Function: createTool()

createTool<TId, TInputSchema, TOutputSchema, TSuspendSchema, TResumeSchema, TRequestContext, TContext>(opts): Tool<InferSchema<TInputSchema>, InferSchema<TOutputSchema>, InferSchema<TSuspendSchema>, InferSchema<TResumeSchema>, TContext, TId, TRequestContext>

Defines a tool with a description, input/output schemas, and an execution function.

Type Parameters

TId

TId extends string = string

TInputSchema

TInputSchema extends SchemaLike = undefined

TOutputSchema

TOutputSchema extends SchemaLike = undefined

TSuspendSchema

TSuspendSchema extends SchemaLike = undefined

TResumeSchema

TResumeSchema extends SchemaLike = undefined

TRequestContext

TRequestContext extends unknown = unknown

TContext

TContext extends ToolExecutionContext<InferSchema<TSuspendSchema>, InferSchema<TResumeSchema>, TRequestContext> = ToolExecutionContext<InferSchema<TSuspendSchema>, InferSchema<TResumeSchema>, TRequestContext>

Parameters

opts

CreateToolOpts<TId, TInputSchema, TOutputSchema, TSuspendSchema, TResumeSchema, TRequestContext, TContext>

Returns

Tool<InferSchema<TInputSchema>, InferSchema<TOutputSchema>, InferSchema<TSuspendSchema>, InferSchema<TResumeSchema>, TContext, TId, TRequestContext>

Example

import { createTool } from '@mastra/core/tools';
import { z } from 'zod';

const greet = createTool({
  id: 'greet',
  description: 'Greet someone by name.',
  inputSchema: z.object({ name: z.string() }),
  outputSchema: z.string(),
  execute: async ({ name }) => `Hello, ${name}!`,
});

See

• For documentation bundled with your installed package, locate @mastra/core/package.json with your project’s resolver or package-manager tooling, then read dist/docs/SKILL.md from that package root and follow its reference links. Use package-manager tools for virtual or archived packages.
• Tool documentation if packaged docs are unavailable.