opencode-plugin-compaction-prompt/README.md

opencode-plugin-compaction-prompt

Customize OpenCode's compaction prompt to guide which context carries forward, which details are omitted, and what the next session should retain.

Install

opencode plugin opencode-plugin-compaction-prompt

Or add it to opencode.json manually:

{
  "$schema": "https://opencode.ai/config.json",
  "plugin": [
    [
      "opencode-plugin-compaction-prompt",
      {
        "memoryFile": ".opencode/compaction.md",
        "mode": "append",
        "completionMarker": "Custom compaction request honored."
      }
    ]
  ]
}

Create .opencode/compaction.md in the project when you have project-specific context to preserve. The file is optional.

Options

Option	Default	Description
memoryFile	.opencode/compaction.md	File resolved relative to the active worktree.
mode	append	Append instructions to OpenCode's default prompt, or use replace to provide a complete prompt.
prompt	Built-in preservation prompt	Additional instructions used together with memoryFile; both are included in the compaction instructions.
completionMarker	Custom compaction request honored.	Exact text the model is asked to append at the end of the summary.

Append mode is the recommended default because it preserves OpenCode's built-in compaction behavior. Replace mode is available when the complete prompt needs to be controlled by this plugin.

Development

bun install
bun test
bun run typecheck
bun run build
bun run pack:check

The npm package exposes the compiled entrypoint at dist/index.js and TypeScript declarations at dist/index.d.ts.

Compatibility

The plugin uses OpenCode's experimental.session.compacting hook. OpenCode may change experimental plugin APIs between releases; test the package against the OpenCode version you support.