set_config_value
Update specific configuration values in Claude Desktop Commander MCP to customize settings like allowed directories, command restrictions, file limits, and telemetry preferences.
Instructions
Set a specific configuration value by key.
WARNING: Should be used in a separate chat from file operations and
command execution to prevent security issues.
Config keys include:
- blockedCommands (array)
- defaultShell (string)
- allowedDirectories (array of paths)
- fileReadLineLimit (number, max lines for read_file)
- fileWriteLineLimit (number, max lines per write_file call)
- telemetryEnabled (boolean)
IMPORTANT: Setting allowedDirectories to an empty array ([]) allows full access
to the entire file system, regardless of the operating system.
This command can be referenced as "DC: ..." or "use Desktop Commander to ..." in your instructions.Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| key | Yes | ||
| value | No |
Implementation Reference
- src/tools/config.ts:61-149 (handler)The core handler function implementing the set_config_value tool. Parses arguments using the schema, handles JSON parsing for complex values, special array handling for certain keys, updates config via configManager, and returns success/error responses with updated config.
export async function setConfigValue(args: unknown) { console.error(`setConfigValue called with args: ${JSON.stringify(args)}`); try { const parsed = SetConfigValueArgsSchema.safeParse(args); if (!parsed.success) { console.error(`Invalid arguments for set_config_value: ${parsed.error}`); return { content: [{ type: "text", text: `Invalid arguments: ${parsed.error}` }], isError: true }; } try { // Parse string values that should be arrays or objects let valueToStore = parsed.data.value; // If the value is a string that looks like an array or object, try to parse it if (typeof valueToStore === 'string' && (valueToStore.startsWith('[') || valueToStore.startsWith('{'))) { try { valueToStore = JSON.parse(valueToStore); console.error(`Parsed string value to object/array: ${JSON.stringify(valueToStore)}`); } catch (parseError) { console.error(`Failed to parse string as JSON, using as-is: ${parseError}`); } } // Special handling for known array configuration keys if ((parsed.data.key === 'allowedDirectories' || parsed.data.key === 'blockedCommands') && !Array.isArray(valueToStore)) { if (typeof valueToStore === 'string') { const originalString = valueToStore; try { const parsedValue = JSON.parse(originalString); valueToStore = parsedValue; } catch (parseError) { console.error(`Failed to parse string as array for ${parsed.data.key}: ${parseError}`); // If parsing failed and it's a single value, convert to an array with one item if (!originalString.includes('[')) { valueToStore = [originalString]; } } } else if (valueToStore !== null) { // If not a string or array (and not null), convert to an array with one item valueToStore = [String(valueToStore)]; } // Ensure the value is an array after all our conversions if (!Array.isArray(valueToStore)) { console.error(`Value for ${parsed.data.key} is still not an array, converting to array`); valueToStore = [String(valueToStore)]; } } await configManager.setValue(parsed.data.key, valueToStore); // Get the updated configuration to show the user const updatedConfig = await configManager.getConfig(); console.error(`setConfigValue: Successfully set ${parsed.data.key} to ${JSON.stringify(valueToStore)}`); return { content: [{ type: "text", text: `Successfully set ${parsed.data.key} to ${JSON.stringify(valueToStore, null, 2)}\n\nUpdated configuration:\n${JSON.stringify(updatedConfig, null, 2)}` }], }; } catch (saveError: any) { console.error(`Error saving config: ${saveError.message}`); // Continue with in-memory change but report error return { content: [{ type: "text", text: `Value changed in memory but couldn't be saved to disk: ${saveError.message}` }], isError: true }; } } catch (error) { console.error(`Error in setConfigValue: ${error instanceof Error ? error.message : String(error)}`); console.error(error instanceof Error && error.stack ? error.stack : 'No stack trace available'); return { content: [{ type: "text", text: `Error setting value: ${error instanceof Error ? error.message : String(error)}` }], isError: true }; } - src/tools/schemas.ts:6-15 (schema)Zod schema defining the input parameters for the set_config_value tool: key (string) and value (string|number|boolean|string[]|null).
export const SetConfigValueArgsSchema = z.object({ key: z.string(), value: z.union([ z.string(), z.number(), z.boolean(), z.array(z.string()), z.null(), ]), }); - src/server.ts:206-232 (registration)Tool registration in the list_tools handler. Defines the tool name, detailed description with warnings and config keys, input schema converted to JSON schema, and annotations indicating it's destructive.
name: "set_config_value", description: ` Set a specific configuration value by key. WARNING: Should be used in a separate chat from file operations and command execution to prevent security issues. Config keys include: - blockedCommands (array) - defaultShell (string) - allowedDirectories (array of paths) - fileReadLineLimit (number, max lines for read_file) - fileWriteLineLimit (number, max lines per write_file call) - telemetryEnabled (boolean) IMPORTANT: Setting allowedDirectories to an empty array ([]) allows full access to the entire file system, regardless of the operating system. ${CMD_PREFIX_DESCRIPTION}`, inputSchema: zodToJsonSchema(SetConfigValueArgsSchema), annotations: { title: "Set Configuration Value", readOnlyHint: false, destructiveHint: true, openWorldHint: false, }, }, - src/server.ts:1110-1119 (registration)Dispatch handler in call_tool request that routes set_config_value calls to the setConfigValue function, with error capturing.
case "set_config_value": try { result = await setConfigValue(args); } catch (error) { capture('server_request_error', { message: `Error in set_config_value handler: ${error}` }); result = { content: [{ type: "text", text: `Error: Failed to set configuration value` }], isError: true, }; }