Title: [Bug]: a2av0 JSON-RPC client fails to decode v0.3 error responses with non-typed data, masking the real error
Summary
The a2av0 compat JSON-RPC transport decodes responses into the shared jsonrpc.ClientResponse, whose Error.Data is typed []*errordetails.Typed (internal/jsonrpc/jsonrpc.go:54-58). JSON-RPC 2.0 / A2A v0.3 define error.data as any JSON value, and v0.3 servers commonly return an object there. When they do, the whole Decode(&resp) fails, so the caller gets failed to decode response: json: cannot unmarshal object into Go struct field ... instead of the server's error — code and message are lost along with the data.
Current behavior
a2acompat/a2av0/jsonrpc_client.go sendRequest (~line 127): json.NewDecoder(httpResp.Body).Decode(&resp) with resp jsonrpc.ClientResponse → any v0.3 error whose data is not []*errordetails.Typed aborts the decode.- Same on the SSE streaming path (~lines 165-175).
- Present in v2.3.1 and current main.
Repro
Point an a2av0 JSON-RPC client at a v0.3 server that returns:
{"jsonrpc":"2.0","id":"1","error":{"code":-32603,"message":"real error message","data":{"reason":"detail"}}}Client surfaces failed to decode response (callers typically wrap this as internal error / -32603); the real message never reaches the caller.
Requested
Decode error.data leniently in the v0 transport (json.RawMessage/any), always preserve code + message, and convert to typed details only when they parse. Same bug class as #318 (REST streaming error events), applied to the JSON-RPC v0 path.
Workarounds
None at the SDK consumer level; the decode failure happens inside the transport.
Title: [Bug]: a2av0 JSON-RPC client fails to decode v0.3 error responses with non-typed
data, masking the real errorSummary
The a2av0 compat JSON-RPC transport decodes responses into the shared
jsonrpc.ClientResponse, whoseError.Datais typed[]*errordetails.Typed(internal/jsonrpc/jsonrpc.go:54-58). JSON-RPC 2.0 / A2A v0.3 defineerror.dataas any JSON value, and v0.3 servers commonly return an object there. When they do, the wholeDecode(&resp)fails, so the caller getsfailed to decode response: json: cannot unmarshal object into Go struct field ...instead of the server's error — code and message are lost along with the data.Current behavior
a2acompat/a2av0/jsonrpc_client.gosendRequest(~line 127):json.NewDecoder(httpResp.Body).Decode(&resp)withresp jsonrpc.ClientResponse→ any v0.3 error whosedatais not[]*errordetails.Typedaborts the decode.Repro
Point an a2av0 JSON-RPC client at a v0.3 server that returns:
{"jsonrpc":"2.0","id":"1","error":{"code":-32603,"message":"real error message","data":{"reason":"detail"}}}Client surfaces
failed to decode response(callers typically wrap this as internal error / -32603); the real message never reaches the caller.Requested
Decode
error.dataleniently in the v0 transport (json.RawMessage/any), always preservecode+message, and convert to typed details only when they parse. Same bug class as #318 (REST streaming error events), applied to the JSON-RPC v0 path.Workarounds
None at the SDK consumer level; the decode failure happens inside the transport.