Skip to main content
Deep Search is the research mode of the Search API. It uses the same /search endpoint, but the retrieval process can issue multiple searches, inspect the evidence, refine its approach, and synthesize a grounded result. Use standard Search when you need ranked pages for a well-formed query. Use Deep when finding the answer requires research.

How Deep Search works

Deep Search adds a research loop before the final response:
1

Plan the search

Exa starts with your query and may expand it into searches that cover different parts of the request. You can supply starting variations with additionalQueries.
2

Search and inspect

Deep searches for evidence, compares the findings with the request, and determines what is supported or still missing.
3

Refine

When the evidence is incomplete or contradictory, Deep can issue a more targeted search instead of returning the first plausible pages.
4

Select and synthesize

Deep selects the useful results and then uses the same synthesis path as other search types. When you provide outputSchema, the response includes structured output.content and field-level citations in output.grounding.
This process is especially useful for lists and structured outputs. Each requested item may require a different search, and Deep can gather and check those results before producing the final structure.

Choose a Deep mode

Start with deep for research workflows. Move to deep-lite when the task is simpler and latency matters.
Instead of deep-reasoning, use Exa Agent for long-running research, list building, and multi-hop enrichment. Agent has more compute per run and returns grounded, structured results.
See Pricing for current cost and latency guidance.

Make a Deep request

Set type on a normal Search API request:
Deep returns the selected search results under results. Add outputSchema when you also want a synthesized answer or structured dataset.

Provide starting queries

Deep normally decides which searches to run. Use additionalQueries when you already know distinct terminology, perspectives, or subproblems that the research should cover:
The main query is always included. You can provide up to 10 additional queries, and the list is available only to Deep search types. Do not provide minor rephrasings just to increase search volume. Add queries when each one contributes a meaningfully different search direction.

Guide behavior and output separately

systemPrompt and outputSchema affect different parts of the request:
  • systemPrompt guides source preferences, novelty, deduplication, and Deep’s research behavior.
  • outputSchema defines the final shape and triggers synthesis.
The query should describe what to research. The system prompt should describe how to conduct and present that research.
Prefer Deep when you need more than two structured items or each item must satisfy several requirements. Standard search types use the same synthesis path, but they do not perform the same iterative research before synthesis.

Read the grounded response

Structured responses separate generated values from their evidence:
Use output.content as the generated result and output.grounding to show or verify the sources supporting each field. Do not add citation or confidence fields to your own schema; Exa returns them automatically. numResults controls how many selected pages are returned in results. It does not set the number of searches Deep may perform.

Stream the synthesis

Set stream: true with outputSchema to receive the synthesized output over server-sent events:
Consume the typed events until done. The final event contains the completed output and search time, with cost information when available. Deep is unnecessary when one retrieval pass can satisfy the request:
  • You need relevant pages, not a researched conclusion.
  • The query already identifies a specific source or narrow topic.
  • Your application performs its own reasoning and only needs retrieval.
  • The request is on an interactive, autocomplete, or voice path.
Use auto for the default quality and speed balance, or fast and instant for measured latency requirements.

Search API guide

Build requests, choose result content, and apply filters.

Search best practices

Improve quality, context, latency, and agent integrations.

Search API reference

See every request parameter and response field.

Pricing

Review current Deep Search costs and latency.
Last modified on September 15, 2026