feat: adapt cloudflare worker ai (#14732)

#### PR Dependency Tree


* **PR #14732** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Cloudflare Workers AI added as a Copilot provider (configurable in
admin settings).
  * Gemini 3.1 Flash Lite Preview model made available.

* **Behavior Changes**
* Reranking now uses a different default model identifier (affects
relevancy scores).

* **Tests**
* Rerank tests adjusted to focus on the updated model and expected
results.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

.docker/selfhost/schema.json

@@ -1005,6 +1005,14 @@
             "baseURL": "https://api.openai.com/v1"
           }
         },
+        "providers.cloudflareWorkersAi": {
+          "type": "object",
+          "description": "The config for the Cloudflare Workers AI provider.\n@default {\"apiToken\":\"\",\"accountId\":\"\"}",
+          "default": {
+            "apiToken": "",
+            "accountId": ""
+          }
+        },
         "providers.fal": {
           "type": "object",
           "description": "The config for the fal provider.\n@default {\"apiKey\":\"\"}",

Cargo.lock

@@ -3371,9 +3371,9 @@ dependencies = [
 
 [[package]]
 name = "llm_adapter"
-version = "0.1.3"
+version = "0.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e98485dda5180cc89b993a001688bed93307be6bd8fedcde445b69bbca4f554d"
+checksum = "cd95a9dd20745f3d80d47460e6cf6131921bef928c38fcd961b10b574d749305"
 dependencies = [
  "base64",
  "serde",

Cargo.toml

@@ -53,7 +53,7 @@ resolver = "3"
   libc = "0.2"
   libwebp-sys = "0.14.2"
   little_exif = "0.6.23"
-  llm_adapter = { version = "0.1.3", default-features = false }
+  llm_adapter = { version = "0.1.4", default-features = false }
   log = "0.4"
   loom = { version = "0.7", features = ["checkpoint"] }
   lru = "0.16"

packages/backend/server/src/__tests__/copilot/copilot-provider.spec.ts

@@ -964,11 +964,11 @@ test(
         'The stock market is experiencing significant fluctuations.',
       ];
 
-      const provider = (await factory.getProviderByModel('gpt-5.2'))!;
+      const provider = (await factory.getProviderByModel('gpt-4o-mini'))!;
       t.assert(provider, 'should have provider for rerank');
 
       const scores = await provider.rerank(
-        { modelId: 'gpt-5.2' },
+        { modelId: 'gpt-4o-mini' },
         {
           query,
           candidates: embeddings.map((text, index) => ({
@@ -990,8 +990,8 @@ test(
       t.log('Rerank scores:', scores);
       t.is(
         scores.filter(s => s > 0.5).length,
-        5,
+        4,
-        'should have 5 related chunks'
+        'should have 4 related chunks'
       );
     });
   }

packages/backend/server/src/__tests__/copilot/provider-native.spec.ts

@@ -3,6 +3,7 @@ import test from 'ava';
 
 import type { NativeLlmRerankRequest } from '../../native';
 import { ProviderMiddlewareConfig } from '../../plugins/copilot/config';
+import { CloudflareWorkersAIProvider } from '../../plugins/copilot/providers/cloudflare';
 import {
   normalizeOpenAIOptionsForModel,
   OpenAIProvider,
@@ -53,7 +54,7 @@ class TestOpenAIProvider extends CopilotProvider<{ apiKey: string }> {
 class NativeRerankProtocolProvider extends OpenAIProvider {
   override readonly models = [
     {
-      id: 'gpt-5.2',
+      id: 'gpt-4o-mini',
       capabilities: [
         {
           input: [ModelInputType.Text],
@@ -77,6 +78,19 @@ class NativeRerankProtocolProvider extends OpenAIProvider {
   }
 }
 
+class NativeCloudflareRerankProtocolProvider extends CloudflareWorkersAIProvider {
+  override get config() {
+    return {
+      apiToken: 'test-key',
+      accountId: 'account-1',
+    };
+  }
+
+  override configured() {
+    return true;
+  }
+}
+
 function createProvider(profileMiddleware?: ProviderMiddlewareConfig) {
   const provider = new TestOpenAIProvider();
   (provider as any).AFFiNEConfig = {
@@ -170,14 +184,14 @@ test('OpenAI rerank should always use chat-completions native protocol', async t
   ) => {
     capturedProtocol = protocol;
     capturedRequest = JSON.parse(requestJson) as NativeLlmRerankRequest;
-    return JSON.stringify({ model: 'gpt-5.2', scores: [0.9, 0.1] });
+    return JSON.stringify({ model: 'gpt-4o-mini', scores: [0.9, 0.1] });
   };
   t.teardown(() => {
     (serverNativeModule as any).llmRerankDispatch = original;
   });
 
   const scores = await provider.rerank(
-    { modelId: 'gpt-5.2' },
+    { modelId: 'gpt-4o-mini' },
     {
       query: 'programming',
       candidates: [
@@ -190,7 +204,7 @@ test('OpenAI rerank should always use chat-completions native protocol', async t
   t.deepEqual(scores, [0.9, 0.1]);
   t.is(capturedProtocol, 'openai_chat');
   t.deepEqual(capturedRequest, {
-    model: 'gpt-5.2',
+    model: 'gpt-4o-mini',
     query: 'programming',
     candidates: [
       { id: 'react', text: 'React is a UI library.' },
@@ -198,3 +212,63 @@ test('OpenAI rerank should always use chat-completions native protocol', async t
     ],
   });
 });
+
+test('Cloudflare rerank should keep native protocol details behind provider', async t => {
+  const provider = new NativeCloudflareRerankProtocolProvider();
+  let capturedProtocol: string | undefined;
+  let capturedRequest: NativeLlmRerankRequest | undefined;
+  let capturedBackendConfig: Record<string, unknown> | undefined;
+
+  const original = (serverNativeModule as any).llmRerankDispatch;
+  (serverNativeModule as any).llmRerankDispatch = (
+    protocol: string,
+    backendConfigJson: string,
+    requestJson: string
+  ) => {
+    capturedProtocol = protocol;
+    capturedBackendConfig = JSON.parse(backendConfigJson) as Record<
+      string,
+      unknown
+    >;
+    capturedRequest = JSON.parse(requestJson) as NativeLlmRerankRequest;
+    return JSON.stringify({
+      model: '@cf/qwen/qwen3-30b-a3b-fp8',
+      scores: [0.9, 0.1],
+    });
+  };
+  t.teardown(() => {
+    (serverNativeModule as any).llmRerankDispatch = original;
+  });
+
+  for (const modelId of [
+    '@cf/qwen/qwen3-30b-a3b-fp8',
+    '@cf/baai/bge-reranker-base',
+  ]) {
+    const scores = await provider.rerank(
+      { modelId },
+      {
+        query: 'programming',
+        candidates: [
+          { id: 'react', text: 'React is a UI library.' },
+          { id: 'weather', text: 'The weather is sunny today.' },
+        ],
+      }
+    );
+
+    t.deepEqual(scores, [0.9, 0.1]);
+    t.is(capturedProtocol, 'openai_chat');
+    t.deepEqual(capturedBackendConfig, {
+      base_url: 'https://api.cloudflare.com/client/v4/accounts/account-1/ai',
+      auth_token: 'test-key',
+      request_layer: 'cloudflare_workers_ai',
+    });
+    t.deepEqual(capturedRequest, {
+      model: modelId,
+      query: 'programming',
+      candidates: [
+        { id: 'react', text: 'React is a UI library.' },
+        { id: 'weather', text: 'The weather is sunny today.' },
+      ],
+    });
+  }
+});

packages/backend/server/src/native.ts

@@ -103,6 +103,7 @@ export type NativeLlmBackendConfig = {
   request_layer?:
     | 'anthropic'
     | 'chat_completions'
+    | 'cloudflare_workers_ai'
     | 'responses'
     | 'vertex'
     | 'vertex_anthropic'

packages/backend/server/src/plugins/copilot/config.ts

@@ -10,6 +10,7 @@ import {
   AnthropicOfficialConfig,
   AnthropicVertexConfig,
 } from './providers/anthropic';
+import { CloudflareWorkersAIConfig } from './providers/cloudflare';
 import type { FalConfig } from './providers/fal';
 import { GeminiGenerativeConfig, GeminiVertexConfig } from './providers/gemini';
 import { MorphConfig } from './providers/morph';
@@ -23,6 +24,7 @@ import {
 
 export type CopilotProviderConfigMap = {
   [CopilotProviderType.OpenAI]: OpenAIConfig;
+  [CopilotProviderType.CloudflareWorkersAi]: CloudflareWorkersAIConfig;
   [CopilotProviderType.FAL]: FalConfig;
   [CopilotProviderType.Gemini]: GeminiGenerativeConfig;
   [CopilotProviderType.GeminiVertex]: GeminiVertexConfig;
@@ -117,6 +119,12 @@ const FalConfigShape = z.object({
   apiKey: z.string(),
 });
 
+const CloudflareWorkersAIConfigShape = z.object({
+  apiToken: z.string(),
+  accountId: z.string().optional(),
+  baseURL: z.string().optional(),
+});
+
 const GeminiGenerativeConfigShape = z.object({
   apiKey: z.string(),
   baseURL: z.string().optional(),
@@ -153,6 +161,10 @@ const CopilotProviderProfileShape = z.discriminatedUnion('type', [
     type: z.literal(CopilotProviderType.FAL),
     config: FalConfigShape,
   }),
+  CopilotProviderProfileBaseShape.extend({
+    type: z.literal(CopilotProviderType.CloudflareWorkersAi),
+    config: CloudflareWorkersAIConfigShape,
+  }),
   CopilotProviderProfileBaseShape.extend({
     type: z.literal(CopilotProviderType.Gemini),
     config: GeminiGenerativeConfigShape,
@@ -205,6 +217,7 @@ declare global {
         profiles: ConfigItem<CopilotProviderProfile[]>;
         defaults: ConfigItem<CopilotProviderDefaults>;
         openai: ConfigItem<OpenAIConfig>;
+        cloudflareWorkersAi: ConfigItem<CloudflareWorkersAIConfig>;
         fal: ConfigItem<FalConfig>;
         gemini: ConfigItem<GeminiGenerativeConfig>;
         geminiVertex: ConfigItem<GeminiVertexConfig>;
@@ -257,6 +270,13 @@ defineModuleConfig('copilot', {
     },
     link: 'https://github.com/openai/openai-node',
   },
+  'providers.cloudflareWorkersAi': {
+    desc: 'The config for the Cloudflare Workers AI provider.',
+    default: {
+      apiToken: '',
+      accountId: '',
+    },
+  },
   'providers.fal': {
     desc: 'The config for the fal provider.',
     default: {

packages/backend/server/src/plugins/copilot/embedding/client.ts

@@ -19,7 +19,7 @@ import {
 import { EmbeddingClient, type ReRankResult } from './types';
 
 const EMBEDDING_MODEL = 'gemini-embedding-001';
-const RERANK_MODEL = 'gpt-5.2';
+const RERANK_MODEL = 'gpt-4o-mini';
 class ProductionEmbeddingClient extends EmbeddingClient {
   private readonly logger = new Logger(ProductionEmbeddingClient.name);
 

packages/backend/server/src/plugins/copilot/providers/cloudflare.ts

@@ -0,0 +1,305 @@
+import {
+  CopilotProviderSideError,
+  metrics,
+  UserFriendlyError,
+} from '../../../base';
+import {
+  llmDispatchStream,
+  llmRerankDispatch,
+  type NativeLlmBackendConfig,
+  type NativeLlmRequest,
+  type NativeLlmRerankRequest,
+  type NativeLlmRerankResponse,
+} from '../../../native';
+import type { NodeTextMiddleware } from '../config';
+import type { CopilotTool, CopilotToolSet } from '../tools';
+import {
+  buildNativeRequest,
+  buildNativeRerankRequest,
+  NativeProviderAdapter,
+} from './native';
+import { CopilotProvider } from './provider';
+import type {
+  CopilotChatOptions,
+  CopilotChatTools,
+  CopilotProviderModel,
+  CopilotRerankRequest,
+  ModelConditions,
+  PromptMessage,
+  StreamObject,
+} from './types';
+import { CopilotProviderType, ModelInputType, ModelOutputType } from './types';
+
+export type CloudflareWorkersAIConfig = {
+  apiToken: string;
+  accountId?: string;
+  baseURL?: string;
+};
+
+function rerankOnlyModel(
+  id: string,
+  name: string,
+  defaultForOutputType = false
+): CopilotProviderModel {
+  return {
+    name,
+    id,
+    capabilities: [
+      {
+        input: [ModelInputType.Text],
+        output: [ModelOutputType.Rerank],
+        ...(defaultForOutputType ? { defaultForOutputType } : {}),
+      },
+    ],
+  };
+}
+
+function chatAndRerankModel(
+  id: string,
+  name: string,
+  defaultForRerank = false
+): CopilotProviderModel {
+  return {
+    name,
+    id,
+    capabilities: [
+      {
+        input: [ModelInputType.Text],
+        output: [
+          ModelOutputType.Text,
+          ModelOutputType.Object,
+          ModelOutputType.Rerank,
+        ],
+        ...(defaultForRerank ? { defaultForOutputType: true } : {}),
+      },
+    ],
+  };
+}
+
+export class CloudflareWorkersAIProvider extends CopilotProvider<CloudflareWorkersAIConfig> {
+  override readonly type = CopilotProviderType.CloudflareWorkersAi;
+
+  override readonly models = [
+    rerankOnlyModel('@cf/baai/bge-reranker-base', 'BGE Reranker Base', true),
+    chatAndRerankModel('@cf/moonshotai/kimi-k2.5', 'Kimi K2.5'),
+    chatAndRerankModel(
+      '@cf/ibm-granite/granite-4.0-h-micro',
+      'Granite 4.0 H Micro'
+    ),
+    chatAndRerankModel(
+      '@cf/aisingapore/gemma-sea-lion-v4-27b-it',
+      'Gemma Sea Lion V4 27B IT'
+    ),
+    chatAndRerankModel(
+      '@cf/nvidia/nemotron-3-120b-a12b',
+      'Nemotron 3 120B A12B'
+    ),
+    chatAndRerankModel('@cf/zai-org/glm-4.7-flash', 'GLM 4.7 Flash'),
+    chatAndRerankModel('@cf/qwen/qwen3-30b-a3b-fp8', 'Qwen3 30B A3B FP8'),
+  ];
+
+  override configured(): boolean {
+    return (
+      !!this.config.apiToken &&
+      (!!this.config.accountId || !!this.config.baseURL)
+    );
+  }
+
+  override async refreshOnlineModels() {}
+
+  override getProviderSpecificTools(
+    toolName: CopilotChatTools,
+    _model: string
+  ): [string, CopilotTool?] | undefined {
+    if (toolName === 'docEdit') {
+      return ['doc_edit', undefined];
+    }
+    return;
+  }
+
+  private handleError(e: any) {
+    if (e instanceof UserFriendlyError) {
+      return e;
+    }
+    return new CopilotProviderSideError({
+      provider: this.type,
+      kind: 'unexpected_response',
+      message: e?.message || 'Unexpected cloudflare workers ai response',
+    });
+  }
+
+  private createNativeConfig(): NativeLlmBackendConfig {
+    return {
+      base_url: this.resolveBaseUrl(),
+      auth_token: this.config.apiToken,
+      request_layer: 'cloudflare_workers_ai',
+    };
+  }
+
+  private createNativeDispatch(
+    backendConfig: NativeLlmBackendConfig,
+    tools: CopilotToolSet,
+    nodeTextMiddleware?: NodeTextMiddleware[]
+  ) {
+    return new NativeProviderAdapter(
+      (request: NativeLlmRequest, signal?: AbortSignal) =>
+        llmDispatchStream('openai_chat', backendConfig, request, signal),
+      tools,
+      this.MAX_STEPS,
+      { nodeTextMiddleware }
+    );
+  }
+
+  private createNativeRerankDispatch(backendConfig: NativeLlmBackendConfig) {
+    return (
+      request: NativeLlmRerankRequest
+    ): Promise<NativeLlmRerankResponse> =>
+      llmRerankDispatch('openai_chat', backendConfig, request);
+  }
+
+  private resolveBaseUrl() {
+    if (this.config.baseURL) {
+      return this.config.baseURL.replace(/\/v1\/?$/, '').replace(/\/$/, '');
+    }
+    const accountId = this.config.accountId ?? '';
+    return `https://api.cloudflare.com/client/v4/accounts/${accountId}/ai`;
+  }
+
+  override async text(
+    cond: ModelConditions,
+    messages: PromptMessage[],
+    options: CopilotChatOptions = {}
+  ): Promise<string> {
+    const normalizedCond = await this.checkParams({
+      messages,
+      cond: { ...cond, outputType: ModelOutputType.Text },
+      options,
+    });
+    const model = this.selectModel(normalizedCond);
+
+    try {
+      metrics.ai.counter('chat_text_calls').add(1, this.metricLabels(model.id));
+      const tools = await this.getTools(options, model.id);
+      const middleware = this.getActiveProviderMiddleware();
+      const { request } = await buildNativeRequest({
+        model: model.id,
+        messages,
+        options,
+        tools,
+        middleware,
+      });
+      return await this.createNativeDispatch(
+        this.createNativeConfig(),
+        tools,
+        middleware.node?.text
+      ).text(request, options.signal, messages);
+    } catch (e: any) {
+      metrics.ai
+        .counter('chat_text_errors')
+        .add(1, this.metricLabels(model.id));
+      throw this.handleError(e);
+    }
+  }
+
+  override async *streamText(
+    cond: ModelConditions,
+    messages: PromptMessage[],
+    options: CopilotChatOptions = {}
+  ): AsyncIterable<string> {
+    const normalizedCond = await this.checkParams({
+      messages,
+      cond: { ...cond, outputType: ModelOutputType.Text },
+      options,
+    });
+    const model = this.selectModel(normalizedCond);
+
+    try {
+      metrics.ai
+        .counter('chat_text_stream_calls')
+        .add(1, this.metricLabels(model.id));
+      const tools = await this.getTools(options, model.id);
+      const middleware = this.getActiveProviderMiddleware();
+      const { request } = await buildNativeRequest({
+        model: model.id,
+        messages,
+        options,
+        tools,
+        middleware,
+      });
+      for await (const chunk of this.createNativeDispatch(
+        this.createNativeConfig(),
+        tools,
+        middleware.node?.text
+      ).streamText(request, options.signal, messages)) {
+        yield chunk;
+      }
+    } catch (e: any) {
+      metrics.ai
+        .counter('chat_text_stream_errors')
+        .add(1, this.metricLabels(model.id));
+      throw this.handleError(e);
+    }
+  }
+
+  override async *streamObject(
+    cond: ModelConditions,
+    messages: PromptMessage[],
+    options: CopilotChatOptions = {}
+  ): AsyncIterable<StreamObject> {
+    const normalizedCond = await this.checkParams({
+      messages,
+      cond: { ...cond, outputType: ModelOutputType.Object },
+      options,
+    });
+    const model = this.selectModel(normalizedCond);
+
+    try {
+      metrics.ai
+        .counter('chat_object_stream_calls')
+        .add(1, this.metricLabels(model.id));
+      const tools = await this.getTools(options, model.id);
+      const middleware = this.getActiveProviderMiddleware();
+      const { request } = await buildNativeRequest({
+        model: model.id,
+        messages,
+        options,
+        tools,
+        middleware,
+      });
+      for await (const chunk of this.createNativeDispatch(
+        this.createNativeConfig(),
+        tools,
+        middleware.node?.text
+      ).streamObject(request, options.signal, messages)) {
+        yield chunk;
+      }
+    } catch (e: any) {
+      metrics.ai
+        .counter('chat_object_stream_errors')
+        .add(1, this.metricLabels(model.id));
+      throw this.handleError(e);
+    }
+  }
+
+  override async rerank(
+    cond: ModelConditions,
+    request: CopilotRerankRequest,
+    options: CopilotChatOptions = {}
+  ): Promise<number[]> {
+    const normalizedCond = await this.checkParams({
+      messages: [],
+      cond: { ...cond, outputType: ModelOutputType.Rerank },
+      options,
+    });
+    const model = this.selectModel(normalizedCond);
+
+    try {
+      const response = await this.createNativeRerankDispatch(
+        this.createNativeConfig()
+      )(buildNativeRerankRequest(model.id, request));
+      return response.scores;
+    } catch (e: any) {
+      throw this.handleError(e);
+    }
+  }
+}

packages/backend/server/src/plugins/copilot/providers/gemini/generative.ts

@@ -81,6 +81,27 @@ export class GeminiGenerativeProvider extends GeminiProvider<GeminiGenerativeCon
         },
       ],
     },
+    {
+      name: 'Gemini 3.1 Flash Lite Preview',
+      id: 'gemini-3.1-flash-lite-preview',
+      capabilities: [
+        {
+          input: [
+            ModelInputType.Text,
+            ModelInputType.Image,
+            ModelInputType.Audio,
+            ModelInputType.File,
+          ],
+          output: [
+            ModelOutputType.Text,
+            ModelOutputType.Object,
+            ModelOutputType.Structured,
+          ],
+          attachments: GEMINI_ATTACHMENT_CAPABILITY,
+          structuredAttachments: GEMINI_ATTACHMENT_CAPABILITY,
+        },
+      ],
+    },
     {
       name: 'Gemini Embedding',
       id: 'gemini-embedding-001',

packages/backend/server/src/plugins/copilot/providers/gemini/vertex.ts

@@ -77,6 +77,27 @@ export class GeminiVertexProvider extends GeminiProvider<GeminiVertexConfig> {
         },
       ],
     },
+    {
+      name: 'Gemini 3.1 Flash Lite Preview',
+      id: 'gemini-3.1-flash-lite-preview',
+      capabilities: [
+        {
+          input: [
+            ModelInputType.Text,
+            ModelInputType.Image,
+            ModelInputType.Audio,
+            ModelInputType.File,
+          ],
+          output: [
+            ModelOutputType.Text,
+            ModelOutputType.Object,
+            ModelOutputType.Structured,
+          ],
+          attachments: GEMINI_ATTACHMENT_CAPABILITY,
+          structuredAttachments: GEMINI_ATTACHMENT_CAPABILITY,
+        },
+      ],
+    },
     {
       name: 'Gemini Embedding',
       id: 'gemini-embedding-001',

packages/backend/server/src/plugins/copilot/providers/index.ts

@@ -2,6 +2,7 @@ import {
   AnthropicOfficialProvider,
   AnthropicVertexProvider,
 } from './anthropic';
+import { CloudflareWorkersAIProvider } from './cloudflare';
 import { FalProvider } from './fal';
 import { GeminiGenerativeProvider, GeminiVertexProvider } from './gemini';
 import { MorphProvider } from './morph';
@@ -10,6 +11,7 @@ import { PerplexityProvider } from './perplexity';
 
 export const CopilotProviders = [
   OpenAIProvider,
+  CloudflareWorkersAIProvider,
   FalProvider,
   GeminiGenerativeProvider,
   GeminiVertexProvider,
@@ -23,6 +25,7 @@ export {
   AnthropicOfficialProvider,
   AnthropicVertexProvider,
 } from './anthropic';
+export { CloudflareWorkersAIProvider } from './cloudflare';
 export { CopilotProviderFactory } from './factory';
 export { FalProvider } from './fal';
 export { GeminiGenerativeProvider, GeminiVertexProvider } from './gemini';

packages/backend/server/src/plugins/copilot/providers/native.ts

@@ -6,6 +6,7 @@ import type {
   NativeLlmCoreMessage,
   NativeLlmEmbeddingRequest,
   NativeLlmRequest,
+  NativeLlmRerankRequest,
   NativeLlmStreamEvent,
   NativeLlmStructuredRequest,
   NativeLlmStructuredResponse,
@@ -19,6 +20,7 @@ import {
 import { NativeDispatchFn, ToolCallLoop, ToolSchemaExtractor } from './loop';
 import type {
   CopilotChatOptions,
+  CopilotRerankRequest,
   CopilotStructuredOptions,
   ModelAttachmentCapability,
   PromptMessage,
@@ -194,6 +196,21 @@ export function parseNativeStructuredOutput(
   );
 }
 
+export function buildNativeRerankRequest(
+  model: string,
+  request: CopilotRerankRequest
+): NativeLlmRerankRequest {
+  return {
+    model,
+    query: request.query,
+    candidates: request.candidates.map(candidate => ({
+      ...(candidate.id ? { id: candidate.id } : {}),
+      text: candidate.text,
+    })),
+    ...(request.topK ? { top_n: request.topK } : {}),
+  };
+}
+
 async function toCoreContents(
   message: PromptMessage,
   withAttachment: boolean,

packages/backend/server/src/plugins/copilot/providers/openai.ts

@@ -27,6 +27,7 @@ import { IMAGE_ATTACHMENT_CAPABILITY } from './attachments';
 import {
   buildNativeEmbeddingRequest,
   buildNativeRequest,
+  buildNativeRerankRequest,
   buildNativeStructuredRequest,
   NativeProviderAdapter,
   parseNativeStructuredOutput,
@@ -133,21 +134,6 @@ function normalizeImageResponseData(
     .filter((value): value is string => typeof value === 'string');
 }
 
-function buildOpenAIRerankRequest(
-  model: string,
-  request: CopilotRerankRequest
-): NativeLlmRerankRequest {
-  return {
-    model,
-    query: request.query,
-    candidates: request.candidates.map(candidate => ({
-      ...(candidate.id ? { id: candidate.id } : {}),
-      text: candidate.text,
-    })),
-    ...(request.topK ? { top_n: request.topK } : {}),
-  };
-}
-
 function createOpenAIMultimodalCapability(
   output: ModelCapability['output'],
   options: Pick<ModelCapability, 'defaultForOutputType'> = {}
@@ -194,6 +180,7 @@ export class OpenAIProvider extends CopilotProvider<OpenAIConfig> {
         createOpenAIMultimodalCapability([
           ModelOutputType.Text,
           ModelOutputType.Object,
+          ModelOutputType.Rerank,
         ]),
       ],
     },
@@ -444,7 +431,7 @@ export class OpenAIProvider extends CopilotProvider<OpenAIConfig> {
     return;
   }
 
-  private createNativeConfig(): NativeLlmBackendConfig {
+  protected createNativeConfig(): NativeLlmBackendConfig {
     const baseUrl = this.config.baseURL || 'https://api.openai.com/v1';
     return {
       base_url: baseUrl.replace(/\/v1\/?$/, ''),
@@ -452,7 +439,7 @@ export class OpenAIProvider extends CopilotProvider<OpenAIConfig> {
     };
   }
 
-  private getNativeProtocol() {
+  protected getNativeProtocol() {
     return this.config.oldApiStyle ? 'openai_chat' : 'openai_responses';
   }
 
@@ -709,7 +696,7 @@ export class OpenAIProvider extends CopilotProvider<OpenAIConfig> {
 
     try {
       const backendConfig = this.createNativeConfig();
-      const nativeRequest = buildOpenAIRerankRequest(model.id, request);
+      const nativeRequest = buildNativeRerankRequest(model.id, request);
       const response =
         await this.createNativeRerankDispatch(backendConfig)(nativeRequest);
       return response.scores;

packages/backend/server/src/plugins/copilot/providers/provider-middleware.ts

@@ -14,6 +14,15 @@ const DEFAULT_MIDDLEWARE_BY_TYPE: Record<
       text: ['citation_footnote', 'callout'],
     },
   },
+  [CopilotProviderType.CloudflareWorkersAi]: {
+    rust: {
+      request: ['normalize_messages'],
+      stream: ['stream_event_normalize', 'citation_indexing'],
+    },
+    node: {
+      text: ['citation_footnote', 'callout'],
+    },
+  },
   [CopilotProviderType.Anthropic]: {
     rust: {
       request: ['normalize_messages', 'tool_schema_rewrite'],

packages/backend/server/src/plugins/copilot/providers/provider-registry.ts

@@ -11,6 +11,7 @@ const PROVIDER_ID_PATTERN = /^[a-zA-Z0-9-_]+$/;
 
 const LEGACY_PROVIDER_ORDER: CopilotProviderType[] = [
   CopilotProviderType.OpenAI,
+  CopilotProviderType.CloudflareWorkersAi,
   CopilotProviderType.FAL,
   CopilotProviderType.Gemini,
   CopilotProviderType.GeminiVertex,

packages/backend/server/src/plugins/copilot/providers/types.ts

@@ -8,6 +8,7 @@ import { JSONSchema } from '../../../base';
 export enum CopilotProviderType {
   Anthropic = 'anthropic',
   AnthropicVertex = 'anthropicVertex',
+  CloudflareWorkersAi = 'cloudflareWorkersAi',
   FAL = 'fal',
   Gemini = 'gemini',
   GeminiVertex = 'geminiVertex',

packages/frontend/admin/src/config.json

@@ -326,6 +326,10 @@
       "desc": "The config for the openai provider.",
       "link": "https://github.com/openai/openai-node"
     },
+    "providers.cloudflareWorkersAi": {
+      "type": "Object",
+      "desc": "The config for the Cloudflare Workers AI provider."
+    },
     "providers.fal": {
       "type": "Object",
       "desc": "The config for the fal provider."