nx/docs/shared/monorepo-ci-circle-ci.md

title	description
Configuring CI Using Circle CI and Nx	Learn how to set up Circle CI for your Nx workspace using the Nx Orb to track successful builds, run affected commands, and optimize CI performance.

Configuring CI Using Circle CI and Nx

Below is an example of a Circle CI setup, building, and testing only what is affected.

version: 2.1

orbs:
  nx: nrwl/nx@1.6.2

jobs:
  main:
    docker:
      - image: cimg/node:lts-browsers
    steps:
      - checkout
      # This line enables distribution
      # The "--stop-agents-after" is optional, but allows idle agents to shut down once the "e2e-ci" targets have been requested
      # - run: npx nx-cloud start-ci-run --distribute-on="3 linux-medium-js" --stop-agents-after="e2e-ci"
      - run: npm ci

      - nx/set-shas

      - run: npx nx-cloud record -- nx format:check
      - run: npx nx affected --base=$NX_BASE --head=$NX_HEAD -t lint test build e2e-ci
workflows:
  build:
    jobs:
      - main

Get the Commit of the Last Successful Build

CircleCI can track the last successful run on the main branch and use this as a reference point for the BASE. The Nx Orb provides a convenient implementation of this functionality, which you can drop into your existing CI workflow. Specifically, for push commits, nx/set-shas populates the $NX_BASE environment variable with the commit SHA of the last successful run.

To understand why knowing the last successful build is important for the affected command, check out the in-depth explanation in Orb's docs.

Using CircleCI in a private repository

To use the Nx Orb with a private repository on your main branch, you need to grant the orb access to your CircleCI API. Create an environment variable called CIRCLE_API_TOKEN in the context of the project.

{% callout type="warning" title="Caution" %} It should be a user token, not the project token. {% /callout %}