Review code changes for security

name: Codex Security review

on:
  pull_request:

jobs:
  security-review:
    if: github.event.pull_request.head.repo.full_name == github.repository
    runs-on: ubuntu-latest
    permissions:
      contents: read
    steps:
      - uses: actions/checkout@v5
        with:
          ref: ${{ github.event.pull_request.head.sha }}
          fetch-depth: 0
          persist-credentials: false

      - name: Install Codex Security
        env:
          CODEX_HOME: ${{ runner.temp }}/codex-home
        run: |
          npm install --global @openai/codex
          codex plugin add codex-security@openai-curated

      - name: Review code changes
        env:
          CODEX_SECURITY_API_KEY: ${{ secrets.CODEX_SECURITY_API_KEY }}
          CODEX_HOME: ${{ runner.temp }}/codex-home
          TMPDIR: ${{ runner.temp }}/codex-security
          BASE_SHA: ${{ github.event.pull_request.base.sha }}
          HEAD_REVISION: ${{ github.event.pull_request.head.sha }}
        run: |
          BASE_REVISION="$(git merge-base "$BASE_SHA" "$HEAD_REVISION")"
          CODEX_API_KEY="$CODEX_SECURITY_API_KEY" codex exec \
            --sandbox workspace-write \
            "Use \$codex-security:security-diff-scan to review changes from $BASE_REVISION to $HEAD_REVISION for security regressions. Do not modify the checkout."

      - uses: actions/upload-artifact@v4
        if: always()
        with:
          name: codex-security-review
          path: ${{ runner.temp }}/codex-security/codex-security-scans

Create a masked CODEX_SECURITY_API_KEY CI/CD variable and review the scan artifacts privately before sharing findings.

codex-security-review:
  rules:
    - if: '$CI_PIPELINE_SOURCE == "merge_request_event" && $CI_MERGE_REQUEST_SOURCE_PROJECT_ID == $CI_PROJECT_ID'
  variables:
    GIT_DEPTH: "0"
  script:
    - |
      codex_security_api_key="$CODEX_SECURITY_API_KEY"
      unset CODEX_SECURITY_API_KEY
      export CODEX_HOME="/tmp/codex-home-$CI_JOB_ID"
      export TMPDIR="/tmp/codex-security-$CI_JOB_ID"
      export BASE_REVISION="$CI_MERGE_REQUEST_DIFF_BASE_SHA"
      export HEAD_REVISION="${CI_MERGE_REQUEST_SOURCE_BRANCH_SHA:-$CI_COMMIT_SHA}"
      npm install --global @openai/codex
      codex plugin add codex-security@openai-curated
      CODEX_API_KEY="$codex_security_api_key" codex exec \
        --sandbox workspace-write \
        "Use \$codex-security:security-diff-scan to review changes from $BASE_REVISION to $HEAD_REVISION for security regressions. Do not modify the checkout."
  after_script:
    - |
      unset CODEX_SECURITY_API_KEY
      scan_root="/tmp/codex-security-$CI_JOB_ID/codex-security-scans"
      if [ -d "$scan_root" ]; then
        tar -czf codex-security-artifacts.tar.gz -C "$scan_root" .
      fi
  artifacts:
    when: always
    paths:
      - codex-security-artifacts.tar.gz

trigger: none

pool:
  vmImage: ubuntu-latest

steps:
  - checkout: self
    fetchDepth: 0

  - bash: |
      set -euo pipefail
      export CODEX_HOME="$AGENT_TEMPDIRECTORY/codex-home"
      npm install --global @openai/codex
      codex plugin add codex-security@openai-curated
    displayName: Install Codex Security

  - bash: |
      set -euo pipefail
      export CODEX_HOME="$AGENT_TEMPDIRECTORY/codex-home"
      export TMPDIR="$AGENT_TEMPDIRECTORY/codex-security"
      export HEAD_REVISION="$SYSTEM_PULLREQUEST_SOURCECOMMITID"
      export BASE_REVISION="$(git merge-base HEAD^1 "$HEAD_REVISION")"
      CODEX_API_KEY="$CODEX_SECURITY_API_KEY" codex exec \
        --sandbox workspace-write \
        "Use \$codex-security:security-diff-scan to review changes from $BASE_REVISION to $HEAD_REVISION for security regressions. Do not modify the checkout."
    displayName: Review code changes
    condition: and(succeeded(), ne(variables['System.PullRequest.IsFork'], 'True'))
    env:
      CODEX_SECURITY_API_KEY: $(CODEX_SECURITY_API_KEY)

  - publish: $(Agent.TempDirectory)/codex-security/codex-security-scans
    artifact: codex-security-review
    condition: always()

For Azure Repos, configure a Build validation branch policy to run the pipeline on pull requests.

pipeline {
  agent { label 'linux' }
  stages {
    stage('Codex Security review') {
      when {
        allOf {
          changeRequest()
          expression { !env.CHANGE_FORK?.trim() }
        }
      }
      steps {
        sh '''#!/usr/bin/env bash
          set -euo pipefail
          export CODEX_HOME="/tmp/codex-home-$BUILD_TAG"
          export TMPDIR="/tmp/codex-security-$BUILD_TAG"
          mkdir -p "$TMPDIR"
          git fetch --no-tags origin "$CHANGE_TARGET"
          target="$(git rev-parse FETCH_HEAD)"
          git fetch --no-tags origin "$CHANGE_BRANCH"
          git rev-parse FETCH_HEAD > "$TMPDIR/head"
          git merge-base "$target" "$(cat "$TMPDIR/head")" > "$TMPDIR/base"
          npm install --global @openai/codex
          codex plugin add codex-security@openai-curated
        '''
        withCredentials([string(credentialsId: 'codex-security-api-key', variable: 'CODEX_SECURITY_API_KEY')]) {
          sh '''#!/usr/bin/env bash
            set +x
            set -euo pipefail
            export CODEX_HOME="/tmp/codex-home-$BUILD_TAG"
            export TMPDIR="/tmp/codex-security-$BUILD_TAG"
            export HEAD_REVISION="$(cat "$TMPDIR/head")"
            export BASE_REVISION="$(cat "$TMPDIR/base")"
            CODEX_API_KEY="$CODEX_SECURITY_API_KEY" codex exec \
              --sandbox workspace-write \
              "Use \$codex-security:security-diff-scan to review changes from $BASE_REVISION to $HEAD_REVISION for security regressions. Do not modify the checkout."
          '''
        }
      }
      post {
        always {
          sh '''#!/usr/bin/env bash
            set -euo pipefail
            scan_root="/tmp/codex-security-$BUILD_TAG/codex-security-scans"
            if [ -d "$scan_root" ]; then
              tar -czf codex-security-artifacts.tar.gz -C "$scan_root" .
            fi
          '''
          archiveArtifacts artifacts: 'codex-security-artifacts.tar.gz', allowEmptyArchive: true
        }
      }
    }
  }
}