Method checkResponse

mcp/streamable.go:2048–2071

checkResponse checks the status code of the provided response, and translates it into an error if the request was unsuccessful. The response body is close if a non-nil error is returned.

(requestSummary string, resp *http.Response)

//
// The response body is close if a non-nil error is returned.
func (c *streamableClientConn) checkResponse(requestSummary string, resp *http.Response) (err error) {
	defer func() {
		if err != nil {
			resp.Body.Close()
		}
	}()
	// §2.5.3: "The server MAY terminate the session at any time, after
	// which it MUST respond to requests containing that session ID with HTTP
	// 404 Not Found."
	if resp.StatusCode == http.StatusNotFound {
		// Return an ErrSessionMissing to avoid sending a redundant DELETE when the
		// session is already gone.
		return fmt.Errorf("%s: failed to connect (session ID: %v): %w", requestSummary, c.sessionID, ErrSessionMissing)
	}
	// Transient server errors (502, 503, 504, 429) should not break the connection.
	// Wrap them with ErrRejected so the jsonrpc2 layer doesn't set writeErr.
	if isTransientHTTPStatus(resp.StatusCode) {
		return fmt.Errorf("%w: %s: %v", jsonrpc2.ErrRejected, requestSummary, http.StatusText(resp.StatusCode))
	}
	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		return fmt.Errorf("%s: %v", requestSummary, http.StatusText(resp.StatusCode))
	}
	return nil
}

// processStream reads from a single response body, sending events to the
// incoming channel. It returns the ID of the last processed event and a flag