What is a deep research API?

A deep research API automates the full research loop: it issues multiple search queries, reads source pages, extracts relevant information, and synthesizes findings into a coherent, cited report. The caller submits a research question and the API handles query planning, source discovery, content extraction, and synthesis internally. This is distinct from a standard search API, which returns ranked URLs but leaves reading and synthesis to the caller. Deep research APIs are built on agentic search principles: the system iterates, evaluates gaps, and continues gathering sources until it has enough evidence to produce a complete answer.

Use a deep research API for tasks that involve synthesizing information across many sources: competitive analysis, due diligence on a company or technology, literature review, or market mapping. A single web search API call is faster when you only need to locate a specific fact or find a page to scrape. Deep research is the right choice when the question requires reading and reconciling many sources before an answer is possible.

Firecrawl's deep research mode accepts a research question and returns a cited report built from dozens of sources, handling query planning, source discovery, content extraction, and synthesis in one request.