Split AI SDK helpers and add Desktop-compatible Beeper streaming

package.json

@@ -9,7 +9,7 @@
     "check": "pnpm typecheck && pnpm test && pnpm test:go && pnpm build && pnpm pack:packages && pnpm smoke:consumer && pnpm smoke:cloudflare",
     "clean": "pnpm -r clean",
     "pack:packages": "mkdir -p .packs && pnpm -r --filter './packages/*' pack --pack-destination ./.packs",
-    "publish:packages": "pnpm --filter @better-matrix-js/cloudflare publish --access public --no-git-checks && pnpm --filter better-matrix-js publish --access public --no-git-checks && pnpm --filter @better-matrix-js/chat-adapter publish --access public --no-git-checks",
+    "publish:packages": "pnpm --filter @better-matrix-js/cloudflare publish --access public --no-git-checks && pnpm --filter better-matrix-js publish --access public --no-git-checks && pnpm --filter @better-matrix-js/chat-adapter publish --access public --no-git-checks && pnpm --filter @better-matrix-js/ai-sdk publish --access public --no-git-checks",
     "smoke:cloudflare": "node scripts/smoke-cloudflare-worker.mjs",
     "smoke:consumer": "node scripts/package-consumer-smoke.mjs",
     "smoke:package-consumer": "node scripts/package-consumer-smoke.mjs",

packages/ai-sdk/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

packages/ai-sdk/README.md

@@ -0,0 +1,5 @@
+# @better-matrix-js/ai-sdk
+
+AI SDK stream adapters for `better-matrix-js`.
+
+This package is separate from `@better-matrix-js/chat-adapter` so Matrix and Chat SDK users do not need the AI SDK integration unless they want it.

packages/ai-sdk/package.json

@@ -0,0 +1,59 @@
+{
+  "name": "@better-matrix-js/ai-sdk",
+  "version": "0.1.0",
+  "description": "AI SDK stream adapters for better-matrix-js",
+  "type": "module",
+  "homepage": "https://github.com/batuhan/better-matrix-js#readme",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/batuhan/better-matrix-js.git",
+    "directory": "packages/ai-sdk"
+  },
+  "bugs": {
+    "url": "https://github.com/batuhan/better-matrix-js/issues"
+  },
+  "main": "./dist/index.js",
+  "module": "./dist/index.js",
+  "types": "./dist/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./dist/index.d.ts",
+      "import": "./dist/index.js"
+    }
+  },
+  "files": [
+    "dist",
+    "README.md",
+    "LICENSE"
+  ],
+  "publishConfig": {
+    "access": "public"
+  },
+  "scripts": {
+    "build": "tsup",
+    "clean": "rm -rf dist",
+    "prepublishOnly": "node ../../scripts/guard-pnpm-publish.mjs",
+    "test": "vitest run --coverage",
+    "typecheck": "tsc --noEmit"
+  },
+  "peerDependencies": {
+    "@better-matrix-js/chat-adapter": "^0.1.0"
+  },
+  "devDependencies": {
+    "@better-matrix-js/chat-adapter": "workspace:*",
+    "@types/node": "^25.3.2",
+    "tsup": "^8.3.5",
+    "typescript": "^5.7.2",
+    "vitest": "^4.0.18"
+  },
+  "keywords": [
+    "matrix",
+    "ai-sdk",
+    "streaming",
+    "beeper"
+  ],
+  "engines": {
+    "node": ">=20"
+  },
+  "license": "MIT"
+}

packages/ai-sdk/src/index.test.ts

@@ -0,0 +1,55 @@
+import { describe, expect, it } from "vitest";
+import { fromAIStreamResult, fromAIUIMessageStream, isAIUIMessageStreamResult } from "./index";
+
+async function collect<T>(iterable: AsyncIterable<T>): Promise<T[]> {
+  const values: T[] = [];
+  for await (const value of iterable) {
+    values.push(value);
+  }
+  return values;
+}
+
+describe("AI SDK stream adapters", () => {
+  it("passes async iterable UI message chunks through structurally", async () => {
+    async function* chunks() {
+      yield { delta: "hello", id: "text-1", type: "text-delta" };
+    }
+
+    await expect(collect(fromAIUIMessageStream(chunks()))).resolves.toEqual([
+      { delta: "hello", id: "text-1", type: "text-delta" },
+    ]);
+  });
+
+  it("converts ReadableStream UI message chunks to async iterable Matrix streams", async () => {
+    const stream = new ReadableStream({
+      start(controller) {
+        controller.enqueue({ id: "reasoning-1", type: "reasoning-start" });
+        controller.enqueue({ delta: "thinking", id: "reasoning-1", type: "reasoning-delta" });
+        controller.close();
+      },
+    });
+
+    await expect(collect(fromAIUIMessageStream(stream))).resolves.toEqual([
+      { id: "reasoning-1", type: "reasoning-start" },
+      { delta: "thinking", id: "reasoning-1", type: "reasoning-delta" },
+    ]);
+  });
+
+  it("accepts streamText-like results with toUIMessageStream", async () => {
+    const result = {
+      toUIMessageStream() {
+        return new ReadableStream({
+          start(controller) {
+            controller.enqueue({ finishReason: "stop", type: "finish" });
+            controller.close();
+          },
+        });
+      },
+    };
+
+    expect(isAIUIMessageStreamResult(result)).toBe(true);
+    await expect(collect(fromAIStreamResult(result))).resolves.toEqual([
+      { finishReason: "stop", type: "finish" },
+    ]);
+  });
+});

packages/ai-sdk/src/index.ts

@@ -0,0 +1,52 @@
+import type { MatrixStream } from "@better-matrix-js/chat-adapter";
+
+export type AIUIMessageChunk = {
+  type: string;
+  [key: string]: unknown;
+};
+
+export type AIUIMessageChunkStream =
+  | AsyncIterable<AIUIMessageChunk>
+  | ReadableStream<AIUIMessageChunk>;
+
+export interface AIUIMessageStreamResult {
+  toUIMessageStream(): AIUIMessageChunkStream;
+}
+
+export function fromAIUIMessageStream(stream: AIUIMessageChunkStream): MatrixStream {
+  if (isAsyncIterable(stream)) {
+    return stream;
+  }
+  return readableStreamToAsyncIterable(stream);
+}
+
+export function fromAIStreamResult(result: AIUIMessageStreamResult): MatrixStream {
+  return fromAIUIMessageStream(result.toUIMessageStream());
+}
+
+export function isAIUIMessageStreamResult(value: unknown): value is AIUIMessageStreamResult {
+  return (
+    typeof value === "object" &&
+    value !== null &&
+    typeof (value as { toUIMessageStream?: unknown }).toUIMessageStream === "function"
+  );
+}
+
+async function* readableStreamToAsyncIterable(stream: ReadableStream<AIUIMessageChunk>): AsyncIterable<AIUIMessageChunk> {
+  const reader = stream.getReader();
+  try {
+    while (true) {
+      const result = await reader.read();
+      if (result.done) {
+        return;
+      }
+      yield result.value;
+    }
+  } finally {
+    reader.releaseLock();
+  }
+}
+
+function isAsyncIterable(value: AIUIMessageChunkStream): value is AsyncIterable<AIUIMessageChunk> {
+  return Symbol.asyncIterator in value;
+}

packages/ai-sdk/tsconfig.json

@@ -0,0 +1,8 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "compilerOptions": {
+    "outDir": "./dist"
+  },
+  "include": ["src/**/*"],
+  "exclude": ["dist", "node_modules", "**/*.test.ts"]
+}

packages/ai-sdk/tsup.config.ts

@@ -0,0 +1,10 @@
+import { defineConfig } from "tsup";
+
+export default defineConfig({
+  entry: ["src/index.ts"],
+  format: ["esm"],
+  dts: true,
+  clean: true,
+  sourcemap: false,
+  external: ["@better-matrix-js/chat-adapter", "ai"],
+});

packages/ai-sdk/vitest.config.ts

@@ -0,0 +1,11 @@
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+  test: {
+    environment: "node",
+    coverage: {
+      provider: "v8",
+      reporter: ["text", "json-summary"],
+    },
+  },
+});