[RFC] add concurrency strategies for overlapping messages (queue, debounce, concurrent)

apps/docs/content/docs/contributing/building.mdx

@@ -31,7 +31,7 @@ Chat SDK ships with Vercel-maintained adapters for Slack, Teams, Google Chat, Di
 
 #### Qualifications for vendor official tier
 
-- Committment for continued maintenance of the adapter.
+- Commitment for continued maintenance of the adapter.
 - GitHub hosting in official vendor-owned org.
 - Documentation of the adapter in primary vendor docs.
 - Announcement of the adapter in blog post or changelog and social media.

packages/adapter-discord/CHANGELOG.md

@@ -1,5 +1,19 @@
 # @chat-adapter/discord
 
+## 4.21.0
+
+### Minor Changes
+
+- d778f72: Switch adapters from optional dep to full dep on chat
+
+### Patch Changes
+
+- Updated dependencies [e45a67f]
+- Updated dependencies [13ba1c7]
+- Updated dependencies [95fd8ce]
+  - chat@4.21.0
+  - @chat-adapter/shared@4.21.0
+
 ## 4.20.2
 
 ### Patch Changes

packages/adapter-discord/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@chat-adapter/discord",
-  "version": "4.20.2",
+  "version": "4.21.0",
   "description": "Discord adapter for chat",
   "type": "module",
   "main": "./dist/index.js",
@@ -25,13 +25,11 @@
   },
   "dependencies": {
     "@chat-adapter/shared": "workspace:*",
+    "chat": "workspace:*",
     "discord-api-types": "^0.37.119",
     "discord-interactions": "^4.4.0",
     "discord.js": "^14.25.1"
   },
-  "peerDependencies": {
-    "chat": "workspace:*"
-  },
   "devDependencies": {
     "@types/node": "^25.3.2",
     "tsup": "^8.3.5",

packages/adapter-gchat/CHANGELOG.md

@@ -1,5 +1,20 @@
 # @chat-adapter/gchat
 
+## 4.21.0
+
+### Minor Changes
+
+- d778f72: Switch adapters from optional dep to full dep on chat
+
+### Patch Changes
+
+- 000792b: Introduce optional gchat signature verification
+- Updated dependencies [e45a67f]
+- Updated dependencies [13ba1c7]
+- Updated dependencies [95fd8ce]
+  - chat@4.21.0
+  - @chat-adapter/shared@4.21.0
+
 ## 4.20.2
 
 ### Patch Changes

packages/adapter-gchat/README.md

@@ -161,6 +161,8 @@ All options are auto-detected from environment variables when not provided.
 | `credentials` | No* | Service account credentials JSON. Auto-detected from `GOOGLE_CHAT_CREDENTIALS` |
 | `useApplicationDefaultCredentials` | No | Use Application Default Credentials. Auto-detected from `GOOGLE_CHAT_USE_ADC` |
 | `pubsubTopic` | No | Pub/Sub topic for Workspace Events. Auto-detected from `GOOGLE_CHAT_PUBSUB_TOPIC` |
+| `pubsubAudience` | No | Expected JWT audience for Pub/Sub webhook verification. Auto-detected from `GOOGLE_CHAT_PUBSUB_AUDIENCE` |
+| `googleChatProjectNumber` | No | GCP project number for direct webhook JWT verification. Auto-detected from `GOOGLE_CHAT_PROJECT_NUMBER` |
 | `impersonateUser` | No | User email for domain-wide delegation. Auto-detected from `GOOGLE_CHAT_IMPERSONATE_USER` |
 | `auth` | No | Custom auth object (advanced) |
 | `logger` | No | Logger instance (defaults to `ConsoleLogger("info")`) |
@@ -175,8 +177,49 @@ GOOGLE_CHAT_CREDENTIALS={"type":"service_account",...}
 # Optional: for receiving all messages
 GOOGLE_CHAT_PUBSUB_TOPIC=projects/your-project/topics/chat-events
 GOOGLE_CHAT_IMPERSONATE_USER=admin@yourdomain.com
+
+# Optional: webhook verification (recommended for production)
+GOOGLE_CHAT_PROJECT_NUMBER=123456789          # For direct webhook JWT verification
+GOOGLE_CHAT_PUBSUB_AUDIENCE=https://your-domain.com/api/webhooks/gchat  # For Pub/Sub JWT verification
+```
+
+## Webhook verification
+
+The adapter supports JWT verification for both webhook types. When configured, the adapter validates the `Authorization: Bearer <JWT>` header on incoming requests using Google's public keys. Requests with missing or invalid tokens are rejected with HTTP 401.
+
+Verification is opt-in — when the config options are not set, webhooks are accepted without signature checks (for backward compatibility and development).
+
+### Direct webhooks (Google Chat API)
+
+Google Chat sends a signed JWT with every webhook request. The JWT audience (`aud` claim) is your GCP project number.
+
+```typescript
+createGoogleChatAdapter({
+  googleChatProjectNumber: "123456789",
+});
+```
+
+Find your project number in the [GCP Console dashboard](https://console.cloud.google.com/home/dashboard) (it's different from the project ID).
+
+### Pub/Sub push messages
+
+Google Cloud Pub/Sub sends a signed OIDC JWT with push deliveries. The JWT audience is whatever you configured on the push subscription.
+
+```typescript
+createGoogleChatAdapter({
+  pubsubAudience: "https://your-domain.com/api/webhooks/gchat",
+});
 ```
 
+To enable authenticated push on your Pub/Sub subscription:
+
+1. Go to **Pub/Sub** then **Subscriptions**
+2. Edit your push subscription
+3. Enable **Authentication**
+4. Select a service account with the **Service Account Token Creator** role
+5. Set the **Audience** to your webhook URL
+6. Use the same URL as `GOOGLE_CHAT_PUBSUB_AUDIENCE`
+
 ## Features
 
 ### Messaging
@@ -237,6 +280,13 @@ Fetching message history requires domain-wide delegation with the `impersonateUs
 
 ## Troubleshooting
 
+### 401 Unauthorized on webhooks
+
+- For direct webhooks: verify `GOOGLE_CHAT_PROJECT_NUMBER` matches your GCP project number (not project ID)
+- For Pub/Sub: verify `GOOGLE_CHAT_PUBSUB_AUDIENCE` matches the audience configured on your push subscription
+- Check that authentication is enabled on your Pub/Sub push subscription
+- Ensure the service account used for push authentication has the **Service Account Token Creator** role
+
 ### No webhook received
 
 - Verify the App URL is correct in Google Chat configuration

packages/adapter-gchat/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@chat-adapter/gchat",
-  "version": "4.20.2",
+  "version": "4.21.0",
   "description": "Google Chat adapter for chat",
   "type": "module",
   "main": "./dist/index.js",
@@ -26,9 +26,7 @@
   "dependencies": {
     "@chat-adapter/shared": "workspace:*",
     "@googleapis/chat": "^44.6.0",
-    "@googleapis/workspaceevents": "^9.1.0"
-  },
-  "peerDependencies": {
+    "@googleapis/workspaceevents": "^9.1.0",
     "chat": "workspace:*"
   },
   "devDependencies": {