ContextQMD
Back to Mastra

Reference: registerApiRoute() | Server

docs/src/content/en/reference/server/register-api-route.mdx

2025-12-186.9 KB
Original Source

import PropertiesTable from "@site/src/components/PropertiesTable";

registerApiRoute()

The registerApiRoute() function creates custom HTTP routes that integrate with the Mastra server. Routes can include OpenAPI metadata to appear in the Swagger UI documentation.

Import

typescript
import { registerApiRoute } from '@mastra/core/server'

Parameters

path

The URL path for the route. Supports path parameters using :param syntax.

typescript
registerApiRoute("/items/:itemId", { ... })

Note: Paths can't start with /api/ as this prefix is reserved for Mastra server routes.

options

<PropertiesTable content={[ { name: 'method', type: "'GET' | 'POST' | 'PUT' | 'DELETE' | 'PATCH' | 'ALL'", description: 'HTTP method for the route', isOptional: false, }, { name: 'handler', type: 'Handler', description: 'Route handler function receiving Hono Context. Use either handler or createHandler, not both.', isOptional: true, }, { name: 'createHandler', type: '(c: Context) => Promise<Handler>', description: 'Async factory function to create the handler. Use either handler or createHandler, not both.', isOptional: true, }, { name: 'middleware', type: 'MiddlewareHandler | MiddlewareHandler[]', description: 'Route-specific middleware functions', isOptional: true, }, { name: 'openapi', type: 'DescribeRouteOptions', description: 'OpenAPI metadata for Swagger UI documentation', isOptional: true, }, ]} />

OpenAPI options

The openapi property accepts standard OpenAPI 3.1 operation fields from hono-openapi. Routes without an openapi property aren't included in Swagger UI.

<PropertiesTable content={[ { name: 'summary', type: 'string', description: 'Short summary of the operation', isOptional: true, }, { name: 'description', type: 'string', description: 'Detailed description of the operation', isOptional: true, }, { name: 'tags', type: 'string[]', description: "Tags for grouping in Swagger UI. Defaults to ['custom'] if not specified.", isOptional: true, }, { name: 'deprecated', type: 'boolean', description: 'Mark the operation as deprecated', isOptional: true, }, { name: 'parameters', type: 'ParameterObject[]', description: 'Path, query, and header parameters', isOptional: true, }, { name: 'requestBody', type: 'RequestBodyObject', description: 'Request body specification', isOptional: true, }, { name: 'responses', type: 'ResponsesObject', description: 'Response specifications by status code', isOptional: true, }, { name: 'security', type: 'SecurityRequirementObject[]', description: 'Security requirements for the operation', isOptional: true, }, ]} />

Return value

Returns an ApiRoute object to be passed to server.apiRoutes in the Mastra configuration.

Handler context

The handler receives a Hono Context object with access to:

typescript
handler: async c => {
  // Get the Mastra instance
  const mastra = c.get('mastra')

  // Get request context
  const requestContext = c.get('requestContext')

  // Access path parameters
  const itemId = c.req.param('itemId')

  // Access query parameters
  const filter = c.req.query('filter')

  // Access request body
  const body = await c.req.json()

  // Return JSON response
  return c.json({ data: 'value' })
}

Examples

Basic GET Route

typescript
import { Mastra } from '@mastra/core'
import { registerApiRoute } from '@mastra/core/server'

export const mastra = new Mastra({
  server: {
    apiRoutes: [
      registerApiRoute('/health-check', {
        method: 'GET',
        handler: async c => {
          return c.json({ status: 'ok' })
        },
      }),
    ],
  },
})

Route with Path Parameters

typescript
registerApiRoute('/users/:userId/posts/:postId', {
  method: 'GET',
  handler: async c => {
    const userId = c.req.param('userId')
    const postId = c.req.param('postId')

    return c.json({ userId, postId })
  },
})

POST Route with Body

typescript
registerApiRoute('/items', {
  method: 'POST',
  handler: async c => {
    const body = await c.req.json()
    const mastra = c.get('mastra')

    // Process the request...

    return c.json({ id: 'new-id', ...body }, 201)
  },
})

Route with Middleware

typescript
registerApiRoute('/protected', {
  method: 'GET',
  middleware: [
    async (c, next) => {
      const token = c.req.header('Authorization')
      if (!token) {
        return c.json({ error: 'Unauthorized' }, 401)
      }
      await next()
    },
  ],
  handler: async c => {
    return c.json({ data: 'protected content' })
  },
})

Route with OpenAPI Documentation

typescript
import { z } from 'zod'

const ItemSchema = z.object({
  id: z.string(),
  name: z.string(),
  price: z.number(),
})

registerApiRoute('/items/:itemId', {
  method: 'GET',
  openapi: {
    summary: 'Get item by ID',
    description: 'Retrieves a single item by its unique identifier',
    tags: ['Items'],
    parameters: [
      {
        name: 'itemId',
        in: 'path',
        required: true,
        description: 'The item ID',
        schema: { type: 'string' },
      },
    ],
    responses: {
      200: {
        description: 'Item found',
        content: {
          'application/json': {
            schema: ItemSchema, // Zod schemas are converted to JSON Schema during OpenAPI generation
          },
        },
      },
      404: {
        description: 'Item not found',
      },
    },
  },
  handler: async c => {
    const itemId = c.req.param('itemId')
    return c.json({ id: itemId, name: 'Example', price: 9.99 })
  },
})

Using createHandler()

For routes that need async initialization:

typescript
registerApiRoute('/dynamic', {
  method: 'GET',
  createHandler: async c => {
    // Perform async setup
    const config = await loadConfig()

    return async c => {
      return c.json({ config })
    }
  },
})

Error handling

Throw errors with status codes using Hono's HTTPException:

typescript
import { HTTPException } from 'hono/http-exception'

registerApiRoute('/items/:itemId', {
  method: 'GET',
  handler: async c => {
    const itemId = c.req.param('itemId')
    const item = await findItem(itemId)

    if (!item) {
      throw new HTTPException(404, { message: 'Item not found' })
    }

    return c.json(item)
  },
})