Knowledge > Runbooks > Agent Ops > How to Update the Decision Log
How to Update the Decision Log
Document significant decisions, course changes, and key learnings in the shared decision journal so future agents and the founder have institutional memory.
Why This Matters
ChurchWiseAI is a solo-founder operation with multiple concurrent Claude agents. Without a decision log, the same mistakes get made repeatedly and the same decisions get relitigated. The log is how context survives across sessions.
The File
C:\dev\DECISION_LOG.md — append-only. Never edit previous entries.
When to Update
Append an entry when you:
| Trigger | Example |
|---|---|
| Architecture change | Switched from Railway to LiveKit Cloud for voice |
| Technology choice | Chose isomorphic-dompurify over jsdom for sanitization (then found it fails — documented that too) |
| Feature added or removed | Added trial_will_end webhook handler to all 3 codebases |
| Problem encountered + course change | Discovered chatbot was using 261K church count; fixed filter |
| Surprising system behavior | Cartesia SDK 0.2.4 has a known crash with the wrapper |
| Founder expressed a clear preference | John said never to suggest stopping a session |
| Security or data incident | Rotated service role key after suspected exposure |
| Pricing or policy decision | Decided voice plans will not have annual billing due to per-minute cost variability |
Do NOT add entries for:
- Routine bug fixes with no architectural significance
- Minor UI changes
- Updating a knowledge doc (that's tracked by git)
Format
- YYYY-MM-DD: What happened and WHY. Keep to 1-2 lines max.
Rules:
- Use absolute dates — never "today", "yesterday", "last Thursday"
- Write what happened AND the reasoning — "WHY" is the part that decays without documentation
- Keep it brief — 1-2 lines max per entry
- Use past tense: "Switched", "Found", "Decided", "Rotated"
How to Append
Read the file first to understand the current format and find the end, then append:
# Check the current end of the file
tail -20 /c/dev/DECISION_LOG.md
# Then append (using the Edit tool is preferred — never overwrite the file)
Use the Edit tool to append to the bottom of the file. Never use a write tool that overwrites the whole file — you would destroy previous entries.
Example entry:
- 2026-03-25: Switched chatbot primary LLM from gpt-4o-mini to Claude Haiku 4.5 — better theological reasoning and consistent with the brand narrative of being Anthropic-native.
Entries Written By Agents
Agents should sign their entries when the context is useful:
- 2026-03-25: [Agent: knowledge-expansion] Added 29 runbook files to knowledge/runbooks/ — covers technical-ops, agent-ops, and business-ops.
This is optional but helpful when the log shows a burst of related entries from a multi-file task.
Do Not Edit Previous Entries
The decision log is append-only. If a previous decision turned out to be wrong, add a new entry explaining the course correction:
# DO THIS:
- 2026-03-25: Reverted the jsdom sanitizer added on 2026-03-10 — discovered it crashes in Vercel serverless (see feedback_dompurify_serverless.md). Now using blocklist sanitizer instead.
# NOT THIS: (editing the old entry)
Verification
- The entry appears at the bottom of
DECISION_LOG.md - The date is correct (today's date: 2026-03-25)
- The entry explains WHAT happened AND WHY
- Previous entries are unchanged
See Also
- Starting a New Task Runbook
- Knowledge Maintenance Runbook
- Founder Actions — for founder-required items (separate from the decision log)
- Institutional knowledge summary:
C:\dev\INSTITUTIONAL_KNOWLEDGE.md