Talos session management — append-only session logging with tree-branching support.

Sessions are stored as append-only files, organized by working directory. New sessions use the compact text .tlog format by default; existing .jsonl files are read transparently for backward compatibility. Each line in a session file represents a [SessionEntry] with fields for id, parent_id, timestamp, role, content, and optional metadata.

Directory Layout

~/.talos/sessions/
  <project>/
    <uuid>.jsonl

Branching Model

Each session supports multiple branches. A branch is a linear sequence of entries rooted at a specific entry. The fork method creates a new branch from any existing entry, enabling tree-structured conversations.

Crash Safety

JSONL is append-only. If a crash occurs, only the last line may be corrupted, which can be detected and skipped during reads.

Backward Compatibility

Entries without id or parent_id fields (from older JSONL files) are treated as part of a single linear branch. They are assigned synthetic IDs on load.