molecule-ai-workspace-template-claude-code/.gitea/workflows/mcp-plugin-delivery-contract-drift.yml

name: mcp-plugin-delivery-contract-drift

# Cross-repo drift gate for the MCP-plugin delivery contract (core#3080).
#
# The contract file contracts/mcp-plugin-delivery.contract.json is the SSOT
# shared between molecule-core (producer side) and this template repo
# (consumer side). This workflow fetches core's copy via the Gitea raw
# endpoint and byte-compares it against the template's local copy. RED if they
# differ — the two repos must stay byte-identical so the drift gate and
# runtime agree on the same contract.
#
# ENFORCEMENT GATING: standalone workflow, NOT a job in ci.yml and NOT in
# branch protection (soak-then-promote; mirrors molecule-core's
# mcp-plugin-delivery-contract-drift.yml).
#
# AUTH: uses AUTO_SYNC_TOKEN (the existing cross-repo read token). If the
# secret is absent on a trusted context the job fails closed; on untrusted
# fork PRs it soft-skips.

on:
  pull_request:
    types: [opened, synchronize, reopened]
    paths:
      - 'contracts/mcp-plugin-delivery.contract.json'
      - '.gitea/workflows/mcp-plugin-delivery-contract-drift.yml'
  push:
    branches: [main]
    paths:
      - 'contracts/mcp-plugin-delivery.contract.json'
      - '.gitea/workflows/mcp-plugin-delivery-contract-drift.yml'
  workflow_dispatch:

permissions:
  contents: read

concurrency:
  group: mcp-plugin-delivery-contract-drift-${{ github.ref }}
  cancel-in-progress: true

jobs:
  # bp-required: pending #3080 — soak-then-promote; standalone drift gate, not in branch protection yet.
  compare:
    name: Compare MCP plugin delivery contract against core canonical
    runs-on: ubuntu-latest
    timeout-minutes: 6
    steps:
      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2

      - name: Fetch core contract and byte-compare
        env:
          AUTO_SYNC_TOKEN: ${{ secrets.AUTO_SYNC_TOKEN }}
          API_ROOT: ${{ github.server_url }}/api/v1
        run: |
          set -euo pipefail
          case "${{ github.event_name }}" in
            push|schedule|workflow_dispatch)
              is_trusted=true
              ;;
            pull_request)
              if [ "${{ github.event.pull_request.head.repo.fork }}" = "false" ]; then
                is_trusted=true
              else
                is_trusted=false
              fi
              ;;
            *)
              is_trusted=true
              ;;
          esac
          if [ -z "${AUTO_SYNC_TOKEN:-}" ]; then
            if [ "$is_trusted" = "true" ]; then
              echo "::error::AUTO_SYNC_TOKEN secret missing on trusted context (${{ github.event_name }}). Live cross-repo contract-drift detection cannot run."
              exit 1
            fi
            echo "::warning::AUTO_SYNC_TOKEN secret missing on untrusted fork PR — skipping live cross-repo compare."
            exit 0
          fi
          REF="${{ github.head_ref || github.ref_name }}"
          CANON_URL="${API_ROOT}/repos/molecule-ai/molecule-core/raw/contracts/mcp-plugin-delivery.contract.json?ref=${REF}"
          set +e
          curl -fsS \
            -H "Authorization: token ${AUTO_SYNC_TOKEN}" \
            "${CANON_URL}" -o /tmp/canonical-mcp-plugin-delivery.contract.json
          curl_status=$?
          set -e
          if [ "$curl_status" -ne 0 ]; then
            if [ "$curl_status" -eq 22 ]; then
              echo "::warning::Canonical contract not found on core ref ${REF} (HTTP 404); falling back to main."
              CANON_URL="${API_ROOT}/repos/molecule-ai/molecule-core/raw/contracts/mcp-plugin-delivery.contract.json?ref=main"
              set +e
              curl -fsS \
                -H "Authorization: token ${AUTO_SYNC_TOKEN}" \
                "${CANON_URL}" -o /tmp/canonical-mcp-plugin-delivery.contract.json
              curl_status=$?
              set -e
              if [ "$curl_status" -eq 22 ]; then
                echo "::warning::Canonical contract not found on core main either (HTTP 404) — expected during bootstrap. Skipping drift check."
                exit 0
              fi
              if [ "$curl_status" -ne 0 ]; then
                echo "::error::Failed to fetch canonical contract from core main (exit $curl_status)."
                exit 1
              fi
            else
              echo "::error::Failed to fetch canonical contract (exit $curl_status)."
              exit 1
            fi
          fi
          LOCAL=contracts/mcp-plugin-delivery.contract.json
          if diff -u /tmp/canonical-mcp-plugin-delivery.contract.json "$LOCAL"; then
            echo "OK — template's contract is byte-identical to the core canonical."
          else
            echo "::error::template's mcp-plugin-delivery.contract.json DRIFTED from the core canonical."
            echo "Re-sync: copy molecule-core contracts/mcp-plugin-delivery.contract.json verbatim over $LOCAL."
            exit 1
          fi