Title Gen

⚠️ DEPRECATED

OpenCode now has built-in session title generation. This plugin is no longer needed.

OpenCode natively includes a hidden title agent that automatically generates session titles after the first user message, using a lightweight model. Configure it in your opencode.json:

{
  // Use a cheap, fast model for title generation
  "small_model": "anthropic/claude-haiku-4-5",

  // Or override the title agent specifically
  "agent": {
    "title": {
      "model": "github-copilot/gpt-5-mini",
    },
  },
}

See the OpenCode docs for more details.

Migration: Remove this plugin from your OpenCode config. The native title generation works out of the box.

---

Your OpenCode sessions are all called New session - 2026-03-26T15:32:42.757Z. Every single one.

This plugin fixes that. Session goes idle → AI reads the conversation → generates a meaningful title → done. Zero interaction.

---

Installation

For Humans

Copy and paste this prompt to your LLM agent (Claude Code, OpenCode agent, etc.):

Install and configure opencode-title-gen by following the instructions here:
https://raw.githubusercontent.com/wowuliao11/opencode-title-gen/main/docs/guide/installation.md

Or read the Installation Guide, but seriously, let an agent do it.

For LLM Agents

Fetch the installation guide and follow it:

curl -fsSL https://raw.githubusercontent.com/wowuliao11/opencode-title-gen/main/docs/guide/installation.md

---

Skip This README

We're past the era of reading docs. Just paste this into your agent:

Read this and set up the plugin: https://raw.githubusercontent.com/wowuliao11/opencode-title-gen/main/README.md

---

Before / After

Before:                                        After:
├── New session - 2026-03-26T15:32:42.757Z     ├── Fix auth middleware token refresh
├── New session - 2026-03-26T14:18:03.221Z     ├── Add pagination to /api/users
├── New session - 2026-03-25T22:47:11.089Z     ├── Refactor DB connection pooling
├── New session - 2026-03-25T19:05:58.443Z     ├── Debug CI flaky test in auth.spec
└── New session - 2026-03-25T16:33:27.615Z     └── Set up ESLint v9 flat config

---

Highlights

	Feature	What it does
🎯	Auto Title	Session goes idle → AI reads conversation → generates title. Zero interaction.
🔄	Two Modes	once (default): set and forget. continuous: title evolves with the chat.
🧠	Smart Compression	First + last assistant message per turn. Saves ~60% tokens.
🔒	Race-Safe	Debounced. Locked per-session. No duplicate generation.
⚡	Lightweight	10.9kb bundled. Zero runtime dependencies. ESM only.
🛠️	Configurable	Model, threshold, mode — all optional. Works out of the box.

---

How It Works

Step	What happens
1	Listens for session.idle and session.status (type=idle) events
2	Counts idle events per session; triggers at threshold (default: 2)
3	Skips sub-sessions and sessions with custom titles (in once mode)
4	Extracts conversation (first + last assistant message — saves ~60% tokens)
5	Creates a temporary sub-session, prompts the model for a concise title (3–7 words, ≤60 chars)
6	Updates the session title, cleans up the sub-session

---

Configuration

Create ~/.config/opencode/smart-title.jsonc:

{
  // "once" = generate title once (default), "continuous" = update as conversation evolves
  "mode": "once",
  // Uncomment to use a specific model (default: your OpenCode default model)
  // "model": "github-copilot/claude-haiku-4.5",
}

Option	Default	What it does
enabled	true	Kill switch
debug	false	Verbose logging
mode	"once"	"once": title once, "continuous": title evolves
model	(your default)	Model for title generation, providerID/modelID format
updateThreshold	2	Generate title after N idle events per session
maxTurns	10	Max conversation turns fed to the model
maxCharsPerPart	300	Truncate each message part to N chars
debounceMs	1500	Ignore rapid-fire idle events within this window

Tip: Use a cheap, fast model. Haiku is perfect for this. You're generating 5-word titles, not writing essays.

Title Modes

once (default): Generate a title when the session has a default title (New session - <timestamp>). Once a real title is set, it stays. Best for most users.

continuous: Re-generate the title every time the idle threshold is reached. The title evolves as the conversation progresses — from "Setting up auth" to "Debugging OAuth token refresh". Best for long, multi-topic sessions.

---

Debug

# Latest log file
tail -f ~/.local/share/opencode/log/$(ls -t ~/.local/share/opencode/log/ | head -1)

# Filter for this plugin
grep smart-title ~/.local/share/opencode/log/$(ls -t ~/.local/share/opencode/log/ | head -1)

Set "debug": true in config for verbose output.

---

Architecture

src/
  index.ts           → Plugin entry point (registers hooks)
  types.ts           → SmartTitleConfig, ResolvedConfig, TitleMode
  config.ts          → JSONC config loader with defaults
  logger.ts          → Structured logger via client.app.log
  event-handler.ts   → Idle event handler: threshold, debounce, per-session lock, mode logic
  title-generator.ts → Sub-session title generation with XML prompt
  utils.ts           → extractConversation, isDefaultTitle, cleanTitle
tests/
  utils.test.ts      → 24 unit tests (vitest)
docs/
  guide/
    installation.md  → Step-by-step setup guide (for humans and agents)

10.9kb bundled. Zero runtime dependencies. ESM only.

---

Development

pnpm install          # install deps
pnpm build            # TypeScript + esbuild bundle
pnpm test             # vitest
pnpm lint             # ESLint v9 flat config
pnpm format:check     # Prettier
pnpm typecheck        # strict mode (noUncheckedIndexedAccess, etc.)

Tooling: ESLint 9 + Prettier + Husky + lint-staged + commitlint (conventional commits). All pre-configured.

---

Contributing

1. Fork → branch (git checkout -b feat/my-feature)
2. Make changes
3. pnpm lint && pnpm test && pnpm build
4. Commit with Conventional Commits (feat:, fix:, docs:)
5. Open a PR

---

License

MIT

---

This plugin is not affiliated with the OpenCode team. Built independently because I got tired of New session - <timestamp> titles.