Work in rat-stack mode

AGENTS.md is law. VISION.md sets the intent, reliability goals, scope²⁰, package-removal test, and shrinking debt. Use this skill to choose playbooks under those rules.¶

A capability is one named action with shared value definitions and a server-side implementation. A cartridge³⁶ is a package for one job with its implementation and required infrastructure.¶

Non-negotiables

Start a todo list with reading the principles index below.¶
Open every leaf that bears on a decision. Report which rules changed which choices.¶
Name the data shape, authoritative store, copies calculated from it, and writer before writing code.¶
Reuse stores when their facts and operation guarantees fit. Reporting does not justify gating unrelated execution.¶
Measure before setting a timeout, rate cap, batch size, or concurrency limit. Put the baseline first; requested values remain hypotheses.¶

Principles index

Leaves live in the repo; read them from a checkout.¶

Product and UX¶

skills/rat-stack-mode/principles/judge-through-the-person.md: changing an interface or user-visible behavior.¶
skills/rat-stack-mode/principles/keep-boundary-words-honest.md: naming failures, outcomes, and public claims.¶

Architecture¶

skills/rat-stack-mode/principles/one-contract-many-projections.md: adding actions for agents or browser clients.¶
skills/rat-stack-mode/principles/keep-the-stack-floor.md: choosing runtime patterns, infrastructure, and validation.¶
skills/rat-stack-mode/principles/prove-move-delete.md: replacing an internal API or implementation.¶
skills/rat-stack-mode/principles/use-real-provider-guarantees.md: choosing an adapter or testing its behavior.¶
skills/rat-stack-mode/principles/gates-guard-invariants.md: adding a gate or approval check.¶
skills/rat-stack-mode/principles/keep-unknown-distinct.md: handling crashes, refusal, or missing results.¶

Data and truth¶

skills/rat-stack-mode/principles/name-the-system-of-record.md: adding stores, caches, aggregates, or nightly reports.¶
skills/rat-stack-mode/principles/store-source-facts.md: capturing observations or interpreting missing fields.¶
skills/rat-stack-mode/principles/keep-execution-receipts.md: recording runs or claiming an operation succeeded.¶
skills/rat-stack-mode/principles/scope-private-data.md: handling identities, credentials, logs, or analytics.¶
skills/rat-stack-mode/principles/version-content-artifacts.md: writing public content or quoting code.¶
skills/rat-stack-mode/principles/no-dual-writes.md: copying a fact across stores or maintaining a read model.¶
skills/rat-stack-mode/principles/validate-before-durable-write.md: recording rows, events, or snapshots.¶
skills/rat-stack-mode/principles/bound-every-read.md: listing, querying, exporting, or rebuilding data.¶
skills/rat-stack-mode/principles/one-writer-per-partition.md: updating shared mutable state.¶
skills/rat-stack-mode/principles/make-operations-idempotent.md: replaying commands or recovering after crashes.¶
skills/rat-stack-mode/principles/subtract-before-you-add.md: sequencing new work or removing unused interfaces.¶

Verification¶

skills/rat-stack-mode/principles/check-the-actual-artifact.md: finishing work or reviewing another agent’s result.¶
skills/rat-stack-mode/principles/prove-the-recipient-path.md: changing runtime wiring or deployed interfaces.¶
skills/rat-stack-mode/principles/tests-detect-broken-behavior.md: adding tests or judging their coverage.¶
skills/rat-stack-mode/principles/find-the-cause-first.md: fixing failures or slow runs.¶
skills/rat-stack-mode/principles/rebuild-what-you-run.md: running or debugging an artifact someone else built.¶
skills/rat-stack-mode/principles/measure-real-limits.md: setting budgets or diagnosing contention.¶

Agents¶

skills/rat-stack-mode/principles/look-it-up-first.md: entering unfamiliar code or deciding whether to ask.¶
skills/rat-stack-mode/principles/ask-one-material-question.md: reaching a decision that needs owner sign-off.¶
skills/rat-stack-mode/principles/separate-writers-verify-readers.md: dividing work or accepting delegated results.¶
skills/rat-stack-mode/principles/encode-lessons-in-structure.md: correcting a repeated bad pattern.¶

Prose and visual¶

skills/rat-stack-mode/principles/use-plain-language.md: writing docs, skills, or system pages.¶
skills/rat-stack-mode/principles/design-serves-function.md: changing layout, focus, or visual emphasis.¶
skills/rat-stack-mode/principles/make-review-views-complete.md: rendering evidence for people and agents.¶

Cost and speed¶

skills/rat-stack-mode/principles/optimise-the-whole-loop.md: changing builds, tests, generation, or feedback time.¶

Playbooks

Match every applicable playbook; a capability with new persistence matches capability and store playbooks. Open each match and copy its steps into the todo list before task-specific steps. For unnumbered skills, copy action lists; keep skipped steps as skip: <reason>. Finish with each matching playbook’s report requirements.¶

New action: add-a-capability.¶
States, retries, or cancellation: add-a-lifecycle-machine.¶
New persistence: add-a-store.¶
Public prose or skill pages: write-a-wiki-page.¶
Package or interface choices: keep-or-cut.¶
Stateful design, replacement, or read-model design: uncomplect.¶
Pins, recurring bad patterns, or repository maintenance: gardener.¶
Peer research or shared dependency updates: find-peers.¶
Cloud resources or unfamiliar deployment wiring: learn-alchemy.¶
Unfamiliar stack integration: learn-rat-stack.¶
Crashes, flaky tests, wrong output, or slow runs: investigate-a-failure.¶

write-a-query, add-a-read-model, and explore-limits are planned. Use applicable leaves and existing playbooks; identify uncovered steps explicitly.¶

Autonomy and child-project slots

Follow AGENTS.md’s Boundaries and sign-off for autonomy. In a child project, name production write authority, deploy gates, and the model roster here and in AGENTS.md.¶

Router and adapted principles credit pstack by Lauren Tan⁹ (MIT, skills/rat-stack-mode/LICENSE-pstack).¶

Last changed 2026-10-10 in 0d43dfc. Source on GitHub. Change log.