fast-jev (OpenCode plugin)

Prunes stale tool calls and bulky results from OpenCode V2 model requests using TypeSafe's Jev. Runs through the context hook.

Main guarantees:

• Rewrites only the outgoing request: stored history, /compact and automatic compaction are untouched.
• Fails open — a missing key, timeout, transport/HTTP error, malformed answer or unreadable config leaves the request unmodified.
• Leaves the live turn and the configured protected tool calls in place by default.
• Reuses prior decisions across requests and reloads.

Install

OpenCode loads every plugin folder under its config directory (global ~/.config/opencode/plugins/, or per project .opencode/plugins/):

git clone https://github.com/nrdz-labs/fast-jev-opencode.git \
  ~/.config/opencode/plugins/fast-jev
cd ~/.config/opencode/plugins/fast-jev
cp config.example.json config.json   # optional: the compiled defaults apply

There is nothing to build and no runtime dependency — only node: builtins and its own files. Development scripts need Node and Bun (see CONTRIBUTING.md).

The Jev key is read from TYPESAFE_API_KEY, then from ~/.config/opencode/.env (the file the jev CLI uses; read per request). Put it there or in the server environment, then restart so the server picks it up:

opencode service restart

Without a key the plugin stands down and logs the reason (fail-open).

The shipped defaults and config.example.json are observe-only (enabled: true, dryRun: true): decisions are scored and logged and the request is left untouched. Going live means "dryRun": false in config.json. See docs/CONFIGURATION.md for every field and override.

Usage

Nothing to turn on once dryRun is off: the plugin is active for every session and project. Edit config.json and save — it is re-read on mtime change, so edits apply to the next request without a restart.

/jev-prune reports the current state: enabled/dry-run, cached decisions, how many would be dropped at the current keepThreshold, and the last run's drops, truncations, saved percentage and latency. It is a report, not a trigger — pruning happens per model request and cannot rewrite one already dispatched. Send any message to have the next request prune.

Compatibility

Built and validated against OpenCode v2.0.7: the runtime fixture pins a real context hook payload from that version, and CI type-checks the SDK contracts against @opencode/plugin 2.0.7 and 2.0.8 (CONTRIBUTING.md, tests/fixtures/README.md).

Docs

• docs/CONFIGURATION.md — all fields, defaults, environment overrides, logs and troubleshooting.
• docs/DESIGN.md — the Jev questions, thresholds and guardrails behind the defaults, and where this diverges from upstream.
• CONTRIBUTING.md — setup, checks, fixtures and PR rules.
• CHANGELOG.md — release history.
• SECURITY.md — what is read and written, and how to report.
• config.example.json — a copyable observe-only config.

License

MIT — see LICENSE. This is the OpenCode counterpart of the Claude Code fast-jev-compaction plugin; the vendored library keeps its own MIT license in vendor/fast-jev-compaction/LICENSE.