Change Journal

Query the project's change journal for cross-session and cross-workspace awareness.

Journal Location

Journal data lives in ~/.claude/projects/<slug>/journal/ (outside the project tree):

• JOURNAL.md — Human-readable rolling summary (quick overview)
• entries.jsonl — Structured entries (one JSON per line, for filtering)
• summary.txt — Compact summary (auto-injected into subagents)

The $CHANGE_JOURNAL_DIR environment variable points to this directory (exported by the SessionStart hook).

Quick Start

Read the journal summary for a quick overview:

cat "$CHANGE_JOURNAL_DIR/JOURNAL.md"

Query Patterns

Filter by workspace

jq 'select(.workspace == "agent-1")' "$CHANGE_JOURNAL_DIR/entries.jsonl"

Filter by file path

jq 'select(.file_path | contains("auth"))' "$CHANGE_JOURNAL_DIR/entries.jsonl"

Filter by time range

jq 'select(.timestamp >= "2026-02-12")' "$CHANGE_JOURNAL_DIR/entries.jsonl"

Most frequently changed files

grep file_change "$CHANGE_JOURNAL_DIR/entries.jsonl" | jq -r .file_path | sort | uniq -c | sort -rn

Full diff for a specific session

jq -r 'select(.session_id == "SESSION_ID" and .type == "session_summary") | .diff_preview' "$CHANGE_JOURNAL_DIR/entries.jsonl"

What are other agents/workspaces working on?

jq 'select(.type == "session_summary")' "$CHANGE_JOURNAL_DIR/entries.jsonl" | jq -r '"\(.workspace): \(.intent)"'

Changes from a specific workspace

jq 'select(.workspace == "WORKSPACE" and .type == "file_change")' "$CHANGE_JOURNAL_DIR/entries.jsonl"

Entry Types

file_change

Recorded per Edit/Write operation. Fields: timestamp, session_id, workspace, vcs, file_path, action (edit/write), change_preview, lines_added, lines_removed.

session_summary

One per session (on stop). Fields: timestamp, session_id, workspace, vcs, intent (extracted from user's first message), file_count, files_changed, diff_stat, diff_preview.

subagent_work

Tracks subagent completions. Fields: timestamp, session_id, agent_id, agent_type, workspace.