version: "1.0.1" name: update-topic-ledger description: Maintains substacker shared-context/topic-ledger.md as an append-and-update index of all topics in the corpus. Each topic row tracks seed/draft/published counts, last-touched date, top-3 seed ids by density, and a hot/warm/cold temperature indicator. Use after any seed is created, promoted to draft, published, or killed. Trigger keywords — ledger, topic index, update index, topic ledger, hot/cold topics.

Update Topic Ledger

Table of Contents

• Ledger row schema
• Workflow
• Temperature rules
• Worked example
• Guardrails

Related skills: Called by ingest-inbox-item step 8 for each topic on a new seed. Called by any status-changing agent on promote/publish/kill events.

Ledger row schema

Each topic gets a block in shared-context/topic-ledger.md:

## {topic-slug}
-seeds: N
-drafts: N
-published: N
-last_touched: YYYY-MM-DD
-temperature: hot | warm | cold
-top_seeds:
  -{seed-id} (density={N})
  -{seed-id} (density={N})
  -{seed-id} (density={N})

Workflow

Update ledger for one topic + event:
- [ ] Step 1: Read the ledger; find or create the row for {topic}
- [ ] Step 2: Update counts based on event (ADDED | PROMOTED | PUBLISHED | KILLED)
- [ ] Step 3: Update last_touched = today
- [ ] Step 4: Recompute temperature
- [ ] Step 5: Recompute top_seeds = top 3 by density across all statuses except dead
- [ ] Step 6: Write the updated row back

Step 2: Event → count change

Temperature rules

• hot: last_touched within last 14 days.
• warm: last_touched 14–60 days ago.
• cold: last_touched >60 days ago.

Temperature is computed, not stored — recompute on every update.

Worked example

Event: {topic: regularization, event: ADDED, seed_id: 2026-04-21-dropout-as-ensemble-thinned-networks, density: 7}

Existing row:

## regularization
- seeds: 3
- drafts: 1
- published: 1
- last_touched: 2026-03-11
- temperature: warm
- top_seeds:
  - 2026-03-11-l2-as-gaussian-prior (density=6)
  - 2025-11-14-noise-as-regularization (density=5)
  - 2025-09-22-weight-decay-intuition (density=4)

Updated row:

## regularization
- seeds: 4
- drafts: 1
- published: 1
- last_touched: 2026-04-21
- temperature: hot
- top_seeds:
  - 2026-04-21-dropout-as-ensemble-thinned-networks (density=7)
  - 2026-03-11-l2-as-gaussian-prior (density=6)
  - 2025-11-14-noise-as-regularization (density=5)

Guardrails

1. Never remove a topic row even if count drops to 0. Mark temperature: cold to preserve historical signal.
2. Never promote a pending tag to canonical silently. The writer reviews #pending-tags; this skill only updates rows for tags already in canonical.
3. Temperature is recomputed every time, not stored. If today differs from last_touched, the temperature reflects today.
4. top_seeds excludes dead seeds. A seed promoted from seed → draft retains its density score.
5. Never re-order rows alphabetically in bulk — preserve whatever order the ledger is in (last-touched DESC is the current convention).
6. Single-threaded. The Librarian serializes calls so the ledger doesn't race.

Quick reference

• Input: {topic: str, event: str, seed_id: str, density: int}.
• Output: updated topic-ledger.md.
• Side effect: single file write with diff-style edit.