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Defined in: server/middleware.ts:298 Normalises errors thrown by handlers to proper MCP shapes:
  • tools/call plain errors → { isError: true, content: […] } (per MCP spec)
  • tools/call McpError → re-thrown as a protocol-level error
  • all other methods → McpError(InternalError, message)
Re-throwing McpError from onCallTool ensures that middleware-level errors (e.g. from RateLimitingMiddleware or SizeLimitingMiddleware stacked before this middleware) always propagate as protocol errors and are never silently converted to isError:true tool responses.

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Implements

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Constructors

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Constructor

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Returns

ErrorNormalizationMiddleware

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Methods

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onCallTool()

Defined in: server/middleware.ts:299

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Parameters

ctx
MiddlewareContext
next
Next

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Returns

Promise<unknown>

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Implementation of

Middleware.onCallTool

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onRequest()

Defined in: server/middleware.ts:311

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Parameters

ctx
MiddlewareContext
next
Next

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Returns

Promise<unknown>

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Implementation of

Middleware.onRequest