JSON Editor

You have an MCP server that edits JSON files with read, write, and deep merge capabilities. It helps you target specific paths in large JSON files, supports multi-file operations, and keeps existing structure intact while applying precise changes. This is especially useful for multilingual JSON translations and configuration files where full-file edits are costly or risky.

How to use

Use this MCP server alongside your MCP client to read, write, or delete values in JSON files by specifying dot notation paths. You can read only the values you need, write or update specific paths (missing nested structures are created automatically), delete paths, and perform deep merges when duplicates exist. For multilingual projects, you can compare translations across language files or update translations without loading entire files into memory.

Typical workflows include reading a value from multiple JSON files in one operation, updating a single key in one file, deleting an unnecessary key across several files, or merging duplicate keys in a file so the final structure remains coherent.

To integrate with an AI assistant or development tool, configure the MCP client to point to the JSON editor server using the supplied MCP configuration snippet.

How to install

Prerequisites: ensure you have a modern Node-like JavaScript runtime available. This guide uses Bun for package management and execution. If Bun is not installed, install Bun first following the official instructions for your operating system.

bun add json-editor-mcp

Add the MCP server configuration to your client so it can discover and use the JSON editor server.

{
  "mcpServers": {
    "json-editor": {
      "command": "bunx",
      "args": ["json-editor-mcp"]
    }
  }
}

If you want to enable AI assistants to use MCP tools in your project, copy the cursor rule file into your project rules folder so the assistant can discover and use the MCP endpoints.

cp .cursor/rules/json-editor-mcp.mdc /path/to/your/project/.cursor/rules/

Notes and tips

This server focuses on targeted JSON operations. It supports reading values from multiple files, writing or updating nested paths, deleting values, and performing deep merges for duplicate keys. It also supports multi-file operations so you can work with several translation files or configurations at once.

There are dedicated tools that demonstrate the supported operations, including reading multiple values, writing values, deleting values, and merging duplicate keys.

About the available tools

The following tools are available to perform common JSON editing tasks across one or more files.

read_multiple_json_values

Reads the same dot notation path from one or more JSON files in a single operation. Returns a map with file paths as keys and the extracted values as values. This is useful for comparing translations across language files or reading from a single file.

read_multiple_json_values(["messages/en.json", "messages/es.json"], "common.welcome")

write_json_values

Writes a value to a JSON file at a specified dot notation path. Automatically creates missing nested paths and preserves existing structure.

{"path":"/absolute/path/to/messages/en.json","pathValue":"pages.about.title","value":"About Us"}

delete_multiple_json_values

Deletes a value at a specified dot notation path from one or more JSON files. Returns a map with file paths as keys and deletion results as values.

delete_multiple_json_values(["messages/en.json", "messages/es.json"], "common.goodbye")

merge_duplicate_keys

Performs a deep merge of duplicate keys in a JSON file. Primitives use last-value-wins, objects merge recursively, and arrays use last-value-wins.

merge_duplicate_keys("messages/en.json")

Available tools

read_multiple_json_values

Reads a dot notation path from one or more JSON files in a single operation and returns a map of file paths to the extracted values.

write_json_values

Writes a value to a JSON file at a specified dot notation path, auto-creating missing nested structures while preserving existing data.

delete_multiple_json_values

Deletes a value at a specified dot notation path from one or more JSON files and returns a map of results.

merge_duplicate_keys

Performs a deep merge of duplicate keys in a JSON file with recursive object merging and last-value-wins for primitives and arrays.