ProtoBuffers debug with CURL. ProtoBuffers should be installed first: "yum install protobuf" or "brew install protobuf".

proto.msg

key:"string value"
int_key:22

req

#!/bin/bash
#### Decode
# protoc \
#     --proto_path=<path-to-folder-containing-imported-.proto-files> \
#     --decode <msg-definition-name> \
#     <path-to-.proto-file> < <path-to-binary-encoded-msg-file>

#### Encode
# protoc \
#     --proto_path=<path-to-folder-containing-imported-.proto-files> \
#     --encode <msg-definition-name> \
#     example_msg.proto < <path-to-clear-text-msg-file> > <path-to-binary-encoded-msg-file>

URL=full_method_url                # i.e. "http://server.com/my/method" (without quotes)
REQUEST=request_message_name       # i.e. "Request"
RESPONSE=response_message_name     # i.e. "Response"
PROTO=proto_file_name              # i.e. "./Protocol.proto"

cat proto.msg | protoc --encode $REQUEST $PROTO | curl -sS -X POST --data-binary @- $URL | protoc --decode $RESPONSE $PROTO