Claude Session Stores

Observed Claude formats:

• ~/.claude/projects/<encoded-cwd>/*.jsonl: Claude Code project sessions (main sessions; filename = session ID).
• ~/.claude/transcripts/ses_*.jsonl: compact transcript exports with simple type, timestamp, content, and tool fields.
• ~/.claude/pre-compact-session-histories/*.jsonl: pre-compaction histories with sessionId, cwd, message, uuid, parentUuid, and tool result metadata.

For project files, sessionId, cwd, version, gitBranch, and message.model are usually embedded in each line. For transcript exports, the filename may be the only stable session ID.

When reconstructing a Claude session, preserve the event order from the JSONL file and distinguish assistant text, thinking, tool use, tool result, and progress events.

Subagent transcripts (per-session directory)

Each main session may own a sibling directory named after the session ID:

projects/<encoded-cwd>/<session-id>/
├── subagents/
│   ├── agent-<agentId>.jsonl        # Task-tool subagent transcript
│   ├── agent-<agentId>.meta.json    # {"agentType", "description", "toolUseId"}
│   └── workflows/wf_<id>/
│       ├── agent-<agentId>.jsonl    # Workflow-spawned agent transcripts
│       ├── agent-<agentId>.meta.json
│       └── journal.jsonl            # workflow orchestration journal — NOT a session
├── workflows/wf_<id>.json           # workflow run metadata
└── tool-results/*.txt               # persisted oversized tool outputs

Subagent JSONL lines look like main-session lines but carry isSidechain: true, agentId, promptId, and sessionId pointing at the PARENT session — never treat a subagent file's sessionId as its own identity; use the agentId (also in the filename) and take the parent from the directory path. The first line's user message is the delegated task prompt; agent-*.meta.json gives the human-readable description and agentType.

The finder models these as platform: claude sessions with id = <agentId>, parent_id = <session-id>, agent = agentType. get <main-session-id> lists them under subagents; get <agentId> returns the child transcript events. Older Claude Code versions inlined sidechains in the main JSONL (isSidechain: true lines) instead of separate files.