nautechsystems/nautilus_trader · error

Error parsing payload kind: {e}

Error message

Error parsing payload kind: {e}

What it means

The optional `payload_kind` header (PAYLOAD_KIND_FIELD) must decode as valid UTF-8 so it can be compared against PAYLOAD_KIND_TYPED. This error is thrown when the bytes are not valid UTF-8. (A well-formed but unrecognized kind value raises the separate 'Unknown payload kind' error instead.)

Source

Thrown at crates/infrastructure/src/redis/msgbus.rs:851

                    String::from_utf8(bytes.clone())
                        .map_err(|e| anyhow::anyhow!("Error parsing topic: {e}"))?,
                );
            }
            b"type" => {
                let redis::Value::BulkString(bytes) = &pair[1] else {
                    anyhow::bail!("Invalid type format: {stream_msg:?}");
                };
                type_name = Some(
                    String::from_utf8(bytes.clone())
                        .map_err(|e| anyhow::anyhow!("Error parsing type: {e}"))?,
                );
            }
            key if key == PAYLOAD_KIND_FIELD.as_bytes() => {
                let redis::Value::BulkString(bytes) = &pair[1] else {
                    anyhow::bail!("Invalid payload kind format: {stream_msg:?}");
                };
                let value = std::str::from_utf8(bytes)
                    .map_err(|e| anyhow::anyhow!("Error parsing payload kind: {e}"))?;
                anyhow::ensure!(
                    value == PAYLOAD_KIND_TYPED,
                    "Unknown payload kind '{value}'"
                );
                typed_payload = true;
            }
            b"encoding" => {
                let redis::Value::BulkString(bytes) = &pair[1] else {
                    anyhow::bail!("Invalid encoding format: {stream_msg:?}");
                };
                let value = std::str::from_utf8(bytes)
                    .map_err(|e| anyhow::anyhow!("Error parsing encoding: {e}"))?;
                encoding = value
                    .parse()
                    .map_err(|e| anyhow::anyhow!("Error parsing encoding: {e}"))?;
            }
            b"payload" => {
                let redis::Value::BulkString(bytes) = &pair[1] else {

View on GitHub (pinned to 18893faf8b)

Solutions

  1. Inspect the entry's payload_kind bytes and fix the producer to write the literal UTF-8 marker used by PAYLOAD_KIND_TYPED.
  2. Align producer/consumer versions so both use the same payload-kind convention.
  3. Delete the corrupt entry and republish.
Defensive patterns

Strategy: try-catch

Validate before calling

if std::str::from_utf8(&kind_bytes).is_err() {
    return Err("payload_kind header is not UTF-8".into());
}

Try / catch

match decode_bus_message(entry) {
    Ok(m) => handle(m),
    Err(e) if e.to_string().contains("Error parsing payload kind") => log::warn!("corrupt payload_kind, skipping"),
    Err(e) => return Err(e),
}

Prevention

When it happens

Trigger: decode_bus_message (via stream_messages) reads a `payload_kind` BulkString whose bytes fail std::str::from_utf8.

Common situations: A producer wrote raw/binary data into the payload_kind header; custom or older publishers emitting non-UTF-8 kind markers; stream corruption.

Related errors

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/7800ee2c29fcb30e. Report an issue: GitHub.