# LastSearch

> Research infrastructure for AI agents. Real-time web search with evidence-backed citations and confidence scores.

LastSearch gives AI agents structured, verifiable web research. Unlike chat-based search engines, it returns JSON with extracted claims, cited sources, confidence scores, and contradiction detection — designed for programmatic evaluation by agents.

## Available As
- MCP Server: `npx lastsearch` (13 tools)
- REST API: `https://lastsearch.ai/api/browse/*`
- Python SDK: `pip install lastsearch`
- LangChain: `pip install langchain-lastsearch`
- CrewAI: `pip install crewai-lastsearch`
- LlamaIndex: `pip install llamaindex-lastsearch`

Previously known as `lastsearch` (npm) and `lastsearch` (PyPI) — renamed to `lastsearch` and `lastsearch`. The old names still work and redirect to the new packages.

## Key Capabilities
- **Search**: Web search returning ranked results
- **Answer**: Full pipeline — search, fetch, extract claims, verify, cite, score confidence
- **Extract**: Structured claim extraction from any URL
- **Compare**: Side-by-side raw LLM vs evidence-backed answer
- **Clarity**: Anti-hallucination answer engine — three modes: (1) prompt mode returns enhanced prompts only for your own LLM, (2) answer mode gives fast LLM-only answer with grounding techniques (no internet), (3) verified mode runs web pipeline and fuses LLM + sources into one source-backed answer
- **Research Sessions**: Persistent multi-query sessions with knowledge accumulation
- **Feedback**: Submit result feedback to improve future accuracy

## Verification Pipeline
1. Web search (Tavily API)
2. Page fetch and parse
3. Claim extraction via LLM
4. Sentence-level verification
5. Cross-source consensus detection
6. Contradiction detection
7. Domain authority scoring (10,000+ domains)
8. Evidence-based confidence scoring

## Confidence Score
Not LLM self-assessed. Computed from: verification rate, domain authority, source count, consensus score, domain diversity, claim grounding, source recency, citation depth. Contradiction penalty applied.

## Links
- Website: https://lastsearch.ai
- Docs: https://lastsearch.ai/docs
- GitHub: https://github.com/lastsearch-hq/lastsearch
- npm: https://www.npmjs.com/package/lastsearch (renamed from lastsearch, old name still works)
- PyPI: https://pypi.org/project/lastsearch/ (renamed from lastsearch, old name still works)
- LangChain: https://pypi.org/project/langchain-lastsearch/
- CrewAI: https://pypi.org/project/crewai-lastsearch/
- LlamaIndex: https://pypi.org/project/llamaindex-lastsearch/
- Agent Skills: https://github.com/lastsearch-hq/lastsearch-skills
- Discord: https://discord.gg/ubAuT4YQsT

## Optional
- [Full documentation](https://lastsearch.ai/llms-full.txt)