Answer

Get an LLM answer to a question informed by Exa search results. /answer performs an Exa search and uses an LLM to generate either:

1. A direct answer for specific queries. (i.e. “What is the capital of France?” would return “Paris”)
2. A detailed summary with citations for open-ended queries (i.e. “What is the state of ai in healthcare?” would return a summary with citations to relevant sources)

The response includes both the generated answer and the sources used to create it. The endpoint also supports streaming (as stream=True), which will return tokens as they are generated.

Alternatively, you can use the OpenAI compatible chat completions interface.

POST /answer

Answer

cURL

curl --request POST \
  --url https://api.exa.ai/answer \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "query": "What is the latest valuation of SpaceX?",
  "stream": false,
  "text": false,
  "model": "exa",
  "systemPrompt": "Prefer official sources and avoid duplicate results.",
  "userLocation": "US",
  "outputSchema": {
    "type": "object",
    "properties": {},
    "required": [
      "<string>"
    ],
    "description": "<string>",
    "additionalProperties": false
  }
}
'

200

{
  "answer": "$350 billion.",
  "requestId": "b5947044c4b78efa9552a7c89b306d95",
  "citations": [
    {
      "title": "SpaceX valued at $350bn as company agrees to buy shares from ...",
      "url": "https://www.theguardian.com/science/2024/dec/11/spacex-valued-at-350bn-as-company-agrees-to-buy-shares-from-employees",
      "publishedDate": "2023-11-16T01:36:32.547Z",
      "author": "Humza Naveed",
      "id": "https://arxiv.org/abs/2307.06435",
      "image": "https://arxiv.org/pdf/2307.06435.pdf/page_1.png",
      "favicon": "https://arxiv.org/favicon.ico",
      "text": "SpaceX valued at $350bn as company agrees to buy shares from ..."
    }
  ],
  "costDollars": {
    "total": 0.007,
    "search": {
      "neural": 0.007,
      "keyword": 0.0025
    },
    "summary": 0.005,
    "contents": {
      "text": 0.001,
      "highlights": 0.001,
      "summary": 0.001
    }
  }
}

Get your Exa API key

/answer supports structured output via the outputSchema parameter. Pass a JSON Schema object and the answer will be returned as structured JSON matching your schema instead of a plain string.

Authorizations

apiKeybearer

x-api-key · string · header · required

Pass your Exa API key in the x-api-key header. You can also authenticate with Authorization: Bearer .

Body

application/json

query · string · required

Natural-language question or instructions for the request.

Minimum string length: 1

Example:

"What is the latest valuation of SpaceX?"

stream · boolean · default: false

If true, the response is returned as a server-sent events (SSE) stream.

text · boolean · default: false

If true, returns full page text with default settings. If false, disables text return.

model · enum<string> · default: exa

The model used to generate the answer.

Available options: exa, exa-pro, exa-research, exa-fast

systemPrompt · string

Additional instructions that guide generated output or agent behavior. Use this for source preferences, novelty constraints, duplication constraints, or other behavior guidance.

Example:

"Prefer official sources and avoid duplicate results."

userLocation · string | null

The two-letter ISO country code of the user, e.g. US.

Example:

"US"

outputSchema · object

A JSON Schema Draft 7 specification for the desired answer structure. When provided, the answer is returned as a structured object matching the schema instead of a plain string.

Show child attributes

Response

200

application/json

OK

answer · string object · required

The generated answer based on search results. Returns a string by default, or a structured object matching the provided outputSchema.

Example:

"$350 billion."

requestId · string

Unique identifier for the request.

Example:

"b5947044c4b78efa9552a7c89b306d95"

citations · object[]

Search results used to generate the answer.

Show child attributes

costDollars · object

Endpoint-dependent estimated dollar cost breakdown for the completed request. Billing is computed from usage counters rather than this response object.

Show child attributes