mcp-after-effects

Instructions

Implementation Reference

• src/index.ts:682-720 (registration)

  Registers the 'apply-effect' MCP tool with input schema, description, and handler function that queues the 'applyEffect' command to a temporary file for execution by the After Effects bridge panel.

  server.tool(
    "apply-effect",
    "Apply an effect to a layer in After Effects",
    {
      compIndex: z.number().int().positive().describe("1-based index of the target composition in the project panel."),
      layerIndex: z.number().int().positive().describe("1-based index of the target layer within the composition."),
      effectName: z.string().optional().describe("Display name of the effect to apply (e.g., 'Gaussian Blur')."),
      effectMatchName: z.string().optional().describe("After Effects internal name for the effect (more reliable, e.g., 'ADBE Gaussian Blur 2')."),
      effectCategory: z.string().optional().describe("Optional category for filtering effects."),
      presetPath: z.string().optional().describe("Optional path to an effect preset file (.ffx)."),
      effectSettings: z.record(z.any()).optional().describe("Optional parameters for the effect (e.g., { 'Blurriness': 25 }).")
    },
    async (parameters) => {
      try {
        // Queue the command for After Effects
        writeCommandFile("applyEffect", parameters);
        
        return {
          content: [
            {
              type: "text",
              text: `Command to apply effect to layer ${parameters.layerIndex} in composition ${parameters.compIndex} has been queued.\n` +
                    `Use the "get-results" tool after a few seconds to check for confirmation.`
            }
          ]
        };
      } catch (error) {
        return {
          content: [
            {
              type: "text",
              text: `Error queuing apply-effect command: ${String(error)}`
            }
          ],
          isError: true
        };
      }
    }
  );

• src/index.ts:694-719 (handler)

  Handler function for the 'apply-effect' tool. Writes the command parameters to ae_command.json for the After Effects MCP Bridge Auto panel to detect and execute the actual effect application.

  async (parameters) => {
    try {
      // Queue the command for After Effects
      writeCommandFile("applyEffect", parameters);
      
      return {
        content: [
          {
            type: "text",
            text: `Command to apply effect to layer ${parameters.layerIndex} in composition ${parameters.compIndex} has been queued.\n` +
                  `Use the "get-results" tool after a few seconds to check for confirmation.`
          }
        ]
      };
    } catch (error) {
      return {
        content: [
          {
            type: "text",
            text: `Error queuing apply-effect command: ${String(error)}`
          }
        ],
        isError: true
      };
    }
  }

• src/index.ts:685-692 (schema)

  Zod input schema defining parameters for the 'apply-effect' tool: composition and layer indices, effect names, category, preset path, and custom settings.

  {
    compIndex: z.number().int().positive().describe("1-based index of the target composition in the project panel."),
    layerIndex: z.number().int().positive().describe("1-based index of the target layer within the composition."),
    effectName: z.string().optional().describe("Display name of the effect to apply (e.g., 'Gaussian Blur')."),
    effectMatchName: z.string().optional().describe("After Effects internal name for the effect (more reliable, e.g., 'ADBE Gaussian Blur 2')."),
    effectCategory: z.string().optional().describe("Optional category for filtering effects."),
    presetPath: z.string().optional().describe("Optional path to an effect preset file (.ffx)."),
    effectSettings: z.record(z.any()).optional().describe("Optional parameters for the effect (e.g., { 'Blurriness': 25 }).")

• src/index.ts:156-170 (helper)

  Helper function used by the 'apply-effect' handler to write the command and parameters to the temporary ae_command.json file, which is monitored by the After Effects bridge.

  function writeCommandFile(command: string, args: Record<string, any> = {}): void {
    try {
      const commandFile = path.join(process.env.TEMP || process.env.TMP || '', 'ae_command.json');
      const commandData = {
        command,
        args,
        timestamp: new Date().toISOString(),
        status: "pending"  // pending, running, completed, error
      };
      fs.writeFileSync(commandFile, JSON.stringify(commandData, null, 2));
      console.error(`Command "${command}" written to ${commandFile}`);
    } catch (error) {
      console.error("Error writing command file:", error);
    }
  }

• src/index.ts:87-123 (helper)

  Helper function to read results from the ae_mcp_result.json file produced by After Effects after executing the applyEffect command. Used in companion 'get-results' tool.

  function readResultsFromTempFile(): string {
    try {
      const tempFilePath = path.join(process.env.TEMP || process.env.TMP || '', 'ae_mcp_result.json');
      
      // Add debugging info
      console.error(`Checking for results at: ${tempFilePath}`);
      
      if (fs.existsSync(tempFilePath)) {
        // Get file stats to check modification time
        const stats = fs.statSync(tempFilePath);
        console.error(`Result file exists, last modified: ${stats.mtime.toISOString()}`);
        
        const content = fs.readFileSync(tempFilePath, 'utf8');
        console.error(`Result file content length: ${content.length} bytes`);
        
        // If the result file is older than 30 seconds, warn the user
        const thirtySecondsAgo = new Date(Date.now() - 30 * 1000);
        if (stats.mtime < thirtySecondsAgo) {
          console.error(`WARNING: Result file is older than 30 seconds. After Effects may not be updating results.`);
          return JSON.stringify({ 
            warning: "Result file appears to be stale (not recently updated).",
            message: "This could indicate After Effects is not properly writing results or the MCP Bridge Auto panel isn't running.",
            lastModified: stats.mtime.toISOString(),
            originalContent: content
          });
        }
        
        return content;
      } else {
        console.error(`Result file not found at: ${tempFilePath}`);
        return JSON.stringify({ error: "No results file found. Please run a script in After Effects first." });
      }
    } catch (error) {
      console.error("Error reading results file:", error);
      return JSON.stringify({ error: `Failed to read results: ${String(error)}` });
    }
  }