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Create an MCP from an API

Create an MCP from an API that has an OpenAPI or Swagger spec. Each API endpoint you pick becomes a tool that agents can use.

Before you start​

  • Have the API's base URL and any credentials it needs.
  • Have the spec's URL, or a spec file. OpenAPI 3 and Swagger 2 specs are accepted, in JSON or YAML, up to 16 MiB.

Name rules​

Name can use letters and numbers only, with no spaces, dashes or special characters. It can be up to 100 characters, and must not already be used by another MCP.

Steps​

  1. In MCP Builder, select Create MCP.

  2. Under the connection section, enter a Name, for example MyConnector.

  3. In Base URL, enter the API's base URL, starting with http:// or https://.

  4. Optional: enter a Description of up to 500 characters, and add Tags.

  5. Leave Enabled - agents can use this connector immediately after save ticked, or untick it to save the MCP turned off.

  6. Under Scope, select User — visible only to you or Account — visible to everyone in your account. For Account scope, choose Read or Full access.

  7. Under Authentication, choose the Auth type and fill in its fields:

    Auth typeRequired fields
    No AuthNone
    Bearer Token or TokenToken
    Basic or DigestUsername and Password
    API KeyAPI key and Header name
    Custom HeaderHeader name and Header value
    OAuth 2.0Client ID, Client secret and Token URL

  8. Optional: open Client settings to set timeouts, retries, rate limits, a proxy or custom headers.

  9. Under Tools, get the API's tools in one of these ways:

    • Enter the spec's address in OpenAPI spec URL, or leave it blank to probe the base URL, then select Auto-discover.
    • Select Upload spec and choose the spec file. The file is checked against the base URL.

  10. In the tool list, untick any endpoints you don't want. Only ticked endpoints are saved. Type in Search tools by name or path… to find one.

  11. Optional: select Test Connection to check the connection. See Test an MCP connection.

  12. Select Save MCP.

Create several MCPs from one API​

For a large API, the tools may be shown in groups, and one MCP is created for each group. You can create up to 25 at a time.

  1. Check the name under Save MCP as for each group. Expand a group to drop endpoints you don't want.
  2. Optional: tick Group these under one parent to keep the new MCPs together in the list.
  3. Select Save MCP, then select Create in the Create MCPs dialog.

What happens next​

The message MCP saved appears, and the MCP list opens.

Troubleshooting​

MessageFix
Name is requiredEnter a Name.
Only letters and numbers — no spaces, dashes, or special charactersRemove spaces and special characters from the name.
A MCP named "name" already existsChoose a different name.
URL must start with http:// or https://Add the scheme to the URL.
Enter a base URL or an OpenAPI spec URLEnter at least one of them.
Field is requiredFill in the named authentication field.
Choose Read or Full access for an account-scoped MCPChoose an access level.
Retry count must be between 0 and 10Enter a value from 0 to 10.
Use duration format: 30s, 1m, 500ms, 2hEnter a duration such as 30s.
Cannot save more than 2000 tools at onceUntick some tools.
Tool names must be uniqueRename the tools that share a name.
Enter the base URL first — the uploaded spec is checked against it.Enter the Base URL, then upload the spec.
Select at least one group to create.Tick at least one group.
Save failed. Check the form values and try again.Check the fields marked in red.

If the spec's host doesn't match your base URL, select Use my base URL anyway to keep your base URL.