openapi: 3.0.3
info:
title: Fern Fern Ask Website Sources API
description: The Ask Fern API is Fern's hosted, public REST surface for the "Ask Fern" AI documentation-search feature. It lets you index a documentation website and then query it programmatically, so you can build your own support integrations on top of Fern's AI-powered, docs-grounded answers. This is the primary documented hosted REST API that Fern exposes to customers; the rest of the Fern platform (SDK generation, docs generation, API-reference builds) is driven through the open-source `fern` CLI and the Fern dashboard rather than a public REST API. Requests are authenticated with a Bearer token generated by the `fern token` CLI command; the Ask Fern API is available on the Team and Enterprise plans. The website index/status endpoints are grounded in Fern's published API reference; the /ask query endpoint shape is modeled from the documented feature and should be reconciled against the live reference. Not all fields are exhaustively documented here.
version: '1.0'
contact:
name: Fern
url: https://buildwithfern.com
license:
name: Apache-2.0
url: https://github.com/fern-api/fern/blob/main/LICENSE
servers:
- url: https://fai.buildwithfern.com
description: Ask Fern API (production)
security:
- bearerAuth: []
tags:
- name: Website Sources
description: Index documentation websites and check indexing job status.
paths:
/sources/website/{domain}/index:
post:
operationId: indexWebsite
tags:
- Website Sources
summary: Index a documentation website
description: Start an indexing job that crawls and indexes the pages of a documentation website so its content can be queried through Ask Fern. Returns a job_id used to poll indexing status. (Path and body modeled from the documented feature; reconcile against the live reference.)
parameters:
- name: domain
in: path
required: true
description: The documentation domain to index (for example, docs.example.com).
schema:
type: string
requestBody:
required: false
content:
application/json:
schema:
type: object
properties:
base_url:
type: string
description: Base URL to begin crawling from.
responses:
'200':
description: Indexing job accepted.
content:
application/json:
schema:
type: object
properties:
job_id:
type: string
description: Identifier of the indexing job to poll for status.
'401':
$ref: '#/components/responses/Unauthorized'
/sources/website/{domain}/status:
get:
operationId: getWebsiteStatus
tags:
- Website Sources
summary: Get website indexing status
description: Return the status of a website indexing job, including how many pages were indexed or failed.
parameters:
- name: domain
in: path
required: true
description: The documentation domain being indexed.
schema:
type: string
- name: job_id
in: query
required: true
description: The job ID returned from the index endpoint.
schema:
type: string
responses:
'200':
description: Indexing job status.
content:
application/json:
schema:
$ref: '#/components/schemas/WebsiteStatus'
'401':
$ref: '#/components/responses/Unauthorized'
components:
schemas:
WebsiteStatus:
type: object
properties:
job_id:
type: string
status:
type: string
description: 'Job status: PENDING, PROCESSING, COMPLETED, or FAILED.'
enum:
- PENDING
- PROCESSING
- COMPLETED
- FAILED
base_url:
type: string
pages_indexed:
type: integer
description: Count of successfully indexed pages.
pages_failed:
type: integer
description: Count of pages that failed to index.
error:
type: string
nullable: true
description: Error message if the job failed.
responses:
Unauthorized:
description: Missing or invalid API token.
content:
application/json:
schema:
type: object
properties:
error:
type: string
securitySchemes:
bearerAuth:
type: http
scheme: bearer
description: 'Bearer token generated with the `fern token` CLI command. Passed as `Authorization: Bearer YOUR_API_TOKEN`. Tokens are scoped to your organization and do not expire.'