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FAQ

Common questions and answers for developers during integration.

Signature Verification Error​

If the API returns 0004 Signature verification error, please check the following:

  1. Parameter sorting: Are parameters sorted in ascending ASCII (lexicographic) order?
  2. Parameter filtering: Have you excluded sign and parameters with empty values?
  3. Key appending: Is the key correctly appended to the end of the parameter string as &{platform_key}? (Append the key directly, without a key= prefix)
  4. Encryption method: Are you using the MD5 algorithm and converting the result to lowercase?
  5. Encoding: It is recommended to use UTF-8 encoding for all Chinese parameters to avoid signature mismatches caused by encoding issues.

For more signature details, please refer to Signature Guide.