jackc/pgx · error

invalid length for ReadyForQuery.TxStatus

Error message

invalid length for ReadyForQuery.TxStatus

What it means

ReadyForQuery.UnmarshalJSON guard: the JSON representation's TxStatus field does not have exactly one character. The PostgreSQL wire protocol defines ReadyForQuery's transaction status as a single byte ('I', 'T', or 'E'), so any other length cannot be mapped; the malformed JSON field is the faulty input.

Solutions

1. Supply TxStatus as exactly one of "I", "T", or "E"
2. Fix the JSON generator that produced the multi-character status

When it happens

Trigger: Thrown at pgproto3/ready_for_query.go:57 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of jackc/pgx@ec1a0befd2 (2026-08-04). Data as JSON: /api/errors/c0d46a8090b3a21d. Report an issue: GitHub.

Appendix: source

Thrown at pgproto3/ready_for_query.go:57

		TxStatus: string(src.TxStatus),
	})
}

// UnmarshalJSON implements encoding/json.Unmarshaler.
func (dst *ReadyForQuery) UnmarshalJSON(data []byte) error {
	// Ignore null, like in the main JSON package.
	if string(data) == "null" {
		return nil
	}

	var msg struct {
		TxStatus string
	}
	if err := json.Unmarshal(data, &msg); err != nil {
		return err
	}
	if len(msg.TxStatus) != 1 {
		return errors.New("invalid length for ReadyForQuery.TxStatus")
	}
	dst.TxStatus = msg.TxStatus[0]
	return nil
}

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