Your API already does the work. Let AI agents use it.

0mcp turns your existing OpenAPI, Swagger, or Postman definition into a hosted MCP server — so AI clients can use your product without a backend rewrite.

Import your API · choose capabilities · connect AI clients

Your API

Business logic, data, and permissions stay here.

0mcp

Adds the hosted MCP interface AI clients understand.

AI clients

Discover tools and use your product through one endpoint.

yourserver.0mcp.dev/mcp
No backend rewrite

Start with the API definition you already have

Swagger 2.0
OpenAPI 3.0
OpenAPI 3.1
Postman collections
On this page

Give AI agents a reliable way to use your API

Traditional API integrations are built for software developers. A developer decides which endpoint to call, how to format the request, which authentication header to send, and how to interpret the response.

MCP gives AI clients a structured way to discover and use capabilities. An MCP server exposes functions as tools with names, descriptions, input schemas, and controlled access. The AI client can then select the right capability for a user request and call it through the MCP protocol.

API to MCP means turning the capabilities your API already has into an interface AI clients can understand — without rewriting your backend.
One backend. Two ways to use it.No rewrite

Your API

Built for software

GET /accounts
query + auth headers
JSON response

MCP interface

Built for AI clients

search_accounts
tool input schema
controlled access
0mcp adds the interface. Your API still runs the business logic.

How API capabilities become MCP capabilities

When you import an API definition, 0mcp helps you create an MCP server from the operations your API already exposes. The result is not just a list of URLs. It is a controlled interface that helps an AI client understand what your product can do and when to use each capability.

Mapping API definitions to MCP capabilities
API definitionMCP result
API operation or endpointMCP tool or selected capability
Operation ID and summaryTool name and description
Path, query, header, and body parametersStructured tool input schema
Request and response schemasInformation the AI client uses to form and understand calls
Authentication schemesRuntime-authenticated requests to the original API
Selected operationsThe allowlist of capabilities exposed to AI clients

Why SaaS teams use 0mcp for API to MCP

Launch an official MCP integration faster

Move from “we should build an MCP integration” to a hosted, usable endpoint without making MCP infrastructure a new internal project.

Keep your existing backend

Your API continues to own business logic, data validation, and application behavior. 0mcp adds an MCP interface on top of the capabilities you choose to expose.

Control what AI clients can access

Select operations, edit tool names and descriptions, and create or update tools, resources, and prompts when your use case needs more than a direct endpoint mapping.

Operate the server after launch

Hosting, authentication, testing, version control, usage visibility, and API-change workflows stay in the same platform after the first deployment.

How to create an MCP server from an API

Start with a useful, intentional set of capabilities. You do not need to expose every internal endpoint on the first version of your MCP server.

  1. Step 01

    Sign up and start a workspace

    Create an account and start with the 14-day free trial. No credit card is required, and the trial starts with Starter-level limits.

  2. Step 02

    Import your API definition

    Import Swagger 2.0, OpenAPI 3.0, OpenAPI 3.1, or a Postman collection. OpenAPI is the clearest starting point because it describes operations, parameters, security schemes, and response formats.

  3. Step 03

    Review the detected operations

    0mcp validates the imported specification and detects available API operations. Review warnings and errors, then choose the functions you want AI clients to access.

  4. Step 04

    Configure and improve the MCP capabilities

    Select API functions to expose and customize names and descriptions so they are clear to an AI client and to the people using your integration. Create tools, resources, and prompts as your use case grows.

  5. Step 05

    Test the server in the 0mcp Playground

    Inspect tools, call capabilities, test resources and prompts, verify authentication, and inspect individual usage logs before sharing the server with customers.

  6. Step 06

    Deploy a hosted MCP endpoint

    0mcp hosts the server and manages the infrastructure. The default endpoint uses Streamable HTTP and can connect to MCP-compatible clients such as Claude Desktop, Cursor, ChatGPT, Codex, or a custom agent.

    yourservername.0mcp.dev/mcp
  7. Step 07

    Maintain the server as your API evolves

    Save configuration versions, review changes, restore an earlier version, and keep the public integration stable as your API evolves. Saving an MCP configuration updates the hosted server without changing its URL.

create-mcp-server
Ready to publish
Imported operations
12 detected
search_accountsGET
create_reportPOST
list_projectsGET

Hosted MCP endpoint

acme.0mcp.dev/mcp

Transport

Streamable HTTP

Auth

Runtime pass-through

Status

Online

Playground test passed

What you get beyond an API-to-MCP converter

Many API-to-MCP tools focus on generating code or configuration. 0mcp is designed for the complete lifecycle of a hosted MCP server.

API import

Start from OpenAPI, Swagger, or a Postman collection instead of hand-writing every tool.

Capability selection

Expose only the API functions your AI users need.

Tools, resources, and prompts

Create a more useful MCP interface than a raw list of endpoints.

Hosted deployment

Use a managed Streamable HTTP endpoint without running MCP infrastructure.

Runtime authentication

Pass API keys, Bearer tokens, or OAuth credentials at request time.

Playground testing

Verify tools, inputs, authentication, responses, and logs before launch.

Version management

Review changes and restore an earlier configuration when needed.

Analytics and logs

Understand requests, errors, latency, client sources, and most-used capabilities.

Proactive error alerts

Get notified when tool calls return API errors such as 401 or 500.

Custom domains

Use a branded subdomain on eligible plans.

Your credentials, your rules.

Keep credentials out of the platform.

0mcp forwards API keys, Bearer tokens, and OAuth credentials at request time. Your API still authenticates the call. Nothing is saved.

One request No credential vault

Read the security details · Privacy policy

You provide

Credential in the AI client

0mcp forwards

Only for the request

Your API checks

Your auth rules apply

Never stored.

The credential leaves with the request.

Build it yourself or use a hosted API-to-MCP platform?

Building an MCP server internally can be the right choice when you need complete control over custom business logic. It also means your team owns every part of the implementation and operation.

Responsibilities when building an MCP server internally versus using 0mcp
ResponsibilityBuild internallyWith 0mcp
MCP implementationYour engineering team builds the serverImport and configure your API capabilities
HostingYour team chooses and operates infrastructure0mcp hosts the MCP server
AuthenticationYou implement and maintain the auth flowUse runtime API key, Bearer, or OAuth pass-through
Tool configurationDevelopers maintain schemas and descriptions in codeEdit capabilities in the dashboard
TestingBuild your own testing workflowUse the 0mcp Playground
Version changesCreate your own deployment and rollback processSave versions, review changes, and restore earlier configurations
Usage visibilityAdd logs and analytics to your stackView usage, errors, latency, client sources, and capability usage
Custom domainConfigure and maintain it yourselfAvailable on eligible plans

0mcp is useful when your team wants an official MCP integration but does not want to become an MCP infrastructure company.

Who is API to MCP for?

0mcp is built for founders, CTOs, and product teams at growing B2B SaaS companies that already have useful API capabilities and want to make them available to AI agents.

It is a good fit when your product already has an OpenAPI or Swagger specification, you want to launch an official MCP integration quickly, and your team needs control over operations, credentials, and production visibility.

Common use cases include sales operations, marketing analytics, reporting and BI, productivity workflows, developer tools, and other SaaS products that can be used through structured API operations.

It fits when you need

  • An OpenAPI or Swagger specification
  • A fast official MCP integration
  • A deliberate operation allowlist
  • Runtime auth without stored credentials
  • Logs and analytics after launch
  • Versioning as the API evolves

Before you import

Prepare your API for better MCP tools.

0mcp can validate an imported specification, but the quality of the resulting MCP tools depends on the quality of the API definition. Clear API documentation gives AI clients better information for choosing and calling the right tools.

  • Operations have clear, unique names.
  • Parameters have accurate types and descriptions.
  • Authentication schemes are documented.
  • Request and response schemas match real API behavior.
  • Sensitive or internal operations are identified.
  • The API returns JSON responses supported by your intended workflow.
  • Pagination and rate-limit behavior is understood by your team.

Frequently asked questions

What is API to MCP?

API to MCP is the process of exposing existing API capabilities through the Model Context Protocol. An MCP server turns selected API operations into structured tools, resources, or prompts that compatible AI clients can discover and use.

Can I create an MCP server from an existing API?

Yes. With 0mcp, start with a supported Swagger or OpenAPI specification, or import a Postman collection. 0mcp detects the available operations, lets you select what to expose, and creates a hosted MCP server.

Is 0mcp only an API-to-MCP converter?

No. Conversion is the starting point. 0mcp also provides hosted deployment, runtime authentication, capability customization, testing, version management, analytics, logs, and ongoing server maintenance.

Does 0mcp store my API credentials?

No. API keys, Bearer tokens, and OAuth credentials are passed through at runtime by the user's MCP client. 0mcp does not store those credentials.

What authentication methods are supported?

0mcp supports API key, Bearer token, and OAuth authentication for supported API connections. The exact behavior depends on the authentication scheme defined by the original API.

Do I need to run my own MCP server?

No. 0mcp hosts the MCP server and provides a hosted Streamable HTTP endpoint. Your team can focus on API capabilities and customer experience instead of operating MCP infrastructure.

Can I choose which API endpoints become MCP tools?

Yes. You select the API operations to expose. You can also edit capability names and descriptions and create or update tools, resources, and prompts as your integration develops.

Can I test an MCP server before publishing it?

Yes. The 0mcp Playground lets you inspect capabilities, call tools, test resources and prompts, verify authentication, and review individual usage logs before you share the server with customers.

Can I use a custom domain for my MCP server?

Custom domains are available on eligible plans. You can configure a branded subdomain, verify it through DNS, and use the resulting HTTPS endpoint for your hosted MCP server.

Turn your API into a hosted MCP integration.

Your API is already the foundation of your product. 0mcp helps you turn that foundation into a hosted MCP integration that AI clients can discover, use, and rely on — without building the infrastructure yourself.