feat(platform): add standalone HTTP Bot adapter

A first-class, vendor-neutral message-platform adapter (http_bot) for server-to-server integrations (LangBot Space ticketing et al). Drives a pipeline over plain HTTP with no long-lived connection: - Inbound: signed POST to the existing unified webhook route /bots/<uuid>, carrying a caller-defined session_id mapped to the LangBot launcher id via get_launcher_id -> per-session isolation. Preserves pipeline-native N->1 aggregation for free. - Outbound: each reply_message / reply_message_chunk becomes one signed callback POST to the config-only callback_url, delivered in per-session sequence order with retry/backoff -> 1->M multi-reply. - Sub-paths: /reset (drop a session) and /sync (block for the collapsed reply). - Auth: symmetric HMAC-SHA256 both directions (timestamp + replay window), no JWT/Turnstile, no socket. Decisions: callback URL is config-only (SSRF closed); reset + sync shipped; Python + TS reference clients shipped (signing verified byte-identical 3-way). No core changes: the unified webhook router, aggregator, query pool and pipeline are untouched. Adapter is auto-discovered from platform/sources/. Adds: src/langbot/pkg/platform/sources/http_bot.{py,yaml,svg} src/langbot/pkg/platform/sources/http_bot_signing.py docs/platforms/http-bot.md, docs/http-bot-openapi.json examples/http-bot/{client.py,client.ts,README.md} Updates docs/HTTP_BOT_ADAPTER_DESIGN.md (status: implemented).
2026-06-22 13:34:24 +00:00 · 2026-06-21 21:45:37 -04:00
parent 87f4b9c838
commit c85b9401b8
10 changed files with 1615 additions and 22 deletions
@@ -0,0 +1,51 @@
+# HTTP Bot Adapter — Reference Clients
+
+Minimal, dependency-light clients for the LangBot **HTTP Bot** platform adapter.
+They show the whole loop: signing a request, pushing a message, and receiving
+multi-part replies on a callback endpoint.
+
+Full guide: [`docs/platforms/http-bot.md`](../../docs/platforms/http-bot.md).
+Machine-readable contract: [`docs/http-bot-openapi.json`](../../docs/http-bot-openapi.json).
+
+## Files
+
+| File | What it is |
+|---|---|
+| `client.py` | Python client + Flask callback receiver (`pip install flask requests`). |
+| `client.ts` | TypeScript/Node 18+ client + callback receiver, **zero deps** (`npx tsx client.ts`). |
+
+Both implement the identical HMAC-SHA256 scheme
+(`sha256=hex(HMAC(secret, "{timestamp}." + body))`) — verified byte-for-byte
+against the adapter.
+
+## Quickstart
+
+```bash
+# Python — Terminal 1: callback receiver (your callback_url target)
+python client.py serve --port 8900 --secret SHARED_SECRET
+
+# Python — Terminal 2: push a message
+python client.py push --url https://your-langbot/bots/<BOT_UUID> \
+    --secret SHARED_SECRET --session ticket-1 --text "hello"
+
+# blocking sync mode
+python client.py sync  --url https://your-langbot/bots/<BOT_UUID> \
+    --secret SHARED_SECRET --session ticket-1 --text "hello"
+
+# reset a session
+python client.py reset --url https://your-langbot/bots/<BOT_UUID> \
+    --secret SHARED_SECRET --session ticket-1
+```
+
+```bash
+# TypeScript (Node 18+)
+npx tsx client.ts serve 8900 SHARED_SECRET
+npx tsx client.ts push  https://your-langbot/bots/<BOT_UUID> SHARED_SECRET ticket-1 "hello"
+```
+
+When the bot replies, the receiver prints each part with its `sequence` and an
+`[FINAL]` marker on the last one — that's the 1→M multi-reply model in action.
+
+> The bot's `callback_url` must be reachable from LangBot. For local testing,
+> expose your receiver with a tunnel (cloudflared / ngrok) and set that URL in
+> the bot config.
@@ -0,0 +1,167 @@
+#!/usr/bin/env python3
+"""LangBot HTTP Bot adapter — reference client (Python).
+
+Two things in one file:
+
+1. ``push()`` / ``push_sync()`` — send a message into a LangBot ``http_bot`` bot.
+2. A tiny Flask callback receiver that verifies signatures and prints replies,
+   so you can watch N->1 aggregation and 1->M multi-reply working live.
+
+Usage
+-----
+    pip install flask requests
+
+    # Terminal 1 — start the callback receiver (this is your callback_url):
+    python client.py serve --port 8900 --secret SHARED_SECRET
+
+    # Terminal 2 — push a message (async; reply lands on the receiver):
+    python client.py push \
+        --url   https://your-langbot/bots/<BOT_UUID> \
+        --secret SHARED_SECRET \
+        --session ticket-10293 \
+        --text "Export keeps failing on the dashboard."
+
+    # Or push and block for the collapsed reply (sync convenience mode):
+    python client.py sync --url https://your-langbot/bots/<BOT_UUID> \
+        --secret SHARED_SECRET --session ticket-10293 --text "hi"
+
+The signing scheme is HMAC-SHA256 over ``"{timestamp}." + raw_body``; see
+``sign()`` below — it is intentionally tiny and easy to port.
+"""
+
+from __future__ import annotations
+
+import argparse
+import hashlib
+import hmac
+import json
+import sys
+import time
+import uuid
+
+HEADER_TIMESTAMP = 'X-LB-Timestamp'
+HEADER_SIGNATURE = 'X-LB-Signature'
+HEADER_IDEMPOTENCY = 'X-LB-Idempotency-Key'
+REPLAY_WINDOW = 300
+
+
+def sign(secret: str, body: bytes, timestamp: int | None = None) -> tuple[str, str]:
+    """Return (timestamp, signature) for *body*."""
+    ts = str(timestamp if timestamp is not None else int(time.time()))
+    mac = hmac.new(secret.encode(), f'{ts}.'.encode() + body, hashlib.sha256)
+    return ts, 'sha256=' + mac.hexdigest()
+
+
+def verify(secret: str, body: bytes, timestamp: str | None, signature: str | None) -> bool:
+    """Verify an inbound signature (used by the callback receiver)."""
+    if not timestamp or not signature:
+        return False
+    try:
+        if abs(int(time.time()) - int(float(timestamp))) > REPLAY_WINDOW:
+            return False
+    except ValueError:
+        return False
+    _, expected = sign(secret, body, int(float(timestamp)))
+    return hmac.compare_digest(expected, signature)
+
+
+def _post(url: str, secret: str, payload: dict, idempotency: bool = True):
+    import requests
+
+    body = json.dumps(payload, ensure_ascii=False).encode()
+    ts, sig = sign(secret, body)
+    headers = {
+        'Content-Type': 'application/json',
+        HEADER_TIMESTAMP: ts,
+        HEADER_SIGNATURE: sig,
+    }
+    if idempotency:
+        headers[HEADER_IDEMPOTENCY] = uuid.uuid4().hex
+    resp = requests.post(url, data=body, headers=headers, timeout=30)
+    print(f'-> {resp.status_code} {resp.text}')
+    return resp
+
+
+def push(url: str, secret: str, session: str, text: str, session_type: str = 'person'):
+    """Fire-and-collect: returns 202 immediately; reply arrives on your callback."""
+    payload = {
+        'session_id': session,
+        'session_type': session_type,
+        'message': [{'type': 'Plain', 'text': text}],
+    }
+    return _post(url.rstrip('/'), secret, payload)
+
+
+def push_sync(url: str, secret: str, session: str, text: str, session_type: str = 'person'):
+    """Blocking convenience: POST to /sync and get the collapsed reply back."""
+    payload = {
+        'session_id': session,
+        'session_type': session_type,
+        'message': [{'type': 'Plain', 'text': text}],
+    }
+    resp = _post(url.rstrip('/') + '/sync', secret, payload, idempotency=False)
+    return resp
+
+
+def reset(url: str, secret: str, session: str, session_type: str = 'person'):
+    """Reset a session's conversation (next message starts fresh)."""
+    payload = {'session_id': session, 'session_type': session_type}
+    return _post(url.rstrip('/') + '/reset', secret, payload, idempotency=False)
+
+
+def serve(port: int, secret: str):
+    """Run a callback receiver that verifies signatures and prints replies."""
+    from flask import Flask, request
+
+    app = Flask(__name__)
+
+    @app.route('/', methods=['POST'])
+    def recv():
+        raw = request.get_data()
+        ok = verify(secret, raw, request.headers.get(HEADER_TIMESTAMP), request.headers.get(HEADER_SIGNATURE))
+        if not ok:
+            print('!! signature verification FAILED — rejecting')
+            return {'error': 'bad signature'}, 401
+        data = json.loads(raw)
+        text_parts = [c.get('text', '') for c in data.get('message', []) if c.get('type') == 'Plain']
+        marker = 'FINAL' if data.get('is_final') else 'part '
+        print(
+            f'[{marker}] session={data["session_id"]} seq={data["sequence"]} '
+            f'reply_to={data.get("reply_to")}: {" ".join(text_parts)}'
+        )
+        return {'ok': True}
+
+    print(f'callback receiver listening on http://0.0.0.0:{port}/  (Ctrl-C to stop)')
+    app.run(host='0.0.0.0', port=port)
+
+
+def main(argv=None):
+    p = argparse.ArgumentParser(description='LangBot HTTP Bot reference client')
+    sub = p.add_subparsers(dest='cmd', required=True)
+
+    sp = sub.add_parser('serve', help='run the callback receiver')
+    sp.add_argument('--port', type=int, default=8900)
+    sp.add_argument('--secret', required=True)
+
+    for name in ('push', 'sync', 'reset'):
+        c = sub.add_parser(name)
+        c.add_argument('--url', required=True, help='https://host/bots/<BOT_UUID>')
+        c.add_argument('--secret', required=True)
+        c.add_argument('--session', required=True)
+        c.add_argument('--session-type', default='person', choices=['person', 'group'])
+        if name != 'reset':
+            c.add_argument('--text', required=True)
+
+    args = p.parse_args(argv)
+    if args.cmd == 'serve':
+        serve(args.port, args.secret)
+    elif args.cmd == 'push':
+        push(args.url, args.secret, args.session, args.text, args.session_type)
+    elif args.cmd == 'sync':
+        push_sync(args.url, args.secret, args.session, args.text, args.session_type)
+    elif args.cmd == 'reset':
+        reset(args.url, args.secret, args.session, args.session_type)
+
+
+if __name__ == '__main__':
+    sys.exit(main())
@@ -0,0 +1,123 @@
+/**
+ * LangBot HTTP Bot adapter — reference client (TypeScript / Node 18+).
+ *
+ * Zero runtime dependencies (uses global `fetch`, `crypto`, and `http`).
+ *
+ *   - `push()`      : fire-and-collect; reply lands on your callback URL.
+ *   - `pushSync()`  : POST /sync and await the collapsed reply.
+ *   - `reset()`     : reset a session's conversation.
+ *   - `startReceiver()` : a callback server that verifies signatures and logs
+ *                         replies, so you can watch N->1 and 1->M live.
+ *
+ * Run the demos:
+ *   npx tsx client.ts serve   8900 SHARED_SECRET
+ *   npx tsx client.ts push    https://host/bots/<UUID> SHARED_SECRET ticket-1 "hello"
+ *   npx tsx client.ts sync    https://host/bots/<UUID> SHARED_SECRET ticket-1 "hello"
+ *   npx tsx client.ts reset   https://host/bots/<UUID> SHARED_SECRET ticket-1
+ */
+
+import { createHmac, randomUUID, timingSafeEqual } from 'node:crypto';
+import { createServer } from 'node:http';
+
+const HEADER_TIMESTAMP = 'X-LB-Timestamp';
+const HEADER_SIGNATURE = 'X-LB-Signature';
+const HEADER_IDEMPOTENCY = 'X-LB-Idempotency-Key';
+const REPLAY_WINDOW = 300;
+
+/** Compute the `sha256=<hex>` signature over `"{ts}." + body`. */
+export function sign(secret: string, body: Buffer | string, timestamp?: number): [string, string] {
+  const ts = String(timestamp ?? Math.floor(Date.now() / 1000));
+  const buf = typeof body === 'string' ? Buffer.from(body) : body;
+  const mac = createHmac('sha256', secret).update(Buffer.concat([Buffer.from(`${ts}.`), buf])).digest('hex');
+  return [ts, `sha256=${mac}`];
+}
+
+/** Verify an inbound signature (used by the callback receiver). */
+export function verify(secret: string, body: Buffer, timestamp?: string, signature?: string): boolean {
+  if (!timestamp || !signature) return false;
+  if (Math.abs(Math.floor(Date.now() / 1000) - Number(timestamp)) > REPLAY_WINDOW) return false;
+  const [, expected] = sign(secret, body, Number(timestamp));
+  const a = Buffer.from(expected);
+  const b = Buffer.from(signature);
+  return a.length === b.length && timingSafeEqual(a, b);
+}
+
+interface Segment { type: string; text?: string; url?: string; [k: string]: unknown }
+
+async function post(url: string, secret: string, payload: object, idempotency = true) {
+  const body = Buffer.from(JSON.stringify(payload));
+  const [ts, sig] = sign(secret, body);
+  const headers: Record<string, string> = {
+    'Content-Type': 'application/json',
+    [HEADER_TIMESTAMP]: ts,
+    [HEADER_SIGNATURE]: sig,
+  };
+  if (idempotency) headers[HEADER_IDEMPOTENCY] = randomUUID();
+  const resp = await fetch(url, { method: 'POST', headers, body });
+  const text = await resp.text();
+  console.log(`-> ${resp.status} ${text}`);
+  return { status: resp.status, text };
+}
+
+/** Fire-and-collect: 202 now, reply later on your callback URL. */
+export function push(url: string, secret: string, session: string, text: string, sessionType = 'person') {
+  return post(url.replace(/\/$/, ''), secret, {
+    session_id: session,
+    session_type: sessionType,
+    message: [{ type: 'Plain', text }] as Segment[],
+  });
+}
+
+/** Blocking convenience: POST /sync, get the collapsed reply. */
+export function pushSync(url: string, secret: string, session: string, text: string, sessionType = 'person') {
+  return post(`${url.replace(/\/$/, '')}/sync`, secret, {
+    session_id: session,
+    session_type: sessionType,
+    message: [{ type: 'Plain', text }] as Segment[],
+  }, false);
+}
+
+/** Reset a session's conversation. */
+export function reset(url: string, secret: string, session: string, sessionType = 'person') {
+  return post(`${url.replace(/\/$/, '')}/reset`, secret, { session_id: session, session_type: sessionType }, false);
+}
+
+/** Run a callback receiver that verifies signatures and prints replies. */
+export function startReceiver(port: number, secret: string) {
+  const server = createServer((req, res) => {
+    if (req.method !== 'POST') { res.writeHead(405).end(); return; }
+    const chunks: Buffer[] = [];
+    req.on('data', (c) => chunks.push(c));
+    req.on('end', () => {
+      const raw = Buffer.concat(chunks);
+      const ok = verify(secret, raw, req.headers[HEADER_TIMESTAMP.toLowerCase()] as string,
+        req.headers[HEADER_SIGNATURE.toLowerCase()] as string);
+      if (!ok) {
+        console.log('!! signature verification FAILED — rejecting');
+        res.writeHead(401, { 'Content-Type': 'application/json' }).end(JSON.stringify({ error: 'bad signature' }));
+        return;
+      }
+      const data = JSON.parse(raw.toString());
+      const parts = (data.message as Segment[]).filter((c) => c.type === 'Plain').map((c) => c.text).join(' ');
+      const marker = data.is_final ? 'FINAL' : 'part ';
+      console.log(`[${marker}] session=${data.session_id} seq=${data.sequence} reply_to=${data.reply_to}: ${parts}`);
+      res.writeHead(200, { 'Content-Type': 'application/json' }).end(JSON.stringify({ ok: true }));
+    });
+  });
+  server.listen(port, () => console.log(`callback receiver listening on http://0.0.0.0:${port}/  (Ctrl-C to stop)`));
+}
+
+// --- CLI ---
+const [cmd, ...rest] = process.argv.slice(2);
+if (cmd === 'serve') {
+  startReceiver(Number(rest[0] ?? 8900), rest[1] ?? 'SHARED_SECRET');
+} else if (cmd === 'push') {
+  push(rest[0], rest[1], rest[2], rest[3]);
+} else if (cmd === 'sync') {
+  pushSync(rest[0], rest[1], rest[2], rest[3]);
+} else if (cmd === 'reset') {
+  reset(rest[0], rest[1], rest[2]);
+} else if (cmd) {
+  console.error(`unknown command: ${cmd}`);
+  process.exit(1);
+}