What is Seltz?
Web Knowledge API for AI agents and RAG that runs its own Rust-built crawler and hybrid lexical, semantic, and graph index rather than wrapping Google or Bing.
Our verdict
Most search APIs in this category are thin layers over Google or Bing. Seltz is not: it runs its own crawler, index, and retrieval models, all written in Rust, behind two endpoints. A search call returns ranked documents (url plus content) shaped for LLM context windows, and an answer call returns a markdown response with citations. There is also an OpenAI-compatible chat-completions surface and an MCP server. Founder Antonio Mallia has a real information-retrieval track record (NYU PhD, ex-Pinecone, ex-Amazon, and creator of the open-source PISA search engine), which is the substance behind the owns-the-whole-pipeline pitch.
The honest caveat is maturity. Seltz launched its Web Knowledge API publicly in 2026, and its coverage began US-news-first but has since expanded to general web search and people data, though full open-web reach is still a work in progress and remains narrower than Exa or Tavily. The founder's published latency and accuracy figures are self-reported on Hacker News and have not been independently reproduced, so treat them as vendor claims. Seltz was selected for the AWS and NVIDIA Startup Village at VivaTech 2026 and, in June 2026, raised a $12.5M seed round co-led by Speedinvest and B Capital, with Italian Founders Fund, United Ventures, and Future Back Ventures also participating.
Worth evaluating if you are building agent loops where latency and full-text, source-cited context matter and you want an index that is not a Google reseller. For broad general-web recall today, the more established peers still have the deeper crawl.
Categories:
AI search APIs are the infrastructure layer that gives large language models access to current web information. Unlike traditional search engines, these APIs return semantically relevant, structured results optimized for retrieval-augmented generation (RAG) and AI agent workflows. They are used by AI products that need to answer questions about the real world beyond their training data.
