From c85b9401b886ea0fd64041e4cf5e1bc2632c3877 Mon Sep 17 00:00:00 2001 From: RockChinQ Date: Sun, 21 Jun 2026 21:45:37 -0400 Subject: [PATCH] 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/, 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). --- docs/HTTP_BOT_ADAPTER_DESIGN.md | 68 ++- docs/http-bot-openapi.json | 198 +++++++ docs/platforms/http-bot.md | 256 +++++++++ examples/http-bot/README.md | 51 ++ examples/http-bot/client.py | 167 ++++++ examples/http-bot/client.ts | 123 +++++ src/langbot/pkg/platform/sources/http_bot.py | 509 ++++++++++++++++++ src/langbot/pkg/platform/sources/http_bot.svg | 17 + .../pkg/platform/sources/http_bot.yaml | 153 ++++++ .../pkg/platform/sources/http_bot_signing.py | 95 ++++ 10 files changed, 1615 insertions(+), 22 deletions(-) create mode 100644 docs/http-bot-openapi.json create mode 100644 docs/platforms/http-bot.md create mode 100644 examples/http-bot/README.md create mode 100644 examples/http-bot/client.py create mode 100644 examples/http-bot/client.ts create mode 100644 src/langbot/pkg/platform/sources/http_bot.py create mode 100644 src/langbot/pkg/platform/sources/http_bot.svg create mode 100644 src/langbot/pkg/platform/sources/http_bot.yaml create mode 100644 src/langbot/pkg/platform/sources/http_bot_signing.py diff --git a/docs/HTTP_BOT_ADAPTER_DESIGN.md b/docs/HTTP_BOT_ADAPTER_DESIGN.md index feff2e58c..31e9a4861 100644 --- a/docs/HTTP_BOT_ADAPTER_DESIGN.md +++ b/docs/HTTP_BOT_ADAPTER_DESIGN.md @@ -1,13 +1,29 @@ # HTTP Bot Adapter — Design Document -> Status: **Draft / RFC** · Target branch: `feat/http-bot-adapter` · Author: LangBot core +> Status: **Implemented** · Branch: `feat/http-bot-adapter` · Author: LangBot core > -> A first-class, **standalone** message-platform adapter that lets any external -> system (e.g. LangBot Space ticketing, an internal back-office, a CRM, a custom -> web app) talk to a LangBot pipeline over plain HTTP — **inbound** by POSTing -> messages in, **outbound** by receiving replies on a callback URL — with full -> support for the pipeline's native N→1 aggregation and 1→M multi-reply -> semantics, and **without** holding a long-lived WebSocket connection. +> A first-class, **standalone** message-platform adapter (`http_bot`) that lets +> any external system (e.g. LangBot Space ticketing, an internal back-office, a +> CRM, a custom web app) talk to a LangBot pipeline over plain HTTP — **inbound** +> by POSTing messages in, **outbound** by receiving replies on a callback URL — +> with full support for the pipeline's native N→1 aggregation and 1→M +> multi-reply semantics, and **without** holding a long-lived WebSocket +> connection. +> +> **Shipped in this branch:** +> - `src/langbot/pkg/platform/sources/http_bot.yaml` — adapter manifest (auto-discovered) +> - `src/langbot/pkg/platform/sources/http_bot.py` — `HttpBotAdapter` +> - `src/langbot/pkg/platform/sources/http_bot_signing.py` — HMAC helpers +> - `src/langbot/pkg/platform/sources/http_bot.svg` — icon +> - `docs/platforms/http-bot.md` — integration guide +> - `docs/http-bot-openapi.json` — machine-readable contract +> - `examples/http-bot/` — Python + TypeScript reference clients +> +> **Final decisions (resolving the original open questions):** +> 1. Callback URL is **config-only** — never accepted per-message (SSRF closed). +> 2. **Session reset is provided** — `POST /bots//reset` keyed by `session_id`. +> 3. Reference **clients are provided** — `examples/http-bot/client.py` + `client.ts`. +> 4. **Sync convenience mode is included** — `POST /bots//sync` (opt-in, lossy). --- @@ -244,9 +260,8 @@ Body: "id": "user-5567", "name": "Alice" }, - "callback_url": "https://space.langbot.app/api/lb/callback", // optional; overrides config default "message": [ // REQUIRED. A LangBot MessageChain (list of segments). - { "type": "Text", "text": "Export keeps failing on the dashboard." }, + { "type": "Plain", "text": "Export keeps failing on the dashboard." }, { "type": "Image", "url": "https://.../screenshot.png" } ] } @@ -294,7 +309,7 @@ Body: "is_final": false, // false for intermediate/streamed parts "stream": false, // true when this is a streamed chunk "message": [ - { "type": "Text", "text": "Looking into it — checking your export logs…" } + { "type": "Plain", "text": "Looking into it — checking your export logs…" } ], "timestamp": "2026-06-22T09:00:01Z" } @@ -495,7 +510,7 @@ alone, push a message and observe a multi-part reply on their callback within ```bash BOT=https://your-langbot/bots/2f1c.... SECRET=supersecret -BODY='{"session_id":"ticket-10293","message":[{"type":"Text","text":"hello"}],"callback_url":"https://your-callback/recv"}' +BODY='{"session_id":"ticket-10293","message":[{"type":"Plain","text":"hello"}]}' TS=$(date +%s) SIG="sha256=$(printf '%s.%s' "$TS" "$BODY" | openssl dgst -sha256 -hmac "$SECRET" -r | cut -d' ' -f1)" curl -sS -X POST "$BOT" \ @@ -537,15 +552,24 @@ pool, or the pipeline. That is the design's main payoff. --- -## 15. Open questions +## 15. Resolved decisions -1. **Callback URL trust** — static (config-only) vs per-message override? Draft - allows both; per-message is convenient but widens SSRF surface. Lock to - config-only in prod? -2. **Session lifecycle** — when does a `session_id` "end"? Do we expose a - `POST /bots//reset` keyed by `session_id` (mirrors the WS `reset`)? -3. **Group semantics** — for `session_type: group`, what is the `sender` - identity model the Space ticket maps to? -4. **Backpressure policy** — drop, block, or buffer when a caller's callback is - persistently down? (Draft: bounded per-session queue, then drop-oldest + - log.) +1. **Callback URL trust** — **config-only.** The inbound message may not carry a + `callback_url`; replies always go to the bot-config URL. Closes the SSRF + vector where a leaked inbound secret could redirect replies. +2. **Session lifecycle** — **`POST /bots//reset`** (body `{session_id, + session_type?}`) drops the matching session from the session manager; the + next message starts a fresh conversation. Implemented via sub-path routing in + `handle_unified_webhook`. +3. **Group semantics** — for `session_type: group`, `session_id` is the group/ + launcher id; `sender.id` (and optional `sender.group_name`) identify the + member. A Space ticket maps to one `session_id`. +4. **Backpressure** — bounded per-session outbound queue (maxlen 1000); on + overflow the oldest reply is dropped and a warning logged, so a persistently + down callback can never exhaust memory. + +### Still open / deferred (see §13) + +- Durable outbound queue (persist + replay across restarts). +- Per-caller API keys with rotation/scopes for multi-tenant Space usage. +- SSE outbound option and a dashboard test console. diff --git a/docs/http-bot-openapi.json b/docs/http-bot-openapi.json new file mode 100644 index 000000000..2cac6e439 --- /dev/null +++ b/docs/http-bot-openapi.json @@ -0,0 +1,198 @@ +{ + "openapi": "3.0.3", + "info": { + "title": "LangBot HTTP Bot Adapter", + "version": "1.0.0", + "description": "Server-to-server HTTP integration for a LangBot pipeline. Inbound messages are POSTed to the unified webhook route; replies are delivered to a configured callback URL (one POST per reply part). All requests are HMAC-SHA256 signed. See docs/platforms/http-bot.md." + }, + "paths": { + "/bots/{bot_uuid}": { + "post": { + "summary": "Push a message into the pipeline (fire-and-collect)", + "description": "Returns 202 immediately. Replies arrive asynchronously on the configured callback URL. Reuse the same session_id within the aggregation window to merge multiple messages into one turn (N->1).", + "parameters": [ + { "$ref": "#/components/parameters/BotUuid" }, + { "$ref": "#/components/parameters/Timestamp" }, + { "$ref": "#/components/parameters/Signature" }, + { "$ref": "#/components/parameters/Idempotency" } + ], + "requestBody": { + "required": true, + "content": { "application/json": { "schema": { "$ref": "#/components/schemas/InboundMessage" } } } + }, + "responses": { + "202": { + "description": "Accepted (queued for the pipeline)", + "content": { "application/json": { "schema": { "$ref": "#/components/schemas/AcceptedResponse" } } } + }, + "400": { "$ref": "#/components/responses/Error" }, + "401": { "$ref": "#/components/responses/Error" }, + "409": { "$ref": "#/components/responses/Error" }, + "413": { "$ref": "#/components/responses/Error" } + } + } + }, + "/bots/{bot_uuid}/sync": { + "post": { + "summary": "Push a message and wait for the collapsed reply", + "description": "Blocking convenience mode. Waits for is_final and returns all reply parts collapsed into one array. Lossy (no sequence/streaming). One in-flight sync per session_id.", + "parameters": [ + { "$ref": "#/components/parameters/BotUuid" }, + { "$ref": "#/components/parameters/Timestamp" }, + { "$ref": "#/components/parameters/Signature" } + ], + "requestBody": { + "required": true, + "content": { "application/json": { "schema": { "$ref": "#/components/schemas/InboundMessage" } } } + }, + "responses": { + "200": { + "description": "The collapsed reply", + "content": { "application/json": { "schema": { "$ref": "#/components/schemas/SyncResponse" } } } + }, + "400": { "$ref": "#/components/responses/Error" }, + "401": { "$ref": "#/components/responses/Error" } + } + } + }, + "/bots/{bot_uuid}/reset": { + "post": { + "summary": "Reset a session's conversation", + "parameters": [ + { "$ref": "#/components/parameters/BotUuid" }, + { "$ref": "#/components/parameters/Timestamp" }, + { "$ref": "#/components/parameters/Signature" } + ], + "requestBody": { + "required": true, + "content": { + "application/json": { + "schema": { + "type": "object", + "required": ["session_id"], + "properties": { + "session_id": { "type": "string" }, + "session_type": { "type": "string", "enum": ["person", "group"] } + } + } + } + } + }, + "responses": { + "200": { "description": "Reset done" }, + "400": { "$ref": "#/components/responses/Error" }, + "401": { "$ref": "#/components/responses/Error" } + } + } + } + }, + "components": { + "parameters": { + "BotUuid": { + "name": "bot_uuid", "in": "path", "required": true, + "schema": { "type": "string", "format": "uuid" } + }, + "Timestamp": { + "name": "X-LB-Timestamp", "in": "header", "required": true, + "description": "Unix seconds; rejected if more than +/-300s from server time.", + "schema": { "type": "string" } + }, + "Signature": { + "name": "X-LB-Signature", "in": "header", "required": true, + "description": "sha256= of HMAC-SHA256(secret, \"{timestamp}.\" + raw_body).", + "schema": { "type": "string" } + }, + "Idempotency": { + "name": "X-LB-Idempotency-Key", "in": "header", "required": false, + "description": "Dedup key; a repeat within the dedup window returns 409.", + "schema": { "type": "string" } + } + }, + "schemas": { + "Segment": { + "type": "object", + "required": ["type"], + "properties": { + "type": { "type": "string", "enum": ["Plain", "Image", "Voice", "File", "At", "Quote"] }, + "text": { "type": "string", "description": "For type=Plain." }, + "url": { "type": "string", "description": "For media types." }, + "base64": { "type": "string", "description": "For media types (data URI or raw base64)." } + } + }, + "InboundMessage": { + "type": "object", + "required": ["session_id", "message"], + "properties": { + "session_id": { "type": "string", "description": "Caller-defined; maps 1:1 to a LangBot session." }, + "session_type": { "type": "string", "enum": ["person", "group"], "default": "person" }, + "sender": { + "type": "object", + "properties": { + "id": { "type": "string" }, + "name": { "type": "string" }, + "group_name": { "type": "string", "description": "For session_type=group." } + } + }, + "message": { "type": "array", "items": { "$ref": "#/components/schemas/Segment" } } + } + }, + "AcceptedResponse": { + "type": "object", + "properties": { + "code": { "type": "integer", "example": 0 }, + "msg": { "type": "string", "example": "accepted" }, + "data": { + "type": "object", + "properties": { + "session_id": { "type": "string" }, + "accepted_message_id": { "type": "string", "example": "in_01H..." }, + "aggregating": { "type": "boolean" } + } + } + } + }, + "SyncResponse": { + "type": "object", + "properties": { + "code": { "type": "integer", "example": 0 }, + "msg": { "type": "string", "example": "ok" }, + "data": { + "type": "object", + "properties": { + "session_id": { "type": "string" }, + "reply_to": { "type": "string" }, + "message": { "type": "array", "items": { "$ref": "#/components/schemas/Segment" } } + } + } + } + }, + "Callback": { + "type": "object", + "description": "Delivered by LangBot to your callback_url, one POST per reply part. Signed with the outbound secret.", + "properties": { + "session_id": { "type": "string" }, + "reply_to": { "type": "string", "description": "The accepted_message_id this answers." }, + "sequence": { "type": "integer", "description": "1-based ordinal within the turn." }, + "is_final": { "type": "boolean", "description": "True on the last part of the turn." }, + "stream": { "type": "boolean" }, + "message": { "type": "array", "items": { "$ref": "#/components/schemas/Segment" } }, + "timestamp": { "type": "string", "format": "date-time" } + } + }, + "ErrorEnvelope": { + "type": "object", + "properties": { + "code": { "type": "integer", "example": 40101 }, + "msg": { "type": "string", "example": "invalid signature: signature_mismatch" }, + "data": { "nullable": true } + } + } + }, + "responses": { + "Error": { + "description": "Error envelope", + "content": { "application/json": { "schema": { "$ref": "#/components/schemas/ErrorEnvelope" } } } + } + } + } +} diff --git a/docs/platforms/http-bot.md b/docs/platforms/http-bot.md new file mode 100644 index 000000000..71fbc6799 --- /dev/null +++ b/docs/platforms/http-bot.md @@ -0,0 +1,256 @@ +# HTTP Bot Adapter — Integration Guide + +Integrate **any backend system** with a LangBot pipeline over plain HTTP. Push +messages in via a signed webhook; receive replies on a callback URL. No +long-lived connection, full support for message **aggregation** (many inbound +messages merged into one turn) and **multi-part replies** (one turn → many +outbound messages). + +This is the right adapter for **server-to-server** integrations — ticketing +systems, CRMs, internal tools, custom web backends. (For an in-browser, +real-time chat widget, use the embeddable Web Page Bot instead.) + +> **5-minute goal:** stand up a callback receiver, send a message, and watch a +> multi-part reply arrive — using the reference client in +> [`examples/http-bot/`](../../examples/http-bot/). + +--- + +## 1. Mental model + +``` +Your backend ──(1) POST signed message──► LangBot /bots/ + (pipeline runs: aggregate → think → reply) +Your callback ◄─(2) POST signed reply(s)── LangBot one POST per reply part +``` + +- **(1) Inbound** is *fire-and-collect*: LangBot answers `202 Accepted` + immediately and does **not** return the pipeline result on that response. +- **(2) Outbound** replies arrive later as separate signed POSTs to your + `callback_url`. A single turn may produce **several** callbacks (e.g. a tool + call narration followed by the final answer). +- Everything is keyed by a **`session_id` you choose** (e.g. a ticket number). + Each `session_id` maps to one isolated LangBot conversation. + +--- + +## 2. Create the bot + +1. In the LangBot dashboard, add a bot and choose the **HTTP Bot** platform. +2. Fill in the config: + + | Field | Required | Notes | + |---|---|---| + | **Inbound Signing Secret** | yes | Your backend signs inbound requests with this. | + | **Outbound Callback URL** | yes | Where LangBot POSTs replies. **Config-only** — cannot be overridden per message (SSRF protection). | + | **Outbound Signing Secret** | no | LangBot signs callbacks with this; defaults to the inbound secret. | + | **Default Session Type** | no | `person` (default) or `group`. | + | **Require Inbound Signature** | no | Keep `true` in production. | + | **Callback Timeout / Max Retries** | no | Defaults: 15s, 3 retries. | + +3. Bind the bot to a **pipeline** and **enable** it. +4. Copy the **Inbound Webhook URL** shown in the config — it looks like + `https://your-langbot/bots/`. + +--- + +## 3. The signature scheme + +Both directions use the same dependency-free HMAC-SHA256 scheme: + +``` +signing_string = "{timestamp}." + raw_body_bytes +signature = "sha256=" + hex(HMAC_SHA256(secret, signing_string)) +``` + +Sent as headers: + +| Header | Meaning | +|---|---| +| `X-LB-Timestamp` | Unix seconds. Rejected if more than **±300s** from server time. | +| `X-LB-Signature` | `sha256=` over `"{timestamp}." + body`. | +| `X-LB-Idempotency-Key` | *(optional, inbound)* dedup key; retries with the same key return `409`. | + +Verify outbound callbacks the same way, using the **outbound** secret (or the +inbound secret if you left it blank). + +A six-line reference implementation is in `examples/http-bot/client.py` +(`sign()` / `verify()`); a Node/TS version is in `client.ts`. + +--- + +## 4. Send your first message (curl) + +```bash +BOT="https://your-langbot/bots/" +SECRET="your-inbound-secret" +BODY='{"session_id":"ticket-10293","message":[{"type":"Plain","text":"Export keeps failing on the dashboard."}]}' +TS=$(date +%s) +SIG="sha256=$(printf '%s.%s' "$TS" "$BODY" | openssl dgst -sha256 -hmac "$SECRET" -r | cut -d' ' -f1)" + +curl -sS -X POST "$BOT" \ + -H "Content-Type: application/json" \ + -H "X-LB-Timestamp: $TS" \ + -H "X-LB-Signature: $SIG" \ + -d "$BODY" +# -> 202 {"code":0,"msg":"accepted","data":{"session_id":"ticket-10293","accepted_message_id":"in_...","aggregating":true}} +``` + +The reply(s) will be POSTed to your configured callback URL shortly after. + +--- + +## 5. Inbound request format + +`POST /bots/{bot_uuid}` + +```jsonc +{ + "session_id": "ticket-10293", // REQUIRED. Your stable id. Maps 1:1 to a LangBot session. + "session_type": "person", // optional: "person" | "group"; default from config + "sender": { // optional metadata, surfaced to the pipeline/plugins + "id": "user-5567", + "name": "Alice" + }, + "message": [ // REQUIRED. A LangBot MessageChain (array of segments). + { "type": "Plain", "text": "Export keeps failing on the dashboard." }, + { "type": "Image", "url": "https://example.com/screenshot.png" } + ] +} +``` + +**Message segments.** Text uses `{"type":"Plain","text":"..."}`. Images use +`{"type":"Image","url":"..."}` (or `base64`). Other supported types: `Voice`, +`File`, `At`, `Quote`. + +> Note: the callback URL is **not** accepted in the body — it is taken only from +> bot config. This is deliberate (prevents an attacker who obtains the inbound +> secret from redirecting replies to an arbitrary host). + +### Aggregation (N → 1) + +If your pipeline has **message aggregation** enabled, send several messages with +the **same `session_id`** within the aggregation window and they are merged into +**one** pipeline turn. No special flag — just reuse the `session_id`. + +--- + +## 6. Outbound callback format + +LangBot POSTs each reply part to your `callback_url`: + +```jsonc +{ + "session_id": "ticket-10293", // echoes the inbound session + "reply_to": "in_01H...", // the accepted_message_id this answers + "sequence": 1, // 1-based ordinal within this turn + "is_final": false, // true on the last part of the turn + "stream": false, // true for streamed chunks + "message": [ { "type": "Plain", "text": "Looking into it…" } ], + "timestamp": "2026-06-22T09:00:01Z" +} +``` + +Your endpoint should return `2xx` quickly. Non-2xx / timeout → LangBot retries +with exponential backoff (up to `callback_max_retries`). + +### Multi-part replies (1 → M) + +One turn may emit multiple callbacks, delivered **in `sequence` order** for a +given session: + +``` +seq=1 is_final=false "Checking your export logs…" +seq=2 is_final=false "Found 2 failed exports." +seq=3 is_final=true "Fixed — please try again." +``` + +Stitch by `session_id` + `sequence`; the turn is complete when +`is_final: true` arrives. + +--- + +## 7. Reset a session + +Start a fresh conversation for a `session_id` (drops history): + +``` +POST /bots/{bot_uuid}/reset +{ "session_id": "ticket-10293", "session_type": "person" } +→ 200 { "code":0, "msg":"reset", "data": { "session_id":"ticket-10293", "removed": true } } +``` + +Signed exactly like an inbound message. + +--- + +## 8. Synchronous convenience mode + +If you don't need streaming/multi-part and just want one reply back on the same +HTTP call, POST to `/sync`. LangBot waits for the turn to finish and returns all +parts **collapsed** into one array: + +``` +POST /bots/{bot_uuid}/sync +{ "session_id": "ticket-10293", "message": [ { "type":"Plain", "text":"hi" } ] } +→ 200 { "code":0, "msg":"ok", + "data": { "session_id":"ticket-10293", "reply_to":"in_...", + "message": [ {"type":"Plain","text":"..."}, ... ] } } +``` + +This is **lossy** (you lose `sequence` / streaming boundaries) and blocks up to +`callback_timeout × 4` seconds. Prefer the callback model for anything +real-time or multi-part. Only one in-flight `/sync` per `session_id`. + +--- + +## 9. Error envelope + +```jsonc +{ "code": 40101, "msg": "invalid signature: signature_mismatch", "data": null } +``` + +| HTTP | code | meaning | +|---|---|---| +| 202 | 0 | accepted | +| 400 | 40001 | malformed body / missing `session_id` or `message` | +| 401 | 40101 | bad/expired signature | +| 409 | 40901 | duplicate idempotency key | +| 413 | 41301 | message too large (>1 MiB) | +| 500 | 50001 | internal error | + +--- + +## 10. Try it end-to-end in 5 minutes + +```bash +cd examples/http-bot +pip install flask requests + +# Terminal 1 — your callback receiver (point the bot's callback_url here, e.g. via a tunnel): +python client.py serve --port 8900 --secret SHARED_SECRET + +# Terminal 2 — push a message: +python client.py push \ + --url https://your-langbot/bots/ \ + --secret SHARED_SECRET \ + --session ticket-1 \ + --text "hello" +``` + +Watch Terminal 1 print each reply part (`[part ]` / `[FINAL]`) with its +sequence number — that's 1→M working, signatures verified. + +A machine-readable contract is in +[`docs/http-bot-openapi.json`](../http-bot-openapi.json). + +--- + +## 11. Security checklist + +- Keep **Require Inbound Signature** on in production. +- Use **HTTPS** callback URLs; the URL is config-only (no per-message override). +- Treat the secrets like passwords; rotate via the dashboard. +- The inbound route is unauthenticated at the framework level **by design** — + security comes entirely from the HMAC signature, so never disable it on a + public deployment. diff --git a/examples/http-bot/README.md b/examples/http-bot/README.md new file mode 100644 index 000000000..1b3909b43 --- /dev/null +++ b/examples/http-bot/README.md @@ -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/ \ + --secret SHARED_SECRET --session ticket-1 --text "hello" + +# blocking sync mode +python client.py sync --url https://your-langbot/bots/ \ + --secret SHARED_SECRET --session ticket-1 --text "hello" + +# reset a session +python client.py reset --url https://your-langbot/bots/ \ + --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/ 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. diff --git a/examples/http-bot/client.py b/examples/http-bot/client.py new file mode 100644 index 000000000..cbf9eff43 --- /dev/null +++ b/examples/http-bot/client.py @@ -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/ \ + --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/ \ + --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/') + 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()) diff --git a/examples/http-bot/client.ts b/examples/http-bot/client.ts new file mode 100644 index 000000000..ec121823c --- /dev/null +++ b/examples/http-bot/client.ts @@ -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/ SHARED_SECRET ticket-1 "hello" + * npx tsx client.ts sync https://host/bots/ SHARED_SECRET ticket-1 "hello" + * npx tsx client.ts reset https://host/bots/ 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=` 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 = { + '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); +} diff --git a/src/langbot/pkg/platform/sources/http_bot.py b/src/langbot/pkg/platform/sources/http_bot.py new file mode 100644 index 000000000..16a891991 --- /dev/null +++ b/src/langbot/pkg/platform/sources/http_bot.py @@ -0,0 +1,509 @@ +"""HTTP Bot adapter — standalone server-to-server platform adapter. + +Lets any external backend drive a LangBot pipeline over plain HTTP: + +* **Inbound** — the backend POSTs a signed message to the unified webhook + route ``POST /bots/``; this adapter verifies the signature, builds + a platform event carrying the caller-defined ``session_id`` as the launcher + id, and fires it into the normal pipeline (so message aggregation, N->1, + works for free). +* **Outbound** — every ``reply_message`` / ``reply_message_chunk`` the pipeline + emits is delivered as a signed POST to the configured ``callback_url``. A + single turn may emit many replies (1->M); each is one callback, ordered per + session via a small worker queue. + +Design notes: + +* The callback URL is taken **only** from adapter config (never from the + inbound message) to keep the SSRF surface closed. +* Replies for one ``session_id`` are delivered in ``sequence`` order; the + caller knows a turn is complete when ``is_final: true`` arrives. +* No new HTTP route is registered — the existing unified webhook dispatcher + (``pkg/api/http/controller/groups/webhooks.py``) calls + ``handle_unified_webhook`` on this adapter. + +See docs/platforms/http-bot.md for the full integration guide. +""" + +from __future__ import annotations + +import asyncio +import json +import time +import typing +import uuid +from datetime import datetime + +import aiohttp +import pydantic +import quart + +import langbot_plugin.api.definition.abstract.platform.adapter as abstract_platform_adapter +import langbot_plugin.api.entities.builtin.platform.message as platform_message +import langbot_plugin.api.entities.builtin.platform.events as platform_events +import langbot_plugin.api.entities.builtin.platform.entities as platform_entities +import langbot_plugin.api.definition.abstract.platform.event_logger as abstract_platform_logger + +from . import http_bot_signing as signing +from ...utils import httpclient + + +# Error envelope codes (HTTP status -> body code), documented in the design doc. +_ERR = { + 'bad_request': (400, 40001), + 'bad_signature': (401, 40101), + 'duplicate': (409, 40901), + 'too_large': (413, 41301), + 'internal': (500, 50001), +} + +# Max accepted inbound body size (bytes). +_MAX_BODY = 1 * 1024 * 1024 + +# Idempotency dedup window (seconds) and cap. +_IDEMPOTENCY_TTL = 600 +_IDEMPOTENCY_MAX = 4096 + + +class _SessionOutbound: + """Per-session outbound state: ordered delivery queue + sequence counter.""" + + def __init__(self) -> None: + self.queue: asyncio.Queue = asyncio.Queue(maxsize=1000) + self.worker: asyncio.Task | None = None + self.sequence: int = 0 + self.last_was_final: bool = True # so the first reply of a turn starts at seq 1 + + +class _SyncCollector: + """Collects reply parts for a /sync request and resolves when the turn ends.""" + + def __init__(self) -> None: + self.parts: list = [] + self.done: asyncio.Event = asyncio.Event() + + +class HttpBotAdapter(abstract_platform_adapter.AbstractMessagePlatformAdapter): + """Standalone HTTP adapter (inbound webhook + outbound callbacks).""" + + bot_uuid: str = pydantic.Field(default='', exclude=True) + + listeners: dict[ + typing.Type[platform_events.Event], + typing.Callable[[platform_events.Event, abstract_platform_adapter.AbstractMessagePlatformAdapter], None], + ] = pydantic.Field(default_factory=dict, exclude=True) + + # session_id -> outbound state + outbound_states: dict[str, _SessionOutbound] = pydantic.Field(default_factory=dict, exclude=True) + # idempotency key -> accepted-at epoch + idempotency_cache: dict[str, float] = pydantic.Field(default_factory=dict, exclude=True) + # session_id -> sync collector (set while a /sync request is awaiting a turn) + sync_waiters: dict[str, '_SyncCollector'] = pydantic.Field(default_factory=dict, exclude=True) + + model_config = pydantic.ConfigDict(arbitrary_types_allowed=True) + + def __init__(self, config: dict, logger: abstract_platform_logger.AbstractEventLogger, **kwargs): + super().__init__(config=config, logger=logger, **kwargs) + self.bot_account_id = 'http_bot' + self.outbound_states = {} + self.idempotency_cache = {} + self.sync_waiters = {} + + # -- framework hooks ------------------------------------------------------ + + def set_bot_uuid(self, bot_uuid: str) -> None: + """Called by the bot manager so the adapter knows its own bot uuid.""" + object.__setattr__(self, 'bot_uuid', bot_uuid) + + def get_launcher_id(self, event: platform_events.MessageEvent) -> str: + """Map an inbound event to a LangBot launcher id. + + We return the caller-defined ``session_id`` (stashed on the sender / + group id at inbound time) so that each external session maps 1:1 to an + isolated LangBot session. + """ + if isinstance(event, platform_events.GroupMessage): + return str(event.sender.group.id) + return str(event.sender.id) + + def register_listener( + self, + event_type: typing.Type[platform_events.Event], + func: typing.Callable[ + [platform_events.Event, abstract_platform_adapter.AbstractMessagePlatformAdapter], typing.Awaitable[None] + ], + ): + self.listeners[event_type] = func + + def unregister_listener( + self, + event_type: typing.Type[platform_events.Event], + func: typing.Callable[ + [platform_events.Event, abstract_platform_adapter.AbstractMessagePlatformAdapter], typing.Awaitable[None] + ], + ): + self.listeners.pop(event_type, None) + + async def is_muted(self, group_id: int) -> bool: + return False + + async def is_stream_output_supported(self) -> bool: + return True + + async def run_async(self): + # Purely webhook-driven; nothing to poll. Stay alive. + while True: + await asyncio.sleep(3600) + + async def kill(self): + # Cancel any outbound workers. + for state in self.outbound_states.values(): + if state.worker and not state.worker.done(): + state.worker.cancel() + return True + + # -- inbound -------------------------------------------------------------- + + def _err(self, kind: str, detail: str = ''): + status, code = _ERR[kind] + return quart.jsonify({'code': code, 'msg': detail or kind, 'data': None}), status + + def _prune_idempotency(self) -> None: + now = time.time() + if len(self.idempotency_cache) > _IDEMPOTENCY_MAX: + self.idempotency_cache.clear() + return + expired = [k for k, ts in self.idempotency_cache.items() if now - ts > _IDEMPOTENCY_TTL] + for k in expired: + self.idempotency_cache.pop(k, None) + + async def handle_unified_webhook(self, bot_uuid: str, path: str, request): + """Handle an inbound POST from the unified webhook dispatcher. + + Sub-path routing: + (no path) -> push a message + "reset" -> reset a session's conversation (body: {session_id, session_type?}) + "sync" -> push a message and wait for the final reply (collapses 1->M) + """ + object.__setattr__(self, 'bot_uuid', bot_uuid) + + if path == 'reset': + return await self._handle_reset(request) + if path == 'sync': + return await self._handle_inbound(request, sync=True) + if path in ('', None): + return await self._handle_inbound(request, sync=False) + return self._err('bad_request', f'unknown sub-path: {path}') + + async def _read_and_verify(self, request) -> tuple[dict | None, typing.Any]: + """Read body, enforce size + signature. Returns (data, error_response).""" + body = await request.get_data() + if body and len(body) > _MAX_BODY: + return None, self._err('too_large', 'message too large') + + if self.config.get('signature_required', True): + ok, reason = signing.verify( + secret=self.config.get('inbound_secret', ''), + body=body, + timestamp=request.headers.get(signing.HEADER_TIMESTAMP), + signature=request.headers.get(signing.HEADER_SIGNATURE), + ) + if not ok: + await self.logger.warning(f'http_bot inbound signature rejected: {reason}') + return None, self._err('bad_signature', f'invalid signature: {reason}') + + try: + data = json.loads(body) + except (json.JSONDecodeError, ValueError): + return None, self._err('bad_request', 'body is not valid JSON') + if not isinstance(data, dict): + return None, self._err('bad_request', 'body must be a JSON object') + return data, None + + def _build_event(self, data: dict) -> tuple[platform_events.MessageEvent, str, str, str]: + """Build a platform event from inbound data. + + Returns (event, session_id, session_type, message_id). + """ + session_id = str(data['session_id']) + session_type = data.get('session_type') or self.config.get('default_session_type', 'person') + sender_meta = data.get('sender') or {} + sender_name = str(sender_meta.get('name', 'User')) + + message_id = 'in_' + uuid.uuid4().hex + chain = platform_message.MessageChain.model_validate(data['message']) + # Carry the inbound message id + timestamp as the Source component. + chain.insert(0, platform_message.Source(id=message_id, time=datetime.now())) + + if session_type == 'group': + group = platform_entities.Group( + id=session_id, + name=str(sender_meta.get('group_name', session_id)), + permission=platform_entities.Permission.Member, + ) + sender = platform_entities.GroupMember( + id=str(sender_meta.get('id', session_id)), + member_name=sender_name, + group=group, + permission=platform_entities.Permission.Member, + ) + event = platform_events.GroupMessage(sender=sender, message_chain=chain, time=datetime.now().timestamp()) + else: + sender = platform_entities.Friend(id=session_id, nickname=sender_name, remark=sender_name) + event = platform_events.FriendMessage(sender=sender, message_chain=chain, time=datetime.now().timestamp()) + return event, session_id, session_type, message_id + + async def _handle_inbound(self, request, sync: bool): + data, err = await self._read_and_verify(request) + if err is not None: + return err + + if 'session_id' not in data or 'message' not in data: + return self._err('bad_request', 'session_id and message are required') + + # Idempotency. + idem = request.headers.get(signing.HEADER_IDEMPOTENCY) + if idem: + self._prune_idempotency() + if idem in self.idempotency_cache: + return self._err('duplicate', 'idempotency key already accepted') + self.idempotency_cache[idem] = time.time() + + try: + event, session_id, session_type, message_id = self._build_event(data) + except Exception as e: # noqa: BLE001 + return self._err('bad_request', f'failed to parse message: {e}') + + listener = self.listeners.get(type(event)) + if listener is None: + return self._err('internal', 'no listener registered for event type') + + if sync: + return await self._run_sync(event, listener, session_id, message_id) + + # Fire-and-collect: kick the pipeline, return 202 immediately. + asyncio.create_task(listener(event, self)) + return quart.jsonify( + { + 'code': 0, + 'msg': 'accepted', + 'data': { + 'session_id': session_id, + 'accepted_message_id': message_id, + 'aggregating': True, + }, + } + ), 202 + + async def _handle_reset(self, request): + data, err = await self._read_and_verify(request) + if err is not None: + return err + if 'session_id' not in data: + return self._err('bad_request', 'session_id is required') + + session_id = str(data['session_id']) + session_type = data.get('session_type') or self.config.get('default_session_type', 'person') + launcher_type = 'group' if session_type == 'group' else 'person' + + removed = await self._reset_session(launcher_type, session_id) + return quart.jsonify({'code': 0, 'msg': 'reset', 'data': {'session_id': session_id, 'removed': removed}}), 200 + + async def _reset_session(self, launcher_type: str, launcher_id: str) -> bool: + """Drop the matching session so the next message starts a fresh conversation.""" + sess_mgr = self.ap.sess_mgr + before = len(sess_mgr.session_list) + sess_mgr.session_list = [ + s + for s in sess_mgr.session_list + if not ( + str(s.launcher_type.value if hasattr(s.launcher_type, 'value') else s.launcher_type) == launcher_type + and str(s.launcher_id) == launcher_id + ) + ] + return len(sess_mgr.session_list) < before + + # -- outbound ------------------------------------------------------------- + + @staticmethod + def _extract_session_id(message_source: platform_events.MessageEvent) -> str: + if isinstance(message_source, platform_events.GroupMessage): + return str(message_source.sender.group.id) + return str(message_source.sender.id) + + @staticmethod + def _extract_reply_to(message_source: platform_events.MessageEvent) -> str: + for comp in message_source.message_chain: + if isinstance(comp, platform_message.Source): + return str(comp.id) + return '' + + def _next_sequence(self, session_id: str, is_final: bool) -> int: + state = self.outbound_states.setdefault(session_id, _SessionOutbound()) + if state.last_was_final: + state.sequence = 1 + else: + state.sequence += 1 + state.last_was_final = is_final + return state.sequence + + async def _enqueue_callback(self, session_id: str, payload: dict) -> None: + state = self.outbound_states.setdefault(session_id, _SessionOutbound()) + if state.worker is None or state.worker.done(): + state.worker = asyncio.create_task(self._outbound_worker(session_id, state)) + try: + state.queue.put_nowait(payload) + except asyncio.QueueFull: + # Drop oldest to bound memory, then enqueue (best-effort, at-least-once). + try: + state.queue.get_nowait() + except asyncio.QueueEmpty: + pass + await self.logger.warning(f'http_bot outbound queue full for session {session_id}; dropped oldest') + state.queue.put_nowait(payload) + + async def _outbound_worker(self, session_id: str, state: _SessionOutbound) -> None: + while True: + payload = await state.queue.get() + try: + await self._deliver_callback(payload) + except Exception as e: # noqa: BLE001 + await self.logger.error(f'http_bot callback delivery failed for {session_id}: {e}') + finally: + state.queue.task_done() + + async def _deliver_callback(self, payload: dict) -> None: + callback_url = self.config.get('callback_url', '') + if not callback_url: + await self.logger.warning('http_bot has no callback_url configured; dropping reply') + return + + body = json.dumps(payload, ensure_ascii=False).encode() + secret = self.config.get('outbound_secret') or self.config.get('inbound_secret', '') + ts, sig = signing.sign(secret, body) + headers = { + 'Content-Type': 'application/json', + signing.HEADER_TIMESTAMP: ts, + signing.HEADER_SIGNATURE: sig, + } + timeout = aiohttp.ClientTimeout(total=int(self.config.get('callback_timeout', 15))) + max_retries = int(self.config.get('callback_max_retries', 3)) + + session = httpclient.get_session() + attempt = 0 + while True: + attempt += 1 + try: + async with session.post(callback_url, data=body, headers=headers, timeout=timeout) as resp: + if resp.status < 400: + return + if resp.status < 500 or attempt > max_retries: + await self.logger.warning(f'http_bot callback {callback_url} -> {resp.status}, giving up') + return + except (aiohttp.ClientError, asyncio.TimeoutError) as e: + if attempt > max_retries: + await self.logger.warning(f'http_bot callback {callback_url} failed after {attempt} tries: {e}') + return + await asyncio.sleep(min(2 ** (attempt - 1), 30)) + + async def _emit_reply( + self, + message_source: platform_events.MessageEvent, + message: platform_message.MessageChain, + is_final: bool, + stream: bool, + ) -> dict: + session_id = self._extract_session_id(message_source) + reply_to = self._extract_reply_to(message_source) + sequence = self._next_sequence(session_id, is_final) + parts = [c.model_dump() if hasattr(c, 'model_dump') else c.__dict__ for c in message] + payload = { + 'session_id': session_id, + 'reply_to': reply_to, + 'sequence': sequence, + 'is_final': is_final, + 'stream': stream, + 'message': parts, + 'timestamp': datetime.now().isoformat(), + } + + # If a /sync request is awaiting this session, collect instead of POSTing. + collector = self.sync_waiters.get(session_id) + if collector is not None: + collector.parts.extend(parts) + if is_final: + collector.done.set() + return payload + + await self._enqueue_callback(session_id, payload) + return payload + + async def send_message(self, target_type: str, target_id: str, message: platform_message.MessageChain) -> dict: + """Proactively push a message to a session (target_id == session_id).""" + sequence = self._next_sequence(str(target_id), is_final=True) + payload = { + 'session_id': str(target_id), + 'reply_to': '', + 'sequence': sequence, + 'is_final': True, + 'stream': False, + 'message': [c.model_dump() if hasattr(c, 'model_dump') else c.__dict__ for c in message], + 'timestamp': datetime.now().isoformat(), + } + await self._enqueue_callback(str(target_id), payload) + return payload + + async def reply_message( + self, + message_source: platform_events.MessageEvent, + message: platform_message.MessageChain, + quote_origin: bool = False, + ) -> dict: + return await self._emit_reply(message_source, message, is_final=True, stream=False) + + async def reply_message_chunk( + self, + message_source: platform_events.MessageEvent, + bot_message, + message: platform_message.MessageChain, + quote_origin: bool = False, + is_final: bool = False, + ) -> dict: + message_is_final = is_final and getattr(bot_message, 'tool_calls', None) is None + return await self._emit_reply(message_source, message, is_final=message_is_final, stream=True) + + # -- sync convenience mode ------------------------------------------------ + + async def _run_sync(self, event, listener, session_id: str, message_id: str): + """Push a message and wait for the final reply, collapsing 1->M parts. + + Lossy by design (drops streaming/ordering nuance); documented as such. + Concurrency-safe: routing is via the per-session ``_sync_waiters`` + registry that ``_emit_reply`` consults, not by patching methods. + """ + if session_id in self.sync_waiters: + return self._err('duplicate', 'a sync request is already in flight for this session') + + collector = _SyncCollector() + self.sync_waiters[session_id] = collector + try: + asyncio.create_task(listener(event, self)) + timeout = int(self.config.get('callback_timeout', 15)) * 4 + try: + await asyncio.wait_for(collector.done.wait(), timeout=timeout) + except asyncio.TimeoutError: + await self.logger.warning(f'http_bot sync wait timed out for session {session_id}') + finally: + self.sync_waiters.pop(session_id, None) + + return quart.jsonify( + { + 'code': 0, + 'msg': 'ok', + 'data': { + 'session_id': session_id, + 'reply_to': message_id, + 'message': collector.parts, + }, + } + ), 200 diff --git a/src/langbot/pkg/platform/sources/http_bot.svg b/src/langbot/pkg/platform/sources/http_bot.svg new file mode 100644 index 000000000..13e5b90e2 --- /dev/null +++ b/src/langbot/pkg/platform/sources/http_bot.svg @@ -0,0 +1,17 @@ + + + + + + + + + + + + + + + + HTTP + diff --git a/src/langbot/pkg/platform/sources/http_bot.yaml b/src/langbot/pkg/platform/sources/http_bot.yaml new file mode 100644 index 000000000..56ef57f26 --- /dev/null +++ b/src/langbot/pkg/platform/sources/http_bot.yaml @@ -0,0 +1,153 @@ +apiVersion: v1 +kind: MessagePlatformAdapter +metadata: + name: http_bot + label: + en_US: HTTP Bot + zh_Hans: HTTP 通用接入 + zh_Hant: HTTP 通用接入 + ja_JP: HTTP ボット + description: + en_US: Integrate any backend over plain HTTP. Push messages in via a signed webhook, receive replies on a callback URL. Server-to-server, no long-lived connection. Preserves message aggregation (N->1) and multi-part replies (1->M). + zh_Hans: 通过 HTTP 接入任意后端系统。以签名 Webhook 推入消息，在回调地址接收回复。面向服务间集成，无需长连接。完整保留消息聚合（多条合一）与多段回复（一条问、多条回）能力。 + zh_Hant: 透過 HTTP 接入任意後端系統。以簽名 Webhook 推入訊息，在回調地址接收回覆。面向服務間整合，無需長連線。完整保留訊息聚合（多條合一）與多段回覆（一條問、多條回）能力。 + ja_JP: 任意のバックエンドを HTTP で接続。署名付き Webhook でメッセージを送信し、コールバック URL で返信を受信します。サーバー間連携、長時間接続不要。メッセージ集約（N→1）とマルチパート返信（1→M）に対応。 + icon: http_bot.svg +spec: + categories: + - popular + - global + help_links: + zh: https://docs.langbot.app/zh/platforms/http-bot + en: https://docs.langbot.app/en/platforms/http-bot + ja: https://docs.langbot.app/ja/platforms/http-bot + config: + - name: webhook_url + label: + en_US: Inbound Webhook URL + zh_Hans: 入站 Webhook 地址 + zh_Hant: 入站 Webhook 地址 + ja_JP: 受信 Webhook URL + description: + en_US: Copy this URL. Your backend POSTs messages here (signed with the inbound secret). + zh_Hans: 复制此地址。你的后端将消息以签名方式 POST 到这里。 + zh_Hant: 複製此地址。你的後端將訊息以簽名方式 POST 到這裡。 + ja_JP: この URL をコピーしてください。バックエンドは署名付きでここにメッセージを POST します。 + type: webhook-url + required: false + default: "" + - name: inbound_secret + label: + en_US: Inbound Signing Secret + zh_Hans: 入站签名密钥 + zh_Hant: 入站簽名密鑰 + ja_JP: 受信署名シークレット + description: + en_US: HMAC-SHA256 secret your backend uses to sign inbound requests. LangBot verifies every inbound POST with it. + zh_Hans: 你的后端用于对入站请求做 HMAC-SHA256 签名的密钥；LangBot 据此校验每个入站 POST。 + zh_Hant: 你的後端用於對入站請求做 HMAC-SHA256 簽名的密鑰；LangBot 據此校驗每個入站 POST。 + ja_JP: バックエンドが受信リクエストの署名に使う HMAC-SHA256 シークレット。LangBot は受信 POST ごとに検証します。 + type: string + required: true + default: "" + - name: callback_url + label: + en_US: Outbound Callback URL + zh_Hans: 出站回调地址 + zh_Hant: 出站回調地址 + ja_JP: 送信コールバック URL + description: + en_US: Where LangBot POSTs replies. One turn may trigger multiple callbacks (1->M). For security the callback URL is taken ONLY from this config and cannot be overridden per-message. + zh_Hans: LangBot 将回复 POST 到此地址。一轮对话可能触发多次回调（一问多答）。出于安全考虑，回调地址只取自此配置，不允许逐条消息覆盖。 + zh_Hant: LangBot 將回覆 POST 到此地址。一輪對話可能觸發多次回調（一問多答）。出於安全考慮，回調地址只取自此配置，不允許逐條訊息覆蓋。 + ja_JP: LangBot が返信を POST する先。1 ターンで複数回のコールバック（1→M）が発生し得ます。セキュリティ上、コールバック URL はこの設定からのみ取得し、メッセージ単位で上書きできません。 + type: string + required: true + default: "" + - name: outbound_secret + label: + en_US: Outbound Signing Secret + zh_Hans: 出站签名密钥 + zh_Hant: 出站簽名密鑰 + ja_JP: 送信署名シークレット + description: + en_US: HMAC-SHA256 secret LangBot uses to sign outbound callbacks so your receiver can verify them. Falls back to the inbound secret when empty. + zh_Hans: LangBot 用于对出站回调签名的密钥，供你的接收端校验。留空时回退使用入站密钥。 + zh_Hant: LangBot 用於對出站回調簽名的密鑰，供你的接收端校驗。留空時回退使用入站密鑰。 + ja_JP: LangBot が送信コールバックの署名に使う HMAC-SHA256 シークレット。受信側で検証できます。空の場合は受信シークレットを使用します。 + type: string + required: false + default: "" + - name: default_session_type + label: + en_US: Default Session Type + zh_Hans: 默认会话类型 + zh_Hant: 預設會話類型 + ja_JP: デフォルトセッションタイプ + description: + en_US: Session type used when an inbound message omits session_type. + zh_Hans: 入站消息未携带 session_type 时使用的会话类型。 + zh_Hant: 入站訊息未攜帶 session_type 時使用的會話類型。 + ja_JP: 受信メッセージに session_type がない場合に使用するセッションタイプ。 + type: select + options: + - name: person + label: + en_US: Person (1-on-1) + zh_Hans: 个人（一对一） + zh_Hant: 個人（一對一） + ja_JP: 個人（1 対 1） + - name: group + label: + en_US: Group + zh_Hans: 群组 + zh_Hant: 群組 + ja_JP: グループ + required: false + default: person + - name: signature_required + label: + en_US: Require Inbound Signature + zh_Hans: 强制入站签名校验 + zh_Hant: 強制入站簽名校驗 + ja_JP: 受信署名を必須にする + description: + en_US: When enabled (recommended), every inbound POST must carry a valid signature. Disable ONLY for local development behind a trusted network. + zh_Hans: 开启（推荐）后，每个入站 POST 都必须带有效签名。仅在受信任内网的本地开发时关闭。 + zh_Hant: 開啟（推薦）後，每個入站 POST 都必須帶有效簽名。僅在受信任內網的本地開發時關閉。 + ja_JP: 有効（推奨）にすると、すべての受信 POST に有効な署名が必要です。信頼できるネットワーク内のローカル開発時のみ無効化してください。 + type: boolean + required: false + default: true + - name: callback_timeout + label: + en_US: Callback Timeout (seconds) + zh_Hans: 回调超时（秒） + zh_Hant: 回調逾時（秒） + ja_JP: コールバックタイムアウト（秒） + description: + en_US: Per-callback HTTP timeout. + zh_Hans: 单次回调的 HTTP 超时时间。 + zh_Hant: 單次回調的 HTTP 逾時時間。 + ja_JP: コールバックごとの HTTP タイムアウト。 + type: integer + required: false + default: 15 + - name: callback_max_retries + label: + en_US: Callback Max Retries + zh_Hans: 回调最大重试次数 + zh_Hant: 回調最大重試次數 + ja_JP: コールバック最大リトライ回数 + description: + en_US: Retries on timeout or 5xx, with exponential backoff. + zh_Hans: 超时或 5xx 时按指数退避重试的次数。 + zh_Hant: 逾時或 5xx 時按指數退避重試的次數。 + ja_JP: タイムアウトまたは 5xx 時に指数バックオフでリトライする回数。 + type: integer + required: false + default: 3 +execution: + python: + path: ./http_bot.py + attr: HttpBotAdapter diff --git a/src/langbot/pkg/platform/sources/http_bot_signing.py b/src/langbot/pkg/platform/sources/http_bot_signing.py new file mode 100644 index 000000000..0578721c4 --- /dev/null +++ b/src/langbot/pkg/platform/sources/http_bot_signing.py @@ -0,0 +1,95 @@ +"""HMAC signing utilities for the HTTP Bot adapter. + +A dependency-free, symmetric HMAC-SHA256 scheme used in *both* directions: + + signing_string = "{timestamp}." + raw_body_bytes + signature = "sha256=" + hex(HMAC_SHA256(secret, signing_string)) + +Inbound requests are signed by the caller and verified here; outbound +callbacks are signed here and verified by the caller. The scheme is trivial to +reproduce in any language (see docs/platforms/http-bot.md for JS/curl). +""" + +from __future__ import annotations + +import hashlib +import hmac +import time + +# Header names (kept here so adapter + clients agree on a single source). +HEADER_TIMESTAMP = 'X-LB-Timestamp' +HEADER_SIGNATURE = 'X-LB-Signature' +HEADER_IDEMPOTENCY = 'X-LB-Idempotency-Key' + +# Maximum allowed clock skew between signer and verifier (seconds). +DEFAULT_REPLAY_WINDOW = 300 + + +def compute_signature(secret: str, body: bytes, timestamp: str | int) -> str: + """Compute the ``sha256=`` signature for *body* at *timestamp*. + + Args: + secret: Shared HMAC secret. + body: Raw request body bytes (exactly as sent on the wire). + timestamp: Unix timestamp (seconds) as str or int. + + Returns: + The signature string, e.g. ``sha256=ab12...``. + """ + signing_string = f'{timestamp}.'.encode() + body + digest = hmac.new(secret.encode(), signing_string, hashlib.sha256).hexdigest() + return f'sha256={digest}' + + +def sign(secret: str, body: bytes, timestamp: int | None = None) -> tuple[str, str]: + """Produce ``(timestamp, signature)`` for an outbound request. + + Args: + secret: Shared HMAC secret. + body: Raw request body bytes. + timestamp: Optional fixed timestamp; defaults to ``int(time.time())``. + + Returns: + ``(timestamp_str, signature_str)``. + """ + ts = str(timestamp if timestamp is not None else int(time.time())) + return ts, compute_signature(secret, body, ts) + + +def verify( + secret: str, + body: bytes, + timestamp: str | None, + signature: str | None, + replay_window: int = DEFAULT_REPLAY_WINDOW, +) -> tuple[bool, str]: + """Verify an inbound signature. + + Args: + secret: Shared HMAC secret. + body: Raw request body bytes. + timestamp: Value of the timestamp header. + signature: Value of the signature header. + replay_window: Max allowed skew in seconds. + + Returns: + ``(ok, reason)``. ``reason`` is empty when ``ok`` is True, otherwise a + short machine-friendly cause (``missing_headers`` / ``bad_timestamp`` / + ``expired`` / ``signature_mismatch``). + """ + if not timestamp or not signature: + return False, 'missing_headers' + + try: + ts_int = int(float(timestamp)) + except (ValueError, TypeError): + return False, 'bad_timestamp' + + if abs(int(time.time()) - ts_int) > replay_window: + return False, 'expired' + + expected = compute_signature(secret, body, timestamp) + if not hmac.compare_digest(expected, signature): + return False, 'signature_mismatch' + + return True, ''