Publish to the MCP Registry from the tag

.github/workflows/ci.yml

@@ -100,3 +100,16 @@ jobs:
 
       - name: Show what a release would contain
         run: ls -l dist/*.tar.gz dist/checksums.txt
+
+      # server.json is only exercised during a tag release, which is a bad
+      # place to discover it is malformed: the image is already pushed and the
+      # GitHub release already cut by then. Validating on every PR moves that
+      # failure to where it is cheap to fix.
+      #
+      # This checks shape, not version numbers -- the release workflow rewrites
+      # `version` and the image tag from the tag before publishing, so the
+      # values committed here are last release's and are expected to lag.
+      - name: Validate server.json
+        run: |
+          curl -fsSL "https://github.com/modelcontextprotocol/registry/releases/latest/download/mcp-publisher_linux_amd64.tar.gz" | tar xz mcp-publisher
+          ./mcp-publisher validate

.github/workflows/release.yml

@@ -117,3 +117,50 @@ jobs:
             dist/checksums.txt
           retention-days: 7
           if-no-files-found: error
+
+  # Listing the release in the MCP Registry, which is metadata only: it records
+  # that this version exists and which image holds it. Kept as its own job that
+  # needs `release`, because the entry names an image tag -- publishing before
+  # goreleaser has pushed it would advertise something nobody can pull.
+  mcp-registry:
+    name: mcp registry
+    needs: release
+    # Tag pushes only. A workflow_dispatch run has a branch in GITHUB_REF_NAME
+    # rather than a version, so there is no release for an entry to describe,
+    # and a dry run pushes no image at all.
+    if: startsWith(github.ref, 'refs/tags/v')
+    runs-on: ubuntu-latest
+    permissions:
+      # The whole authentication story. `login github-oidc` trades this
+      # workflow's identity for a short-lived registry token, so there is no
+      # registry secret in this repository to store, rotate or leak, and no
+      # device-code flow to sit through by hand.
+      id-token: write
+      contents: read
+    steps:
+      - name: Check out
+        uses: actions/checkout@v4
+
+      - name: Install mcp-publisher
+        run: |
+          curl -fsSL "https://github.com/modelcontextprotocol/registry/releases/latest/download/mcp-publisher_$(uname -s | tr '[:upper:]' '[:lower:]')_$(uname -m | sed 's/x86_64/amd64/;s/aarch64/arm64/').tar.gz" | tar xz mcp-publisher
+
+      # The committed server.json carries the version of the *previous*
+      # release, so by the time this runs it is stale by exactly one tag. The
+      # tag is the truth. Both fields are rewritten from it, and they have to
+      # move together: `version` is what the registry lists, `identifier` is
+      # the image that version actually lives in.
+      - name: Stamp the tag into server.json
+        run: |
+          version="${GITHUB_REF_NAME#v}"
+          jq --arg v "$version" \
+             --arg img "ghcr.io/${{ github.repository }}:" \
+            '.version = $v | .packages[0].identifier = $img + $v' \
+            server.json > server.tmp && mv server.tmp server.json
+          cat server.json
+
+      - name: Authenticate to the MCP Registry
+        run: ./mcp-publisher login github-oidc
+
+      - name: Publish
+        run: ./mcp-publisher publish

README.md

@@ -440,6 +440,15 @@ The image is also what backs the [MCP Registry](https://registry.modelcontextpro
 listing; [`server.json`](server.json) is that entry, and its `name` has to match
 the `io.modelcontextprotocol.server.name` label baked into the image.
 
+Publishing that entry is automatic. Tagging a release builds and pushes the
+image, and then a second job rewrites `version` and the image tag in
+`server.json` from the git tag and publishes to the registry, authenticating
+with the workflow's own OIDC identity rather than a stored token.
+
+**So the `version` committed in `server.json` is last release's, and lags by
+one tag on purpose.** The tag is the source of truth; the file is a template
+that CI stamps. Bumping it by hand achieves nothing.
+
 ### As a Claude Code skill
 
 The repo ships a skill and plugin package under [`skills/`](skills/), which