feat: add Chat SDK integration for persistent chat bot memory (#442)

Adds @vectorize-io/hindsight-chat, a wrapper for the Vercel Chat SDK
that gives any chat bot (Slack, Discord, Teams, etc.) long-term memory
via Hindsight. Includes withHindsightChat() handler wrapper with
auto-recall, auto-retain, and memoriesAsSystemPrompt() formatting.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: benfrank241

hindsight-integrations/chat/.gitignore

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+# Dependencies
+node_modules/
+
+# Build output
+dist/
+
+# Test coverage
+coverage/
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Environment
+.env
+.env.local
+.env.*.local

hindsight-integrations/chat/README.md

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+# @vectorize-io/hindsight-chat
+
+Give your [Vercel Chat SDK](https://github.com/vercel/chat) bots persistent, per-user memory with a single handler wrapper. Works with Slack, Discord, Teams, Google Chat, GitHub, and Linear.
+
+## Quick Start
+
+```bash
+npm install @vectorize-io/hindsight-chat
+```
+
+```typescript
+import { Chat } from 'chat';
+import { HindsightClient } from '@vectorize-io/hindsight-client';
+import { withHindsightChat } from '@vectorize-io/hindsight-chat';
+import { streamText } from 'ai';
+import { openai } from '@ai-sdk/openai';
+
+const chat = new Chat({ connectors: [/* your connectors */] });
+const hindsight = new HindsightClient({ apiKey: process.env.HINDSIGHT_API_KEY });
+
+chat.onNewMention(
+  withHindsightChat(
+    {
+      client: hindsight,
+      bankId: (msg) => msg.author.userId, // per-user memory
+    },
+    async (thread, message, ctx) => {
+      await thread.subscribe();
+
+      const result = await streamText({
+        model: openai('gpt-4o'),
+        system: ctx.memoriesAsSystemPrompt(),
+        messages: [{ role: 'user', content: message.text }],
+      });
+
+      // Stream the response
+      const chunks: string[] = [];
+      for await (const chunk of result.textStream) {
+        chunks.push(chunk);
+      }
+      const fullResponse = chunks.join('');
+      await thread.post(fullResponse);
+
+      // Store the conversation in memory
+      await ctx.retain(
+        `User: ${message.text}\nAssistant: ${fullResponse}`
+      );
+    }
+  )
+);
+```
+
+## Configuration
+
+### `withHindsightChat(options, handler)`
+
+Returns a standard Chat SDK handler `(thread, message) => Promise<void>`.
+
+#### Options
+
+| Option | Type | Default | Description |
+|--------|------|---------|-------------|
+| `client` | `HindsightClient` | *required* | Hindsight client instance |
+| `bankId` | `string \| (msg) => string` | *required* | Memory bank ID or resolver function |
+| `recall.enabled` | `boolean` | `true` | Auto-recall memories before handler |
+| `recall.budget` | `'low' \| 'mid' \| 'high'` | `'mid'` | Processing budget for recall |
+| `recall.maxTokens` | `number` | API default | Max tokens for recall results |
+| `recall.types` | `FactType[]` | all | Filter to specific fact types |
+| `recall.includeEntities` | `boolean` | `true` | Include entity observations |
+| `retain.enabled` | `boolean` | `false` | Auto-retain inbound messages |
+| `retain.async` | `boolean` | `true` | Fire-and-forget retain |
+| `retain.tags` | `string[]` | – | Tags for retained memories |
+| `retain.metadata` | `Record<string, string>` | – | Metadata for retained memories |
+
+### Context (`ctx`)
+
+The third argument passed to your handler:
+
+| Property/Method | Description |
+|----------------|-------------|
+| `ctx.bankId` | Resolved bank ID |
+| `ctx.memories` | Array of recalled memories |
+| `ctx.entities` | Entity observations (or null) |
+| `ctx.memoriesAsSystemPrompt(options?)` | Format memories for LLM system prompt |
+| `ctx.retain(content, options?)` | Store content in memory |
+| `ctx.recall(query, options?)` | Search memories |
+| `ctx.reflect(query, options?)` | Reason over memories |
+
+## Examples
+
+### Subscribed Message Handler
+
+```typescript
+chat.onSubscribedMessage(
+  withHindsightChat(
+    {
+      client: hindsight,
+      bankId: (msg) => msg.author.userId,
+      recall: { budget: 'high', maxTokens: 1000 },
+    },
+    async (thread, message, ctx) => {
+      const result = await generateText({
+        model: openai('gpt-4o'),
+        system: ctx.memoriesAsSystemPrompt(),
+        messages: [{ role: 'user', content: message.text }],
+      });
+      await thread.post(result.text);
+    }
+  )
+);
+```
+
+### Auto-Retain Inbound Messages
+
+```typescript
+chat.onNewMention(
+  withHindsightChat(
+    {
+      client: hindsight,
+      bankId: (msg) => msg.author.userId,
+      retain: { enabled: true, tags: ['slack', 'inbound'] },
+    },
+    async (thread, message, ctx) => {
+      // Inbound message is already being retained automatically
+      const result = await generateText({
+        model: openai('gpt-4o'),
+        system: ctx.memoriesAsSystemPrompt(),
+        messages: [{ role: 'user', content: message.text }],
+      });
+      await thread.post(result.text);
+
+      // Retain the assistant response separately
+      await ctx.retain(`Assistant: ${result.text}`, {
+        tags: ['slack', 'outbound'],
+      });
+    }
+  )
+);
+```
+
+### Static Bank ID (Shared Memory)
+
+```typescript
+// All users share the same memory bank
+chat.onNewMention(
+  withHindsightChat(
+    { client: hindsight, bankId: 'shared-team-memory' },
+    async (thread, message, ctx) => {
+      // ...
+    }
+  )
+);
+```
+
+## Error Handling
+
+Memory failures never break your bot. Auto-recall and auto-retain errors are logged as warnings and the handler continues with empty memories. Manual `ctx.retain()`, `ctx.recall()`, and `ctx.reflect()` calls propagate errors normally so you can handle them as needed.
+
+## License
+
+MIT