database_mcp_postgres/tools/
create_database.rs

1//! MCP tool: `createDatabase`.
2
3use std::borrow::Cow;
4
5use database_mcp_server::types::{CreateDatabaseRequest, MessageResponse};
6use database_mcp_sql::Connection as _;
7use database_mcp_sql::SqlError;
8use database_mcp_sql::sanitize::{quote_ident, validate_ident};
9use rmcp::handler::server::router::tool::{AsyncTool, ToolBase};
10use rmcp::model::{ErrorData, ToolAnnotations};
11use sqlparser::dialect::PostgreSqlDialect;
12
13use crate::PostgresHandler;
14
15/// Marker type for the `createDatabase` MCP tool.
16pub(crate) struct CreateDatabaseTool;
17
18impl CreateDatabaseTool {
19    const NAME: &'static str = "createDatabase";
20    const TITLE: &'static str = "Create Database";
21    const DESCRIPTION: &'static str = r#"Create a new database on the connected server.
22
23<usecase>
24Use when:
25- Setting up a new database for a project or application
26- The user asks to create a database
27</usecase>
28
29<examples>
30✓ "Create a database called analytics" → createDatabase(database="analytics")
31✗ "Create a table" → use writeQuery with CREATE TABLE
32</examples>
33
34<important>
35Database names must contain only alphanumeric characters and underscores.
36</important>
37
38<what_it_returns>
39A confirmation message with the created database name.
40</what_it_returns>"#;
41}
42
43impl ToolBase for CreateDatabaseTool {
44    type Parameter = CreateDatabaseRequest;
45    type Output = MessageResponse;
46    type Error = ErrorData;
47
48    fn name() -> Cow<'static, str> {
49        Self::NAME.into()
50    }
51
52    fn title() -> Option<String> {
53        Some(Self::TITLE.into())
54    }
55
56    fn description() -> Option<Cow<'static, str>> {
57        Some(Self::DESCRIPTION.into())
58    }
59
60    fn annotations() -> Option<ToolAnnotations> {
61        Some(
62            ToolAnnotations::new()
63                .read_only(false)
64                .destructive(false)
65                .idempotent(false)
66                .open_world(false),
67        )
68    }
69}
70
71impl AsyncTool<PostgresHandler> for CreateDatabaseTool {
72    async fn invoke(handler: &PostgresHandler, params: Self::Parameter) -> Result<Self::Output, Self::Error> {
73        Ok(handler.create_database(params).await?)
74    }
75}
76
77impl PostgresHandler {
78    /// Creates a database if it doesn't exist.
79    ///
80    /// # Errors
81    ///
82    /// Returns [`SqlError`] if read-only or the query fails.
83    pub async fn create_database(
84        &self,
85        CreateDatabaseRequest { database }: CreateDatabaseRequest,
86    ) -> Result<MessageResponse, SqlError> {
87        if self.config.read_only {
88            return Err(SqlError::ReadOnlyViolation);
89        }
90
91        validate_ident(&database)?;
92
93        let create_sql = format!("CREATE DATABASE {}", quote_ident(&database, &PostgreSqlDialect {}));
94        self.connection.execute(&create_sql, None).await.map_err(|e| {
95            let msg = e.to_string();
96            if msg.contains("already exists") {
97                return SqlError::Query(format!("Database '{database}' already exists."));
98            }
99            e
100        })?;
101
102        Ok(MessageResponse {
103            message: format!("Database '{database}' created successfully."),
104        })
105    }
106}
database_mcp_postgres/tools/create_database.rs

database_mcp_postgres/tools/
create_database.rs
