Neovim MCP Server

Instructions

Implementation Reference

• lib/nvim-operations.js:154-176 (handler)

  The core handler function that locates the Neovim buffer by path across instances and updates its content by setting new lines.

  export async function updateBuffer(bufferPath, newContent) {
    const instances = await getNvimInstancesInCwd();
  
    for (const { nvim } of instances) {
      try {
        const buffers = await nvim.buffers;
  
        for (const buf of buffers) {
          const name = await buf.name;
          if (name === bufferPath) {
            const lines = newContent.split("\n");
            await buf.setLines(lines, { start: 0, end: -1 });
  
            return { success: true, path: bufferPath };
          }
        }
      } catch (error) {
        console.error("Error updating buffer:", error.message);
      }
    }
  
    throw new Error(`Buffer not found: ${bufferPath}`);
  }

• index.js:145-163 (schema)

  The tool schema definition provided in the ListTools response, specifying the input parameters 'path' and 'content'.

  {
    name: "update_buffer",
    description:
      "Update the content of a buffer in Neovim. Changes appear immediately in the editor.",
    inputSchema: {
      type: "object",
      properties: {
        path: {
          type: "string",
          description: "The file path of the buffer to update",
        },
        content: {
          type: "string",
          description: "The new content for the buffer",
        },
      },
      required: ["path", "content"],
    },
  },

• index.js:262-271 (registration)

  The registration and dispatch logic within the CallToolRequestHandler that matches the tool name and invokes the updateBuffer function.

  if (name === "update_buffer") {
    const result = await updateBuffer(args.path, args.content);
    return {
      content: [
        {
          type: "text",
          text: `Successfully updated buffer: ${result.path}`,
        },
      ],
    };