Postmortem

Postmortem is a decision-archaeology agent for any GitHub repo. Point it at a codebase and it reads every PR review, every rejected alternative, every architectural debate — and builds a queryable decision ledger. Ask why the code is the way it is and get a cited answer back in seconds, with every claim traceable to the exact reviewer quote that decided it. Five interaction modes ship: 1. Ask — natural-language query over the ledger; answers stream with live adaptive-thinking tokens and a self-check pass that verifies every inline citation before the answer is trusted. 2. Impact Ripple — BFS across the decision graph to trace what breaks when an assumption moves. 3. Open Decision — the full rationale + rejected alternatives for any single PR, cited. 4. Ghost Interview — pick a maintainer; Opus speaks in their register using only their own verbatim quotes, with every paraphrase openly disclosed. 5. Conflict Finder — scans the whole ledger for pairs of decisions that quietly contradict each other, ranked by severity. Shipped with six hero ledgers (hono, zustand, next.js, shadcn-ui, supabase, and the Postmortem repo itself) totaling 155 decisions, 1,876 citations, and 410 rejected alternatives — a queryable public-domain artifact. Also ships as a Claude Code MCP server so all five modes are one claude mcp add postmortem away. Live: postmortem-mauve.vercel.app · Video: youtu.be/9nbIVa_jnsU · 100% citation-grounded.