Error Handling¶

RpcError¶

RpcError represents a protocol-level error with a type and message:

return "", &vgirpc.RpcError{
    Type:    "ValueError",
    Message: "parameter out of range",
}

The Type field uses Python exception class names by convention (e.g. "ValueError", "RuntimeError", "TypeError"). This ensures compatibility with Python clients that map error types to exception classes.

ErrRpc Sentinel¶

Use errors.Is(err, vgirpc.ErrRpc) to check whether any error in a chain is an *RpcError:

if errors.Is(err, vgirpc.ErrRpc) {
    // handle RPC-level error
}

Error Types¶

Type	Typical use
`ValueError`	Invalid parameter value
`TypeError`	Wrong parameter type or method type mismatch
`RuntimeError`	General server-side error
`AttributeError`	Unknown method name
`VersionError`	Protocol version mismatch
`SerializationError`	Failed to serialize result

Returning Errors from Handlers¶

Any handler can return an *RpcError to send a typed error to the client:

vgirpc.Unary(server, "divide", func(_ context.Context, _ *vgirpc.CallContext, p DivideParams) (float64, error) {
    if p.B == 0 {
        return 0, &vgirpc.RpcError{
            Type:    "ValueError",
            Message: "division by zero",
        }
    }
    return p.A / p.B, nil
})

Non-RpcError errors returned from handlers are wrapped as RuntimeError automatically.