CC Fig MCP

Instructions

Implementation Reference

• src/talk_to_figma_mcp/tools/document-tools.ts:285-324 (handler)

  The handler function for the 'join_channel' MCP tool. It validates the channel input, calls the joinChannel utility to join the WebSocket channel, and returns success or error messages.

  async ({ channel }) => {
    try {
      if (!channel) {
        // If no channel provided, ask the user for input
        return {
          content: [
            {
              type: "text",
              text: "Please provide a channel name to join:",
            },
          ],
          followUp: {
            tool: "join_channel",
            description: "Join the specified channel",
          },
        };
      }
  
      // Use joinChannel instead of sendCommandToFigma to ensure currentChannel is updated
      await joinChannel(channel);
      
      return {
        content: [
          {
            type: "text",
            text: `Successfully joined channel: ${channel}`,
          },
        ],
      };
    } catch (error) {
      return {
        content: [
          {
            type: "text",
            text: `Error joining channel: ${error instanceof Error ? error.message : String(error)}`,
          },
        ],
      };
    }
  }

• src/talk_to_figma_mcp/tools/document-tools.ts:282-284 (schema)

  Zod input schema defining the 'channel' parameter for the join_channel tool.

  {
    channel: z.string().describe("The name of the channel to join").default(""),
  },

• src/talk_to_figma_mcp/tools/document-tools.ts:278-325 (registration)

  Direct registration of the 'join_channel' tool using server.tool(), including schema and handler.

  // Join Channel Tool
  server.tool(
    "join_channel",
    "Join a specific channel to communicate with Figma",
    {
      channel: z.string().describe("The name of the channel to join").default(""),
    },
    async ({ channel }) => {
      try {
        if (!channel) {
          // If no channel provided, ask the user for input
          return {
            content: [
              {
                type: "text",
                text: "Please provide a channel name to join:",
              },
            ],
            followUp: {
              tool: "join_channel",
              description: "Join the specified channel",
            },
          };
        }
  
        // Use joinChannel instead of sendCommandToFigma to ensure currentChannel is updated
        await joinChannel(channel);
        
        return {
          content: [
            {
              type: "text",
              text: `Successfully joined channel: ${channel}`,
            },
          ],
        };
      } catch (error) {
        return {
          content: [
            {
              type: "text",
              text: `Error joining channel: ${error instanceof Error ? error.message : String(error)}`,
            },
          ],
        };
      }
    }
  );

• src/talk_to_figma_mcp/utils/websocket.ts:225-238 (helper)

  Helper function that sends the 'join' command to Figma WebSocket and updates the current channel state. Called by the tool handler.

  export async function joinChannel(channelName: string): Promise<void> {
    if (!ws || ws.readyState !== WebSocket.OPEN) {
      throw new Error("Not connected to Figma");
    }
  
    try {
      await sendCommandToFigma("join", { channel: channelName });
      currentChannel = channelName;
      logger.info(`Joined channel: ${channelName}`);
    } catch (error) {
      logger.error(`Failed to join channel: ${error instanceof Error ? error.message : String(error)}`);
      throw error;
    }
  }

• src/talk_to_figma_mcp/tools/index.ts:12-18 (registration)

  Top-level registration function that calls registerDocumentTools(server), which in turn registers the join_channel tool.

  export function registerTools(server: McpServer): void {
    registerDocumentTools(server);
    registerCreationTools(server);
    registerModificationTools(server);
    registerTextTools(server);
    registerComponentTools(server);
  }