engineering-practices

Use when designing or changing a CLI, API, control plane, or automation surface that an agent must inspect, operate, and verify safely.

Use when working with atlas.hcl, Atlas CLI commands, schema HCL/SQL files, or migration planning and reviews, including Atlas v1.1 security, data, and exporter capabilities.

Use when creating, reviewing, or updating a BRIEF.md (the quality law for a surface), defining what "good"/shippable means, or setting up a verified autonomous loop.

Use when working with Canton Network participants, DAML smart contracts, Splice applications, or debugging LF version and package ID issues.

Use when writing or changing code in any language — the craft law (types, assertions, bounds, errors, naming, comments, scope) and the system properties (deterministic, hermetic, idempotent, isolated, observable, evented, contextual) with the floor that proves each one. Not for prose, docs-only, or config-only changes.

Use when reading, writing, or piping secrets with fnox — authoring fnox.toml, resolving a secret that comes back empty, diagnosing the caching daemon, or running a program with secrets in its environment.

Use when invoking the GitHub CLI for structured output, pagination, repository targeting, search, or API fallbacks.

Use when creating commits, managing branches, opening PRs, or rewriting history. Not for non-git implementation tasks or repo-specific release policy decisions.

Use when reading or writing Go files (.go, go.mod).

Use when working with Nix flakes, overlays, shell.nix, or flake.nix files.

Use when reading, writing, or piping secrets with the 1Password CLI (op) — resolving op:// references, choosing an account, finding an item, or handling an op auth failure.

Use when working with OrbStack Linux VMs, Docker on macOS, orbctl commands, or orb machine lifecycle.

Use when working with Electrobun desktop apps, physical iOS devices through pymobiledevice3, or AXe automation of iOS Simulator.

Use when writing or modifying Playwright tests (.spec.ts, .test.ts with @playwright/test imports).

Use when reading or writing Python files (.py, pyproject.toml, requirements.txt).

Use when reading or writing React components (.tsx, .jsx files with React imports).

Use when reading or writing Rust files (.rs, Cargo.toml).

Use when creating, reviewing, updating, interviewing for, completing, or finding gaps in SPEC.md files, or entering the ADF SPEC gate.

Use when working with Tamagui projects (tamagui.config.ts, @tamagui imports).

Use when designing tests, writing test cases, planning test strategy, building or judging a verifier, or attributing test failures. Covers verifier design, unit/integration/e2e layering, and verifier discipline (flake attribution, base-commit repro, broken-verifier handling).

Use when reading or writing TypeScript or JavaScript files (.ts, .tsx, .js, tsconfig.json).

Use when fetching documentation, articles, or reference pages from HTTP or HTTPS URLs as clean Markdown.

Use when reading or writing Zig files (.zig, build.zig, build.zig.zon).