String AI Web Access MCP Server
The official Model Context Protocol (MCP) server for
String AI's Web Access API. Search the web, fetch any URL or send it a
request, and map a site's URLs — all returned as clean, LLM-ready Markdown. Proxy rotation,
session handling and JavaScript rendering happen server-side, so the agent gets usable
page content rather than an error page. Connect any MCP-compatible client — VS Code, Cursor,
Windsurf, Claude Desktop, and more.
| Tool | Description |
|---|
web_access_fetch | Fetch one URL and get clean, LLM-ready Markdown back |
web_access_product_help | Ask about String products or services; get one source (two for comparisons), with a shared 4 KiB excerpt budget and source links |
web_access_request | Send a POST, PUT or PATCH with a body to a URL |
web_access_search | Search the web: ranked results plus the knowledge panel, AI overview, local pack and other surfaces Google rendered; optional searchCount (1–300) pages Google |
web_access_sitemap | Crawl a site and map its URLs as an asynchronous job, driven by action |
web_access_report | Send one redacted, credit-free failure diagnostic to String support |
web_access_fetch, web_access_search, and web_access_product_help are read-only. web_access_request writes, and
web_access_sitemap creates billed crawl jobs. Pages that rate-limit, geo-gate or block
automated traffic come back as Markdown rather than an error page: proxy rotation, session
handling and JavaScript rendering happen server-side.
The six-tool shape above is what the hosted server at https://mcp.usestring.ai/v1/mcp
serves. The npm package ships five of them: it includes product help and failure reporting but
omits web_access_request, sending writes through web_access_fetch's method and body
parameters instead.
web_access_sitemap — sitemap crawl jobs
A crawl is a two-phase, asynchronous quote → approve → poll → read job:
nothing is crawled or billed until the quote is explicitly approved.
action | What it does |
|---|
submit | Quote a crawl (url required; maxPages ≤ 10000 default 10, maxDepth ≤ 100 default 2, pathPrefix, budgetUsd, useSitemap optional). Returns jobId + estimatedCostUsd + estimatedPages, status awaiting_approval. |
approve | Billing consent — starts the crawl. 402 = insufficient funds; 409 partial_state = retry approve. |
status | Poll progress: awaiting_approval → running (pending/processed) → completed | failed | canceled | token_cap_exceeded; partial_state = retry approve. Returns counts only — URLs come from results. |
results | Paginated discovered URLs (limit ≤ 5000 default 1000, offset). Durable after completion; per-URL discoveredUrls is only present for ~1h. |
cancel | Stop a non-terminal job; already-fetched pages stay billed and readable. |
list | The account's recent crawl jobs (limit ≤ 100 default 20, offset). |
web_access_report — failure diagnostics
Reporting is optional and best-effort. Continue useful recovery first. If reporting remains useful
and permitted, send at most one report per distinct failure per task, not per retry. Report exceptions,
timeouts, tool errors, or unusable output; exclude usable origin statuses, valid negatives, empty 204
responses, running sitemap jobs, and cancellations. Each reporting attempt has a two-second deadline.
Remove Authorization headers, API keys, cookies, session tokens, personal data, and unrelated
conversation content before calling. The server redacts common credential forms again. Never
report a web_access_report failure or repeat a failed call only to gather reporting context.
Reports use the configured API key for authentication but do not consume Web Access credits.
If reporting is unavailable, unauthorized, rate-limited, or fails, stop reporting for the task.
Quick Start
Run with npx
env STRING_AI_API_KEY=your-key npx @usestring/mcp
Install globally
npm install -g @usestring/mcp
STRING_AI_API_KEY=your-key string-ai-mcp
Build from source
git clone https://github.com/usestring/string-ai-mcp.git
cd string-ai-mcp
npm install
npm run build
STRING_AI_API_KEY=your-key node build/index.js
Environment Variables
| Variable | Required | Description |
|---|
STRING_AI_API_KEY | Yes | Your String AI API key |
Client Configuration
VS Code
Press Ctrl+Shift+P → Preferences: Open User Settings (JSON) and add:
{
"inputs": [
{
"type": "promptString",
"id": "stringAiKey",
"description": "String AI API Key",
"password": true
}
],
"servers": {
"string-ai": {
"command": "npx",
"args": ["-y", "@usestring/mcp"],
"env": {
"STRING_AI_API_KEY": "${input:stringAiKey}"
}
}
}
}
Or add a .vscode/mcp.json file to share the configuration with your team.
Cursor
Open Settings → Features → MCP Servers → + Add new global MCP server and paste:
{
"mcpServers": {
"string-ai": {
"command": "npx",
"args": ["-y", "@usestring/mcp"],
"env": {
"STRING_AI_API_KEY": "YOUR_API_KEY"
}
}
}
}
Windsurf
Add to ~/.codeium/windsurf/model_config.json:
{
"mcpServers": {
"string-ai": {
"command": "npx",
"args": ["-y", "@usestring/mcp"],
"env": {
"STRING_AI_API_KEY": "YOUR_API_KEY"
}
}
}
}
Claude Desktop
Add to your claude_desktop_config.json:
{
"mcpServers": {
"string-ai": {
"command": "npx",
"args": ["-y", "@usestring/mcp"],
"env": {
"STRING_AI_API_KEY": "YOUR_API_KEY"
}
}
}
}
Testing with the MCP Inspector
The MCP Inspector lets you test your server interactively in a browser:
npx @modelcontextprotocol/inspector node build/index.js
Then open http://127.0.0.1:6274, connect via stdio, and try calling each
tool from the UI.
How It Works
┌──────────────────┐ stdio (JSON-RPC) ┌──────────────────┐ HTTPS ┌──────────────────┐
│ VS Code / Cursor │ ◄──────────────────► │ String AI │ ────────► │ String AI │
│ Windsurf / Claude│ │ Web Access MCP │ │ Web Access API │
└──────────────────┘ └──────────────────┘ └──────────────────┘
- The IDE spawns this server as a child process and communicates over stdio.
- When the LLM decides it needs web content, it invokes
web_access_fetch,
web_access_search, or web_access_sitemap. Every failed call is reported exactly once with
web_access_report, even when recovery later succeeds.
- This server forwards the request to String AI's Web Access API (using your API key from
the environment) and returns the result to the LLM.
About String AI
String AI provides a powerful web access API that handles proxies,
session handling, and JavaScript rendering automatically. Get your API key at
usestring.ai.
License
MIT
Security
Please report security vulnerabilities privately as described in SECURITY.md.