# Free2AItools > Agent-native structured index of 533,000+ AI models, datasets, papers, agents, spaces, tools, and prompts. > Cross-source aggregator (HuggingFace, GitHub, ArXiv, Replicate, Civitai, etc.) > ranked by FNI (Free2AITools Nexus Index) — designed for AI agents, not human browsing. This file follows the llms.txt convention (llmstxt.org). It is the canonical discovery surface for autonomous agents, MCP clients, and LLM-based tooling that need to consume Free2AItools data programmatically. ## What you can do here - Search and rank 533,000+ AI entities by FNI score across HuggingFace, GitHub, ArXiv, Ollama, Replicate, Civitai, and other sources - Compare 2-10 models side-by-side with technical specs and license breakdown - Fetch full structured metadata for any entity by ID - Get FNI badges (SVG) for any entity for README embedding - Discover via MCP (Model Context Protocol) — drop-in for Claude Desktop, Cursor, and similar ## Primary API surface All endpoints return JSON unless noted. CORS open. Free tier hard-cap: 5 results per search; auth/paid tiers (TBD) raise the cap. ### Discovery - `GET /.well-known/mcp.json` — MCP server manifest (transport, protocol version, tool catalog with input schemas) - `GET /llms.txt` — this file - `GET /sitemap.xml` — full URL index ### MCP server (JSON-RPC 2.0) - `POST /api/mcp` — JSON-RPC dispatch - `method: initialize` → server info + capabilities - `method: tools/list` → 5 tools: free2aitools_search / _rank / _explain / _select_model / _compare - `method: tools/call` → invoke a tool with arguments ### Search and lookup - `GET /api/v1/search?q=[&type=][&limit=N]` — FNI-ranked search - `type` accepts canonical values (`model`, `paper`, `tool`, `dataset`) AND common id-prefix aliases (`hf-model`, `arxiv-paper`, `gh-model`, `replicate-model`, etc.) — both resolve to the canonical type - `limit` clamped to 1-5 for free tier - Response includes FNI score breakdown (semantic / authority / popularity / recency / quality) per result - `GET /api/v1/entity/[?include=body]` — full structured metadata for one entity (search → detail Agent journey) - Lean default response: ~30 Agent-relevant fields grouped into identity / classification / fni / specs / stats / links / relations - `?include=body` adds readme_html (~250KB) - 404 with `{"error":"Entity not found: "}` when no match - `GET /api/v1/compare?ids=,[,...]` — side-by-side comparison of 2-10 entities. Returns FNI factors + technical specs + license per entity. - `GET /api/v1/health` — VFS layer observability snapshot: cache-hit counters (L0/L1/L2), short-read retry stats, isolate uptime. No auth, not cached. - `GET /api/v1/badge/` — SVG badge with FNI score, color-coded (green ≥ 90 excellent, blue ≥ 70 good, yellow ≥ 50 average, red below). Suitable for README embedding. ## FNI score interpretation FNI v2.0 = `min(99.9, 0.35·S + 0.25·A + 0.15·P + 0.15·R + 0.10·Q)` - `S` Semantic relevance (ANN cosine similarity, query-time) - `A` Authority (mesh gravity / cross-source corroboration) - `P` Popularity (log-compressed downloads / stars / citations) - `R` Recency (exponential decay on last-modified) - `Q` Quality (completeness + utility signals) Scoring is deterministic per snapshot; daily snapshots are taken at 00:00 UTC. ## Update cadence - Factory cron: Mon and Thu at 02:00 UTC — full harvest + enrichment + aggregation + R2 upload + CDN purge + probe - Daily Snapshot: 00:00 UTC — snapshot the current registry to time-series archive for FNI trend analysis ## Entity types Canonical types (use in `?type=` filter): - `model` — AI models (HF / GH / Replicate / Civitai / Kaggle / Ollama sources) - `paper` — research papers (ArXiv, Hugging Face papers, Semantic Scholar) - `tool` — open-source developer tools (GitHub repos) - `dataset` — public datasets - `space` — interactive demos - `agent` — agent frameworks and templates - `prompt` — prompt templates / instruction collections ## ID format Entity IDs use the `-----` convention: - `hf-model--meta-llama--Llama-3-8B-Instruct` - `arxiv-paper--unknown--` - `gh-tool----` - `replicate-model----` IDs are stable across snapshots; `slug` (lowercase normalized form) is the canonical sharding key. ## Project positioning Free2AItools is the **structured knowledge layer between raw AI ecosystem sources and AI agents**. Raw data lives at HuggingFace, GitHub, ArXiv, etc. This project adds: - Unified schema across sources - FNI ranking (deterministic, time-stable, explainable) - Mesh-graph relations between entities (base_model, datasets_used, citations) - Daily snapshot archive (FNI trends over time) - Agent-first API (this file, MCP, structured JSON) Comparable in posture to Bloomberg Terminal for finance: not the data source, but the canonical structured query layer that downstream consumers depend on. ## Contact - Site: https://free2aitools.com - Strategic positioning + roadmap: see Free2AItools V∞ Roadmap (internal) - Free tier supports anonymous public API access; auth + raised limits TBD. ## Notes for agent implementers - Prefer MCP (`POST /api/mcp`) for first-class Agent integration — JSON-RPC 2.0, tool catalog discoverable via `tools/list`, structured tool responses - For HTTP-only flows: `search` → `entity` → optional `compare` - All scoring is FNI v2.0; the `fni_version` field in responses identifies the exact algorithm version (forward-compatible across snapshots) - Field semantics: `0` means measured-zero, `null` means not-measured. Treat them differently when scoring downstream - Booleans (ollama_compatible, can_run_local, is_trending) are tri-state: `true` / `false` / `null` (unknown) This file is updated when the API contract changes. Last revision tracks the state of MCP tool catalog + endpoint surface as of the current deploy.