Synthesize Ledgers

You are tasked with synthesizing session event files from parallel agents into a unified current.md ledger.

Background

When multiple agents work in parallel (worktrees, branches), each writes session events to thoughts/shared/handoffs/events/. This skill synthesizes those events into a single unified ledger using CRDT-like merge semantics to avoid conflicts.

Process

1. Discover event files:

   ls -la thoughts/shared/handoffs/events/
   

2. Preview what will be merged:

   • Read each event file to understand contents
   • Show the user:
     • Number of events found
     • Agents/branches represented
     • Timestamp range
     • Key sections that will be merged

3. Explain merge semantics: | Section | Strategy | |---------|----------| | Now | Latest timestamp wins (LWW) | | This Session | Union of all items, dedupe by hash | | Decisions | Merge by key, latest timestamp per key | | Checkpoints | Concatenate, sort by time, dedupe by phase | | Open Questions | Union of all, exact match dedupe |

4. Run synthesis:

   cd ~/.claude/hooks && node dist/synthesize-ledgers.mjs "$(pwd)/thoughts/shared/handoffs/events" "$(pwd)/thoughts/shared/handoffs/current.md"
   

5. Show results:

   • Display the generated current.md
   • Highlight any conflicts resolved (e.g., different "Now" values)
   • Report event count and branches combined

6. Offer next steps:

   • Archive source events? (move to archive/YYYY-MM-DD/)
   • Commit the synthesized ledger?
   • Clean up old events (retention policy)?

YAML Event File Format

Each event file has YAML frontmatter:

---
ts: 2026-01-11T10:00:00Z
agent: abc12345
branch: feat/feature-a
reason: clear
---

now: Current focus description

this_session:
- Completed task 1
- Completed task 2

decisions:
  key: "value with rationale"

checkpoints:
- phase: 1
  status: completed
  updated: 2026-01-11T09:00:00Z

Output Format

The synthesized current.md includes:

• Unified ledger sections
• Metadata footer showing source events and branches

When to Use

• After parallel work completes (merge branches)
• On session start (automatic via hook)
• Before creating a PR (ensure ledger is up-to-date)
• When resolving ledger conflicts manually

Triggers

• /synthesize-ledgers
• "synthesize ledgers"
• "merge ledgers"
• "combine events"