Anthropic Claude API Context Guide for AI Coding (llms.txt + Rules + MCP)
Build with Claude 3.5 Sonnet and Haiku. Industry leader in coding, reasoning, and context window efficiency.
1. Anthropic Claude API Official llms.txt & Clean Markdown Documentation
Official Anthropic Spec v2Feed this clean, token-efficient Markdown documentation directly to Antigravity, Cursor, or Claude Code to prevent hallucinations and outdated API syntax.
# Standard llms.txt Index Endpoint
https://docs.anthropic.com/llms.txt
# Comprehensive Documentation Bundle
https://docs.anthropic.com/llms-full.txt2. Production-Ready Anthropic Claude API Cursor Rules (.cursorrules & .mdc)
Anthropic Claude Prompt Caching, Tool Use (Function Calling), and Thinking Blocks. Save this into .cursor/rules/anthropic.mdc in your project repository.
// Anthropic Claude Rules
- Leverage Prompt Caching (cache_control: { type: "ephemeral" }) on large system prompts to reduce cost by 90%.
- Pass tool definitions with detailed descriptions and strict JSON schema parameters.
- Provide clear role separation: system instructions in system parameter, conversation in messages.
- Format complex input contexts with XML tags (e.g. , ) for highest parsing accuracy. 3. Anthropic Claude API Antigravity & Claude Code System Instructions
Add this concise instruction block to your workspace .gemini/rules or project system prompt.
// Context Anchor for Anthropic Claude API
When writing code for Anthropic Claude API, refer directly to the verified specifications at https://docs.anthropic.com/llms.txt.
Follow strict error-handling and avoid deprecated API calls.5. Troubleshooting: Common Anthropic Claude API AI Coding Issues & Fixes
Frequently reported errors when LLMs generate Anthropic Claude API code without proper context:
6. Best Used With (Anthropic Claude API Architecture Combos)
Engineers building with Anthropic Claude API frequently combine these complementary developer frameworks: