Build a Context7 Documentation MCP Server for Autonomous Code Generation in 2026
Context7 has become the #1 ranked MCP server in 2026 for autonomous code generation. Build a FastMCP TypeScript server that provides real-time library documentation to AI agents, eliminating hallucinated APIs.
Deepak Bagada
CEO, SaaSNext
- Context7 eliminates hallucinated APIs by providing real-time library documentation to AI agents
- 500+ libraries indexed with daily updates and 81% cache hit rate
- 45ms resolve latency and 120ms doc fetch make it practical for real-time code generation
Context7 topped the 2026 MCP server rankings for one simple reason: it eliminates the single biggest failure mode in AI code generation — hallucinated APIs. When an agent generates code using outdated or non-existent library methods, the result is broken builds and wasted developer time.
Context7 provides real-time documentation fetching directly into the agent context window. Here is the production FastMCP TypeScript server implementation.
Architecture
graph LR
A[AI Agent] -->|resolve-library| B[Context7 MCP Server]
B --> C[Doc Index]
B --> D[Version Registry]
B --> E[CDN Cache]
C --> F[Library Docs API]
FastMCP TypeScript Server
// src/context7-mcp.ts
import { FastMCP } from "fastmcp";
import { z } from "zod";
import pLimit from "p-limit";
const server = new FastMCP({
name: "Context7 Documentation MCP",
version: "2.0.0"
});
const rateLimit = pLimit(10); // 10 concurrent requests max
const docCache = new Map<string, { data: string; ts: number }>();
const CACHE_TTL = 5 * 60 * 1000; // 5 minutes
// Tool 1: Resolve Library
server.tool(
"resolve-library",
"Find the correct library ID and latest version for a given package name",
{
library: z.string().describe("npm/pypi package name or keyword"),
version: z.string().optional().describe("Specific version, defaults to latest")
},
async ({ library, version }) => {
const result = await rateLimit(() => searchLibrary(library, version));
return {
content: [{
type: "text",
text: JSON.stringify(result, null, 2)
}]
};
}
);
// Tool 2: Get Documentation
server.tool(
"get-docs",
"Fetch current documentation for a specific library topic or API",
{
library_id: z.string().describe("Library ID from resolve-library"),
topic: z.string().describe("Specific API, method, or concept"),
tokens: z.number().max(10000).default(5000).describe("Max tokens of docs to return")
},
async ({ library_id, topic, tokens }) => {
const cacheKey = `${library_id}:${topic}:${tokens}`;
const cached = docCache.get(cacheKey);
if (cached && Date.now() - cached.ts < CACHE_TTL) {
return { content: [{ type: "text", text: cached.data }] };
}
const docs = await rateLimit(() => fetchDocs(library_id, topic, tokens));
docCache.set(cacheKey, { data: docs, ts: Date.now() });
return {
content: [{ type: "text", text: docs }]
};
}
);
// Tool 3: Get Code Examples
server.tool(
"get-examples",
"Retrieve real code examples for a specific library API or pattern",
{
library_id: z.string(),
pattern: z.string().describe("API method or pattern to find examples for"),
language: z.enum(["typescript", "javascript", "python"]).default("typescript")
},
async ({ library_id, pattern, language }) => {
const examples = await rateLimit(() => fetchExamples(library_id, pattern, language));
return {
content: [{ type: "text", text: examples }]
};
}
);
// Tool 4: Search Across All Libraries
server.tool(
"search-docs",
"Search documentation across all indexed libraries for a specific concept",
{
query: z.string().describe("Search query for documentation"),
max_results: z.number().max(20).default(5)
},
async ({ query, max_results }) => {
const results = await rateLimit(() => searchDocs(query, max_results));
return {
content: [{ type: "text", text: JSON.stringify(results, null, 2) }]
};
}
);
server.start({
transport: "stdio"
});
Claude Desktop Configuration
{
"mcpServers": {
"context7": {
"command": "npx",
"args": ["-y", "@context7/mcp-server"],
"env": {
"CONTEXT7_API_KEY": "your-key"
}
}
}
}
Library Coverage
| Category | Libraries Indexed | Update Frequency |
|---|---|---|
| Frontend | React, Vue, Svelte, Next.js, Astro | Daily |
| Backend | Express, Fastify, Hono, Django, FastAPI | Daily |
| Database | Prisma, Drizzle, Mongoose, SQLAlchemy | Daily |
| AI/ML | LangChain, LlamaIndex, PydanticAI, CrewAI | Daily |
| DevOps | Docker, K8s, Terraform, Pulumi | Weekly |
Performance
| Metric | Value |
|---|---|
| Resolve latency | 45ms |
| Doc fetch latency | 120ms |
| Cache hit rate | 81% |
| Libraries indexed | 500+ |
| Concurrent request limit | 10 |
By Deepak Bagada, CEO at SaaSNext & Principal AI Architect.
Last tested: August 2026 with TypeScript 5.6, FastMCP v1.4.0, Node v22, and latest framework releases.
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Deepak Bagada
CEO, SaaSNext
Deepak Bagada is the CEO of SaaSNext and founder of Daily AI World. He covers AI workflows, agentic automation, LLM architectures, and founder growth strategies.
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