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POST
Call a tool

Authorizations

Authorization
string
header
required

MCPJam API key (sk_…). Create one at Settings → API keys. Guest sessions cannot use the API, and API keys cannot manage other API keys.

Path Parameters

projectId
string
required

ID of the hosted project that contains the server.

serverId
string
required

ID of the server inside the project.

Body

application/json
toolName
string
required

Tool name, exactly as returned by the tools list.

parameters
object

Tool arguments matching the tool's inputSchema. Defaults to {}.

Response

The MCP CallToolResult plus additive durationMs. Check isError for tool-level failures.

MCP tool execution result, returned verbatim from the server, plus additive durationMs measured at the public API boundary.

content
object[]
required

Content blocks (text, image, resource, ...).

structuredContent
object

Structured output matching the tool's outputSchema, when declared.

isError
boolean

true when the tool reported a failure. The HTTP call still succeeds — the server answered.

durationMs
integer

Wall-clock milliseconds spent in executeTool on this request. Additive MCPJam field; not part of the MCP CallToolResult spec. A server that already returns its own top-level durationMs keeps it — MCPJam never overwrites the field — so this value is MCPJam's measurement only when the server did not report one.

Required range: x >= 0