Run Nx Checks

SkillAI & models

Run nx format, lint, test, and build on affected or specified projects, then fix unambiguous failures

Available today. Use it from your connected AI after setup.

Connect ahel once, and every AI you use reads what you have installed.

Then ask your AI: use the Run Nx Checks skill

What this skill tells your AI

The instructions your AI receives, as published by eai-org/agent-toolkit in skills/run-nx-checks/SKILL.md and read by ahel’s review.

Run format, lint, test, build. Fix unambiguous failures. Report anything judgment-laden.

Arguments

$ARGUMENTS — optional, space-separated: [cpuCount] [projectName] [--remote-cache]. Number token → cpuCount. Non-number, non-flag token → projectName. --remote-cache flag → opt back into the remote cache by dropping the remote-cache-off prefix. Default cpuCount = cores - 4 (min 1); count cores with getconf _NPROCESSORS_ONLN (nproc is GNU-only). Default project scope = affected. Default remote-cache state = off (see Steps).

Workspace

Run nx commands from wherever nx.json lives in this repo (commonly the root; in some repos a subdirectory).

Setup (before step 1)

Keep the Nx daemon warm so the project graph is reused across targets:

NX_DAEMON=true npx nx daemon --start >/dev/null 2>&1 || true

Fix rule

  • Apply only mechanical/unambiguous fixes: lint auto-fix output, missing imports/types, obvious type errors, test expectations that mirror a clear code change.
  • Never guess on anything judgment-laden: test failure that could be a real bug vs. an outdated assertion, errors pointing at unrelated areas, pre-existing failures unrelated to recent work, anything where multiple plausible fixes exist. Running forked, you can't ask mid-run: leave such failures unfixed and carry them, with your analysis, into the final report.
  • Keep changes minimal and scoped to the failure. No drive-by refactors.
  • After fixing, re-run the check. Repeat until clean or only judgment-laden failures remain.

Affected scope — sanity-check before build/test

Affected runs can balloon. Before steps 3–4, check scope with the graph-only npx nx show projects --affected (fast, no build):

  • Sandbox .env false positives. The sandbox denies reading **/.env; nx affected hashes changed files, so an unreadable .env reads as changed and marks its project affected. Repos with .env-bearing apps (e.g. apps/*-api) thus drag those into every affected run and build them for nothing. Tell-tale: git status prints <path>/.env: Operation not permitted for exactly those projects. Fix: rerun the nx commands with the sandbox disabled so .env reads succeed, or --exclude those projects.
  • Large fan-out. If the set is large (e.g. a widely-shared lib change rippling across the workspace), don't build the world unprompted: skip steps 3–4 and report the project count and scope in the final report so the user can re-run with an explicit scope.

Steps

Scope is mandatory — never narrow it yourself. With no $projectName argument, every target runs at full scope — nx affected for lint/test/build, whole-changeset format:write. The single-project forms in the steps below apply only when the user explicitly passed $projectName. Never substitute nx run <proj>:<target>, nx <target> <changedLib>, or file-scoped format --files for the affected sweep: that skips every other affected project — exactly where a shared-lib change regresses (a dependent project whose tests import the changed lib). And never add --skip-nx-cache (see below).

Always prefix each nx command with both remote-cache-off env vars inline (NX_POWERPACK_CACHE_MODE=no-cache for Powerpack remote caches, NX_NO_CLOUD=true for Nx Cloud). They're additive and the unrecognized one is a no-op, so this is safe regardless of which remote-cache backend (if any) the repo uses.

The invariant: remote cache always off (unless the user passed --remote-cache), local cache always on — always disable, never autodetect (a passing shell-side auth check doesn't predict the in-process credential chain). Why: remote-cache-rationale.md.

If the user explicitly passed --remote-cache, drop both prefixes.

Always keep the local cache on. The env vars above disable only the remote read-through cache; the local Nx cache must stay enabled so unchanged targets are replayed instead of re-run. Do not add --skip-nx-cache (nor NX_SKIP_NX_CACHE=true) to any command — it bypasses the local cache too, making every run slower for no benefit. The only valid reason to pass --skip-nx-cache is a specific, stated need to bypass the local cache — e.g. investigating a failure you suspect is caused by a stale cache entry. In that case, scope it to the single command under investigation and say why; never use it as the default.

Write both env vars literally at the start of each nx command, exactly as in the steps below. Do not rely on export — each Bash tool call is a fresh shell, so exports do not carry across calls (true for any nx env var). Never stash the prefix in a shell variable (NX_OFF="…"; $NX_OFF npx nx … fails with "command not found": expanded variables are not parsed as assignments).

  1. Lint — NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx affected -t lint --parallel=$cpuCount --fix (or NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx lint $projectName --fix).
  2. Format — NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx format:write
  3. Test — NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx affected -t test --parallel=$cpuCount --maxWorkers=1 (or NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx test $projectName).
  4. Build — NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx affected -t build --parallel=$cpuCount (or NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx build $projectName --parallel=$cpuCount).

Apply the fix rule on any failure in steps 1–4.

--maxWorkers=1 on the test step

--parallel caps concurrent projects; each test task still fans out to ~all cores internally, so without this the cores oversubscribe (CPU pegs at 100%). --maxWorkers=1 pins each task to one worker → --parallel=$cpuCount$cpuCount cores. Both Vitest and Jest accept the flag.

  • Test step only. Forwarding --maxWorkers to lint (ESLint) or build (esbuild) fails as an unknown option.
  • Affected/run-many only, not single-project. With one project there's no project-level fan-out, so capping to one worker just serializes it — let a single project use all cores.

Same reason, --parallel is dropped from single-project lint and test (one task each — no fan-out). It stays on single-project build, because build has dependsOn: ["^build"], so building one project fans out across its whole dependency chain.

Flaky tests — retry once to classify

A failed test target may be flaky, not a real break. On a test failure, re-run that one target once: NX_POWERPACK_CACHE_MODE=no-cache NX_NO_CLOUD=true npx nx test <project>. If it then passes, or Nx prints NX detected a flaky task, it's flaky — don't try to "fix" it; record it as a flaky project:target for the report. If it fails the same way again, treat it as real under the Fix rule.

Final report (mandatory)

This skill runs in a forked context, so its final message is the only channel back to the caller. End by listing, per target (lint / format / test / build): clean, skipped (with the reason — for large fan-out, the project count and scope), or each failing project:target with its cause, plus any flaky project:target. Never report a bare "checks passed" — an unlisted failure or skipped target reads as green and the caller can't act on it.

Signals

GitHub stars
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Last commit
Sep 2026
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run-nx-checks
Source
github.com/eai-org/agent-toolkit