feat(agent-opencode): hooks-based activity detection

[harshitsinghbhandari]

Summary

Replaces OpenCode's fragile terminal-regex activity inference with authoritative platform events, mirroring the hook-driven model already shipped for Claude Code (#1941) and Codex. Partially addresses #19 (richer activity detection).

OpenCode exposes a plugin/event system (.opencode/plugins/, auto-loaded at startup) that streams 25+ lifecycle events. Critically, permission.asked is the only authoritative source of waiting_input OpenCode offers — terminal regex was guessing before.

What changed

• setupWorkspaceHooks installs an auto-loaded activity plugin into the workspace's .opencode/plugins/ao-activity.js and excludes it from git via a worktree-aware info/exclude entry, so it never lands in the agent's PRs (best-effort).
• The plugin maps events → states and appends to .ao/activity.jsonl with source: "hook":
  • permission.asked → waiting_input
  • session.error → blocked
  • session.idle → ready (never idle — AO age-decay derives idle)
  • tool.execute.* / file.edited / message.updated → active (coalesced to bound JSONL growth)
  • No-ops without AO_SESSION_ID; honors AO_OPENCODE_HOOK_ACTIVITY=0 opt-out.
• getActivityState now prefers fresh hook entries over the polled opencode session list API for every state; the session-list API remains the fallback when no hook entry exists.
• recordActivity removed — the plugin is the sole JSONL writer, so terminal-derived writes can no longer shadow authoritative hook events (mirrors Claude RFC: replace Claude Code terminal-regex activity detection with hooks (and a hash-delta safety net) #1941). The terminal detectActivity classifier stays as the lifecycle's last resort.

Design decisions (confirmed with maintainer)

• Plugin installed project-local in .opencode/plugins/ + gitignored (vs. global install or opencode.json edit) — auto-loaded, zero config-file edits.
• Hooks win over the polled API for all states, not just the actionable ones.

Test plan

• pnpm --filter @aoagents/ao-plugin-agent-opencode test — 106/106 pass
• New integration test executes the real generated plugin against synthetic events (mapping, env guards, dedup)
• New unit tests: plugin install + git-exclude (idempotent, best-effort), hook-priority in getActivityState, recordActivity removal
• pnpm build + pnpm typecheck green across all packages; pnpm lint 0 errors
• Manual: run an OpenCode session and confirm dashboard reflects waiting_input on a permission prompt

Note: pre-existing local tracker-linear test failures are an unrelated missing optional dep (@composio/core), not touched by this PR.

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR updates the OpenCode agent plugin to derive activity state from authoritative OpenCode lifecycle events (via an auto-loaded workspace plugin) instead of fragile terminal-regex inference, aligning OpenCode with the hook-driven model used for other agents.

Changes:

• Install a generated .opencode/plugins/ao-activity.js plugin via setupWorkspaceHooks, and best-effort exclude it from git via info/exclude.
• Prefer source: "hook" JSONL entries in getActivityState (including for active/ready/idle via age-decay fallback), while removing recordActivity to avoid terminal-driven shadow writes.
• Add unit + integration tests to validate plugin installation, git-exclude behavior, and the real generated plugin’s event→state mapping/dedup/guards.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

File	Description
packages/plugins/agent-opencode/src/index.ts	Adds hook plugin source + installer, updates getActivityState to prioritize hook entries, removes recordActivity.
packages/plugins/agent-opencode/src/index.test.ts	Adds tests for plugin install + git exclude idempotence; updates recordActivity expectations.
packages/plugins/agent-opencode/src/activity-plugin.integration.test.ts	New integration test that executes the generated plugin against synthetic events and asserts JSONL output.
.changeset/opencode-activity-hooks.md	Publishes a minor release note for the OpenCode hook-based activity detection change.

[greptile-apps]

Greptile Summary

This PR replaces fragile terminal-regex activity inference for the OpenCode agent with an authoritative hook-based model, mirroring what was already shipped for Claude Code (#1941) and Codex. An auto-loaded plugin is installed into .opencode/plugins/ao-activity.js that maps OpenCode's 25+ lifecycle events to AO activity states and appends them to .ao/activity.jsonl with source: "hook". getActivityState is updated to prefer fresh hook entries over the polled opencode session list API.

• Plugin install & git exclude: setupWorkspaceHooks now calls installOpenCodeActivityPlugin, which writes the plugin source and, best-effort, adds it to the worktree-aware info/exclude so it doesn't appear in agent PRs.
• Event → state mapping: permission.asked → waiting_input, session.error → blocked, session.idle → ready, tool/file/message events → active (coalesced at 5 s); no-ops without AO_SESSION_ID and honors AO_OPENCODE_HOOK_ACTIVITY=0.
• recordActivity removed: the plugin is the sole JSONL writer; terminal-derived writes that could shadow authoritative hook events are gone.

Confidence Score: 5/5

Safe to merge — the change is additive and the fallback chain means a plugin install failure cannot regress activity detection below the pre-existing session-list API baseline.

The hook priority logic in getActivityState is sound: checkActivityLogState returns waiting_input/blocked first, then step 1b promotes only source === 'hook' entries over the polled API, and the session-list API + age-decay fallback remain for all other cases. No existing behavior is silently removed.

No files require special attention.

Important Files Changed

Filename	Overview
packages/plugins/agent-opencode/src/activity-plugin.ts	New file: implements plugin install + git-exclude logic. Uses isWindows() correctly, handles absolute vs relative exclude paths, wraps all I/O in best-effort try/catch where appropriate.
packages/plugins/agent-opencode/src/index.ts	getActivityState updated to prefer hook entries over the session-list API (step 1b); recordActivity removed; setupWorkspaceHooks delegates to installOpenCodeActivityPlugin.
packages/plugins/agent-opencode/src/activity-plugin.integration.test.ts	New integration test executes the real generated plugin source against synthetic events. Covers event mapping, env guards, and deduplication.
packages/plugins/agent-opencode/src/index.test.ts	New tests for setupWorkspaceHooks, hook-priority in getActivityState, and recordActivity removal. Windows branch tested via mockIsWindows.
.changeset/opencode-activity-hooks.md	Minor version bump with accurate changelog.

_{Reviews (2): Last reviewed commit: "fix(agent-opencode): address PR review o..." | Re-trigger Greptile}

[harshitsinghbhandari]

Addressed all review feedback in f7c1fd2:

• Stale step-1 comment (index.ts): rewritten — the JSONL is now written by the hook plugin (not the removed recordActivity), and waiting_input/blocked have an authoritative hook source.
• WorkspaceHooksConfig (index.test.ts): tests now pass { dataDir: ws } instead of {}, matching the production caller.
• process.env restore (integration test): restores only the mutated keys individually instead of reassigning process.env wholesale.
• Windows path coverage (addToGitExclude): added a test forcing the Windows branch and feeding git an absolute exclude path, asserting it's used verbatim.

107/107 tests pass; typecheck/build clean; 0 lint errors.