TNT/docs/MESSAGE_LOG.md

Message Log

This document defines the persisted chat-history format used by TNT 1.x.

Format: messages.log v1

Each record is one UTF-8 line:

RFC3339_UTC|username|content\n

Example:

2026-05-27T12:34:56Z|alice|hello

Rules:

• Timestamp is strict UTC RFC3339: YYYY-MM-DDTHH:MM:SSZ.
• The separator is literal |.
• A valid record has exactly three fields and exactly two separators.
• username and content must be non-empty valid UTF-8.
• username must fit MAX_USERNAME_LEN; content must fit MAX_MESSAGE_LEN.
• Every complete record ends with \n.

The file has no header. The version is defined by this record contract so existing append-only logs remain readable.

Write Behavior

message_save() sanitizes fields before appending:

• |, \n, and \r in usernames become _.
• |, \n, and \r in content become spaces.
• Timestamps are written in UTC.

Private messages are not written to messages.log.

Replay And Search

Replay and search use the same strict parser. TNT skips records that are:

• malformed or missing fields
• invalid UTF-8
• too long
• outside the accepted timestamp window
• terminated without a trailing newline
• written with extra separators

Skipping a bad record is intentional recovery behavior. A truncated final line is treated as a partial append and ignored rather than replayed.

Compatibility

The v1 record format is stable for TNT 1.x. Future incompatible storage changes must document downgrade behavior in release notes and provide an operator-visible migration or export path.