WebHooker/AGENTS.md

# AGENTS.md — WebHooker

## Project Purpose

Cloudflare Worker that receives GitHub webhooks and dispatches processed events to Discord channels/threads, and receives Discord interactions (slash commands, buttons, modals) via the Interactions Endpoint.

Core pipeline: GitHub Webhook → Worker (verify + filter + format) → Discord (REST)

## Key Decisions

- Runtime: Cloudflare Workers
- HTTP framework: Hono
- Discord interactions: HTTPS Interactions Endpoint (`POST /discord/interactions`, Ed25519-signed) — no Discord Gateway / Durable Object; bot stays offline, messages always sent via REST
- Storage: Cloudflare KV (tokens, OAuth state, route config, admin sessions)
- Signature verification: Web Crypto API (HMAC-SHA256 for GitHub, Ed25519 for Discord)
- GitHub OAuth: octokit + jose (JWT)
- Admin WebUI: `/admin` config console, OAuth-session protected via `ADMIN_USER_IDS` whitelist
- Local dev: wrangler + Miniflare

## Architecture

```text
src/
├── index.ts              # CF Workers entry (fetch + scheduled), scheduled = command sync
├── types.ts              # Env, Config, Route, Filter, WebhookEvent, NeutralMessage
├── config.ts             # loadRoutes/saveRoutes (KV config:routes, cache w/ 60s TTL), loadConfig from env
├── server.ts             # Hono app: /health, /webhook, /discord/interactions, mounts /auth, /admin + /
├── core/
│   └── dispatch.ts       # Platform-neutral dispatch: match routes → formatEvent → driver.send (recordSend + group filter)
├── events/               # GitHub webhook pipeline (was webhook.ts)
│   ├── verify.ts         # HMAC signature verify (Web Crypto, timing-safe)
│   ├── parse.ts          # parseEvent (headers + body → WebhookEvent)
│   └── match.ts          # matchRoute, eventOwners, extractBranch, keyword regex filtering
├── formatters/           # Platform-neutral message formatters (was formatter.ts)
│   ├── index.ts          # formatEvent: 24-event switch → NeutralMessage + re-exports
│   ├── colors.ts         # GITHUB_COLORS + WORKFLOW_CONCLUSION_EMOJI
│   ├── helpers.ts        # emojiPrefix, T, buildMessage
│   └── *.ts              # push, pull-request, issues, comments, workflow, release, create,
│                         # repo, check, review, commit-comment, deployment, member, label,
│                         # milestone, discussion, repository, security, generic
├── drivers/              # Platform drivers (pluggable push targets)
│   ├── types.ts          # PlatformDriver interface + SendResult
│   ├── index.ts          # getDriver() registry (discord default + telegram stub)
│   ├── discord/
│   │   ├── index.ts      # DiscordDriver: send → renderNeutralMessage + rest.sendMessage
│   │   ├── render.ts     # renderNeutralMessage: NeutralMessage → Discord FormattedMessage
│   │   ├── rest.ts       # Discord REST sendMessage with retry + rate-limit handling
│   │   ├── interactions.ts # Ed25519 verify + interaction handlers (/gh, buttons, modals)
│   │   └── commands.ts   # APP_COMMANDS + registerGlobalCommands/syncGuildCommands/syncCommands
│   └── telegram/
│       └── index.ts      # TelegramDriver stub (not implemented yet)
├── github/
│   ├── oauth.ts          # OAuth URL, callback token exchange, getUserOctokit, comment/merge/close actions
│   └── store.ts          # KV-based token CRUD + discord-link mapping (was token-store.ts)
├── web/                  # HTTP UI/API routes
│   ├── oauth-routes.ts   # GET /auth/github, callback (admin session / discord-link), DELETE /token/:userId
│   ├── action-routes.ts  # POST /api/comment|merge|react (Bearer token auth via KV lookup)
│   ├── admin-routes.ts   # /admin UI + GET/PUT /admin/api/routes (session + ADMIN_USER_IDS auth, validation)
│   ├── session.ts        # Session CRUD (KV session:{id}), isAdminUser, cookie helpers
│   ├── groups.ts         # Group CRUD (config:groups), resolveScope, hasAnyAccess
│   ├── home-routes.ts    # home page
│   └── legal-routes.ts   # legal / privacy / terms pages
└── lib/                  # shared infra
    ├── i18n.ts           # loadTranslations, t() with param interpolation
    ├── send-log.ts       # SendRecord, recordSend, getSendLog
    ├── log.ts            # JSON console logger (info/warn/error/fatal)
    └── locales/          # en.ts, zh.ts translation dictionaries
```

## Responsibilities

- Verify GitHub webhook signatures (Web Crypto HMAC-SHA256)
- Verify Discord interactions (Web Crypto Ed25519, X-Signature-Ed25519 over timestamp + body)
- Filter events by: event type, repo name, actor, action, branch, keyword (regex supported)
- Format 23+ event types as Discord embeds
- Route messages to Discord channels/threads via REST
- Serve `/gh` slash commands + message context-menu commands + PR merge/close buttons + comment modals
- Sync application commands from the scheduled trigger (global ~1h propagation + per-guild instant)

## Message Format Spec

- Every embed title must start with the repo, then optional `#number`, then `: subject`:
  `{repo}{#number}: {subject}` (e.g. `acme/widget#7: Add feature`). Repo comes from
  `payload.repository.full_name`; fall back to `t("common.repository")` when missing.
- Do NOT use `"Comment on org/repo"` / `"Review on org/repo"` prefixes. Comments, reviews
  and inline comments use the same `{repo}{#number}: {title}` title as their parent object.
- All event-specific emoji live in `src/formatters/` (via the `emojiPrefix` helper), never in
  the locale files. Emoji is controlled per group through the `Group.emoji` toggle (default true);
  `showEmoji=false` must strip every emoji from titles, descriptions, fields and links.
- Milestone progress bars (🟢🟡🟠⬜) are data visualization and are exempt from the emoji toggle.
- Locale templates use a `{emoji}` placeholder immediately followed by the text (no space);
  the formatter injects `em(...)` which carries the trailing space.

## Development

```bash
npx wrangler dev      # Local dev (Miniflare)
npm run typecheck     # Type checking
npm run lint          # ESLint
```

## Configuration

- **Local dev**: `.dev.vars` (wrangler reads this for env bindings)
- **Production**: `wrangler secret put <NAME>` for each secret
- **Routes**: KV key `config:routes` (JSON array, empty until configured)
- **KV namespace**: Required binding for token/state/config storage
- **Discord**: `DISCORD_PUBLIC_KEY` (Interactions Endpoint signature verification, from Discord Developer Portal) and `DISCORD_APPLICATION_ID` (optional, auto-resolved via `GET /oauth2/applications/@me` when omitted) are required for interactions

## Deployment

```bash
npx wrangler secret put GITHUB_WEBHOOK_SECRET
npx wrangler secret put DISCORD_TOKEN
npx wrangler secret put DISCORD_PUBLIC_KEY
npx wrangler kv namespace create KV
# Update wrangler.jsonc with KV ID
npx wrangler deploy
```

## Notes

- Commands sync from the scheduled trigger (`*/5 * * * *`): registered per-guild for instant availability and globally (24h dedup, ~1h propagation).
- The bot is always offline (no Discord Gateway); interactions arrive via the HTTP endpoint.