feat(mcp-registry): publish custom tools server to mcp-registry (#1834)

## Description

This PR adds a new [github
action](https://github.com/modelcontextprotocol/registry/blob/main/docs/guides/publishing/github-actions.md)
workflow to publish Toolbox to mcp-registry. This only publishes the
custom tools server, prebuilt-tools will be added in a different PR once
this is successful.

The workflow will be triggered on (1) any new release tag (v*) or (2)
manually via GHA workflow dispatch. It will grab the version number from
the `server.json` file.

The server.json file will be updated by release please during every
release.


Note: server that are published in the mcp-registry is immutable. In
cases where we successfully published a server and would like to make an
update, we will have to update the `version` field in
`.registry/server.json` and manually publish another server with a new
version.

## PR Checklist

> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:

- [x] Make sure you reviewed

[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [x] Make sure to open an issue as a

[bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose)
  before writing your code! That way we can discuss the change, evaluate
  designs, and agree on the general idea
- [x] Ensure the tests and linter pass
- [x] Code coverage does not decrease (if any source code was changed)
- [x] Appropriate docs were updated (if necessary)
- [x] Make sure to add `!` if this involve a breaking change

🛠️ Fixes #1659

Issue at mcp-registry to support GAR
([#427](modelcontextprotocol/registry#427))

Author: Yuan325

.github/release-please.yml

@@ -38,4 +38,14 @@ extraFiles: [
     "docs/en/how-to/connect-ide/neo4j_mcp.md",
     "docs/en/how-to/connect-ide/sqlite_mcp.md",
     "gemini-extension.json",
-]
+    {
+        "type": "json",
+        "path": ".registry/server.json",
+        "jsonpath": "$.version"
+    },
+    {
+        "type": "json",
+        "path": ".registry/server.json",
+        "jsonpath": "$.packages[0].identifier"
+    },
+]

.github/workflows/publish-mcp.yml

@@ -0,0 +1,73 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+name: Publish to MCP Registry
+
+on:
+  push:
+    tags: ["v*"]  # Triggers on version tags like v1.0.0
+  # allow manual triggering with no inputs required
+  workflow_dispatch:
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write  # Required for OIDC authentication
+      contents: read
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v5
+
+      - name: Wait for image in Artifact Registry
+        shell: bash
+        run: |
+          MAX_ATTEMPTS=10
+          VERSION=$(jq -r '.version' server.json)
+          REGISTRY_URL="https://us-central1-docker.pkg.dev/v2/database-toolbox/toolbox/toolbox/manifests/${VERSION}"
+
+          # initially sleep time to wait for the version release
+          sleep 3m
+
+          for i in $(seq 1 ${MAX_ATTEMPTS}); do
+            echo "Attempt $i: Checking for image ${REGISTRY_URL}..."
+            # Use curl to check the manifest header
+            # Using -I to fetch headers only, -s silent, -f fail fast on errors.
+            curl -Isf "${REGISTRY_URL}" > /dev/null
+
+            if [ $? -eq 0 ]; then
+              echo "✅ Image found! Continuing to next steps."
+              exit 0
+            else
+              echo "❌ Image not found (likely 404 error) on attempt $i."
+              if [ $i -lt ${MAX_ATTEMPTS} ]; then
+                echo "Sleeping for 5 minutes before next attempt..."
+                sleep 2m
+              else
+                echo "Maximum attempts reached. Image not found."
+                exit 1
+              fi
+            fi
+          done
+
+      - name: Install MCP Publisher
+        run: |
+          curl -L "https://github.com/modelcontextprotocol/registry/releases/latest/download/mcp-publisher_$(uname -s | tr '[:upper:]' '[:lower:]')_$(uname -m | sed 's/x86_64/amd64/;s/aarch64/arm64/').tar.gz" | tar xz mcp-publisher
+
+      - name: Login to MCP Registry
+        run: ./mcp-publisher login github-oidc
+
+      - name: Publish to MCP Registry
+        run: ./mcp-publisher publish --file=.registry/server.json

.registry/server.json

@@ -0,0 +1,71 @@
+{
+  "$schema": "https://static.modelcontextprotocol.io/schemas/2025-10-17/server.schema.json",
+  "name": "io.github.googleapis/genai-toolbox",
+  "description": "MCP Toolbox for Databases enables your agent to connect to your database.",
+  "title": "MCP Toolbox",
+  "websiteUrl": "https://github.com/googleapis/genai-toolbox",
+  "icons": [
+    {
+      "src": "https://github.com/googleapis/genai-toolbox/blob/main/.hugo/assets/icons/logo.svg",
+      "mimeType": "image/svg+xml"
+    }
+  ],
+  "repository": {
+    "url": "https://github.com/googleapis/genai-toolbox",
+    "source": "github"
+  },
+  "version": "0.19.1",
+  "packages": [
+    {
+      "registryType": "oci",
+      "registryBaseUrl": "https://artifactregistry.googleapis.com",
+      "identifier": "us-central1-docker.pkg.dev/database-toolbox/toolbox/toolbox:0.19.1",
+      "transport": {
+        "type": "streamable-http",
+        "url": "http://{host}:{port}/mcp"
+      },
+      "runtimeArguments": [
+        {
+            "type": "named",
+            "name": "--tools-file",
+            "description": "File path specifying the tool configuration.",
+            "default": "tools.yaml",
+            "isRequired": false
+        },
+        {
+            "type": "named",
+            "name": "--address",
+            "description": "Address of the interface the server will listen on.",
+            "value": "{host}",
+            "variables": {
+                "host": {
+                    "description": "ip address",
+                    "isRequired": true,
+                    "default": "127.0.0.1"
+                }
+            }
+        },
+        {
+            "type": "named",
+            "name": "--port",
+            "description": "Port the server will listen on.",
+            "value": "{port}",
+            "variables": {
+                "port": {
+                    "description": "port",
+                    "isRequired": true,
+                    "default": "5000"
+                }
+            }
+        },
+        {
+            "type": "named",
+            "name": "--log-level",
+            "description": "Specify the minimum level logged.",
+            "default": "info",
+            "choices": ["debug", "info", "warn", "error"]
+        }
+      ]
+    }
+  ]
+}