> ## Documentation Index > Fetch the complete documentation index at: https://withcoral.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Query databases > Connect your database to Coral through MCP Toolbox for Databases. [MCP Toolbox for Databases](https://mcp-toolbox.dev/documentation/introduction/) exposes database tools through MCP. Add Toolbox as a Coral provider so your agents can query your database. You need a running Coral instance and a workspace that you own. Supported databases and query engines include: * **Relational:** [PostgreSQL](https://mcp-toolbox.dev/integrations/postgres/), [MySQL](https://mcp-toolbox.dev/integrations/mysql/), [MariaDB](https://mcp-toolbox.dev/integrations/mariadb/), [SQL Server](https://mcp-toolbox.dev/integrations/mssql/), [SQLite](https://mcp-toolbox.dev/integrations/sqlite/), [Oracle](https://mcp-toolbox.dev/integrations/oracle/), and [Firebird](https://mcp-toolbox.dev/integrations/firebird/). * **Distributed SQL:** [CockroachDB](https://mcp-toolbox.dev/integrations/cockroachdb/), [OceanBase](https://mcp-toolbox.dev/integrations/oceanbase/), [TiDB](https://mcp-toolbox.dev/integrations/tidb/), and [YugabyteDB](https://mcp-toolbox.dev/integrations/yuagbytedb/). * **NoSQL:** [MongoDB](https://mcp-toolbox.dev/integrations/mongodb/), [Couchbase](https://mcp-toolbox.dev/integrations/couchbase/), [Cassandra](https://mcp-toolbox.dev/integrations/cassandra/), [ScyllaDB](https://mcp-toolbox.dev/integrations/scylladb/), [Redis](https://mcp-toolbox.dev/integrations/redis/), and [Valkey](https://mcp-toolbox.dev/integrations/valkey/). * **Graph:** [Neo4j](https://mcp-toolbox.dev/integrations/neo4j/), [Dgraph](https://mcp-toolbox.dev/integrations/dgraph/), [FalkorDB](https://mcp-toolbox.dev/integrations/falkordb/), and [ArcadeDB](https://mcp-toolbox.dev/integrations/arcadedb/). * **Analytics and search:** [ClickHouse](https://mcp-toolbox.dev/integrations/clickhouse/), [Snowflake](https://mcp-toolbox.dev/integrations/snowflake/), [SingleStore](https://mcp-toolbox.dev/integrations/singlestore/), [Elasticsearch](https://mcp-toolbox.dev/integrations/elasticsearch/), [Trino](https://mcp-toolbox.dev/integrations/trino/), and [MindsDB](https://mcp-toolbox.dev/integrations/mindsdb/). * **Google Cloud:** [AlloyDB](https://mcp-toolbox.dev/integrations/alloydb/), Cloud SQL for [PostgreSQL](https://mcp-toolbox.dev/integrations/cloud-sql-pg/), [MySQL](https://mcp-toolbox.dev/integrations/cloud-sql-mysql/), and [SQL Server](https://mcp-toolbox.dev/integrations/cloud-sql-mssql/), [BigQuery](https://mcp-toolbox.dev/integrations/bigquery/), [Bigtable](https://mcp-toolbox.dev/integrations/bigtable/), [Firestore](https://mcp-toolbox.dev/integrations/firestore/), and [Spanner](https://mcp-toolbox.dev/integrations/spanner/). See [Toolbox's integration catalog](https://mcp-toolbox.dev/integrations/) for the full list and available tools. ## Run Toolbox 1. [Install Toolbox](https://mcp-toolbox.dev/documentation/introduction/) on a host that can reach your database. 2. For trusted development, choose a [prebuilt configuration](https://mcp-toolbox.dev/documentation/configuration/prebuilt-configs/) for your database. 3. Set the connection and credential environment variables listed in that configuration's documentation. For example, after setting the [PostgreSQL environment variables](https://mcp-toolbox.dev/integrations/postgres/prebuilt-configs/postgresql/), start a local server: ```shellscript theme={"theme":{"light":"github-light","dark":"github-dark"}} toolbox --prebuilt postgres --address 127.0.0.1 --port 5000 ``` This loads Toolbox's built-in PostgreSQL tools without a `tools.yaml` file. For custom tools or databases without a prebuilt configuration, [define `tools.yaml`](https://mcp-toolbox.dev/documentation/configuration/) and use `--config tools.yaml` instead. Coral recommends exposing only an `execute_sql` tool, using a database account with the minimum permissions required for your agent's work. See [Toolbox's security guidance](https://mcp-toolbox.dev/documentation/configuration/prebuilt-configs/#security-for-dynamic-sql-tools). Its MCP endpoint is `http://127.0.0.1:5000/mcp`. To expose a specific toolset, use `/mcp/` instead. For containers or a remote server, use an address reachable from the Coral runtime. See [Deploy with Coral](#deploy-with-coral) below. Configure database credentials in Toolbox. If Toolbox requires client authentication, follow its [authentication documentation](https://mcp-toolbox.dev/documentation/configuration/authentication/) and configure the corresponding credentials in Coral. ## Add Toolbox to Coral 1. Open your workspace and select **Providers**, then **Add provider**. 2. Select **Add custom** and enter the Toolbox endpoint in **MCP server URL**. 3. Select **Connect**. 4. Set the display name and namespace, then choose the sign-in method that matches your Toolbox configuration. 5. Select **Next**. Authenticate if prompted, then review the discovered operations with **Expand all**. 6. Select **Next**, choose the account setting, and select **Add provider**. For a server without authentication, select **No authentication** and confirm **No account needed**. Review the provider's [operation policy](/docs/guides/concepts#operation-policy) to choose which operations can run or require approval. The database account's permissions still apply to every query. ## Query through Coral [Connect your MCP client to Coral](/docs/getting-started/quickstart#connect-an-mcp-client). Give your client the Coral workspace URL, and keep the Toolbox URL in the provider configuration. Ask your agent to query the database using the provider's namespace. ## Deploy with Coral Without Toolbox client authentication, allow only Coral to reach its MCP endpoint. Direct access bypasses Coral's operation policy. ### Local Run Toolbox on the same host as Coral with `--address 127.0.0.1`, as shown above. Use `http://127.0.0.1:5000/mcp` as the provider URL. Loopback binding blocks remote connections, but other processes on the host can still access Toolbox. ### Docker Compose Follow [Toolbox's Docker Compose guide](https://mcp-toolbox.dev/documentation/deploy-to/docker/) to add it to your [Coral deployment](/docs/getting-started/self-host/docker-compose). Connect Coral and Toolbox through a private network shared only by these services. Omit Toolbox's `ports` mapping to keep its MCP port unpublished. Keep Toolbox connected to a network that can reach your database. For a service named `toolbox` on port `5000`, use `http://toolbox:5000/mcp` as the provider URL. ### Kubernetes Follow [Toolbox's Kubernetes guide](https://mcp-toolbox.dev/documentation/deploy-to/kubernetes/) alongside [Coral's Kubernetes guide](/docs/getting-started/self-host/kubernetes). For a sidecar, run Toolbox in Coral's Pod with `--address 127.0.0.1`. Use `http://127.0.0.1:5000/mcp` as the provider URL, without a Service for Toolbox. For a separate Deployment, use an internal ClusterIP Service and a NetworkPolicy that permits inbound connections only from Coral. For a Service named `toolbox` in the `coral` namespace, use `http://toolbox.coral.svc.cluster.local:5000/mcp`. Adjust the namespace, port, and cluster domain to match your deployment. For each deployment, include the provider URL's hostname and port in Toolbox's `--allowed-hosts`. Configure Coral's [outbound permissions](/docs/reference/configuration#outbound) for the endpoint in its `[outbound]` configuration: * For loopback HTTP endpoints, including `127.0.0.1` sidecars, set `loopback = "http-and-https"`. * For private network HTTP endpoints, including Compose services and Kubernetes ClusterIP Services, set `private_networks = "http-and-https"`. These permissions are independent and default to `deny` in server deployments. Desktop and implicit-user local deployments allow both by default, unless you explicitly override them. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.