# npm EACCES "permission denied" on the npm cache - Fix in CI

> Fix npm "EACCES: permission denied" errors on ~/.npm or node_modules in CI and Docker - caused by files owned by root or the wrong user.

Source: https://latchkey.dev/learn/node-js/npm-eacces-cache-permission  
Updated: 2026-06-25

EACCES on the npm cache or node_modules means the user running npm cannot write where it needs to. In CI and Docker this is almost always a directory owned by root from an earlier step.

## Diagnose it: reproduce the CI install locally

Install failures are usually environment drift rather than a broken lockfile: a different package-manager major, a different Node version, or a cache that is being restored from a run with different inputs. Reproduce the CI conditions before changing the lockfile, because regenerating it hides the real cause.

```Terminal
# match the runner exactly, then install from a clean slate
node --version && npm --version
rm -rf node_modules
npm ci --foreground-scripts

# if that succeeds locally but fails in CI, the difference is the cache
# or the package-manager version, not your lockfile
```

> Pin the package manager with Corepack (`"packageManager"` in package.json) so the runner and every developer machine resolve the same version. Version skew is the single most common source of lockfile errors that only appear in CI.

## Verify the fix survives a cold cache

A green run immediately after a fix often proves nothing, because it restored a cache written before the change. Force a cold install once to confirm the fix is real.

```.github/workflows/ci.yml
# temporarily bust the cache key to prove the fix on a cold runner
- uses: actions/setup-node@v4
  with:
    node-version: 22
    cache: npm
    cache-dependency-path: package-lock.json
# then bump this suffix once, run, and remove it
#   key: ${{ runner.os }}-node-${{ hashFiles('package-lock.json') }}-v2
```

## FAQ

### What causes npm EACCES "permission denied" on the npm cache?

There are 2 common causes: cache or node_modules owned by root and installing globally without permission. A previous step (often a Docker build run as root, or a sudo npm call) created ~/.npm or node_modules owned by root.

### How do I fix npm EACCES "permission denied" on the npm cache?

There are 2 fixes depending on which cause you have: fix ownership of the cache and modules and avoid root-owned state and sudo installs. Work through them in order, since the first is the most common.

### What does npm EACCES "permission denied" on the npm cache actually mean?

npm fails while writing to ~/.npm/_cacache or node_modules with "EACCES: permission denied".

### How do I stop npm EACCES "permission denied" on the npm cache happening again?

Never mix root and non-root npm runs in the same workspace. The prevention section lists 3 changes that keep it from recurring.

### Can Latchkey fix this automatically?

Yes. Latchkey runs your GitHub Actions on managed runners that detect this failure, apply the fix, and retry the job automatically - self-healing is on by default.

---

Latchkey runs CI/CD that repairs its own failures. Agent entry points: https://latchkey.dev/agent.txt, https://latchkey.dev/openapi.json, https://latchkey.dev/llms.txt