fix(anthropic): accept stable and beta SDK events

API.md

@@ -336,6 +336,10 @@ composable integration value:
 | `streamfold/langchain` | `langchain` |
 | `streamfold/ag-ui` | `agUI` |
 
+The Anthropic integration accepts both `client.messages.create({ ..., stream: true })`
+and `client.beta.messages.create({ ..., stream: true })` directly. Text, thinking,
+and other non-tool SDK events can remain in the stream and are ignored.
+
 The OpenAI integration accepts `client.responses.create({ ..., stream: true })`
 directly, including SDK event interfaces for text and other non-tool events.
 Non-tool events are ignored; callers do not need to cast or filter the stream.

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- Accept Anthropic stable and beta SDK message event interfaces directly in
+  the Anthropic adapter and managed reader.
 - Accept OpenAI SDK response stream event types directly in the OpenAI adapter
   and managed reader, including non-tool events.
 - Preserve Gemini Interactions tool arguments from `arguments_delta` events

examples/tsconfig.json

@@ -5,5 +5,5 @@
     "checkJs": true,
     "skipLibCheck": true
   },
-  "files": ["assistant-ui.mjs", "vercel-ai.mjs", "custom.mjs", "../tests/langchain-sdk.ts", "../tests/gemini-sdk.ts", "../tests/openai-sdk.ts"]
+  "files": ["assistant-ui.mjs", "vercel-ai.mjs", "custom.mjs", "../tests/langchain-sdk.ts", "../tests/gemini-sdk.ts", "../tests/openai-sdk.ts", "../tests/anthropic-sdk.ts"]
 }

package.json

@@ -31,6 +31,7 @@
     "verify": "pnpm check && pnpm pack:check && pnpm bench && pnpm bench:sdk"
   },
   "devDependencies": {
+    "@anthropic-ai/sdk": "1.3.0",
     "@google/genai": "2.31.0",
     "@langchain/core": "1.3.0",
     "ai": "7.0.152",

packages/core/src/anthropic.d.ts

@@ -28,6 +28,7 @@ export type AnthropicToolInputEvent =
       readonly type: "content_block_stop";
       readonly index: number;
     }
+  | { readonly type: string }
   | {
       readonly type: string;
       readonly index?: number;

tests/anthropic-sdk.ts

@@ -0,0 +1,20 @@
+import Anthropic from "@anthropic-ai/sdk";
+import { readStructured } from "streamfold";
+import { anthropic } from "streamfold/anthropic";
+
+const client = new Anthropic({ apiKey: "typecheck-only" });
+const request = {
+  model: "fixture", max_tokens: 32,
+  messages: [{ role: "user" as const, content: "Weather in Paris?" }],
+  stream: true as const,
+};
+const events = await client.messages.create(request);
+readStructured(events, { integration: anthropic });
+const stream = anthropic();
+for await (const event of events) stream.pushAll(event);
+
+const betaEvents = await client.beta.messages.create(request);
+readStructured(betaEvents, { integration: anthropic });
+const betaStream = anthropic();
+for await (const event of betaEvents) betaStream.push(event);
+stream.pushAll({ type: "provider_metadata", metadata: { region: "test" } });