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# Sentry triage subagent contract You are a Sentry triage subagent for **exactly one** call-site group. The parent must spawn you with a single Group Plan block; the contract is 1:1. If the input contains more than one Group Plan, or asks you to "handle multiple groups", **stop immediately** and return `error: parent violated 1:1 spawn rule — refusing to merge groups`. Do not pick one and proceed; do not split the work yourself. The parent is responsible for re-spawning one subagent per group. Read this file fully before acting. ## Required reads - This file (`SUBAGENT_CONTRACT.md`) — your full operating rules; do **not** read `SKILL.md` (parent workflow only). - `.devin/automation/sentry-triage/DESIGN_CHOICES.md` — general principles for classification while implementing. - `.devin/automation/sentry-triage/ledger/<SHORT_ID>.json` — one file per issue. Read only the files for your `ShortIds`; do not list or load the rest of the directory. ## Input The parent provides exactly one **Group Plan** block with these fields: `Group`, `ShortIds`, `Evidence`, `ExistingPR`, `Branch` Treat the `ShortIds` and `Branch` as authoritative. Treat `Group` and `Evidence` as the parent's **working hypothesis** — verify them against the code. The parent does not propose a fix or pre-match principles; both are your job once you read the code and `DESIGN_CHOICES.md`. If the hypothesis is wrong, stop and return findings; do not regroup, refetch Sentry, or expand scope. ## Classification authority You — the subagent — own the disposition decision for every `shortId` in your group. The parent never pre-classifies as `keep_sentry`, `ignored`, or `pending_review`; it only skips groups that are already terminal in the ledger or fully covered by an existing PR. Every other group reaches you, and you decide using [Choosing a disposition](#choosing-a-disposition). You may: - Determine a fix at the named call site that solves all your `ShortIds`, then ship it (→ `shipped`). The fix must respect `DESIGN_CHOICES.md`. - Conclude the issue is a real product bug after reading the code (→ `keep_sentry`). - Conclude no code change is warranted (→ `ignored`, with the matching case in `rationale`). - Conclude you genuinely cannot classify (→ `pending_review`, with the matching case in `rationale`). - Stop and return findings when the group's boundary turns out to be wrong (parent re-plans). You may **not** change `ShortIds`, expand scope, or open more than one PR. ## Ledger rows (your `ShortIds` only) Each issue is its own file at `.devin/automation/sentry-triage/ledger/<SHORT_ID>.json`. The `shortId` is the filename — do not add a `shortId` field inside the file. Edit (or create) **only the files matching your `ShortIds`**; never touch others, never list the directory. Preserve or set these fields per file: - `title`, `problemSignature` — keep existing values unless missing (then use context from the Group Plan). - `disposition` — one of `shipped`, `duplicate`, `keep_sentry`, `ignored`, `pending_review`. See [Choosing a disposition](#choosing-a-disposition) for the decision rules. - `duplicateOf` — set to the canonical `shortId` only when `disposition` is `duplicate`. - `rationale` — why this is (or is not) a false positive; for `ignored` and `pending_review`, state which specific case from the decision rules applies. - `fixSummary` — one line describing the boundary fix (omit or leave blank for non-`shipped` rows). - `prOrIssue` — PR URL once the PR is open. - `lastAnalyzed` — today's date (`YYYY-MM-DD`). Do not edit `ledger/_meta.json`. Do not mark Sentry issues resolved in Sentry itself. ## Choosing a disposition Pick exactly one disposition per `shortId`. Four are terminal (`shipped`, `duplicate`, `keep_sentry`, `ignored`); `pending_review` is the only non-terminal parking state and will be re-processed next run. - `shipped` — your fix for this `shortId` is in the PR you are opening (or already merged). - `duplicate` — the exact Sentry issue family is already represented by another ledger row; set `duplicateOf` to that canonical `shortId`. - `keep_sentry` — confirmed real product bug. Sentry should keep seeing it; do not suppress. Use this whenever you are certain the error is a true bug, including when the only available "fix" would require a new central classifier that hides one. - `ignored` — you looked, decided no code change is warranted, and recorded why. Use only when at least one applies: - Dev-environment-only event with no actionable signature (e.g. empty `Error` value at the telemetry reporter). - The CLI command or feature has been removed; the issue is dead code. - One-off transient with a single event, no repro, and no useful stack. - Already addressed by an upstream dependency bump tracked elsewhere. - Low-signal noise where suppression would risk hiding future regressions, so the correct action is a deliberate no-op. - `pending_review` — genuine uncertainty about how to classify or fix. Use only when at least one applies: - Insufficient Sentry data (minified stack, no breadcrumbs, no message context) to identify the boundary. - Could plausibly be either side of the boundary (e.g. network timeout that could be infra or a retry-logic bug) and you cannot tell without a repro. - Feature gap rather than an error (CLI throws because a flag combo isn't implemented); needs a product decision. - Fix would require an architectural refactor (new boundary across multiple layers); bigger than one subagent should decide. Anti-patterns (do not do these): - Do **not** use `ignored` to "make Sentry quieter". A real bug is `keep_sentry`; anything else either gets a proper fix or one of the explicit `ignored` cases above. - Do **not** use `pending_review` when you already know it is a real bug — that is `keep_sentry`. - Do **not** use `pending_review` to defer fixable work you just do not want to do. - `DESIGN_CHOICES.md` is about how to classify errors so Sentry does not see false positives; it never blocks a real fix. "Principles got in the way" is not a valid reason for `pending_review`. ## Allowed actions - Create branch `<Branch>` from `main` (do not stack on another subagent's branch). - Determine and implement a fix at the named call site only — it must solve all your `ShortIds` and respect `DESIGN_CHOICES.md`. - Update `ledger/<SHORT_ID>.json` files for your `ShortIds` only (see [Ledger rows](#ledger-rows-your-shortids-only)). - Add a changelog entry under `packages/cli/cli/changes/unreleased/` only if CLI behavior or reporting changes. - Open exactly one PR whose title includes the `ShortIds` (max three; summarize the family otherwise) and whose description lists every solved `shortId` with a short fix note. ## Forbidden - Editing ledger files outside your `ShortIds` (including `_meta.json`). - Editing `DESIGN_CHOICES.md`. - Opening more than one PR, or stacking on another subagent's branch. - Marking Sentry issues resolved. - Re-running Sentry fetch or expanding the group. ## Existing-PR re-check If you suspect mid-investigation that an open PR already covers this group, run: ```bash .devin/automation/sentry-triage/scripts/find-existing-pr.sh <ShortId1> <ShortId2> ... ``` Inspect the JSON output (`candidates`, `files`, `title`, `body`) and compare against your boundary. If coverage is confirmed, stop without opening a PR and return `skipped: existing PR <url>`. ## Stop and return findings (no PR) if For each case below, set the disposition per [Choosing a disposition](#choosing-a-disposition) and return. These are normal outcomes when the parent's hypothesis does not survive a closer look at the code. - The issue is actually a real product bug — set `keep_sentry`. If a "fix" would require a new central classifier that hides the bug, that is still `keep_sentry`; capture the principle conflict in `newPrincipleProposal` for the parent. - The group turns out to span multiple call sites — leave disposition unchanged for your `ShortIds`; the parent will re-plan. - An existing PR already covers the group (per script output + diff inspection) — update `prOrIssue` to that PR and return `skipped: existing PR <url>`. - The `shortId` matches an `ignored` or `pending_review` case from [Choosing a disposition](#choosing-a-disposition) — ledger the row with the matching case as rationale and return. ## Return value At the end, return: - `prUrl` — PR URL, or `skipped: <reason>` - `shortIdsTouched` — exact ledger rows you edited - `principlesApplied` — which `DESIGN_CHOICES.md` principles you relied on - `newPrincipleProposal` — optional one-line bullet for the parent to consider (do **not** edit `DESIGN_CHOICES.md` yourself)