From tRPC

Expose tRPC router procedures as MCP tools without rewriting them as hand-written Zod tools.

Quick start

import { createStdioServer } from '@bridgent/core'
import { fromTrpc } from '@bridgent/source-trpc'
import { appRouter } from './router'

await createStdioServer({
  name: 'trpc-app',
  version: '0.0.1',
  tools: fromTrpc({
    router: appRouter,
    createContext: () => ({ userId: 'demo-user' }),
  }),
})

What gets exposed

• query procedures become read tools by default.
• mutation procedures are hidden by default.
• subscription procedures are not exposed.

Procedure path user.getById becomes tool name trpc_user_getById. Set toolPrefix to replace the default prefix:

fromTrpc({
  router: appRouter,
  toolPrefix: 'app',
})

This produces names such as app_user_getById.

Mutation opt-in

Mutations require both a broad safety switch and a final tool-name allowlist:

fromTrpc({
  router: appRouter,
  allow: {
    mutating: true,
    tools: ['trpc_user_updateName'],
  },
})

The allowlist uses final generated tool names, matching Prisma write-tool allowlists.

Input schemas

Bridgent maps Zod v4 object inputs to MCP input schemas. Procedures without input get an empty strict object schema.

Unsupported or opaque parser shapes fail during tool generation. This is intentional: Bridgent does not generate permissive any tool inputs.

Options

Option	Purpose
router	tRPC v10/v11 router object
createContext	Sync or async context factory called per tool invocation
toolPrefix	Generated tool-name prefix. Default: trpc
procedureFilter	RegExp or function filter for procedure paths
allow.mutating	Required before exposing mutation procedures
allow.tools	Final generated mutation tool names to expose