Grammar checking, AI content detection, paraphrasing, and the rest of Sapling's language tools — available directly inside Claude, Claude Code, and any other MCP-compatible AI assistant.
claude mcp add sapling --env SAPLING_API_KEY=YOUR_API_KEY \
-- npx -y @saplingai/mcp-serverThe Model Context Protocol is an open standard that lets AI assistants call external tools and APIs in a structured way. The Sapling MCP Server exposes Sapling's language tools as MCP tools — so you can ask your assistant to grammar-check a document, detect AI-generated content, paraphrase a sentence, or analyze sentiment without leaving the conversation.
"Check this email for grammar errors." Your assistant decides a Sapling tool is the right way to answer.
Your client starts @saplingai/mcp-server on your machine over stdio — no remote endpoint to expose.
The tool calls the Sapling API and returns structured results — edits, scores, and suggestions — back into the conversation.
Seven tools, one API key. Every tool takes text and returns structured JSON your assistant can reason over.
sapling_grammar_check
sapling_spell_check
Catch grammar errors, spelling mistakes, punctuation issues, and style problems in any text. Returns edit suggestions with types (preposition, verb tense, etc.) and confidence scores.
sapling_ai_detect
Detect whether text was written by a human or generated by GPT-5, Claude 4.5, Gemini 2.5, Qwen3, DeepSeek-V3, or other AI models. Returns an overall score plus per-sentence predictions.
sapling_rephrase
Rewrite text with different tone, formality level, or style while preserving meaning. Useful for adapting content for different audiences.
sapling_summarize
Generate concise summaries of longer documents, emails, or articles.
sapling_sentiment
Classify text as positive, negative, or neutral. Useful for reviewing customer feedback, tickets, or social media posts within an AI workflow.
sapling_language_detect
Identify the language of a text snippet. Supports 30+ languages including English, Spanish, French, German, Chinese, Japanese, Arabic, and more.
Three steps, about two minutes. See the complete setup guide for other MCP clients and troubleshooting.
You need Node.js 18 or newer (including npx) and a
Sapling API key. Trial keys are available right after registration. Keep the key in your client's environment configuration — not in prompts or committed files.
Claude Code
Run in your terminal, replacing YOUR_API_KEY with your Sapling API key:
claude mcp add sapling --env SAPLING_API_KEY=YOUR_API_KEY \
-- npx -y @saplingai/mcp-serverThen run claude mcp list to confirm sapling is configured.
Claude Desktop
Add to ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or %APPDATA%\Claude\claude_desktop_config.json (Windows), then restart Claude Desktop:
{
"mcpServers": {
"sapling": {
"command": "npx",
"args": ["-y", "@saplingai/mcp-server"],
"env": {
"SAPLING_API_KEY": "YOUR_API_KEY"
}
}
}
}Other MCP clients
Any client that accepts a command, arguments, and environment variables can run the server:
| Transport | stdio |
|---|---|
| Command | npx |
| Arguments | -y, @saplingai/mcp-server |
| Environment | SAPLING_API_KEY=YOUR_API_KEY |
The package does not expose a remote HTTP MCP endpoint — your client starts the local process, which then calls https://api.sapling.ai.
Claude Code asks for approval the first time each Sapling tool runs. To pre-approve them — or if a call is denied instead of prompting — run /permissions and add an allow rule for mcp__sapling (all Sapling tools) or a single tool such as mcp__sapling__sapling_grammar_check. See tool permissions for details.
The package doesn't log or persist your key or your text. Optional no-data-retention mode, plus on-premises deployment for HIPAA and PCI compliance.
Sapling's API is optimized for real-time use. Grammar checks typically return in under 200 ms, so tool calls don't stall the conversation.
Grammar checking and language detection across 30+ languages including Chinese, German, Spanish, Japanese, and more.
Any MCP client that supports local stdio servers, including Claude Desktop and Claude Code. Clients that accept a command, arguments, and environment variables can run it with command npx, arguments -y @saplingai/mcp-server, and SAPLING_API_KEY in the environment.
Node.js 18 or newer, including the npx command, plus a Sapling API key. The server runs locally on your machine and calls the Sapling API over HTTPS.
Yes. Set your key as the SAPLING_API_KEY environment variable in your MCP client's server configuration. Trial keys are available after registration.
The MCP package does not log or persist your API key or submitted text. Tool inputs are sent to the configured Sapling API endpoint for processing. Contact us if you require no-data-retention or an on-premises deployment.
Yes. Set SAPLING_API_BASE_URL to your own Sapling endpoint. Only point it at an endpoint you trust — your API key and submitted text are sent there.
Grab an API key, paste one command, and start grammar-checking, detecting, and rephrasing from inside the tools you already use.
Need volume pricing, no-data-retention, or on-premises? Talk to us.