/ripwire-handoff

name: ripwire-handoff
description: >
  Brief someone ELSE on a subsystem — 'hand this area off' to a successor, teammate or fresh session:
  purpose, the 2-3 entry points with bodies, the design docs that say WHY, hotspot/bus-factor risk — a
  compact pasteable brief, not a wall of source. Understanding it yourself → orient.
allowed-tools: Bash, Read

Handoff with ripwire

> Nearest neighbours: > • You need to UNDERSTAND the subsystem yourself first (not brief someone else) → **ripwire-orient**. > • You need ONE symbol's full contract, not a whole-subsystem brief → **ripwire-navigate** (`--expand`). > • The recipient needs an architecture/layering read specifically → **ripwire-layers**.

Trigger: you're handing a subsystem to another agent or developer and want to give them a fast, accurate brief — not a wall of source code.

`<dir>` = repo root. `SUBSYSTEM` = the area in plain words (e.g. "ingest pipeline", "graph ranking", "MCP server loop").

1. **Task-relevant symbols** — `ripwire <dir> --for="SUBSYSTEM" --signatures-only` Output: `<sigs>` ranked by relevance. The top 10 are the symbols the recipient most needs to know. Note their file paths, complexity (`cx=`), and reuse count (`in=`). (`--top-k` does not narrow `--for` — the binary says so on stderr and serves the whole list; `--signatures-only` skips the inline bodies, since step 2 expands the ones you pick.)

2. **Expand the key symbols** — `ripwire <dir> --expand=SYM1,SYM2,SYM3 --legend=compact` (Pick the top 3 by rank from step 1.) Output: full bodies + callee signatures (no ranked map rides along; step 1 was your orient). This is the actual contract — paste it into the handoff verbatim rather than paraphrasing. **Bodies are redacted by default** — high-confidence credentials (API keys, tokens, connection strings) are masked before you see them, so pasting this straight into a handoff doc is safe as-is; pass `--no-redact` only if you deliberately need the verbatim secret (e.g. auditing the credential-handling code itself).

3. **Design rationale** — `ripwire <dir> --recall="SUBSYSTEM"` Output: most relevant markdown docs (planning/design notes, READMEs) in full. Read and summarize the key decisions — why this design, not another. That's what the recipient most needs and least gets from reading code. Also check `ripwire <dir> --notes --legend=compact` for this subsystem's symbols/files — any gotcha a prior agent already pinned (`<note d="date">…</note>`) surfaces automatically on the symbols step 1/2 emit; fold it into the brief instead of letting the recipient rediscover it. Before you hand off, `--note-add="SYM_or_path: text"` any trap you found yourself that isn't already written down — the cheapest thing you can leave the successor. If the same symbol has collected several notes across handoffs, that's a signal to graduate it out of prose entirely, into a `--quality-ack` reason or a standing `--arch` deny rule.

4. **Maintenance risk, scoped to the subsystem** — point `--hotspots` straight at the subsystem instead of filtering the whole-repo list: `ripwire <subdir> --hotspots` (verified: subdir scoping works, same as `--dead-code=DIR`). If the subsystem isn't a clean subdirectory, keep the repo root and `--exclude` the rest (repeatable flag) to fence the scan to just the area you're briefing on. Also worth a look: `ripwire <dir> --hotspots --legend=compact` (whole-repo, no scoping) to see whether any subsystem file also lands in the *global* top-10 — a file can be locally worst-in-subsystem and still unremarkable repo-wide, or vice versa; that distinction matters to the recipient. Tell them: "this file is gnarly — high churn, high complexity — be careful and run tests after any change here."

Calibration — what's fact vs framing here

• Steps 1–3 are direct reads (ranked signatures, full bodies, doc text) — trustworthy as far as the

underlying call graph goes (name-based edges; a symbol with high `amb=` in `--expand`'s `<calls>` block means some of ITS calls were ambiguous — don't present those as certain in the brief, flag them). `--recall` returns doc *text*, not a verified fact — summarize what the docs claim, not what's provably still true; a stale design doc will still get picked up.

• Step 4 (hotspots) is `churn × cognitive complexity` — a maintenance-pain *signal*, not a defect count.

Frame it to the recipient as "developers keep touching this, tread carefully," not "this file has bugs."

Stamp the commit you measured at — `at="<sha>[+dirty]"`

A brief is read hours or days later, against a HEAD that has moved. **Every number you quote must carry the commit it was measured at**, or the recipient cannot tell a stale finding from a live one.

Several repo-reading verbs now do this for you: the header carries `at="<sha>"`, and `at="<sha>+dirty"` when the working tree had uncommitted changes at measure time. Real output from this repo:

<quality-delta baseline="git-HEAD" regressions="0" … gating="0" at="f0a45e43d">

**`+dirty` is the important half.** A stamp ending in `+dirty` means the numbers describe a working tree that exists on exactly one machine and is not recoverable from the sha — it is *not* reproducible by the recipient. Either commit first and re-measure, or say so explicitly in the brief.

**What actually carries a stamp today (verified by running each verb — do not assume it is universal):**

| verb | stamp | |---|---| | `--quality-delta` · `--pr-context` · `--test-gate` · `--map-diff` · `--doc-drift` | `at="<sha>[+dirty]"` | | `--stray-content` | `head="<sha>"` — different attribute name, and **no `+dirty` suffix** | | `--situ` · `--cochange` · `--owners` | **none** — record the sha yourself (`git rev-parse --short HEAD`) |

Two traps: the attribute is `head=` rather than `at=` on `--stray-content`, so a script grepping only for `at=` silently gets nothing; and in `--doc-drift` the name `at=` is