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-32600

Invalid Request

JSON-RPC 2.0

JSON-RPC invalid request (-32600) means the received JSON is valid but does not conform to the JSON-RPC 2.0 structure. The message is missing required fields (jsonrpc, method) or has incorrect field types.

Code

-32600

Decimal

-32600

Standard

JSON-RPC 2.0

Description

Invalid Request fires when the server parses the JSON successfully but the object does not match the JSON-RPC 2.0 schema. Required fields include jsonrpc (must be exactly "2.0"), method (must be a string), and id (if present, must be string, number, or null). Common in MCP context: sending a request without the jsonrpc field, using a numeric method name, or sending an array of batched requests (MCP does not support JSON-RPC batching).

Common Causes

  • Missing jsonrpc: "2.0" field
  • method field is not a string
  • Sending JSON-RPC batch (array) – MCP does not support batching
  • id field is an object instead of string, number, or null
  • Empty object {} sent as a request