feat: Add support for skills

.github/workflows/skills-validate-fallback.yml

@@ -0,0 +1,37 @@
+# Copyright 2026 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: lint
+
+on:
+  push:
+    paths-ignore:
+      - "skills/**"
+  pull_request:
+    paths-ignore:
+      - "skills/**"
+  pull_request_target:
+    types: [labeled]
+    paths-ignore:
+      - "skills/**"
+  workflow_dispatch:
+
+jobs:
+  skills-validate:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Skip Skill Validation
+        run: |
+          echo "No changes detected in 'skills/' directory. Skipping validation."
+          echo "This job ensures the required 'skills-validate' status check passes."

.github/workflows/skills-validate.yml

@@ -0,0 +1,56 @@
+# Copyright 2026 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: Validate Skills
+
+on:
+  push:
+    paths:
+      - "skills/**"
+  pull_request:
+    paths:
+      - "skills/**"
+  pull_request_target:
+    types: [labeled]
+    paths:
+      - "skills/**"
+
+jobs:
+  skills-validate:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+
+      - name: Set up Python
+        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
+        with:
+          python-version: "3.11"
+
+      - name: Install skills-ref
+        run: |
+          pip install "git+https://github.com/agentskills/agentskills.git#subdirectory=skills-ref"
+
+      - name: Validate Skills
+        run: |
+          failed=0
+          for skill_dir in skills/*/; do
+            if [ -d "$skill_dir" ]; then
+              echo "Validating $skill_dir..."
+              if ! skills-ref validate "$skill_dir"; then
+                echo "Validation failed for $skill_dir"
+                failed=1
+              fi
+            fi
+          done
+          exit $failed

gemini-extension.json

@@ -2,16 +2,6 @@
   "name": "bigquery-data-analytics",
   "version": "0.1.7",
   "description": "Connect, query, and generate data insights for BigQuery datasets and data.",
-  "mcpServers": {
-    "bigquery_data_analytics": {
-      "command": "${extensionPath}${/}toolbox",
-      "args": [
-        "--tools-file",
-        "${extensionPath}${/}tools.yaml",
-        "--stdio"
-      ]
-    }
-  },
   "contextFileName": "BIGQUERY.md",
   "settings": [
     {
@@ -25,4 +15,4 @@
       "envVar": "BIGQUERY_LOCATION"
     }
   ]
-}
+}

skills/bigquery-analytics/SKILL.md

@@ -0,0 +1,101 @@
+---
+name: bigquery-analytics
+description: Use these skills when you need to handle advanced data intelligence and predictive tasks. Use when a user asks "why" data changed or needs future projections. Provides automated insight generation and time-series forecasting.
+---
+
+## Usage
+
+All scripts can be executed using Node.js. Replace `<param_name>` and `<param_value>` with actual values.
+
+**Bash:**
+`node <skill_dir>/scripts/<script_name>.js '{"<param_name>": "<param_value>"}'`
+
+**PowerShell:**
+`node <skill_dir>/scripts/<script_name>.js '{\"<param_name>\": \"<param_value>\"}'`
+
+Note: The scripts automatically load the environment variables from various .env files. Do not ask the user to set vars unless skill executions fails due to env var absence.
+
+
+## Scripts
+
+
+### analyze_contribution
+
+Use this skill to analyze the contribution about changes to key metrics in multi-dimensional data.
+
+#### Parameters
+
+| Name | Type | Description | Required | Default |
+| :--- | :--- | :--- | :--- | :--- |
+| input_data | string | The data that contain the test and control data to analyze. Can be a fully qualified BigQuery table ID or a SQL query. | Yes |  |
+| contribution_metric | string | The name of the column that contains the metric to analyze.
+		Provides the expression to use to calculate the metric you are analyzing.
+		To calculate a summable metric, the expression must be in the form SUM(metric_column_name),
+		where metric_column_name is a numeric data type.
+
+		To calculate a summable ratio metric, the expression must be in the form
+		SUM(numerator_metric_column_name)/SUM(denominator_metric_column_name),
+		where numerator_metric_column_name and denominator_metric_column_name are numeric data types.
+
+		To calculate a summable by category metric, the expression must be in the form
+		SUM(metric_sum_column_name)/COUNT(DISTINCT categorical_column_name). The summed column must be a numeric data type.
+		The categorical column must have type BOOL, DATE, DATETIME, TIME, TIMESTAMP, STRING, or INT64. | Yes |  |
+| is_test_col | string | The name of the column that identifies whether a row is in the test or control group. | Yes |  |
+| dimension_id_cols | array | An array of column names that uniquely identify each dimension. | No |  |
+| top_k_insights_by_apriori_support | integer | The number of top insights to return, ranked by apriori support. | No | `30` |
+| pruning_method | string | The method to use for pruning redundant insights. Can be 'NO_PRUNING' or 'PRUNE_REDUNDANT_INSIGHTS'. | No | `PRUNE_REDUNDANT_INSIGHTS` |
+
+
+---
+
+### ask_data_insights
+
+Use this skill to perform data analysis, get insights,
+or answer complex questions about the contents of specific
+BigQuery tables.
+
+
+#### Parameters
+
+| Name | Type | Description | Required | Default |
+| :--- | :--- | :--- | :--- | :--- |
+| user_query_with_context | string | The user's question, potentially including conversation history and system instructions for context. | Yes |  |
+| table_references | string | A JSON string of a list of BigQuery tables to use as context. Each object in the list must contain 'projectId', 'datasetId', and 'tableId'. Example: '[{"projectId": "my-gcp-project", "datasetId": "my_dataset", "tableId": "my_table"}]'. | Yes |  |
+
+
+---
+
+### forecast
+
+Use this skill to forecast time series data.
+
+#### Parameters
+
+| Name | Type | Description | Required | Default |
+| :--- | :--- | :--- | :--- | :--- |
+| history_data | string | The table id or the query of the history time series data. | Yes |  |
+| timestamp_col | string | The name of the time series timestamp column. | Yes |  |
+| data_col | string | The name of the time series data column. | Yes |  |
+| id_cols | array | An array of the time series id column names. | No | `[]` |
+| horizon | integer | The number of forecasting steps. | No | `10` |
+
+
+---
+
+### search_catalog
+
+Use this skill to find tables, views, models, routines or connections.
+
+#### Parameters
+
+| Name | Type | Description | Required | Default |
+| :--- | :--- | :--- | :--- | :--- |
+| prompt | string | Prompt representing search intention. Do not rewrite the prompt. | Yes |  |
+| datasetIds | array | Array of dataset IDs. | No | `[]` |
+| projectIds | array | Array of project IDs. | No | `[]` |
+| types | array | Array of data types to filter by. | No | `[]` |
+| pageSize | integer | Number of results in the search page. | No | `5` |
+
+
+---
+

skills/bigquery-analytics/scripts/analyze_contribution.js

@@ -0,0 +1,107 @@
+#!/usr/bin/env node
+
+// Copyright 2026 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.
+
+const { spawn, execSync } = require('child_process');
+const path = require('path');
+const fs = require('fs');
+const os = require('os');
+
+const toolName = "analyze_contribution";
+const configArgs = ["--prebuilt", "bigquery"];
+
+const OPTIONAL_VARS_TO_OMIT_IF_EMPTY = [
+    'BIGQUERY_LOCATION',
+    'BIGQUERY_USE_CLIENT_OAUTH',
+    'BIGQUERY_SCOPES',
+    'BIGQUERY_MAX_QUERY_RESULT_ROWS',
+    'BIGQUERY_IMPERSONATE_SERVICE_ACCOUNT',
+];
+
+
+function mergeEnvVars(env) {
+	if (process.env.GEMINI_CLI === '1') {
+		const envPath = path.resolve(__dirname, '../../../.env');
+		if (fs.existsSync(envPath)) {
+			const envContent = fs.readFileSync(envPath, 'utf-8');
+			envContent.split('\n').forEach(line => {
+				const trimmed = line.trim();
+				if (trimmed && !trimmed.startsWith('#')) {
+					const splitIdx = trimmed.indexOf('=');
+					if (splitIdx !== -1) {
+						const key = trimmed.slice(0, splitIdx).trim();
+						let value = trimmed.slice(splitIdx + 1).trim();
+						value = value.replace(/(^['"]|['"]$)/g, '');
+						if (env[key] === undefined) {
+							env[key] = value;
+						}
+					}
+				}
+			});
+		}
+	} else if (process.env.CLAUDECODE === '1') {
+		const prefix = 'CLAUDE_PLUGIN_OPTION_';
+		for (const key in process.env) {
+			if (key.startsWith(prefix)) {
+				env[key.substring(prefix.length)] = process.env[key];
+			}
+		}
+	}
+}
+
+function prepareEnvironment() {
+	let env = { ...process.env };
+	let userAgent = "skills";
+	if (process.env.GEMINI_CLI === '1') {
+		userAgent = "skills-geminicli";
+	} else if (process.env.CLAUDECODE === '1') {
+		userAgent = "skills-claudecode";
+	} else if (process.env.CODEX_CI === '1') {
+        userAgent = "skills-codex";
+    }
+	mergeEnvVars(env);
+
+	OPTIONAL_VARS_TO_OMIT_IF_EMPTY.forEach(varName => {
+		if (env[varName] === '') {
+			delete env[varName];
+		}
+	});
+
+
+	return { env, userAgent };
+}
+
+function main() {
+    const { env, userAgent } = prepareEnvironment();
+    const args = process.argv.slice(2);
+
+		const command = os.platform() === 'win32' ? 'npx.cmd' : 'npx';
+		const processedArgs = os.platform() === 'win32' ? args.map(arg => arg.includes('"') ? '"' + arg.replace(/"/g, '""') + '"' : arg) : args;
+		const npxArgs = ["--yes", "@toolbox-sdk/server@1.1.0", "--log-level", "error", ...configArgs, "invoke", toolName, "--user-agent-metadata", userAgent, ...processedArgs];
+
+		const child = spawn(command, npxArgs, { shell: os.platform() === 'win32', stdio: 'inherit', env });
+
+
+    child.on('close', (code) => {
+        process.exit(code);
+    });
+
+    child.on('error', (err) => {
+        console.error("Error executing toolbox:", err);
+        process.exit(1);
+    });
+}
+
+main();