fix(ai): preserve provider tool identity across step boundaries

.changeset/fix-provider-tool-identity.md

@@ -0,0 +1,7 @@
+---
+'@workflow/ai': patch
+---
+
+fix(ai): preserve provider tool identity across step boundaries
+
+Provider tools (e.g. `anthropic.tools.webSearch`) were being converted to plain function tools in `toolsToModelTools`, stripping `type: 'provider'`, `id`, and `args`. This caused providers like Anthropic Gateway to not recognize them as provider-executed tools.

packages/ai/src/agent/tools-to-model-tools.test.ts

@@ -0,0 +1,106 @@
+import { describe, expect, it } from 'vitest';
+import { tool } from 'ai';
+import { z } from 'zod';
+import { toolsToModelTools } from './tools-to-model-tools.js';
+
+describe('toolsToModelTools', () => {
+ it('serializes function tools with description and inputSchema', async () => {
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ };
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toMatchObject({
+ type: 'function',
+ name: 'weather',
+ description: 'Get the weather',
+ });
+ expect(result[0]).toHaveProperty('inputSchema');
+ expect(result[0]).not.toHaveProperty('id');
+ expect(result[0]).not.toHaveProperty('args');
+ });
+
+ it('preserves provider tool type, id, and args', async () => {
+ // Simulate a provider tool (e.g. anthropic.tools.webSearch)
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: { maxUses: 5 },
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: { maxUses: 5 },
+ });
+ });
+
+ it('handles mixed function and provider tools', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: {},
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(2);
+
+ const functionTool = result.find((t) => t.name === 'weather');
+ const provider = result.find((t) => t.name === 'webSearch');
+
+ expect(functionTool).toMatchObject({ type: 'function', name: 'weather' });
+ expect(provider).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: {},
+ });
+ });
+
+ it('defaults args to empty object when not provided on provider tool', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.code_execution' as const,
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ codeExec: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.code_execution',
+ name: 'codeExec',
+ args: {},
+ });
+ });
+});

packages/ai/src/agent/tools-to-model-tools.ts

@@ -1,15 +1,31 @@
-import type { LanguageModelV3FunctionTool } from '@ai-sdk/provider';
+import type {
+ LanguageModelV3FunctionTool,
+ LanguageModelV3ProviderTool,
+} from '@ai-sdk/provider';
 import { asSchema, type ToolSet } from 'ai';
 
 export async function toolsToModelTools(
  tools: ToolSet
-): Promise<LanguageModelV3FunctionTool[]> {
+): Promise<Array<LanguageModelV3FunctionTool | LanguageModelV3ProviderTool>> {
  return Promise.all(
- Object.entries(tools).map(async ([name, tool]) => ({
- type: 'function' as const,
- name,
- description: tool.description,
- inputSchema: await asSchema(tool.inputSchema).jsonSchema,
- }))
+ Object.entries(tools).map(async ([name, tool]) => {
+ // Preserve provider tool identity (e.g. anthropic.tools.webSearch)
+ // instead of converting to a plain function tool
+ if ((tool as any).type === 'provider') {
+ return {
+ type: 'provider' as const,
+ id: (tool as any).id as `${string}.${string}`,
+ name,
+ args: (tool as any).args ?? {},
+ };
+ }
+
+ return {
+ type: 'function' as const,
+ name,
+ description: tool.description,
+ inputSchema: await asSchema(tool.inputSchema).jsonSchema,
+ };
+ })
  );
 }

packages/ai/src/providers/mock.ts

@@ -2,7 +2,13 @@ import { mockProvider } from './mock-function-wrapper.js';
 
 export type MockResponseDescriptor =
  | { type: 'text'; text: string }
- | { type: 'tool-call'; toolName: string; input: string };
+ | { type: 'tool-call'; toolName: string; input: string }
+ | {
+ type: 'provider-tool-call';
+ toolName: string;
+ input: string;
+ result: unknown;
+ };
 
 /**
  * Mock model that returns a fixed text response.
@@ -64,51 +70,85 @@ export function mockSequenceModel(responses: MockResponseDescriptor[]) {
  _responses.length - 1
  );
  const r = _responses[idx];
- const parts =
- r.type === 'text'
- ? [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- { type: 'text-start', id: '1' },
- { type: 'text-delta', id: '1', delta: r.text },
- { type: 'text-end', id: '1' },
- {
- type: 'finish',
- finishReason: { unified: 'stop', raw: 'stop' },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ]
- : [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- {
- type: 'tool-call',
- toolCallId: `call-${idx + 1}`,
- toolName: r.toolName,
- input: r.input,
- },
- {
- type: 'finish',
- finishReason: { unified: 'tool-calls', raw: undefined },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ];
+ let parts: any[];
+ if (r.type === 'text') {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ { type: 'text-start', id: '1' },
+ { type: 'text-delta', id: '1', delta: r.text },
+ { type: 'text-end', id: '1' },
+ {
+ type: 'finish',
+ finishReason: { unified: 'stop', raw: 'stop' },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else if (r.type === 'provider-tool-call') {
+ const callId = `call-${idx + 1}`;
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: callId,
+ toolName: r.toolName,
+ input: r.input,
+ providerExecuted: true,
+ },
+ {
+ type: 'tool-result',
+ toolCallId: callId,
+ toolName: r.toolName,
+ result: r.result,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: `call-${idx + 1}`,
+ toolName: r.toolName,
+ input: r.input,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ }
  return {
  stream: new ReadableStream({
  start(c) {

packages/core/e2e/e2e-agent.test.ts

@@ -95,6 +95,30 @@ describe.skipIf(isCanary)('DurableAgent e2e', { timeout: 120_000 }, () => {
  });
  });
 
+ // ==========================================================================
+ // Provider tool tests
+ // ==========================================================================
+
+ describe('provider tools', () => {
+ it('provider tool identity preserved across step boundaries', async () => {
+ const run = await start(await agentE2e('agentProviderToolE2e'), []);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 2,
+ lastStepText: 'I found a result for you.',
+ });
+ });
+
+ it('mixed provider and function tools', async () => {
+ const run = await start(await agentE2e('agentMixedToolsE2e'), [3, 7]);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 3,
+ lastStepText: 'The answer is 10',
+ });
+ });
+ });
+
  // ==========================================================================
  // onStepFinish callback tests
  // ==========================================================================

.changeset/fix-provider-tool-identity.md

@@ -0,0 +1,7 @@
+---
+'@workflow/ai': patch
+---
+
+fix(ai): preserve provider tool identity across step boundaries
+
+Provider tools (e.g. `anthropic.tools.webSearch`) were being converted to plain function tools in `toolsToModelTools`, stripping `type: 'provider'`, `id`, and `args`. This caused providers like Anthropic Gateway to not recognize them as provider-executed tools.

packages/ai/src/agent/tools-to-model-tools.test.ts

@@ -0,0 +1,106 @@
+import { describe, expect, it } from 'vitest';
+import { tool } from 'ai';
+import { z } from 'zod';
+import { toolsToModelTools } from './tools-to-model-tools.js';
+
+describe('toolsToModelTools', () => {
+ it('serializes function tools with description and inputSchema', async () => {
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ };
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toMatchObject({
+ type: 'function',
+ name: 'weather',
+ description: 'Get the weather',
+ });
+ expect(result[0]).toHaveProperty('inputSchema');
+ expect(result[0]).not.toHaveProperty('id');
+ expect(result[0]).not.toHaveProperty('args');
+ });
+
+ it('preserves provider tool type, id, and args', async () => {
+ // Simulate a provider tool (e.g. anthropic.tools.webSearch)
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: { maxUses: 5 },
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: { maxUses: 5 },
+ });
+ });
+
+ it('handles mixed function and provider tools', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: {},
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(2);
+
+ const functionTool = result.find((t) => t.name === 'weather');
+ const provider = result.find((t) => t.name === 'webSearch');
+
+ expect(functionTool).toMatchObject({ type: 'function', name: 'weather' });
+ expect(provider).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: {},
+ });
+ });
+
+ it('defaults args to empty object when not provided on provider tool', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.code_execution' as const,
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ codeExec: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.code_execution',
+ name: 'codeExec',
+ args: {},
+ });
+ });
+});

packages/ai/src/agent/tools-to-model-tools.ts

@@ -1,15 +1,31 @@
-import type { LanguageModelV3FunctionTool } from '@ai-sdk/provider';
+import type {
+ LanguageModelV3FunctionTool,
+ LanguageModelV3ProviderTool,
+} from '@ai-sdk/provider';
 import { asSchema, type ToolSet } from 'ai';
 
 export async function toolsToModelTools(
  tools: ToolSet
-): Promise<LanguageModelV3FunctionTool[]> {
+): Promise<Array<LanguageModelV3FunctionTool | LanguageModelV3ProviderTool>> {
  return Promise.all(
- Object.entries(tools).map(async ([name, tool]) => ({
- type: 'function' as const,
- name,
- description: tool.description,
- inputSchema: await asSchema(tool.inputSchema).jsonSchema,
- }))
+ Object.entries(tools).map(async ([name, tool]) => {
+ // Preserve provider tool identity (e.g. anthropic.tools.webSearch)
+ // instead of converting to a plain function tool
+ if ((tool as any).type === 'provider') {
+ return {
+ type: 'provider' as const,
+ id: (tool as any).id as `${string}.${string}`,
+ name,
+ args: (tool as any).args ?? {},
+ };
+ }
+
+ return {
+ type: 'function' as const,
+ name,
+ description: tool.description,
+ inputSchema: await asSchema(tool.inputSchema).jsonSchema,
+ };
+ })
  );
 }

packages/ai/src/providers/mock.ts

@@ -2,7 +2,13 @@ import { mockProvider } from './mock-function-wrapper.js';
 
 export type MockResponseDescriptor =
  | { type: 'text'; text: string }
- | { type: 'tool-call'; toolName: string; input: string };
+ | { type: 'tool-call'; toolName: string; input: string }
+ | {
+ type: 'provider-tool-call';
+ toolName: string;
+ input: string;
+ result: unknown;
+ };
 
 /**
  * Mock model that returns a fixed text response.
@@ -64,51 +70,85 @@ export function mockSequenceModel(responses: MockResponseDescriptor[]) {
  _responses.length - 1
  );
  const r = _responses[idx];
- const parts =
- r.type === 'text'
- ? [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- { type: 'text-start', id: '1' },
- { type: 'text-delta', id: '1', delta: r.text },
- { type: 'text-end', id: '1' },
- {
- type: 'finish',
- finishReason: { unified: 'stop', raw: 'stop' },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ]
- : [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- {
- type: 'tool-call',
- toolCallId: `call-${idx + 1}`,
- toolName: r.toolName,
- input: r.input,
- },
- {
- type: 'finish',
- finishReason: { unified: 'tool-calls', raw: undefined },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ];
+ let parts: any[];
+ if (r.type === 'text') {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ { type: 'text-start', id: '1' },
+ { type: 'text-delta', id: '1', delta: r.text },
+ { type: 'text-end', id: '1' },
+ {
+ type: 'finish',
+ finishReason: { unified: 'stop', raw: 'stop' },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else if (r.type === 'provider-tool-call') {
+ const callId = `call-${idx + 1}`;
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: callId,
+ toolName: r.toolName,
+ input: r.input,
+ providerExecuted: true,
+ },
+ {
+ type: 'tool-result',
+ toolCallId: callId,
+ toolName: r.toolName,
+ result: r.result,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: `call-${idx + 1}`,
+ toolName: r.toolName,
+ input: r.input,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ }
  return {
  stream: new ReadableStream({
  start(c) {

packages/core/e2e/e2e-agent.test.ts

@@ -95,6 +95,30 @@ describe.skipIf(isCanary)('DurableAgent e2e', { timeout: 120_000 }, () => {
  });
  });
 
+ // ==========================================================================
+ // Provider tool tests
+ // ==========================================================================
+
+ describe('provider tools', () => {
+ it('provider tool identity preserved across step boundaries', async () => {
+ const run = await start(await agentE2e('agentProviderToolE2e'), []);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 2,
+ lastStepText: 'I found a result for you.',
+ });
+ });
+
+ it('mixed provider and function tools', async () => {
+ const run = await start(await agentE2e('agentMixedToolsE2e'), [3, 7]);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 3,
+ lastStepText: 'The answer is 10',
+ });
+ });
+ });
+
  // ==========================================================================
  // onStepFinish callback tests
  // ==========================================================================

.changeset/fix-provider-tool-identity.md

@@ -0,0 +1,7 @@
+---
+'@workflow/ai': patch
+---
+
+fix(ai): preserve provider tool identity across step boundaries
+
+Provider tools (e.g. `anthropic.tools.webSearch`) were being converted to plain function tools in `toolsToModelTools`, stripping `type: 'provider'`, `id`, and `args`. This caused providers like Anthropic Gateway to not recognize them as provider-executed tools.

packages/ai/src/agent/tools-to-model-tools.test.ts

@@ -0,0 +1,106 @@
+import { describe, expect, it } from 'vitest';
+import { tool } from 'ai';
+import { z } from 'zod';
+import { toolsToModelTools } from './tools-to-model-tools.js';
+
+describe('toolsToModelTools', () => {
+ it('serializes function tools with description and inputSchema', async () => {
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ };
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toMatchObject({
+ type: 'function',
+ name: 'weather',
+ description: 'Get the weather',
+ });
+ expect(result[0]).toHaveProperty('inputSchema');
+ expect(result[0]).not.toHaveProperty('id');
+ expect(result[0]).not.toHaveProperty('args');
+ });
+
+ it('preserves provider tool type, id, and args', async () => {
+ // Simulate a provider tool (e.g. anthropic.tools.webSearch)
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: { maxUses: 5 },
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: { maxUses: 5 },
+ });
+ });
+
+ it('handles mixed function and provider tools', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: {},
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(2);
+
+ const functionTool = result.find((t) => t.name === 'weather');
+ const provider = result.find((t) => t.name === 'webSearch');
+
+ expect(functionTool).toMatchObject({ type: 'function', name: 'weather' });
+ expect(provider).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: {},
+ });
+ });
+
+ it('defaults args to empty object when not provided on provider tool', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.code_execution' as const,
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ codeExec: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.code_execution',
+ name: 'codeExec',
+ args: {},
+ });
+ });
+});

packages/ai/src/agent/tools-to-model-tools.ts

@@ -1,15 +1,31 @@
-import type { LanguageModelV3FunctionTool } from '@ai-sdk/provider';
+import type {
+ LanguageModelV3FunctionTool,
+ LanguageModelV3ProviderTool,
+} from '@ai-sdk/provider';
 import { asSchema, type ToolSet } from 'ai';
 
 export async function toolsToModelTools(
  tools: ToolSet
-): Promise<LanguageModelV3FunctionTool[]> {
+): Promise<Array<LanguageModelV3FunctionTool | LanguageModelV3ProviderTool>> {
  return Promise.all(
- Object.entries(tools).map(async ([name, tool]) => ({
- type: 'function' as const,
- name,
- description: tool.description,
- inputSchema: await asSchema(tool.inputSchema).jsonSchema,
- }))
+ Object.entries(tools).map(async ([name, tool]) => {
+ // Preserve provider tool identity (e.g. anthropic.tools.webSearch)
+ // instead of converting to a plain function tool
+ if ((tool as any).type === 'provider') {
+ return {
+ type: 'provider' as const,
+ id: (tool as any).id as `${string}.${string}`,
+ name,
+ args: (tool as any).args ?? {},
+ };
+ }
+
+ return {
+ type: 'function' as const,
+ name,
+ description: tool.description,
+ inputSchema: await asSchema(tool.inputSchema).jsonSchema,
+ };
+ })
  );
 }

packages/ai/src/providers/mock.ts

@@ -2,7 +2,13 @@ import { mockProvider } from './mock-function-wrapper.js';
 
 export type MockResponseDescriptor =
  | { type: 'text'; text: string }
- | { type: 'tool-call'; toolName: string; input: string };
+ | { type: 'tool-call'; toolName: string; input: string }
+ | {
+ type: 'provider-tool-call';
+ toolName: string;
+ input: string;
+ result: unknown;
+ };
 
 /**
  * Mock model that returns a fixed text response.
@@ -64,51 +70,85 @@ export function mockSequenceModel(responses: MockResponseDescriptor[]) {
  _responses.length - 1
  );
  const r = _responses[idx];
- const parts =
- r.type === 'text'
- ? [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- { type: 'text-start', id: '1' },
- { type: 'text-delta', id: '1', delta: r.text },
- { type: 'text-end', id: '1' },
- {
- type: 'finish',
- finishReason: { unified: 'stop', raw: 'stop' },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ]
- : [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- {
- type: 'tool-call',
- toolCallId: `call-${idx + 1}`,
- toolName: r.toolName,
- input: r.input,
- },
- {
- type: 'finish',
- finishReason: { unified: 'tool-calls', raw: undefined },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ];
+ let parts: any[];
+ if (r.type === 'text') {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ { type: 'text-start', id: '1' },
+ { type: 'text-delta', id: '1', delta: r.text },
+ { type: 'text-end', id: '1' },
+ {
+ type: 'finish',
+ finishReason: { unified: 'stop', raw: 'stop' },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else if (r.type === 'provider-tool-call') {
+ const callId = `call-${idx + 1}`;
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: callId,
+ toolName: r.toolName,
+ input: r.input,
+ providerExecuted: true,
+ },
+ {
+ type: 'tool-result',
+ toolCallId: callId,
+ toolName: r.toolName,
+ result: r.result,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: `call-${idx + 1}`,
+ toolName: r.toolName,
+ input: r.input,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ }
  return {
  stream: new ReadableStream({
  start(c) {

packages/core/e2e/e2e-agent.test.ts

@@ -95,6 +95,30 @@ describe.skipIf(isCanary)('DurableAgent e2e', { timeout: 120_000 }, () => {
  });
  });
 
+ // ==========================================================================
+ // Provider tool tests
+ // ==========================================================================
+
+ describe('provider tools', () => {
+ it('provider tool identity preserved across step boundaries', async () => {
+ const run = await start(await agentE2e('agentProviderToolE2e'), []);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 2,
+ lastStepText: 'I found a result for you.',
+ });
+ });
+
+ it('mixed provider and function tools', async () => {
+ const run = await start(await agentE2e('agentMixedToolsE2e'), [3, 7]);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 3,
+ lastStepText: 'The answer is 10',
+ });
+ });
+ });
+
  // ==========================================================================
  // onStepFinish callback tests
  // ==========================================================================

.changeset/fix-provider-tool-identity.md

@@ -0,0 +1,7 @@
+---
+'@workflow/ai': patch
+---
+
+fix(ai): preserve provider tool identity across step boundaries
+
+Provider tools (e.g. `anthropic.tools.webSearch`) were being converted to plain function tools in `toolsToModelTools`, stripping `type: 'provider'`, `id`, and `args`. This caused providers like Anthropic Gateway to not recognize them as provider-executed tools.

packages/ai/src/agent/tools-to-model-tools.test.ts

@@ -0,0 +1,106 @@
+import { describe, expect, it } from 'vitest';
+import { tool } from 'ai';
+import { z } from 'zod';
+import { toolsToModelTools } from './tools-to-model-tools.js';
+
+describe('toolsToModelTools', () => {
+ it('serializes function tools with description and inputSchema', async () => {
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ };
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toMatchObject({
+ type: 'function',
+ name: 'weather',
+ description: 'Get the weather',
+ });
+ expect(result[0]).toHaveProperty('inputSchema');
+ expect(result[0]).not.toHaveProperty('id');
+ expect(result[0]).not.toHaveProperty('args');
+ });
+
+ it('preserves provider tool type, id, and args', async () => {
+ // Simulate a provider tool (e.g. anthropic.tools.webSearch)
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: { maxUses: 5 },
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: { maxUses: 5 },
+ });
+ });
+
+ it('handles mixed function and provider tools', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: {},
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(2);
+
+ const functionTool = result.find((t) => t.name === 'weather');
+ const provider = result.find((t) => t.name === 'webSearch');
+
+ expect(functionTool).toMatchObject({ type: 'function', name: 'weather' });
+ expect(provider).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: {},
+ });
+ });
+
+ it('defaults args to empty object when not provided on provider tool', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.code_execution' as const,
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ codeExec: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.code_execution',
+ name: 'codeExec',
+ args: {},
+ });
+ });
+});

packages/ai/src/agent/tools-to-model-tools.ts

@@ -1,15 +1,31 @@
-import type { LanguageModelV3FunctionTool } from '@ai-sdk/provider';
+import type {
+ LanguageModelV3FunctionTool,
+ LanguageModelV3ProviderTool,
+} from '@ai-sdk/provider';
 import { asSchema, type ToolSet } from 'ai';
 
 export async function toolsToModelTools(
  tools: ToolSet
-): Promise<LanguageModelV3FunctionTool[]> {
+): Promise<Array<LanguageModelV3FunctionTool | LanguageModelV3ProviderTool>> {
  return Promise.all(
- Object.entries(tools).map(async ([name, tool]) => ({
- type: 'function' as const,
- name,
- description: tool.description,
- inputSchema: await asSchema(tool.inputSchema).jsonSchema,
- }))
+ Object.entries(tools).map(async ([name, tool]) => {
+ // Preserve provider tool identity (e.g. anthropic.tools.webSearch)
+ // instead of converting to a plain function tool
+ if ((tool as any).type === 'provider') {
+ return {
+ type: 'provider' as const,
+ id: (tool as any).id as `${string}.${string}`,
+ name,
+ args: (tool as any).args ?? {},
+ };
+ }
+
+ return {
+ type: 'function' as const,
+ name,
+ description: tool.description,
+ inputSchema: await asSchema(tool.inputSchema).jsonSchema,
+ };
+ })
  );
 }

packages/ai/src/providers/mock.ts

@@ -2,7 +2,13 @@ import { mockProvider } from './mock-function-wrapper.js';
 
 export type MockResponseDescriptor =
  | { type: 'text'; text: string }
- | { type: 'tool-call'; toolName: string; input: string };
+ | { type: 'tool-call'; toolName: string; input: string }
+ | {
+ type: 'provider-tool-call';
+ toolName: string;
+ input: string;
+ result: unknown;
+ };
 
 /**
  * Mock model that returns a fixed text response.
@@ -64,51 +70,85 @@ export function mockSequenceModel(responses: MockResponseDescriptor[]) {
  _responses.length - 1
  );
  const r = _responses[idx];
- const parts =
- r.type === 'text'
- ? [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- { type: 'text-start', id: '1' },
- { type: 'text-delta', id: '1', delta: r.text },
- { type: 'text-end', id: '1' },
- {
- type: 'finish',
- finishReason: { unified: 'stop', raw: 'stop' },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ]
- : [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- {
- type: 'tool-call',
- toolCallId: `call-${idx + 1}`,
- toolName: r.toolName,
- input: r.input,
- },
- {
- type: 'finish',
- finishReason: { unified: 'tool-calls', raw: undefined },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ];
+ let parts: any[];
+ if (r.type === 'text') {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ { type: 'text-start', id: '1' },
+ { type: 'text-delta', id: '1', delta: r.text },
+ { type: 'text-end', id: '1' },
+ {
+ type: 'finish',
+ finishReason: { unified: 'stop', raw: 'stop' },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else if (r.type === 'provider-tool-call') {
+ const callId = `call-${idx + 1}`;
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: callId,
+ toolName: r.toolName,
+ input: r.input,
+ providerExecuted: true,
+ },
+ {
+ type: 'tool-result',
+ toolCallId: callId,
+ toolName: r.toolName,
+ result: r.result,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: `call-${idx + 1}`,
+ toolName: r.toolName,
+ input: r.input,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ }
  return {
  stream: new ReadableStream({
  start(c) {

packages/core/e2e/e2e-agent.test.ts

@@ -95,6 +95,30 @@ describe.skipIf(isCanary)('DurableAgent e2e', { timeout: 120_000 }, () => {
  });
  });
 
+ // ==========================================================================
+ // Provider tool tests
+ // ==========================================================================
+
+ describe('provider tools', () => {
+ it('provider tool identity preserved across step boundaries', async () => {
+ const run = await start(await agentE2e('agentProviderToolE2e'), []);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 2,
+ lastStepText: 'I found a result for you.',
+ });
+ });
+
+ it('mixed provider and function tools', async () => {
+ const run = await start(await agentE2e('agentMixedToolsE2e'), [3, 7]);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 3,
+ lastStepText: 'The answer is 10',
+ });
+ });
+ });
+
  // ==========================================================================
  // onStepFinish callback tests
  // ==========================================================================

.changeset/fix-provider-tool-identity.md

@@ -0,0 +1,7 @@
+---
+'@workflow/ai': patch
+---
+
+fix(ai): preserve provider tool identity across step boundaries
+
+Provider tools (e.g. `anthropic.tools.webSearch`) were being converted to plain function tools in `toolsToModelTools`, stripping `type: 'provider'`, `id`, and `args`. This caused providers like Anthropic Gateway to not recognize them as provider-executed tools.

packages/ai/src/agent/tools-to-model-tools.test.ts

@@ -0,0 +1,106 @@
+import { describe, expect, it } from 'vitest';
+import { tool } from 'ai';
+import { z } from 'zod';
+import { toolsToModelTools } from './tools-to-model-tools.js';
+
+describe('toolsToModelTools', () => {
+ it('serializes function tools with description and inputSchema', async () => {
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ };
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toMatchObject({
+ type: 'function',
+ name: 'weather',
+ description: 'Get the weather',
+ });
+ expect(result[0]).toHaveProperty('inputSchema');
+ expect(result[0]).not.toHaveProperty('id');
+ expect(result[0]).not.toHaveProperty('args');
+ });
+
+ it('preserves provider tool type, id, and args', async () => {
+ // Simulate a provider tool (e.g. anthropic.tools.webSearch)
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: { maxUses: 5 },
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: { maxUses: 5 },
+ });
+ });
+
+ it('handles mixed function and provider tools', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: {},
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(2);
+
+ const functionTool = result.find((t) => t.name === 'weather');
+ const provider = result.find((t) => t.name === 'webSearch');
+
+ expect(functionTool).toMatchObject({ type: 'function', name: 'weather' });
+ expect(provider).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: {},
+ });
+ });
+
+ it('defaults args to empty object when not provided on provider tool', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.code_execution' as const,
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ codeExec: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.code_execution',
+ name: 'codeExec',
+ args: {},
+ });
+ });
+});

packages/ai/src/agent/tools-to-model-tools.ts

@@ -1,15 +1,31 @@
-import type { LanguageModelV3FunctionTool } from '@ai-sdk/provider';
+import type {
+ LanguageModelV3FunctionTool,
+ LanguageModelV3ProviderTool,
+} from '@ai-sdk/provider';
 import { asSchema, type ToolSet } from 'ai';
 
 export async function toolsToModelTools(
  tools: ToolSet
-): Promise<LanguageModelV3FunctionTool[]> {
+): Promise<Array<LanguageModelV3FunctionTool | LanguageModelV3ProviderTool>> {
  return Promise.all(
- Object.entries(tools).map(async ([name, tool]) => ({
- type: 'function' as const,
- name,
- description: tool.description,
- inputSchema: await asSchema(tool.inputSchema).jsonSchema,
- }))
+ Object.entries(tools).map(async ([name, tool]) => {
+ // Preserve provider tool identity (e.g. anthropic.tools.webSearch)
+ // instead of converting to a plain function tool
+ if ((tool as any).type === 'provider') {
+ return {
+ type: 'provider' as const,
+ id: (tool as any).id as `${string}.${string}`,
+ name,
+ args: (tool as any).args ?? {},
+ };
+ }
+
+ return {
+ type: 'function' as const,
+ name,
+ description: tool.description,
+ inputSchema: await asSchema(tool.inputSchema).jsonSchema,
+ };
+ })
  );
 }

packages/ai/src/providers/mock.ts

@@ -2,7 +2,13 @@ import { mockProvider } from './mock-function-wrapper.js';
 
 export type MockResponseDescriptor =
  | { type: 'text'; text: string }
- | { type: 'tool-call'; toolName: string; input: string };
+ | { type: 'tool-call'; toolName: string; input: string }
+ | {
+ type: 'provider-tool-call';
+ toolName: string;
+ input: string;
+ result: unknown;
+ };
 
 /**
  * Mock model that returns a fixed text response.
@@ -64,51 +70,85 @@ export function mockSequenceModel(responses: MockResponseDescriptor[]) {
  _responses.length - 1
  );
  const r = _responses[idx];
- const parts =
- r.type === 'text'
- ? [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- { type: 'text-start', id: '1' },
- { type: 'text-delta', id: '1', delta: r.text },
- { type: 'text-end', id: '1' },
- {
- type: 'finish',
- finishReason: { unified: 'stop', raw: 'stop' },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ]
- : [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- {
- type: 'tool-call',
- toolCallId: `call-${idx + 1}`,
- toolName: r.toolName,
- input: r.input,
- },
- {
- type: 'finish',
- finishReason: { unified: 'tool-calls', raw: undefined },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ];
+ let parts: any[];
+ if (r.type === 'text') {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ { type: 'text-start', id: '1' },
+ { type: 'text-delta', id: '1', delta: r.text },
+ { type: 'text-end', id: '1' },
+ {
+ type: 'finish',
+ finishReason: { unified: 'stop', raw: 'stop' },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else if (r.type === 'provider-tool-call') {
+ const callId = `call-${idx + 1}`;
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: callId,
+ toolName: r.toolName,
+ input: r.input,
+ providerExecuted: true,
+ },
+ {
+ type: 'tool-result',
+ toolCallId: callId,
+ toolName: r.toolName,
+ result: r.result,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: `call-${idx + 1}`,
+ toolName: r.toolName,
+ input: r.input,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ }
  return {
  stream: new ReadableStream({
  start(c) {

packages/core/e2e/e2e-agent.test.ts

@@ -95,6 +95,30 @@ describe.skipIf(isCanary)('DurableAgent e2e', { timeout: 120_000 }, () => {
  });
  });
 
+ // ==========================================================================
+ // Provider tool tests
+ // ==========================================================================
+
+ describe('provider tools', () => {
+ it('provider tool identity preserved across step boundaries', async () => {
+ const run = await start(await agentE2e('agentProviderToolE2e'), []);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 2,
+ lastStepText: 'I found a result for you.',
+ });
+ });
+
+ it('mixed provider and function tools', async () => {
+ const run = await start(await agentE2e('agentMixedToolsE2e'), [3, 7]);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 3,
+ lastStepText: 'The answer is 10',
+ });
+ });
+ });
+
  // ==========================================================================
  // onStepFinish callback tests
  // ==========================================================================

.changeset/fix-provider-tool-identity.md

@@ -0,0 +1,7 @@
+---
+'@workflow/ai': patch
+---
+
+fix(ai): preserve provider tool identity across step boundaries
+
+Provider tools (e.g. `anthropic.tools.webSearch`) were being converted to plain function tools in `toolsToModelTools`, stripping `type: 'provider'`, `id`, and `args`. This caused providers like Anthropic Gateway to not recognize them as provider-executed tools.

packages/ai/src/agent/tools-to-model-tools.test.ts

@@ -0,0 +1,106 @@
+import { describe, expect, it } from 'vitest';
+import { tool } from 'ai';
+import { z } from 'zod';
+import { toolsToModelTools } from './tools-to-model-tools.js';
+
+describe('toolsToModelTools', () => {
+ it('serializes function tools with description and inputSchema', async () => {
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ };
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toMatchObject({
+ type: 'function',
+ name: 'weather',
+ description: 'Get the weather',
+ });
+ expect(result[0]).toHaveProperty('inputSchema');
+ expect(result[0]).not.toHaveProperty('id');
+ expect(result[0]).not.toHaveProperty('args');
+ });
+
+ it('preserves provider tool type, id, and args', async () => {
+ // Simulate a provider tool (e.g. anthropic.tools.webSearch)
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: { maxUses: 5 },
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: { maxUses: 5 },
+ });
+ });
+
+ it('handles mixed function and provider tools', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: {},
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(2);
+
+ const functionTool = result.find((t) => t.name === 'weather');
+ const provider = result.find((t) => t.name === 'webSearch');
+
+ expect(functionTool).toMatchObject({ type: 'function', name: 'weather' });
+ expect(provider).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: {},
+ });
+ });
+
+ it('defaults args to empty object when not provided on provider tool', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.code_execution' as const,
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ codeExec: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.code_execution',
+ name: 'codeExec',
+ args: {},
+ });
+ });
+});

packages/ai/src/agent/tools-to-model-tools.ts

@@ -1,15 +1,31 @@
-import type { LanguageModelV3FunctionTool } from '@ai-sdk/provider';
+import type {
+ LanguageModelV3FunctionTool,
+ LanguageModelV3ProviderTool,
+} from '@ai-sdk/provider';
 import { asSchema, type ToolSet } from 'ai';
 
 export async function toolsToModelTools(
  tools: ToolSet
-): Promise<LanguageModelV3FunctionTool[]> {
+): Promise<Array<LanguageModelV3FunctionTool | LanguageModelV3ProviderTool>> {
  return Promise.all(
- Object.entries(tools).map(async ([name, tool]) => ({
- type: 'function' as const,
- name,
- description: tool.description,
- inputSchema: await asSchema(tool.inputSchema).jsonSchema,
- }))
+ Object.entries(tools).map(async ([name, tool]) => {
+ // Preserve provider tool identity (e.g. anthropic.tools.webSearch)
+ // instead of converting to a plain function tool
+ if ((tool as any).type === 'provider') {
+ return {
+ type: 'provider' as const,
+ id: (tool as any).id as `${string}.${string}`,
+ name,
+ args: (tool as any).args ?? {},
+ };
+ }
+
+ return {
+ type: 'function' as const,
+ name,
+ description: tool.description,
+ inputSchema: await asSchema(tool.inputSchema).jsonSchema,
+ };
+ })
  );
 }

packages/ai/src/providers/mock.ts

@@ -2,7 +2,13 @@ import { mockProvider } from './mock-function-wrapper.js';
 
 export type MockResponseDescriptor =
  | { type: 'text'; text: string }
- | { type: 'tool-call'; toolName: string; input: string };
+ | { type: 'tool-call'; toolName: string; input: string }
+ | {
+ type: 'provider-tool-call';
+ toolName: string;
+ input: string;
+ result: unknown;
+ };
 
 /**
  * Mock model that returns a fixed text response.
@@ -64,51 +70,85 @@ export function mockSequenceModel(responses: MockResponseDescriptor[]) {
  _responses.length - 1
  );
  const r = _responses[idx];
- const parts =
- r.type === 'text'
- ? [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- { type: 'text-start', id: '1' },
- { type: 'text-delta', id: '1', delta: r.text },
- { type: 'text-end', id: '1' },
- {
- type: 'finish',
- finishReason: { unified: 'stop', raw: 'stop' },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ]
- : [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- {
- type: 'tool-call',
- toolCallId: `call-${idx + 1}`,
- toolName: r.toolName,
- input: r.input,
- },
- {
- type: 'finish',
- finishReason: { unified: 'tool-calls', raw: undefined },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ];
+ let parts: any[];
+ if (r.type === 'text') {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ { type: 'text-start', id: '1' },
+ { type: 'text-delta', id: '1', delta: r.text },
+ { type: 'text-end', id: '1' },
+ {
+ type: 'finish',
+ finishReason: { unified: 'stop', raw: 'stop' },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else if (r.type === 'provider-tool-call') {
+ const callId = `call-${idx + 1}`;
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: callId,
+ toolName: r.toolName,
+ input: r.input,
+ providerExecuted: true,
+ },
+ {
+ type: 'tool-result',
+ toolCallId: callId,
+ toolName: r.toolName,
+ result: r.result,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: `call-${idx + 1}`,
+ toolName: r.toolName,
+ input: r.input,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ }
  return {
  stream: new ReadableStream({
  start(c) {

packages/core/e2e/e2e-agent.test.ts

@@ -95,6 +95,30 @@ describe.skipIf(isCanary)('DurableAgent e2e', { timeout: 120_000 }, () => {
  });
  });
 
+ // ==========================================================================
+ // Provider tool tests
+ // ==========================================================================
+
+ describe('provider tools', () => {
+ it('provider tool identity preserved across step boundaries', async () => {
+ const run = await start(await agentE2e('agentProviderToolE2e'), []);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 2,
+ lastStepText: 'I found a result for you.',
+ });
+ });
+
+ it('mixed provider and function tools', async () => {
+ const run = await start(await agentE2e('agentMixedToolsE2e'), [3, 7]);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 3,
+ lastStepText: 'The answer is 10',
+ });
+ });
+ });
+
  // ==========================================================================
  // onStepFinish callback tests
  // ==========================================================================

.changeset/fix-provider-tool-identity.md

@@ -0,0 +1,7 @@
+---
+'@workflow/ai': patch
+---
+
+fix(ai): preserve provider tool identity across step boundaries
+
+Provider tools (e.g. `anthropic.tools.webSearch`) were being converted to plain function tools in `toolsToModelTools`, stripping `type: 'provider'`, `id`, and `args`. This caused providers like Anthropic Gateway to not recognize them as provider-executed tools.

packages/ai/src/agent/tools-to-model-tools.test.ts

@@ -0,0 +1,106 @@
+import { describe, expect, it } from 'vitest';
+import { tool } from 'ai';
+import { z } from 'zod';
+import { toolsToModelTools } from './tools-to-model-tools.js';
+
+describe('toolsToModelTools', () => {
+ it('serializes function tools with description and inputSchema', async () => {
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ };
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toMatchObject({
+ type: 'function',
+ name: 'weather',
+ description: 'Get the weather',
+ });
+ expect(result[0]).toHaveProperty('inputSchema');
+ expect(result[0]).not.toHaveProperty('id');
+ expect(result[0]).not.toHaveProperty('args');
+ });
+
+ it('preserves provider tool type, id, and args', async () => {
+ // Simulate a provider tool (e.g. anthropic.tools.webSearch)
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: { maxUses: 5 },
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: { maxUses: 5 },
+ });
+ });
+
+ it('handles mixed function and provider tools', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: {},
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(2);
+
+ const functionTool = result.find((t) => t.name === 'weather');
+ const provider = result.find((t) => t.name === 'webSearch');
+
+ expect(functionTool).toMatchObject({ type: 'function', name: 'weather' });
+ expect(provider).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: {},
+ });
+ });
+
+ it('defaults args to empty object when not provided on provider tool', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.code_execution' as const,
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ codeExec: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.code_execution',
+ name: 'codeExec',
+ args: {},
+ });
+ });
+});

packages/ai/src/agent/tools-to-model-tools.ts

@@ -1,15 +1,31 @@
-import type { LanguageModelV3FunctionTool } from '@ai-sdk/provider';
+import type {
+ LanguageModelV3FunctionTool,
+ LanguageModelV3ProviderTool,
+} from '@ai-sdk/provider';
 import { asSchema, type ToolSet } from 'ai';
 
 export async function toolsToModelTools(
  tools: ToolSet
-): Promise<LanguageModelV3FunctionTool[]> {
+): Promise<Array<LanguageModelV3FunctionTool | LanguageModelV3ProviderTool>> {
  return Promise.all(
- Object.entries(tools).map(async ([name, tool]) => ({
- type: 'function' as const,
- name,
- description: tool.description,
- inputSchema: await asSchema(tool.inputSchema).jsonSchema,
- }))
+ Object.entries(tools).map(async ([name, tool]) => {
+ // Preserve provider tool identity (e.g. anthropic.tools.webSearch)
+ // instead of converting to a plain function tool
+ if ((tool as any).type === 'provider') {
+ return {
+ type: 'provider' as const,
+ id: (tool as any).id as `${string}.${string}`,
+ name,
+ args: (tool as any).args ?? {},
+ };
+ }
+
+ return {
+ type: 'function' as const,
+ name,
+ description: tool.description,
+ inputSchema: await asSchema(tool.inputSchema).jsonSchema,
+ };
+ })
  );
 }

packages/ai/src/providers/mock.ts

@@ -2,7 +2,13 @@ import { mockProvider } from './mock-function-wrapper.js';
 
 export type MockResponseDescriptor =
  | { type: 'text'; text: string }
- | { type: 'tool-call'; toolName: string; input: string };
+ | { type: 'tool-call'; toolName: string; input: string }
+ | {
+ type: 'provider-tool-call';
+ toolName: string;
+ input: string;
+ result: unknown;
+ };
 
 /**
  * Mock model that returns a fixed text response.
@@ -64,51 +70,85 @@ export function mockSequenceModel(responses: MockResponseDescriptor[]) {
  _responses.length - 1
  );
  const r = _responses[idx];
- const parts =
- r.type === 'text'
- ? [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- { type: 'text-start', id: '1' },
- { type: 'text-delta', id: '1', delta: r.text },
- { type: 'text-end', id: '1' },
- {
- type: 'finish',
- finishReason: { unified: 'stop', raw: 'stop' },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ]
- : [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- {
- type: 'tool-call',
- toolCallId: `call-${idx + 1}`,
- toolName: r.toolName,
- input: r.input,
- },
- {
- type: 'finish',
- finishReason: { unified: 'tool-calls', raw: undefined },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ];
+ let parts: any[];
+ if (r.type === 'text') {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ { type: 'text-start', id: '1' },
+ { type: 'text-delta', id: '1', delta: r.text },
+ { type: 'text-end', id: '1' },
+ {
+ type: 'finish',
+ finishReason: { unified: 'stop', raw: 'stop' },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else if (r.type === 'provider-tool-call') {
+ const callId = `call-${idx + 1}`;
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: callId,
+ toolName: r.toolName,
+ input: r.input,
+ providerExecuted: true,
+ },
+ {
+ type: 'tool-result',
+ toolCallId: callId,
+ toolName: r.toolName,
+ result: r.result,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: `call-${idx + 1}`,
+ toolName: r.toolName,
+ input: r.input,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ }
  return {
  stream: new ReadableStream({
  start(c) {

packages/core/e2e/e2e-agent.test.ts

@@ -95,6 +95,30 @@ describe.skipIf(isCanary)('DurableAgent e2e', { timeout: 120_000 }, () => {
  });
  });
 
+ // ==========================================================================
+ // Provider tool tests
+ // ==========================================================================
+
+ describe('provider tools', () => {
+ it('provider tool identity preserved across step boundaries', async () => {
+ const run = await start(await agentE2e('agentProviderToolE2e'), []);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 2,
+ lastStepText: 'I found a result for you.',
+ });
+ });
+
+ it('mixed provider and function tools', async () => {
+ const run = await start(await agentE2e('agentMixedToolsE2e'), [3, 7]);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 3,
+ lastStepText: 'The answer is 10',
+ });
+ });
+ });
+
  // ==========================================================================
  // onStepFinish callback tests
  // ==========================================================================

.changeset/fix-provider-tool-identity.md

@@ -0,0 +1,7 @@
+---
+'@workflow/ai': patch
+---
+
+fix(ai): preserve provider tool identity across step boundaries
+
+Provider tools (e.g. `anthropic.tools.webSearch`) were being converted to plain function tools in `toolsToModelTools`, stripping `type: 'provider'`, `id`, and `args`. This caused providers like Anthropic Gateway to not recognize them as provider-executed tools.

packages/ai/src/agent/tools-to-model-tools.test.ts

@@ -0,0 +1,106 @@
+import { describe, expect, it } from 'vitest';
+import { tool } from 'ai';
+import { z } from 'zod';
+import { toolsToModelTools } from './tools-to-model-tools.js';
+
+describe('toolsToModelTools', () => {
+ it('serializes function tools with description and inputSchema', async () => {
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ };
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toMatchObject({
+ type: 'function',
+ name: 'weather',
+ description: 'Get the weather',
+ });
+ expect(result[0]).toHaveProperty('inputSchema');
+ expect(result[0]).not.toHaveProperty('id');
+ expect(result[0]).not.toHaveProperty('args');
+ });
+
+ it('preserves provider tool type, id, and args', async () => {
+ // Simulate a provider tool (e.g. anthropic.tools.webSearch)
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: { maxUses: 5 },
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(1);
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: { maxUses: 5 },
+ });
+ });
+
+ it('handles mixed function and provider tools', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.web_search' as const,
+ args: {},
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ weather: tool({
+ description: 'Get the weather',
+ parameters: z.object({ city: z.string() }),
+ execute: async ({ city }) => `Weather in ${city}: sunny`,
+ }),
+ webSearch: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result).toHaveLength(2);
+
+ const functionTool = result.find((t) => t.name === 'weather');
+ const provider = result.find((t) => t.name === 'webSearch');
+
+ expect(functionTool).toMatchObject({ type: 'function', name: 'weather' });
+ expect(provider).toEqual({
+ type: 'provider',
+ id: 'anthropic.web_search',
+ name: 'webSearch',
+ args: {},
+ });
+ });
+
+ it('defaults args to empty object when not provided on provider tool', async () => {
+ const providerTool = {
+ type: 'provider' as const,
+ id: 'anthropic.code_execution' as const,
+ inputSchema: { type: 'object' as const, properties: {} },
+ };
+
+ const tools = {
+ codeExec: providerTool,
+ } as any;
+
+ const result = await toolsToModelTools(tools);
+
+ expect(result[0]).toEqual({
+ type: 'provider',
+ id: 'anthropic.code_execution',
+ name: 'codeExec',
+ args: {},
+ });
+ });
+});

packages/ai/src/agent/tools-to-model-tools.ts

@@ -1,15 +1,31 @@
-import type { LanguageModelV3FunctionTool } from '@ai-sdk/provider';
+import type {
+ LanguageModelV3FunctionTool,
+ LanguageModelV3ProviderTool,
+} from '@ai-sdk/provider';
 import { asSchema, type ToolSet } from 'ai';
 
 export async function toolsToModelTools(
  tools: ToolSet
-): Promise<LanguageModelV3FunctionTool[]> {
+): Promise<Array<LanguageModelV3FunctionTool | LanguageModelV3ProviderTool>> {
  return Promise.all(
- Object.entries(tools).map(async ([name, tool]) => ({
- type: 'function' as const,
- name,
- description: tool.description,
- inputSchema: await asSchema(tool.inputSchema).jsonSchema,
- }))
+ Object.entries(tools).map(async ([name, tool]) => {
+ // Preserve provider tool identity (e.g. anthropic.tools.webSearch)
+ // instead of converting to a plain function tool
+ if ((tool as any).type === 'provider') {
+ return {
+ type: 'provider' as const,
+ id: (tool as any).id as `${string}.${string}`,
+ name,
+ args: (tool as any).args ?? {},
+ };
+ }
+
+ return {
+ type: 'function' as const,
+ name,
+ description: tool.description,
+ inputSchema: await asSchema(tool.inputSchema).jsonSchema,
+ };
+ })
  );
 }

packages/ai/src/providers/mock.ts

@@ -2,7 +2,13 @@ import { mockProvider } from './mock-function-wrapper.js';
 
 export type MockResponseDescriptor =
  | { type: 'text'; text: string }
- | { type: 'tool-call'; toolName: string; input: string };
+ | { type: 'tool-call'; toolName: string; input: string }
+ | {
+ type: 'provider-tool-call';
+ toolName: string;
+ input: string;
+ result: unknown;
+ };
 
 /**
  * Mock model that returns a fixed text response.
@@ -64,51 +70,85 @@ export function mockSequenceModel(responses: MockResponseDescriptor[]) {
  _responses.length - 1
  );
  const r = _responses[idx];
- const parts =
- r.type === 'text'
- ? [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- { type: 'text-start', id: '1' },
- { type: 'text-delta', id: '1', delta: r.text },
- { type: 'text-end', id: '1' },
- {
- type: 'finish',
- finishReason: { unified: 'stop', raw: 'stop' },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ]
- : [
- { type: 'stream-start', warnings: [] },
- {
- type: 'response-metadata',
- id: 'r',
- modelId: 'mock',
- timestamp: new Date(),
- },
- {
- type: 'tool-call',
- toolCallId: `call-${idx + 1}`,
- toolName: r.toolName,
- input: r.input,
- },
- {
- type: 'finish',
- finishReason: { unified: 'tool-calls', raw: undefined },
- usage: {
- inputTokens: { total: 5, noCache: 5 },
- outputTokens: { total: 10, text: 10 },
- },
- },
- ];
+ let parts: any[];
+ if (r.type === 'text') {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ { type: 'text-start', id: '1' },
+ { type: 'text-delta', id: '1', delta: r.text },
+ { type: 'text-end', id: '1' },
+ {
+ type: 'finish',
+ finishReason: { unified: 'stop', raw: 'stop' },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else if (r.type === 'provider-tool-call') {
+ const callId = `call-${idx + 1}`;
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: callId,
+ toolName: r.toolName,
+ input: r.input,
+ providerExecuted: true,
+ },
+ {
+ type: 'tool-result',
+ toolCallId: callId,
+ toolName: r.toolName,
+ result: r.result,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ } else {
+ parts = [
+ { type: 'stream-start', warnings: [] },
+ {
+ type: 'response-metadata',
+ id: 'r',
+ modelId: 'mock',
+ timestamp: new Date(),
+ },
+ {
+ type: 'tool-call',
+ toolCallId: `call-${idx + 1}`,
+ toolName: r.toolName,
+ input: r.input,
+ },
+ {
+ type: 'finish',
+ finishReason: { unified: 'tool-calls', raw: undefined },
+ usage: {
+ inputTokens: { total: 5, noCache: 5 },
+ outputTokens: { total: 10, text: 10 },
+ },
+ },
+ ];
+ }
  return {
  stream: new ReadableStream({
  start(c) {

packages/core/e2e/e2e-agent.test.ts

@@ -95,6 +95,30 @@ describe.skipIf(isCanary)('DurableAgent e2e', { timeout: 120_000 }, () => {
  });
  });
 
+ // ==========================================================================
+ // Provider tool tests
+ // ==========================================================================
+
+ describe('provider tools', () => {
+ it('provider tool identity preserved across step boundaries', async () => {
+ const run = await start(await agentE2e('agentProviderToolE2e'), []);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 2,
+ lastStepText: 'I found a result for you.',
+ });
+ });
+
+ it('mixed provider and function tools', async () => {
+ const run = await start(await agentE2e('agentMixedToolsE2e'), [3, 7]);
+ const rv = await run.returnValue;
+ expect(rv).toMatchObject({
+ stepCount: 3,
+ lastStepText: 'The answer is 10',
+ });
+ });
+ });
+
  // ==========================================================================
  // onStepFinish callback tests
  // ==========================================================================