list-tables.ts•4.15 kB
/**
* list_tables tool - List tables in a database
*/
import { Tool } from "@modelcontextprotocol/sdk/types.js";
import { ListTablesInput, RawOutput } from "../types/index.js";
import { createLogger } from "../utils/logger.js";
import { createUsqlError, formatMcpError, sanitizeConnectionString } from "../utils/error-handler.js";
import { validateConnectionString } from "../usql/connection.js";
import { executeUsqlQuery } from "../usql/process-executor.js";
import { parseUsqlError } from "../usql/parser.js";
import { getQueryTimeout, resolveConnectionStringOrDefault } from "../usql/config.js";
const logger = createLogger("usql-mcp:tools:list-tables");
export const listTablesSchema: Tool = {
name: "list_tables",
description: "List all tables in a database",
inputSchema: {
type: "object",
properties: {
connection_string: {
type: "string",
description: 'Database connection URL or configured connection name (e.g., "oracle" for USQL_ORACLE)',
},
database: {
type: "string",
description: "Optional database name to list tables from (if not specified in connection)",
},
output_format: {
type: "string",
enum: ["json", "csv"],
description: "Output format for results (default: json)",
},
timeout_ms: {
type: ["number", "null"],
description: "Optional timeout in milliseconds for this call (overrides defaults). Use null for unlimited.",
minimum: 1,
},
},
required: [],
},
};
export async function handleListTables(input: ListTablesInput): Promise<RawOutput> {
const outputFormat = input.output_format || "json";
logger.debug("[list-tables] Handling request", {
connectionString: input.connection_string
? sanitizeConnectionString(input.connection_string)
: undefined,
database: input.database,
outputFormat,
});
let resolvedConnectionString: string | undefined;
try {
// Resolve connection string
try {
resolvedConnectionString = resolveConnectionStringOrDefault(input.connection_string);
} catch (error) {
throw createUsqlError("InvalidConnection", `Failed to resolve connection: ${String(error)}`);
}
if (!validateConnectionString(resolvedConnectionString)) {
throw createUsqlError(
"InvalidConnection",
`Invalid connection string format: ${resolvedConnectionString}`
);
}
// Use usql's built-in \dt command to list tables
// This works across most SQL databases
const query = "\\dt";
const timeoutOverride =
input.timeout_ms === null
? undefined
: typeof input.timeout_ms === "number" && Number.isFinite(input.timeout_ms)
? input.timeout_ms
: undefined;
const timeout = timeoutOverride ?? getQueryTimeout();
logger.debug("[list-tables] Executing list command", {
timeout,
database: input.database,
outputFormat,
});
const result = await executeUsqlQuery(resolvedConnectionString, query, {
timeout,
format: outputFormat,
});
logger.debug("[list-tables] Command executed", {
exitCode: result.exitCode,
stdoutLength: result.stdout.length,
stderrLength: result.stderr.length,
});
// Check for errors
if (result.exitCode !== 0 && result.stderr) {
const errorMessage = parseUsqlError(result.stderr);
throw createUsqlError("ListTablesError", errorMessage, { exitCode: result.exitCode });
}
logger.debug("[list-tables] Tables retrieved", {
outputFormat,
database: input.database,
});
return {
format: outputFormat as "json" | "csv",
content: result.stdout,
};
} catch (error) {
const connectionForError = resolvedConnectionString ?? input.connection_string;
const mcpError = formatMcpError(
error,
connectionForError || input.database
? {
connectionString: connectionForError,
database: input.database,
}
: undefined
);
logger.error("[list-tables] Error listing tables", error);
throw mcpError;
}
}