database_mcp_postgres/tools/
list_tables.rs

1//! MCP tool: `list_tables`.
2
3use std::borrow::Cow;
4
5use database_mcp_server::AppError;
6use database_mcp_server::types::{ListTablesRequest, ListTablesResponse};
7use database_mcp_sql::timeout::execute_with_timeout;
8use rmcp::handler::server::router::tool::{AsyncTool, ToolBase};
9use rmcp::model::{ErrorData, ToolAnnotations};
10
11use crate::PostgresHandler;
12
13/// Marker type for the `list_tables` MCP tool.
14pub(crate) struct ListTablesTool;
15
16impl ListTablesTool {
17    const NAME: &'static str = "list_tables";
18    const DESCRIPTION: &'static str =
19        "List all tables in a specific database.\nRequires `database_name` from `list_databases`.";
20}
21
22impl ToolBase for ListTablesTool {
23    type Parameter = ListTablesRequest;
24    type Output = ListTablesResponse;
25    type Error = ErrorData;
26
27    fn name() -> Cow<'static, str> {
28        Self::NAME.into()
29    }
30
31    fn description() -> Option<Cow<'static, str>> {
32        Some(Self::DESCRIPTION.into())
33    }
34
35    fn annotations() -> Option<ToolAnnotations> {
36        Some(
37            ToolAnnotations::new()
38                .read_only(true)
39                .destructive(false)
40                .idempotent(true)
41                .open_world(false),
42        )
43    }
44}
45
46impl AsyncTool<PostgresHandler> for ListTablesTool {
47    async fn invoke(handler: &PostgresHandler, params: Self::Parameter) -> Result<Self::Output, Self::Error> {
48        Ok(handler.list_tables(&params).await?)
49    }
50}
51
52impl PostgresHandler {
53    /// Lists all tables in a database.
54    ///
55    /// # Errors
56    ///
57    /// Returns [`AppError`] if the identifier is invalid or the query fails.
58    pub async fn list_tables(&self, request: &ListTablesRequest) -> Result<ListTablesResponse, AppError> {
59        let db = if request.database_name.is_empty() {
60            None
61        } else {
62            Some(request.database_name.as_str())
63        };
64        let pool = self.get_pool(db).await?;
65        let sql = "SELECT tablename FROM pg_tables WHERE schemaname = 'public' ORDER BY tablename";
66        let rows: Vec<(String,)> =
67            execute_with_timeout(self.config.query_timeout, sql, sqlx::query_as(sql).fetch_all(&pool)).await?;
68        Ok(ListTablesResponse {
69            tables: rows.into_iter().map(|r| r.0).collect(),
70        })
71    }
72}
database_mcp_postgres/tools/list_tables.rs

database_mcp_postgres/tools/
list_tables.rs
