Fine Structure

Fine Structure Bridge API

Generic call-by-name REST bridge

Documentation GitHub OpenAPI

Operations 1

POST /api/mcp/tools/{tool_name} Call any Fine Structure tool by name #

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OpenAPI Specification

openapi: 3.2.0
info:
  title: Fine Structure Bridge API
  version: 1.0.0
  summary: Build, edit, validate and publish complete web applications with AI.
  description: 'Fine Structure is an AI software-building platform: it generates complete applications, runs autonomous AI agent teams, and maintains a business brain over your data.


    Getting started is self-serve: sign up free at https://finestructure.ai (free tier included, no credit card), then create an API/MCP token at https://finestructure.ai/api-keys and pass it as `Authorization: Bearer fse2_mcp_`.


    Every operation below is also available as an MCP tool via the JSON-RPC endpoint POST /api/mcp (Streamable HTTP transport).'
  termsOfService: https://finestructure.ai/terms
  contact:
    name: Fine Structure support
    email: support@finestructure.ai
    url: https://finestructure.ai/contact
servers:
- url: https://finestructure.ai
  description: Production
tags:
- name: Bridge
  description: Generic call-by-name REST bridge
paths:
  /api/mcp/tools/{tool_name}:
    post:
      operationId: call_tool_generic
      summary: Call any Fine Structure tool by name
      description: Generic REST bridge to the Fine Structure tool surface. The request body is the tool's arguments object. Prefer the per-tool operations below, which carry the exact JSON schema for each tool.
      tags:
      - Bridge
      security:
      - bearerAuth: []
      parameters:
      - name: tool_name
        in: path
        required: true
        schema:
          type: string
        description: Name of the tool to execute (see the per-tool operations or GET /api/mcp/manifest)
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              additionalProperties: true
      responses:
        '200':
          description: Tool executed successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ToolResult'
        '400':
          description: Invalid arguments for this tool
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '401':
          description: Missing or invalid bearer token
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '402':
          description: Not enough credits on the account
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '403':
          description: Token scope does not permit this tool
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '404':
          description: Unknown tool name
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '429':
          description: Rate limit exceeded, retry after the indicated delay
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '500':
          description: Internal error while executing the tool
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
components:
  schemas:
    ToolResult:
      type: object
      properties:
        ok:
          type: boolean
        tool:
          type: string
        result:
          type: object
          additionalProperties: true
      required:
      - ok
      - tool
      - result
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            code:
              type: string
            message:
              type: string
          required:
          - code
          - message
      required:
      - error
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: fse2_mcp_<token>
      description: User-created Fine Structure token. Create one self-serve at https://finestructure.ai/api-keys. Tokens are scoped by account, app and permissions.
externalDocs:
  description: Agent integration guide
  url: https://finestructure.ai/api/mcp/docs