> ## Documentation Index > Fetch the complete documentation index at: https://docs.truscan.co/llms.txt > Use this file to discover all available pages before exploring further. # Answer a question with citations ## OpenAPI ````yaml /api-reference/answer.json post /api/answer openapi: 3.1.0 info: title: Truscan Answer version: 1.0.0 description: >- Cited answers assembled from pages the search service ranked and read. Nothing here is generated. Every sentence in `answer` is quoted verbatim from the source its marker points at, which is what makes a citation verifiable rather than plausible: the quoted span and the marker are the same object. One answer is one charge. The search behind it and the pages it reads are included in that price, so the same question at a deeper tier reads further and costs the same. servers: - url: https://api.truscan.co security: - bearerAuth: [] paths: /api/answer: post: summary: Answer a question with citations operationId: answer requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/AnswerRequest' responses: '200': description: The assembled answer content: application/json: schema: $ref: '#/components/schemas/AnswerEnvelope' example: success: true message: Answered from 2 sources. result: id: ans_8d3ddecc038c10d9 query: >- why is TLS certificate pinning discouraged in mobile apps now answer: >- Originally, certificate pinning was designed to prevent monster-in-the-middle (MITM) attacks by associating a hostname with a specific TLS certificate. [2] The cost-benefit equation has changed: the risk of a rogue certificate is now quite low, whereas the risk of your own app breaking due to pinning is comparatively higher. [1] passages: - text: >- Originally, certificate pinning was designed to prevent monster-in-the-middle (MITM) attacks by associating a hostname with a specific TLS certificate. source: 2 score: 0.7412 - text: >- The cost-benefit equation has changed: the risk of a rogue certificate is now quite low, whereas the risk of your own app breaking due to pinning is comparatively higher. source: 1 score: 0.6903 sources: - 'n': 1 url: >- https://blog.cloudflare.com/why-certificate-pinning-is-outdated/ title: >- Avoiding downtime: modern alternatives to outdated certificate pinning practices domain: blog.cloudflare.com score: 0.614 - 'n': 2 url: >- https://www.sans.org/blog/tls-ssl-failures-and-some-thoughts-on-cert-pinning-part-1 title: TLS/SSL failures and some thoughts on cert pinning domain: sans.org author: Jake Williams score: 0.552 format: json usage: answers: 1 search_requests: 1 pages_read: 9 stats: took_ms: 13095 search_ms: 12940 sources_read: 9 considered: 25 cached: false '401': $ref: '#/components/responses/Failure' '402': $ref: '#/components/responses/Failure' '422': $ref: '#/components/responses/Failure' '429': $ref: '#/components/responses/Failure' '502': $ref: '#/components/responses/Failure' components: schemas: AnswerRequest: type: object required: - query properties: query: type: string maxLength: 512 description: The question. `q` is accepted as an alias. tier: type: string enum: - instant - deep - deep_reasoning default: instant description: >- Search depth behind the answer. Instant reads up to 10 pages, deep 50, deep reasoning 100, so a deeper tier has more to quote from. sources: type: integer minimum: 1 maximum: 50 default: 10 description: How many ranked results the answer may quote from. passages: type: integer minimum: 1 maximum: 12 default: 5 description: >- How many quotes the answer carries. Past a dozen it stops reading as an answer and starts reading as the search results again. format: type: string enum: - json - markdown - text default: json site: type: string description: Restrict to one domain. lang: type: string freshness: type: string enum: - any - day - week - month - year category: type: string enum: - general - news - science - images - videos - it AnswerEnvelope: type: object properties: success: type: boolean const: true message: type: string result: $ref: '#/components/schemas/AnswerResponse' AnswerResponse: type: object properties: id: type: string examples: - ans_8d3ddecc038c10d9 query: type: string corrected_query: type: string description: >- Present only when the original question matched nothing and the search behind this answer ran a spelling correction instead. answer: type: string description: >- The assembled prose, with [n] markers pointing into sources. Every marker resolves: a source nothing quoted is dropped from the list and the numbering is contiguous from 1. Empty when nothing quotable was found, which is deliberate. An answer with no support is the one thing this endpoint will not return. passages: type: array items: $ref: '#/components/schemas/Passage' sources: type: array items: $ref: '#/components/schemas/Source' description: >- Only the documents actually quoted. This is a citation list, not the search results. rendered: type: string description: >- The markdown or text view, with the sources as a numbered list underneath. Empty for format=json. format: type: string enum: - json - markdown - text usage: $ref: '#/components/schemas/Usage' stats: $ref: '#/components/schemas/Stats' Failure: type: object properties: success: type: boolean const: false message: type: string result: type: object properties: code: type: string Passage: type: object description: One quoted span and where it came from. properties: text: type: string description: Quoted verbatim from the source. Nothing is rewritten. source: type: integer description: One-based index into sources, matching the [n] marker in answer. score: type: number description: >- The passage's own match against the question, weighted by how well search ranked the page it came from. Source: type: object properties: 'n': type: integer description: The citation number used in answer. url: type: string format: uri title: type: string domain: type: string author: type: string description: >- Present when the page declared one. Read from the page itself, not inferred. published_at: type: string format: date-time score: type: number description: >- The search rank score, carried through so citation order can be checked against the ranking /api/search would have returned. Usage: type: object description: >- What this call consumed. Only answers is billed. The rate is all-inclusive, so search_requests and pages_read report the work that price covered rather than separate charges: they are here so you can see what a question actually took, and tune the tier against it. Units rather than dollars: the rate card belongs to the billing service, and restating prices here is how two numbers drift apart. Multiply answers by /api/billing/pricing, which is generated from the same constants that charge the request. properties: answers: type: integer description: The billed line. One per call. search_requests: type: integer description: >- Covered by the answer price, not charged. Zero when the search behind the answer was served from cache. pages_read: type: integer description: >- Pages search delivered with a body, covered by the answer price. A page that failed to fetch is not counted. Stats: type: object properties: took_ms: type: integer search_ms: type: integer description: >- Time spent in search, including the pages it read. Assembly is the remainder and is measured in milliseconds. sources_read: type: integer description: >- How many results carried page content. A result without a body can still be cited from its engine snippet, scored below any real passage. considered: type: integer description: How many passages were available before selection. cached: type: boolean description: >- Whether the search behind this answer was served from cache. The answer itself is not cached. responses: Failure: description: >- The envelope with success false. result carries the machine-readable code and nothing else; the HTTP status line carries the real status. content: application/json: schema: $ref: '#/components/schemas/Failure' securitySchemes: bearerAuth: type: http scheme: bearer description: >- An API key, sent as `Authorization: Bearer enc_…`. A dashboard session cookie works on the same route. ````