GRPC_PROTOBUF_FIELD_MISMATCH grpc type_error ai_generated true

INTERNAL: grpc: error while parsing response: field 5 has type int64 but message expects string

ID: grpc/protobuf-field-mismatch

Also available as: JSON · Markdown · 中文
95%Fix Rate
90%Confidence
1Evidence
2025-02-20First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
protobuf v3.21.x active — — —
protobuf v4.25.x active — — —
gRPC v1.62.x active — — —

Root Cause

Server and client have mismatched Protobuf definitions for the same RPC, where a field type differs (e.g., server sends int64 but client expects string).

generic

中文

服务器和客户端对同一 RPC 的 Protobuf 定义不匹配，字段类型不同（例如服务器发送 int64 但客户端期望字符串）。

Official Documentation

https://protobuf.dev/programming-guides/proto3/

Workarounds

  1. 95% success Synchronize the .proto file between server and client: run `diff server.proto client.proto` to identify field type differences, then update the incorrect one. Recompile both sides with `protoc --proto_path=. --go_out=. *.proto` (or equivalent for your language). 
    Synchronize the .proto file between server and client: run `diff server.proto client.proto` to identify field type differences, then update the incorrect one. Recompile both sides with `protoc --proto_path=. --go_out=. *.proto` (or equivalent for your language).
  2. 85% success Use a versioned schema registry (e.g., Confluent Schema Registry) to enforce that both sides use the same Protobuf schema version for the RPC. 
    Use a versioned schema registry (e.g., Confluent Schema Registry) to enforce that both sides use the same Protobuf schema version for the RPC.
  3. 70% success As a temporary workaround, change the client field to use `google.protobuf.Any` to accept any type, then manually cast in application code. 
    As a temporary workaround, change the client field to use `google.protobuf.Any` to accept any type, then manually cast in application code.

中文步骤

  1. 同步服务器和客户端的 .proto 文件：使用 `diff server.proto client.proto` 找出字段类型差异，更新错误的一方。使用 `protoc` 重新编译两端。
  2. 使用版本化的模式注册表（如 Confluent Schema Registry），强制 RPC 两端使用相同的 Protobuf 模式版本。
  3. 临时将客户端字段改为 `google.protobuf.Any` 以接受任意类型，然后在应用代码中手动转换。

Dead Ends

Common approaches that don't work:

  1. 80% fail

    If the .proto file itself is outdated, regenerated stubs still have the wrong types; the root cause is the definition mismatch.

  2. 90% fail

    gRPC uses strict Protobuf parsing; custom deserializers are not supported and will cause further parsing errors.

  3. 50% fail

    Version mismatch is not the issue; the .proto file content is what defines the field types.