Pi Session Tracker

Read pi's session JSONL logs, produce a structured quantified report, and optionally loop for periodic updates.

Finding sessions

Sessions live at ~/.pi/agent/sessions/. Folder names are mangled paths (e.g., --Users-vm-code-myproject--/).

# Find recently active sessions
for d in ~/.pi/agent/sessions/*/; do
  f=$(ls -t "$d" 2>/dev/null | head -1)
  if [ -n "$f" ]; then
    mod=$(stat -f '%m' "$d$f")
    age=$(( ($(date +%s) - mod) / 60 ))
    [ $age -lt 60 ] && echo "($age min ago): $d$f"
  fi
done

Session JSONL format

Each line is JSON. Key message structure:

• type: "session" — first line: cwd, timestamp
• type: "model_change" — provider, modelId
• type: "message" — message.role + message.content[] array of blocks:
  • {type: "text"} — visible output. User messages with <skill prefix have user text after </skill>
  • {type: "thinking"} — agent reasoning in .thinking
  • {type: "toolCall"} — .name + .arguments (bash .command, file .path, experiment params)
  • {type: "toolResult"} — tool output in nested .content[].text

Reading and reporting

Read the JSONL directly with the Read tool. For large files, paginate with offset/limit. Categorize what you find:

• bash commands — count total, note hf models ls/info (model search), hf datasets ls/info/sql (dataset search/SQL), hf download/upload, hf repos/buckets create, git commit
• file operations — write, edit, read tool calls with paths
• experiments — init_experiment, run_experiment (command), log_experiment (metric, status, description)
• errors — crashed commands, failed experiments, tracebacks
• agent thinking — key decisions, what it noticed or missed

Report format

Write a markdown file with:

1. Session metadata — project path, model, timestamp
2. User prompts — exact text
3. Chronological phases — group actions into logical phases (recon, data inspection, env setup, file creation, experiment loop). Per-phase tables with action counts and details.
4. Experiment log — numbered: command, config, result, metric value, status, commit hash
5. Cumulative totals — table counting every action type
6. Observations — mistakes, missed signals, interesting decisions
7. Update log — timestamped entries for each report refresh

Quantify everything. "23 SQL queries" not "several". "test_loss 2.988 → 2.495 (-16.5%)" not "loss improved".

Loop mode

When called during an active session or when asked to "keep tracking":

1. Write initial report, note the session file line count
2. Set a 15-minute background timer (sleep 900 with run_in_background)
3. On timer: read only new lines (use offset = previous line count), append update section to report
4. Repeat until user interrupts or no new lines appear