save_workflow_template

Instructions

Implementation Reference

• src/tools/templates.ts:75-124 (handler)

  The handler function for the 'save_workflow_template' tool. It validates the name, checks if template exists, optionally overwrites, creates/updates a StoredTemplate record, and writes to disk as JSON.

  server.tool(
    "save_workflow_template",
    "Save a ComfyUI workflow JSON to the server's template registry under a named slot. Overwrites are disabled by default.",
    saveSchema,
    async (args) => {
      validateName(args.name);
      const file = templatePath(store.dir, args.name);
      let existed = false;
      try {
        await fs.access(file);
        existed = true;
      } catch {
        existed = false;
      }
      if (existed && !args.overwrite) {
        throw new Error(
          `Template "${args.name}" already exists. Pass overwrite=true to replace it.`,
        );
      }
      const now = new Date().toISOString();
      let createdAt = now;
      if (existed) {
        try {
          const prior = JSON.parse(
            await fs.readFile(file, "utf-8"),
          ) as StoredTemplate;
          createdAt = prior.createdAt ?? now;
        } catch {
          // ignore parse failure, treat as fresh create
        }
      }
      const record: StoredTemplate = {
        name: args.name,
        description: args.description,
        createdAt,
        updatedAt: now,
        workflow: args.workflow as Workflow,
      };
      await fs.writeFile(file, JSON.stringify(record, null, 2));
      return {
        content: [
          {
            type: "text" as const,
            text: existed
              ? `Updated template "${args.name}" at ${file}`
              : `Saved template "${args.name}" at ${file}`,
          },
        ],
      };
    },

• src/tools/templates.ts:38-54 (schema)

  Zod schema for the 'save_workflow_template' tool inputs: name (string), workflow (record), description (optional string), overwrite (boolean, default false).

  const saveSchema = {
    name: z
      .string()
      .describe(
        "Template name. Letters, digits, '-', '_'; max 64 chars. Must start alphanumeric.",
      ),
    workflow: z
      .record(z.string(), z.any())
      .describe(
        "Complete ComfyUI workflow JSON (from ComfyUI's 'Save (API Format)').",
      ),
    description: z.string().optional(),
    overwrite: z
      .boolean()
      .default(false)
      .describe("Allow overwriting an existing template with the same name."),
  };

• src/server.ts:48-48 (registration)

  Registration call: registerTemplateTools(s, client, templateStore) wire up the tool in the MCP server.

  registerTemplateTools(s, client, templateStore);

• src/tools/templates.ts:70-125 (registration)

  The registerTemplateTools function that calls server.tool('save_workflow_template', ...) to register the tool with the MCP server.

  export function registerTemplateTools(
    server: McpServer,
    client: ComfyUIClient,
    store: TemplateStore,
  ): void {
    server.tool(
      "save_workflow_template",
      "Save a ComfyUI workflow JSON to the server's template registry under a named slot. Overwrites are disabled by default.",
      saveSchema,
      async (args) => {
        validateName(args.name);
        const file = templatePath(store.dir, args.name);
        let existed = false;
        try {
          await fs.access(file);
          existed = true;
        } catch {
          existed = false;
        }
        if (existed && !args.overwrite) {
          throw new Error(
            `Template "${args.name}" already exists. Pass overwrite=true to replace it.`,
          );
        }
        const now = new Date().toISOString();
        let createdAt = now;
        if (existed) {
          try {
            const prior = JSON.parse(
              await fs.readFile(file, "utf-8"),
            ) as StoredTemplate;
            createdAt = prior.createdAt ?? now;
          } catch {
            // ignore parse failure, treat as fresh create
          }
        }
        const record: StoredTemplate = {
          name: args.name,
          description: args.description,
          createdAt,
          updatedAt: now,
          workflow: args.workflow as Workflow,
        };
        await fs.writeFile(file, JSON.stringify(record, null, 2));
        return {
          content: [
            {
              type: "text" as const,
              text: existed
                ? `Updated template "${args.name}" at ${file}`
                : `Saved template "${args.name}" at ${file}`,
            },
          ],
        };
      },
    );

• src/tools/templates.ts:30-36 (helper)

  StoredTemplate interface defining the shape of saved template data (name, description, createdAt, updatedAt, workflow).

  interface StoredTemplate {
    name: string;
    description?: string;
    createdAt: string;
    updatedAt: string;
    workflow: Workflow;
  }