# UNIMPLEMENTED: grpc: Unsupported compression algorithm: deflate

- **ID:** `grpc/invalid-compression-algorithm`
- **Domain:** grpc
- **Category:** protocol_error
- **Verification:** ai_generated
- **Fix Rate:** 90%

## Root Cause

The client requested a compression algorithm that the server does not support.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| gRPC Python 1.47.0 | active | — | — |
| gRPC C++ 1.49.0 | active | — | — |

## Workarounds

1. **Change the client to use gzip compression. Example: `channel = grpc.insecure_channel('target', options=[('grpc.default_compression_algorithm', grpc.Compression.Gzip)])`** (90% success)
   ```
   Change the client to use gzip compression. Example: `channel = grpc.insecure_channel('target', options=[('grpc.default_compression_algorithm', grpc.Compression.Gzip)])`
   ```
2. **If using custom compression, register it on both sides via `grpc.Compression` API.** (70% success)
   ```
   If using custom compression, register it on both sides via `grpc.Compression` API.
   ```

## Dead Ends

- **** — gRPC does not support deflate; it only supports gzip, identity, and optionally snappy or zstd. (90% fail)
- **** — The server will still reject it because the algorithm is not in its supported list. (70% fail)
- **** — gRPC does not negotiate compression; mismatch causes immediate failure. (95% fail)