4_http_status_code

Opinionated Stance on HTTP Status Codes

There is no official mapping of JSON-RPC error codes to HTTP status codes in the JSON-RPC 2.0 specification. JSON-RPC 2.0 is transport-agnostic and does not mandate any particular use of HTTP status codes.

PATH takes an opinionated stance on mapping JSON-RPC errors to HTTP status codes. This is a common practice but not an industry standard.

JSON-RPC to HTTP Status Code Mapping

It's common practice in JSON-RPC-over-HTTP implementations to map:

• Client errors (e.g., -32600 Invalid Request) to 4xx HTTP statuses

• Server errors (e.g., -32603 Internal error or -32000 "Server error") to 5xx HTTP statuses

PATH follows this practice and maps JSON-RPC errors to HTTP status codes as follows:

JSON-RPC Error Code	Common Meaning	HTTP Status Code
-32700	Parse error	400 Bad Request
-32600	Invalid request	400 Bad Request
-32601	Method not found	404 Not Found
-32602	Invalid params	400 Bad Request
-32603	Internal error	500 Server Error
-32098	Timeout	504 Gateway Timeout
-32097	Rate limited	429 Too Many Requests
-32000…-32099	Server error range	500 Server Error
> 0	Application errors (client-side)	400 Bad Request
< 0 (other negative)	Application errors (server-side)	500 Server Error

Status Code Implementation

PATH implements this mapping in the Response.GetRecommendedHTTPStatusCode() method:

response.go

// GetRecommendedHTTPStatusCode maps a JSON-RPC error response code to an HTTP status code.
func (r Response) GetRecommendedHTTPStatusCode() int {
    // Return 200 OK if no error is present
    if r.Error == nil {
        return http.StatusOK
    }

    // Map standard JSON-RPC error codes to HTTP status codes
    switch r.Error.Code {
    case -32700: // Parse error
        return http.StatusBadRequest // 400
    case -32600: // Invalid request
        return http.StatusBadRequest // 400
    case -32601: // Method not found
        return http.StatusNotFound // 404
    case -32602: // Invalid params
        return http.StatusBadRequest // 400
    case -32603: // Internal error
        return http.StatusInternalServerError // 500
    case -32098: // Timeout (used by some providers)
        return http.StatusGatewayTimeout // 504
    case -32097: // Rate limited (used by some providers)
        return http.StatusTooManyRequests // 429
    }

    // Server error range (-32000 to -32099)
    if r.Error.Code >= -32099 && r.Error.Code <= -32000 {
        return http.StatusInternalServerError // 500
    }

    // Application-defined errors
    if r.Error.Code > 0 {
        // Positive error codes typically indicate client-side issues
        return http.StatusBadRequest // 400
    } else if r.Error.Code < 0 {
        // Other negative error codes typically indicate server-side issues
        return http.StatusInternalServerError // 500
    }

    // This should never be reached, but as a fallback return 500
    return http.StatusInternalServerError // 500
}

References

• Original GitHub Issue can be found here

• Original GitHub PR can be found here