] = { ok: true, stdout: models.join("\n"), stderr: "" };
+      mockCommandResponses[`tmux has-session -t ${session}`] = { ok: false, stdout: "", stderr: "" };
+      // first model success
+      const firstBranch = `opencode/${session}/gpt-5-2`;
+      const firstPath = `/mock/home/.local/share/opencode/multi-model/${session}/gpt-5-2`;
+      mockCommandResponses[`git show-ref --verify --quiet refs/heads/${firstBranch}`] = { ok: false, stdout: "", stderr: "" };
+      mockCommandResponses[`git worktree add -b ${firstBranch} ${firstPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux new-session -d -s ${session} -n gpt-5-2 -c ${firstPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux send-keys -t ${session}:gpt-5-2 ${binary} --model 'openai/gpt-5.2' C-m`] = { ok: true, stdout: "", stderr: "" };
+      // second model fails worktree
+      const secondBranch = `opencode/${session}/gpt-5-2-2`;
+      const secondPath = `/mock/home/.local/share/opencode/multi-model/${session}/gpt-5-2-2`;
+      mockCommandResponses[`git show-ref --verify --quiet refs/heads/${secondBranch}`] = { ok: false, stdout: "", stderr: "" };
+      mockCommandResponses[`git worktree add -b ${secondBranch} ${secondPath}`] = { ok: false, stdout: "", stderr: "wt error" };
+      mockCommandResponses[`git worktree remove -f ${secondPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`git branch -D ${secondBranch}`] = { ok: true, stdout: "", stderr: "" };
+const result = await openMultiModel({ sessionName: session, models, binaryName: binary, mode: "cli" });
+
+
+        expect(result.success).toBe(true);
+        expect(result.instructions).toContain("Error: Created tmux session"); expect(result.instructions).toContain("Failed: anthropic/gpt-5-2");
+        expect(result.windows).toContain("gpt-5-2");
+        expect(result.windows).toContain("gpt-5-2-2");
+    });
+
+    test("second model window creation fails", async () => {
+      const session = "sess-win";
+      const binary = "opencode";
+      const models = ["openai/gpt-5.2", "anthropic/gpt-5-2"];
+      mockCommandResponses["git rev-parse --is-inside-work-tree"] = { ok: true, stdout: "true", stderr: "" };
+      mockCommandResponses["command -v tmux"] = { ok: true, stdout: "tmux", stderr: "" };
+      mockCommandResponses["command -v opencode"] = { ok: true, stdout: "opencode", stderr: "" };
+      mockCommandResponses["opencode models"] = { ok: true, stdout: models.join("\n"), stderr: "" };
+      mockCommandResponses[`tmux has-session -t ${session}`] = { ok: false, stdout: "", stderr: "" };
+      // first model success
+      const firstBranch = `opencode/${session}/gpt-5-2`;
+      const firstPath = `/mock/home/.local/share/opencode/multi-model/${session}/gpt-5-2`;
+      mockCommandResponses[`git show-ref --verify --quiet refs/heads/${firstBranch}`] = { ok: false, stdout: "", stderr: "" };
+      mockCommandResponses[`git worktree add -b ${firstBranch} ${firstPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux new-session -d -s ${session} -n gpt-5-2 -c ${firstPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux send-keys -t ${session}:gpt-5-2 ${binary} --model 'openai/gpt-5.2' C-m`] = { ok: true, stdout: "", stderr: "" };
+      // second model window failure
+      const secondBranch = `opencode/${session}/gpt-5-2-2`;
+      const secondPath = `/mock/home/.local/share/opencode/multi-model/${session}/gpt-5-2-2`;
+      mockCommandResponses[`git show-ref --verify --quiet refs/heads/${secondBranch}`] = { ok: false, stdout: "", stderr: "" };
+      mockCommandResponses[`git worktree add -b ${secondBranch} ${secondPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux new-window -d -t ${session} -n gpt-5-2-2 -c ${secondPath}`] = { ok: false, stdout: "", stderr: "win err" };
+      mockCommandResponses[`git worktree remove -f ${secondPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`git branch -D ${secondBranch}`] = { ok: true, stdout: "", stderr: "" };
+const result = await openMultiModel({ sessionName: session, models, binaryName: binary, mode: "cli" });
+
+
+        expect(result.success).toBe(true);
+        expect(result.instructions).toContain("Error: Created tmux session"); expect(result.instructions).toContain("Failed: anthropic/gpt-5-2");
+        expect(result.windows).toContain("gpt-5-2");
+        expect(result.windows).toContain("gpt-5-2-2");
+    });
+
+    test("second model launch command fails", async () => {
+      const session = "sess-launch";
+      const binary = "opencode";
+      const models = ["openai/gpt-5.2", "anthropic/gpt-5-2"];
+      mockCommandResponses["git rev-parse --is-inside-work-tree"] = { ok: true, stdout: "true", stderr: "" };
+      mockCommandResponses["command -v tmux"] = { ok: true, stdout: "tmux", stderr: "" };
+      mockCommandResponses["command -v opencode"] = { ok: true, stdout: "opencode", stderr: "" };
+      mockCommandResponses["opencode models"] = { ok: true, stdout: models.join("\n"), stderr: "" };
+      mockCommandResponses[`tmux has-session -t ${session}`] = { ok: false, stdout: "", stderr: "" };
+      // first model success
+      const firstBranch = `opencode/${session}/gpt-5-2`;
+      const firstPath = `/mock/home/.local/share/opencode/multi-model/${session}/gpt-5-2`;
+      mockCommandResponses[`git show-ref --verify --quiet refs/heads/${firstBranch}`] = { ok: false, stdout: "", stderr: "" };
+      mockCommandResponses[`git worktree add -b ${firstBranch} ${firstPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux new-session -d -s ${session} -n gpt-5-2 -c ${firstPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux send-keys -t ${session}:gpt-5-2 ${binary} --model 'openai/gpt-5.2' C-m`] = { ok: true, stdout: "", stderr: "" };
+      // second model launch fails
+      const secondBranch = `opencode/${session}/gpt-5-2-2`;
+      const secondPath = `/mock/home/.local/share/opencode/multi-model/${session}/gpt-5-2-2`;
+      mockCommandResponses[`git show-ref --verify --quiet refs/heads/${secondBranch}`] = { ok: false, stdout: "", stderr: "" };
+      mockCommandResponses[`git worktree add -b ${secondBranch} ${secondPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux new-window -d -t ${session} -n gpt-5-2-2 -c ${secondPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux send-keys -t ${session}:gpt-5-2-2 ${binary} --model 'anthropic/gpt-5-2' C-m`] = { ok: false, stdout: "", stderr: "launch err" };
+      mockCommandResponses[`git worktree remove -f ${secondPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`git branch -D ${secondBranch}`] = { ok: true, stdout: "", stderr: "" };
+      const result = await openMultiModel({ sessionName: session, models, binaryName: binary, mode: "cli" });
+      expect(result.success).toBe(true);
+      expect(result.instructions).toContain("Failed: anthropic/gpt-5-2 (launch err");
+      expect(result.windows).toContain("gpt-5-2");
+      expect(result.windows).toContain("gpt-5-2-2");
+    });
+
+    test("second model worktree path already exists", async () => {
+      const session = "sess-wtpath";
+      const binary = "opencode";
+      const models = ["openai/gpt-5.2", "anthropic/gpt-5-2"];
+      mockCommandResponses["git rev-parse --is-inside-work-tree"] = { ok: true, stdout: "true", stderr: "" };
+      mockCommandResponses["command -v tmux"] = { ok: true, stdout: "tmux", stderr: "" };
+      mockCommandResponses["command -v opencode"] = { ok: true, stdout: "opencode", stderr: "" };
+      mockCommandResponses["opencode models"] = { ok: true, stdout: models.join("\n"), stderr: "" };
+      mockCommandResponses[`tmux has-session -t ${session}`] = { ok: false, stdout: "", stderr: "" };
+      // first model success
+      const firstBranch = `opencode/${session}/gpt-5-2`;
+      const firstPath = `/mock/home/.local/share/opencode/multi-model/${session}/gpt-5-2`;
+      mockCommandResponses[`git show-ref --verify --quiet refs/heads/${firstBranch}`] = { ok: false, stdout: "", stderr: "" };
+      mockCommandResponses[`git worktree add -b ${firstBranch} ${firstPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux new-session -d -s ${session} -n gpt-5-2 -c ${firstPath}`] = { ok: true, stdout: "", stderr: "" };
+      mockCommandResponses[`tmux send-keys -t ${session}:gpt-5-2 ${binary} --model 'openai/gpt-5.2' C-m`] = { ok: true, stdout: "", stderr: "" };
+      // second model path exists
+      const secondBranch = `opencode/${session}/gpt-5-2-2`;
+      const secondPath = `/mock/home/.local/share/opencode/multi-model/${session}/gpt-5-2-2`;
+      mockCommandResponses[`git show-ref --verify --quiet refs/heads/${secondBranch}`] = { ok: false, stdout: "", stderr: "" };
+      // mock fs existsSync to return true for secondPath
+      spyOn(fs, "existsSync").mockImplementation((p) => p === secondPath);
+      const result = await openMultiModel({ sessionName: session, models, binaryName: binary, mode: "cli" });
+      expect(result.success).toBe(true);
+      expect(result.instructions).toContain("Error: Created tmux session");
+      expect(result.instructions).toContain("Failed: anthropic/gpt-5-2 (Worktree path already exists at");
+      expect(result.windows).toContain("gpt-5-2");
+      expect(result.windows).toContain("gpt-5-2-2");
+    });
+
+    });

tests/utils.test.ts

@@ -1,7 +1,6 @@
 import { expect, test, mock, spyOn, beforeEach, afterEach, describe } from "bun:test";
 import * as fs from "node:fs";
 import * as os from "node:os";
-import { launchMultiModel } from "../src/core/launch";
 import {
   shellQuote,
   normalizeModels,
@@ -29,9 +28,7 @@ function setupMockBun$() {
   const mockFn = mock((strings: TemplateStringsArray, ...values: any[]) => {
     const parts = values[0] as string[];
     const commandSignature = parts.join(" ");
-
     executedCommands.push(commandSignature);
-
     return {
       quiet: () => ({
         nothrow: async () => {
@@ -45,7 +42,6 @@ function setupMockBun$() {
       }),
     };
   });
-
   (globalThis as any).Bun.$ = mockFn;
   return mockFn;
 }
@@ -54,305 +50,6 @@ function restoreOriginalBun$() {
   (globalThis as any).Bun.$ = originalBun$;
 }
 
-describe("multi-model launch", () => {
-  let existsSyncMock: ReturnType<typeof spyOn>;
-  let bunMock: ReturnType<typeof setupMockBun$>;
-
-  beforeEach(() => {
-    spyOn(os, "homedir").mockReturnValue("/mock/home");
-    existsSyncMock = spyOn(fs, "existsSync").mockReturnValue(false);
-    bunMock = setupMockBun$();
-    executedCommands = [];
-
-    mockCommandResponses = {
-      "git rev-parse --is-inside-work-tree": { ok: true, stdout: "true", stderr: "" },
-      "command -v tmux": { ok: true, stdout: "/usr/bin/tmux", stderr: "" },
-      "command -v opencode": { ok: true, stdout: "/usr/bin/opencode", stderr: "" },
-      "opencode models": { ok: true, stdout: "openai/gpt-5.2\nanthropic/claude-3-5-sonnet", stderr: "" },
-      "tmux has-session -t test-session": { ok: false, stdout: "", stderr: "session not found" },
-      "git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2": { ok: false, stdout: "", stderr: "" },
-    };
-  });
-
-  afterEach(() => {
-    restoreOriginalBun$();
-  });
-
-  test("fails if session name is empty", async () => {
-    const result = await launchMultiModel({
-      sessionName: "",
-      models: ["openai/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(false);
-    expect(result.error).toContain("Error: `sessionName` must not be empty.");
-    expect(executedCommands).toEqual([]);
-  });
-
-  test("fails if no models are provided", async () => {
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: [],
-    });
-
-    expect(result.success).toBe(false);
-    expect(result.error).toContain("Error: Model names must not be empty.");
-    expect(executedCommands).toEqual([]);
-  });
-
-  test("fails if duplicate models are provided", async () => {
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["openai/gpt-5.2", "openai/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(false);
-    expect(result.error).toContain("Duplicate model names are not allowed");
-    expect(executedCommands).toEqual([]);
-  });
-
-  test("fails if not inside a git repository", async () => {
-    mockCommandResponses["git rev-parse --is-inside-work-tree"] = { ok: false, stdout: "", stderr: "not a git repo" };
-
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["openai/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(false);
-    expect(result.error).toContain("Error: `multi-model` requires a git repository.");
-    expect(executedCommands).toEqual(["git rev-parse --is-inside-work-tree"]);
-  });
-
-  test("fails if tmux is not installed", async () => {
-    mockCommandResponses["command -v tmux"] = { ok: false, stdout: "", stderr: "" };
-
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["openai/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(false);
-    expect(result.error).toContain("Error: `tmux` is not installed or not on `PATH`.");
-    expect(executedCommands).toEqual([
-      "git rev-parse --is-inside-work-tree",
-      "command -v tmux"
-    ]);
-  });
-
-  test("fails if opencode is not installed", async () => {
-    mockCommandResponses["command -v opencode"] = { ok: false, stdout: "", stderr: "" };
-
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["openai/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(false);
-    expect(result.error).toContain("Error: `opencode` is not installed or not on `PATH`.");
-    expect(executedCommands).toEqual([
-      "git rev-parse --is-inside-work-tree",
-      "command -v tmux",
-      "command -v opencode"
-    ]);
-  });
-
-  test("fails if model name is not in allowlist", async () => {
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["invalid/model"],
-    });
-
-    expect(result.success).toBe(false);
-    expect(result.error).toContain("Error: Model name 'invalid/model' not found");
-    expect(executedCommands).toEqual([
-      "git rev-parse --is-inside-work-tree",
-      "command -v tmux",
-      "command -v opencode",
-      "opencode models"
-    ]);
-  });
-
-  test("fails if session already exists", async () => {
-    mockCommandResponses["tmux has-session -t test-session"] = { ok: true, stdout: "", stderr: "" };
-
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["openai/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(false);
-    expect(result.error).toContain("Error: Session already exists");
-    expect(executedCommands).toEqual([
-      "git rev-parse --is-inside-work-tree",
-      "command -v tmux",
-      "command -v opencode",
-      "opencode models",
-      "tmux has-session -t test-session"
-    ]);
-  });
-
-  test("successfully plans and executes tmux launch with single model", async () => {
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["openai/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(true);
-    expect(result.instructions).toContain("Use `tmux attach -t test-session` to join session");
-    expect(executedCommands.some(c => c.startsWith("tmux new-session -d -s test-session -n gpt-5-2"))).toBe(true);
-    expect(executedCommands.some(c => c.startsWith("tmux send-keys -t test-session:gpt-5-2"))).toBe(true);
-  });
-
-  test("successfully launches multiple models", async () => {
-    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/claude-3-5-sonnet"] = { ok: false, stdout: "", stderr: "" };
-
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["openai/gpt-5.2", "anthropic/claude-3-5-sonnet"],
-    });
-
-    expect(result.success).toBe(true);
-    expect(result.instructions).toContain("Use `tmux attach -t test-session` to join session");
-    expect(executedCommands.some(c => c.startsWith("tmux new-session -d -s test-session -n gpt-5-2"))).toBe(true);
-    expect(executedCommands.some(c => c.startsWith("tmux new-window -d -t test-session -n claude-3-5-sonnet"))).toBe(true);
-  });
-
-  test("sanitizes session name", async () => {
-    mockCommandResponses["tmux has-session -t test session!"] = { ok: false, stdout: "", stderr: "" };
-    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2"] = { ok: false, stdout: "", stderr: "" };
-
-    const result = await launchMultiModel({
-      sessionName: "test session!",
-      models: ["openai/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(true);
-    expect(result.instructions).toContain("Use `tmux attach -t test session!` to join session");
-    expect(executedCommands.some(c => c.startsWith("git worktree add -b opencode/test-session/gpt-5-2"))).toBe(true);
-  });
-
-  test("fails if tmux new-session fails for the first model and triggers undo", async () => {
-    mockCommandResponses["tmux new-session -d -s test-session -n gpt-5-2 -c /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2"] = { ok: false, stdout: "", stderr: "tmux error" };
-    mockCommandResponses["git worktree remove -f /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2"] = { ok: true, stdout: "", stderr: "" };
-    mockCommandResponses["git branch -D opencode/test-session/gpt-5-2"] = { ok: true, stdout: "", stderr: "" };
-
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["openai/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(false);
-    expect(result.error).toContain("Failed to create tmux session");
-    expect(executedCommands).toEqual([
-      "git rev-parse --is-inside-work-tree",
-      "command -v tmux",
-      "command -v opencode",
-      "opencode models",
-      "tmux has-session -t test-session",
-      "git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2",
-      "git worktree add -b opencode/test-session/gpt-5-2 /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2",
-      "tmux new-session -d -s test-session -n gpt-5-2 -c /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2",
-      "git worktree remove -f /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2",
-      "git branch -D opencode/test-session/gpt-5-2"
-    ]);
-  });
-
-  test("fails if worktree path exists for first model", async () => {
-    existsSyncMock.mockImplementation((path: string) => {
-      return path.includes("test-session/gpt-5-2");
-    });
-
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["openai/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(false);
-    expect(result.error).toContain("Worktree path already exists");
-    expect(executedCommands).toEqual([
-      "git rev-parse --is-inside-work-tree",
-      "command -v tmux",
-      "command -v opencode",
-      "opencode models",
-      "tmux has-session -t test-session"
-    ]);
-  });
-
-  test("fails if git branch exists for first model", async () => {
-    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2"] = { ok: true, stdout: "", stderr: "" };
-
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["openai/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(false);
-    expect(result.error).toContain("Branch 'opencode/test-session/gpt-5-2' already exists");
-    expect(executedCommands).toEqual([
-      "git rev-parse --is-inside-work-tree",
-      "command -v tmux",
-      "command -v opencode",
-      "opencode models",
-      "tmux has-session -t test-session",
-      "git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2"
-    ]);
-  });
-
-  test("fails if git worktree add fails for first model", async () => {
-    mockCommandResponses["git worktree add -b opencode/test-session/gpt-5-2 /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2"] = { ok: false, stdout: "", stderr: "git error" };
-
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["openai/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(false);
-    expect(result.error).toContain("Failed to create worktree");
-    expect(executedCommands).toEqual([
-      "git rev-parse --is-inside-work-tree",
-      "command -v tmux",
-      "command -v opencode",
-      "opencode models",
-      "tmux has-session -t test-session",
-      "git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2",
-      "git worktree add -b opencode/test-session/gpt-5-2 /mock/home/.local/share/opencode/multi-model/test-session/gpt-5-2"
-    ]);
-  });
-
-  test("model name collision creates unique window names", async () => {
-    mockCommandResponses["opencode models"] = { ok: true, stdout: "openai/gpt-5.2\nanthropic/gpt-5.2", stderr: "" };
-    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2"] = { ok: false, stdout: "", stderr: "" };
-    mockCommandResponses["git show-ref --verify --quiet refs/heads/opencode/test-session/gpt-5-2-2"] = { ok: false, stdout: "", stderr: "" };
-
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: ["openai/gpt-5.2", "anthropic/gpt-5.2"],
-    });
-
-    expect(result.success).toBe(true);
-    expect(result.instructions).toContain("Use `tmux attach -t test-session` to join session");
-    expect(executedCommands.some(c => c.startsWith("tmux new-session -d -s test-session -n gpt-5-2"))).toBe(true);
-    expect(executedCommands.some(c => c.startsWith("tmux new-window -d -t test-session -n gpt-5-2-2"))).toBe(true);
-  });
-
-  test("long model name is truncated in window name", async () => {
-    const longModel = "verylongmodelfrontexampleprovider";
-    mockCommandResponses["opencode models"] = { ok: true, stdout: longModel, stderr: "" };
-    mockCommandResponses[`git show-ref --verify --quiet refs/heads/opencode/test-session/${longModel.slice(0, 24)}`] = { ok: false, stdout: "", stderr: "" };
-
-    const result = await launchMultiModel({
-      sessionName: "test-session",
-      models: [longModel],
-    });
-
-    expect(result.success).toBe(true);
-    expect(result.instructions).toContain("Use `tmux attach -t test-session` to join session");
-    const windowName = executedCommands.find(c => c.includes("tmux new-session"))?.match(/-n (\S+)/)?.[1];
-    expect(windowName?.length).toBeLessThanOrEqual(24);
-  });
-});
-
 describe("core utils", () => {
   let bunMock: ReturnType<typeof setupMockBun$>;
 
@@ -371,19 +68,15 @@ describe("core utils", () => {
     test("normal string without special characters", () => {
       expect(shellQuote("test")).toBe("'test'");
     });
-
     test("string with spaces", () => {
       expect(shellQuote("test value")).toBe("'test value'");
     });
-
     test("string with single quotes", () => {
       expect(shellQuote("test'value")).toBe("'test'\"'\"'value'");
     });
-
     test("string with multiple single quotes", () => {
       expect(shellQuote("te's't'v'alue")).toBe("'te'\"'\"'s'\"'\"'t'\"'\"'v'\"'\"'alue'");
     });
-
     test("empty string", () => {
       expect(shellQuote("")).toBe("''");
     });
@@ -393,15 +86,12 @@ describe("core utils", () => {
     test("empty array", () => {
       expect(normalizeModels([])).toEqual([]);
     });
-
     test("undefined input", () => {
       expect(normalizeModels(undefined)).toEqual([]);
     });
-
     test("array with whitespace-only strings", () => {
       expect(normalizeModels(["   ", "  "])).toEqual([]);
     });
-
     test("array with mixed valid models, padded models, and empty strings", () => {
       expect(normalizeModels([" openai/gpt-5.2 ", "", " anthropic/claude "])).toEqual(["openai/gpt-5.2", "anthropic/claude"]);
     });
@@ -411,19 +101,15 @@ describe("core utils", () => {
     test("array with no duplicates", () => {
       expect(findDuplicates(["a", "b", "c"])).toEqual([]);
     });
-
     test("array with one duplicate pair", () => {
       expect(findDuplicates(["a", "b", "a"])).toEqual(["a"]);
     });
-
     test("array with multiple different duplicates", () => {
       expect(findDuplicates(["a", "b", "a", "c", "b"])).toEqual(["a", "b"]);
     });
-
     test("array with a single value repeated more than twice", () => {
       expect(findDuplicates(["a", "a", "a"])).toEqual(["a"]);
     });
-
     test("verifying first-repeated-occurrence order", () => {
       expect(findDuplicates(["x", "a", "b", "a", "x", "b"])).toEqual(["a", "x", "b"]);
     });
@@ -433,20 +119,16 @@ describe("core utils", () => {
     test("normal model name without slashes", () => {
       expect(createWindowBaseName("gpt-5-2")).toBe("gpt-5-2");
     });
-
     test("model with slashes", () => {
       expect(createWindowBaseName("vendor/namespace/model")).toBe("model");
     });
-
     test("model exceeding WINDOW_NAME_LIMIT", () => {
       const longName = "a".repeat(30);
       expect(createWindowBaseName(longName)).toBe("aaaaaaaaaaaaaaaaaaaaaaaa");
     });
-
     test("model with special characters", () => {
       expect(createWindowBaseName("OpenAI/GPT_4.0!")).toBe("gpt-4-0");
     });
-
     test("model made entirely of special characters", () => {
       expect(createWindowBaseName("!@#$%^&*()")).toBe("model");
     });
@@ -456,21 +138,18 @@ describe("core utils", () => {
     test("single model", () => {
       expect(createWindowPlans(["openai/gpt-5-2"])).toEqual([{ model: "openai/gpt-5-2", windowName: "gpt-5-2" }]);
     });
-
     test("two models with the same base name", () => {
       expect(createWindowPlans(["openai/gpt-5-2", "anthropic/gpt-5-2"])).toEqual([
         { model: "openai/gpt-5-2", windowName: "gpt-5-2" },
-        { model: "anthropic/gpt-5-2", windowName: "gpt-5-2-2" }
+        { model: "anthropic/gpt-5-2", windowName: "gpt-5-2-2" },
       ]);
     });
-
     test("multiple collisions", () => {
       const result = createWindowPlans(["a", "b", "c", "a", "b", "a"]);
       expect(result[0]?.windowName).toBe("a");
       expect(result[3]?.windowName).toBe("a-2");
       expect(result[5]?.windowName).toBe("a-3");
     });
-
     test("truncation to accommodate suffix", () => {
       const longBase = "a".repeat(23);
       const result = createWindowPlans([longBase, "b"]);
@@ -482,27 +161,21 @@ describe("core utils", () => {
     test("identical strings", () => {
       expect(levenshtein("test", "test")).toBe(0);
     });
-
     test("one substitution", () => {
       expect(levenshtein("test", "tent")).toBe(1);
     });
-
     test("one insertion", () => {
       expect(levenshtein("test", "tests")).toBe(1);
     });
-
     test("one deletion", () => {
       expect(levenshtein("tests", "test")).toBe(1);
     });
-
     test("completely different strings", () => {
       expect(levenshtein("abc", "xyz")).toBe(3);
     });
-
     test("one empty string", () => {
       expect(levenshtein("", "test")).toBe(4);
     });
-
     test("both empty strings", () => {
       expect(levenshtein("", "")).toBe(0);
     });
@@ -513,21 +186,17 @@ describe("core utils", () => {
       const result = suggestModels("gpt-5.2", ["gpt-5.2", "gpt-5.2-mini"]);
       expect(result[0]).toBe("gpt-5.2");
     });
-
     test("fuzzy match/typo", () => {
       expect(suggestModels("gpt5.4", ["gpt-5.4"])).toEqual(["gpt-5.4"]);
     });
-
     test("fuzzy match with contains boost", () => {
       const suggestions = suggestModels("gpt4o", ["gpt-5.2", "gpt-5.2-mini"]);
       expect(suggestions[0]).toBe("gpt-5.2");
     });
-
     test("maximum of 3 suggestions", () => {
       const allowlist = ["gpt-5.2", "gpt-5.2-mini", "gpt-5.2-pro", "gpt-5.2-ultra"];
       expect(suggestModels("gpt4o", allowlist).length).toBe(3);
     });
-
     test("sorting logic", () => {
       const suggestions = suggestModels("abc", ["abc", "abd", "abe"]);
       expect(suggestions).toEqual(["abc", "abd", "abe"]);
@@ -540,13 +209,11 @@ describe("core utils", () => {
       expect(error).toContain("Model name 'gpt5.4' not found");
       expect(error).toContain("Did you mean");
     });
-
     test("single invalid model without close matches", () => {
       const error = formatInvalidModelError(["xyz"], ["abc", "def"]);
       expect(error).toContain("Model name 'xyz' not found");
       expect(error).toContain("Did you mean");
     });
-
     test("multiple invalid models", () => {
       const error = formatInvalidModelError(["xyz", "abc"], ["def"]);
       expect(error).toContain("Model names not found");
@@ -559,15 +226,12 @@ describe("core utils", () => {
     test("normal alphanumeric name", () => {
       expect(sanitizeName("test-session")).toBe("test-session");
     });
-
     test("name with spaces and special chars", () => {
       expect(sanitizeName("test session!")).toBe("test-session");
     });
-
     test("name with consecutive hyphens", () => {
       expect(sanitizeName("test--session")).toBe("test-session");
     });
-
     test("name with leading/trailing hyphens", () => {
       expect(sanitizeName("-test-session-")).toBe("test-session");
     });
@@ -581,7 +245,6 @@ describe("core utils", () => {
       expect(result.stdout).toBe("hello");
       expect(result.stderr).toBe("");
     });
-
     test("returns ok false for failed command", async () => {
       mockCommandResponses["false"] = { ok: false, stdout: "", stderr: "error" };
       const result = await runCommand(["false"]);
@@ -596,7 +259,6 @@ describe("core utils", () => {
       const result = getWorktreePath("my-session", "gpt-5.2");
       expect(result).toBe("/home/user/.local/share/opencode/multi-model/my-session/gpt-5.2");
     });
-
     test("handles nested session names", () => {
       spyOn(os, "homedir").mockReturnValue("/home/user");
       const result = getWorktreePath("parent/child", "window");
@@ -620,7 +282,6 @@ describe("core utils", () => {
       const errors = await undoWorktree("/path/to/worktree", "opencode/session/window");
       expect(errors).toEqual([]);
     });
-
     test("returns error when worktree remove fails", async () => {
       mockCommandResponses["git worktree remove -f /path/to/worktree"] = { ok: false, stdout: "", stderr: "remove failed" };
       mockCommandResponses["git branch -D opencode/session/window"] = { ok: true, stdout: "", stderr: "" };
@@ -629,7 +290,6 @@ describe("core utils", () => {
       expect(errors.length).toBe(1);
       expect(errors[0]).toContain("Failed to remove worktree");
     });
-
     test("returns error when branch delete fails", async () => {
       mockCommandResponses["git worktree remove -f /path/to/worktree"] = { ok: true, stdout: "", stderr: "" };
       mockCommandResponses["git branch -D opencode/session/window"] = { ok: false, stdout: "", stderr: "branch delete failed" };
@@ -638,7 +298,6 @@ describe("core utils", () => {
       expect(errors.length).toBe(1);
       expect(errors[0]).toContain("Failed to delete branch");
     });
-
     test("returns both errors when both operations fail", async () => {
       mockCommandResponses["git worktree remove -f /path/to/worktree"] = { ok: false, stdout: "", stderr: "remove failed" };
       mockCommandResponses["git branch -D opencode/session/window"] = { ok: false, stdout: "", stderr: "branch delete failed" };
@@ -656,7 +315,6 @@ describe("core utils", () => {
       expect(result.ok).toBe(true);
       expect(executedCommands).toContain("tmux send-keys -t session:window opencode --model 'openai/gpt-5.2' C-m");
     });
-
     test("uses custom binary name", async () => {
       mockCommandResponses["tmux send-keys -t session:window kilo --model 'openai/gpt-5.2' C-m"] = { ok: true, stdout: "", stderr: "" };
 
@@ -680,7 +338,18 @@ describe("core utils", () => {
       expect(worktrees[0]?.path).toBe("/home/user/.local/share/opencode/multi-model/my-session/gpt-5.2");
       expect(worktrees[0]?.branch).toBe("opencode/my-session/gpt-5.2");
     });
+    test("sanitizes session name when filtering worktrees", async () => {
+      spyOn(os, "homedir").mockReturnValue("/home/user");
+      mockCommandResponses["git worktree list --porcelain"] = {
+        ok: true,
+        stdout: "worktree /home/user/.local/share/opencode/multi-model/my-session/gpt-5.2\nbranch refs/heads/opencode/my-session/gpt-5.2",
+        stderr: "",
+      };
 
+      const worktrees = await getWorktreesForSession("my session!");
+      expect(worktrees.length).toBe(1);
+      expect(worktrees[0]?.path).toBe("/home/user/.local/share/opencode/multi-model/my-session/gpt-5.2");
+    });
     test("returns empty array when no matching worktrees", async () => {
       spyOn(os, "homedir").mockReturnValue("/home/user");
       mockCommandResponses["git worktree list --porcelain"] = {
@@ -699,7 +368,6 @@ describe("core utils", () => {
       delete process.env.OPENCODE_MULTI_MODEL_BINARY;
       expect(getBinaryName()).toBe("opencode");
     });
-
     test("returns env var value when set", () => {
       process.env.OPENCODE_MULTI_MODEL_BINARY = "kilo";
       expect(getBinaryName()).toBe("kilo");