Cito is a hybrid search engine over the Semantic Scholar corpus: 236M papers in the keyword index, 146M with SPECTER2 dense vectors, fused with RRF and reranked by a cross-encoder. Free web search with no signup, a plain JSON API, and a native MCP endpoint so agents like Claude Code can run deep literature research without upstream rate limits. Built because every academic API throttled my agents to death.
Hi Product Hunt! I built Cito because I kept hitting rate limits while doing literature research with AI agents. Google Scholar has no API at all, and Semantic Scholar's defaults to 1 request per second. Fine for a human, but an agent doing a deep-research run fires dozens of queries and just stalls.
So I indexed the corpus myself: 236M papers, hybrid BM25 + SPECTER2 dense retrieval fused with RRF, reranked by a cross-encoder, served from a single CPU box in under half a second.
What makes it different:
- Web search works with no signup
- Plain JSON API with honest, generous limits (free keys: 100 req/min, vs 1 req/sec upstream)
- Native MCP endpoint: one command and Claude Code / Cursor can search the literature directly
It is deliberately a retrieval engine, not a chatbot. It returns ranked papers with abstracts, citation counts, open-access PDF links and DOIs; the reasoning layer is your agent's job.
Would love feedback, especially from anyone building research agents. If a rate limit ever blocks legitimate work, tell me and I will raise it.
Really glad someone finally built a search engine that doesn't choke an agent after three requests. If you could expose a streaming endpoint or webhook for long queries, agents could kick off a deep search and poll instead of holding a connection open the whole time. That would make it way easier to chain searches across Claude Code sessions without timing out.
finally a search tool that doesn't choke when my agents hammer it. the MCP integration just worked out of the box with claude code, which is more than i can say for most academic apis.
The MCP endpoint is what sold me. I keep hitting the Semantic Scholar 1 req/sec wall when Claude runs a deep lit-research pass and it just stalls. Does the free 100/min hold up for a full run, or does it throttle once an agent goes wide?
About Cito on Product Hunt
“Hybrid academic search over 236M papers, built for agents”
Cito launched on Product Hunt on July 16th, 2026 and earned 102 upvotes and 5 comments, placing #13 on the daily leaderboard. Cito is a hybrid search engine over the Semantic Scholar corpus: 236M papers in the keyword index, 146M with SPECTER2 dense vectors, fused with RRF and reranked by a cross-encoder. Free web search with no signup, a plain JSON API, and a native MCP endpoint so agents like Claude Code can run deep literature research without upstream rate limits. Built because every academic API throttled my agents to death.
Cito was featured in Developer Tools (515.8k followers), Artificial Intelligence (473.7k followers), Search (18.1k followers) and Vercel Day (26 followers) on Product Hunt. Together, these topics include over 187.7k products, making this a competitive space to launch in.
Who hunted Cito?
Cito was hunted by Tao An. A “hunter” on Product Hunt is the community member who submits a product to the platform — uploading the images, the link, and tagging the makers behind it. Hunters typically write the first comment explaining why a product is worth attention, and their followers are notified the moment they post. Around 79% of featured launches on Product Hunt are self-hunted by their makers, but a well-known hunter still acts as a signal of quality to the rest of the community. See the full all-time top hunters leaderboard to discover who is shaping the Product Hunt ecosystem.
Want to see how Cito stacked up against nearby launches in real time? Check out the live launch dashboard for upvote speed charts, proximity comparisons, and more analytics.
Tao An