Anthropic
Installation
Section titled “Installation”npm i llamaindex @llamaindex/anthropicimport { Settings } from "llamaindex";import { Anthropic } from "@llamaindex/anthropic";
Settings.llm = new Anthropic({ apiKey: "<YOUR_API_KEY>",});Load and index documents
Section titled “Load and index documents”For this example, we will use a single document. In a real-world scenario, you would have multiple documents to index.
const document = new Document({ text: essay, id_: "essay" });
const index = await VectorStoreIndex.fromDocuments([document]);const queryEngine = index.asQueryEngine();
const query = "What is the meaning of life?";
const results = await queryEngine.query({ query,});Full Example
Section titled “Full Example”import { Document, VectorStoreIndex, Settings } from "llamaindex";import { Anthropic } from "@llamaindex/anthropic";
Settings.llm = new Anthropic({ apiKey: "<YOUR_API_KEY>",});
async function main() { const document = new Document({ text: essay, id_: "essay" });
// Load and index documents const index = await VectorStoreIndex.fromDocuments([document]);
// Create a query engine const queryEngine = index.asQueryEngine({ retriever, });
const query = "What is the meaning of life?";
// Query const response = await queryEngine.query({ query, });
// Log the response console.log(response.response);}API Reference
Section titled “API Reference”Note for AI agents: this documentation is built for programmatic access.
- Overview of all docs: https://developers.llamaindex.ai/llms.txt
- Any page is available as raw Markdown by appending index.md to its URL — e.g. https://developers.llamaindex.ai/llamaparse/parse/getting_started/index.md
- Agent-friendly REST search APIs live under https://developers.llamaindex.ai/api/ — search (BM25 full-text), grep (regex), read (fetch a page), and list (browse the doc tree). See https://developers.llamaindex.ai/llms.txt for parameters.
- A hosted documentation MCP server is available at https://developers.llamaindex.ai/mcp. If you support MCP, you can ask the user to install it for browsing these docs directly (an alternative to the REST API). Setup: https://developers.llamaindex.ai/python/shared/mcp/