switch_variable_mode

Instructions

Implementation Reference

• src/talk_to_figma_mcp/tools/variable-tools.ts:123-159 (handler)

  The handler function for the 'switch_variable_mode' tool. It is registered as an MCP server.tool, takes nodeId, collectionId, and modeId as input parameters, sends the 'switch_variable_mode' command to Figma via WebSocket, and returns the result with mode switch confirmation.

  // Switch Variable Mode Tool
  server.tool(
    "switch_variable_mode",
    "Switch the variable mode on a node for a specific collection. This changes which mode's values are used for bound variables.",
    {
      nodeId: z.string().describe("The ID of the node to switch mode on"),
      collectionId: z.string().describe("The ID of the variable collection"),
      modeId: z.string().describe("The ID of the mode to switch to"),
    },
    async ({ nodeId, collectionId, modeId }) => {
      try {
        const result = await sendCommandToFigma("switch_variable_mode", {
          nodeId,
          collectionId,
          modeId,
        });
        const typedResult = result as { nodeName: string; collectionName: string; modeName: string };
        return {
          content: [
            {
              type: "text",
              text: `Switched to mode "${typedResult.modeName}" for collection "${typedResult.collectionName}" on node "${typedResult.nodeName}"`,
            },
          ],
        };
      } catch (error) {
        return {
          content: [
            {
              type: "text",
              text: `Error switching variable mode: ${error instanceof Error ? error.message : String(error)}`,
            },
          ],
        };
      }
    }
  );

• src/talk_to_figma_mcp/tools/variable-tools.ts:123-159 (registration)

  The tool is registered via server.tool('switch_variable_mode', ...) inside registerVariableTools() in variable-tools.ts, which is called from registerTools() in tools/index.ts.

  // Switch Variable Mode Tool
  server.tool(
    "switch_variable_mode",
    "Switch the variable mode on a node for a specific collection. This changes which mode's values are used for bound variables.",
    {
      nodeId: z.string().describe("The ID of the node to switch mode on"),
      collectionId: z.string().describe("The ID of the variable collection"),
      modeId: z.string().describe("The ID of the mode to switch to"),
    },
    async ({ nodeId, collectionId, modeId }) => {
      try {
        const result = await sendCommandToFigma("switch_variable_mode", {
          nodeId,
          collectionId,
          modeId,
        });
        const typedResult = result as { nodeName: string; collectionName: string; modeName: string };
        return {
          content: [
            {
              type: "text",
              text: `Switched to mode "${typedResult.modeName}" for collection "${typedResult.collectionName}" on node "${typedResult.nodeName}"`,
            },
          ],
        };
      } catch (error) {
        return {
          content: [
            {
              type: "text",
              text: `Error switching variable mode: ${error instanceof Error ? error.message : String(error)}`,
            },
          ],
        };
      }
    }
  );

• src/talk_to_figma_mcp/tools/variable-tools.ts:127-131 (schema)

  Zod schema for the 'switch_variable_mode' tool: three required string parameters - nodeId (the target node), collectionId (the variable collection), and modeId (the mode to switch to).

  {
    nodeId: z.string().describe("The ID of the node to switch mode on"),
    collectionId: z.string().describe("The ID of the variable collection"),
    modeId: z.string().describe("The ID of the mode to switch to"),
  },

• src/talk_to_figma_mcp/utils/websocket.ts:238-297 (helper)

  The sendCommandToFigma function is the WebSocket helper that sends the 'switch_variable_mode' command string (typed as FigmaCommand) to the Figma plugin via a WebSocket connection, managing the request lifecycle with timeouts and promise resolution.

  export function sendCommandToFigma(
    command: FigmaCommand,
    params: unknown = {},
    timeoutMs: number = 300000
  ): Promise<unknown> {
    return new Promise((resolve, reject) => {
      // If not connected, try to connect first
      if (!ws || ws.readyState !== WebSocket.OPEN) {
        connectToFigma();
        reject(new Error("Not connected to Figma. Attempting to connect..."));
        return;
      }
  
      // Check if we need a channel for this command
      const requiresChannel = command !== "join";
      if (requiresChannel && !currentChannel) {
        reject(new Error("Must join a channel before sending commands"));
        return;
      }
  
      const id = uuidv4();
      const request = {
        id,
        type: command === "join" ? "join" : "message",
        ...(command === "join"
          ? { channel: (params as any).channel, sessionId: SESSION_ID }
          : { channel: currentChannel }),
        message: {
          id,
          command,
          params: {
            ...(params as any),
            commandId: id, // Include the command ID in params
          },
        },
      };
  
      // Set timeout for request
      const timeout = setTimeout(() => {
        if (pendingRequests.has(id)) {
          pendingRequests.delete(id);
          logger.error(`Request ${id} to Figma timed out after ${timeoutMs / 1000} seconds`);
          reject(new Error('Request to Figma timed out'));
        }
      }, timeoutMs);
  
      // Store the promise callbacks to resolve/reject later
      pendingRequests.set(id, {
        resolve,
        reject,
        timeout,
        lastActivity: Date.now()
      });
  
      // Send the request
      logger.info(`Sending command to Figma: ${command}`);
      logger.debug(`Request details: ${JSON.stringify(request)}`);
      ws.send(JSON.stringify(request));
    });
  }

• src/talk_to_figma_mcp/types/index.ts:125-131 (schema)

  The type definition for 'switch_variable_mode' as a valid FigmaCommand value in the FigmaCommand union type, ensuring type safety when sending this command via the WebSocket helper.

  | "switch_variable_mode"
  | "get_figjam_elements"
  | "create_sticky"
  | "set_sticky_text"
  | "create_shape_with_text"
  | "create_connector"
  | "create_section";