SerpKite Custom Search API

openapi: 3.2.0
info:
  title: SerpKite SERP Customsearch API
  version: 1.12.4
  description: 'Public search API (api.serpkite.com). Google results as clean JSON or Markdown

    for AI agents, plus a Google Custom Search–compatible endpoint. Official SDKs:

    `serpkite` on npm and PyPI, `github.com/serpkite/serpkite-go`. **Auth:** `Authorization: Bearer skt_live_…`. A bare `Authorization: skt_live_…`

    (no scheme) is also accepted, for MCP hosts that can''t add one. GET requests

    may pass `?api_key=` instead. `/customsearch/v1` also accepts Google''s `?key=`. **Bodies:** every vertical accepts `POST` with a JSON object or `GET` with the

    same parameters in the query string (only `GET /v1/search` is spelled out

    here). Unknown parameters are rejected with 400, and so is a parameter the

    endpoint would ignore (e.g. `time` on `/v1/scholar`, `ll` on `/v1/search`). To run many queries at once,

    use `POST /v1/batches`. **Formats:** `format=json` (default) returns the schemas below. `format=markdown` returns `text/markdown` for every vertical. `format=compact` and `fields=` return a reduced JSON object (same top-level

    keys, fewer item fields, `meta` always kept), so required item fields may be

    absent there. **Responses** share one envelope: `request` (the normalised request),

    `results` (the vertical''s primary list), vertical-specific extras and `meta`. All keys are snake_case. **Credits** are decimal numbers (e.g. `0.5`). Failed, empty and blocked

    responses are refunded. Every billed response carries `X-Credits-Used`,

    `X-Credits-Remaining`, `X-Cost-USD`, `X-Cache` (`HIT`|`MISS`), `X-Latency-Ms`,

    `X-Tokens-Estimate` and `X-Request-Id`. **Errors** share one body: `{"error":{"code","message","request_id"}}`. Upstream failures (`upstream_error`, `upstream_blocked`, `upstream_timeout`)

    are `503` with `Retry-After`, never billed and safe to retry. The API never

    returns `502` or `504`. `429` also carries `Retry-After`: `rate_limited` is

    the per-second limit; `daily_limit_reached` is the free daily limit of an

    account that never bought a pack, which resets at 00:00 UTC (the message

    names the limit and the billing page; buying any pack removes it). `403 account_restricted` means the account''s free use is paused because it

    appears to be one of several accounts run by the same person (same device

    or network, or requests in step with other accounts) or uses a disposable

    email address; buying any pack lifts it. **CORS:** `Access-Control-Allow-Origin: *` without credentials; the `X-*`

    headers above are exposed, so a browser playground can call the API with a key. The keyless `/playground/search` is the exception: it only answers serpkite.com

    and app.serpkite.com (other `Origin`s get 403). Credit table: search/news/images/videos/maps/places/shopping/scholar/patents/

    webpage/customsearch = 1 per page; place details = 1; `num=100` depth bundle = 7; reviews = 1 per 10;

    autocomplete = 0.5; `include_content` = +1 per fetched page;

    batches ×0.5 (from 2026-11-23 a batch depth request is 0.5 per page with

    results, without the bundle cap: `num=100` = 5); cache hit via `max_age` ×0.5. `engine=consensus` (search only) =

    the sum of one page per provider that returned results. **AI** (Claude writes, OpenAI''s Decisions API runs typed checks; a failed

    model step is never billed): an answer (`include_answer` on `/v1/search` and

    `/v1/news`, the model part of `/v1/answer`) = +2 over the result page, +4

    when it read pages (`include_content`, `/v1/answer` depth=standard);

    `/v1/extract` `summary` = +4 and `output_schema` = +4 per page;

    `/v1/research` = lite 30, standard 75, deep 200. Responses that used a

    model carry `meta.llm`. **AI assistants** (`/v1/chatgpt`, `/v1/gemini`, `/v1/copilot`,

    `/v1/ai_mode`, `/v1/brave_ai`): a `prompt` sent to the public assistant

    as a logged-out user; the response is its answer

    (`text`, `markdown`) with the `sources` it cited or listed,

    `search_queries`, `products` and `places` where the assistant shows them,

    and `mentions` for the brands and domains in `track`.'
servers:
- url: https://api.serpkite.com
- url: http://localhost:8080
security:
- bearer: []
tags:
- name: Custom Search
paths:
  /customsearch/v1:
    get:
      summary: Google Custom Search JSON API–compatible endpoint (for apps moving off CSE)
      operationId: customSearch
      parameters:
      - name: key
        in: query
        schema:
          type: string
        description: API key (or Authorization Bearer)
      - name: cx
        in: query
        schema:
          type: string
        description: Accepted and ignored
      - name: q
        in: query
        required: true
        schema:
          type: string
      - name: start
        in: query
        schema:
          type: integer
          minimum: 1
          maximum: 91
          default: 1
      - name: num
        in: query
        schema:
          type: integer
          minimum: 1
          maximum: 10
          default: 10
      - name: gl
        in: query
        schema:
          type: string
      - name: hl
        in: query
        schema:
          type: string
      - name: lr
        in: query
        schema:
          type: string
      - name: safe
        in: query
        schema:
          type: string
          enum:
          - active
          - 'off'
      - name: dateRestrict
        in: query
        schema:
          type: string
          examples:
          - d7
          - w2
          - m6
          - y1
      - name: siteSearch
        in: query
        schema:
          type: string
      - name: searchType
        in: query
        schema:
          type: string
          enum:
          - image
      responses:
        '200':
          description: CSE-shaped response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CSEResponse'
        '400':
          $ref: '#/components/responses/Error'
        '401':
          $ref: '#/components/responses/Error'
        '402':
          $ref: '#/components/responses/Error'
        '429':
          $ref: '#/components/responses/Error'
        '503':
          $ref: '#/components/responses/Unavailable'
      tags:
      - Custom Search
components:
  responses:
    Unavailable:
      description: 'Temporarily unavailable, not billed, safe to retry after `Retry-After`.

        Codes: `upstream_error` (the upstream page couldn''t be fetched or parsed),

        `upstream_blocked` (the upstream is rate limiting us or refused the query), `upstream_timeout`

        (the search took too long), `unavailable` (endpoint or dependency down).

        The API never sends 502 or 504.

        '
      headers:
        Retry-After:
          $ref: '#/components/headers/RetryAfter'
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    Error:
      description: Error
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  headers:
    RetryAfter:
      description: Seconds to wait before retrying
      schema:
        type: integer
  schemas:
    Error:
      type: object
      required:
      - error
      properties:
        error:
          type: object
          required:
          - code
          - message
          properties:
            code:
              type: string
              description: '403: spend_cap_reached, key_limit_reached, account_restricted, forbidden. 409/422: idempotency_key_reused. 422: target_unavailable (the URL you asked for failed: its site answered 404, its domain doesn''t resolve; resending won''t help), no_pages. 429: rate_limited, daily_limit_reached. 503: upstream_error, upstream_blocked, upstream_timeout, unavailable (the API never sends 502 or 504)'
              examples:
              - unauthorized
              - invalid_request
              - insufficient_credits
              - rate_limited
              - daily_limit_reached
              - spend_cap_reached
              - key_limit_reached
              - account_restricted
              - idempotency_key_reused
              - forbidden
              - not_found
              - upstream_error
              - upstream_blocked
              - upstream_timeout
              - unavailable
              - internal
            message:
              type: string
            request_id:
              type: string
    CSEResponse:
      type: object
      required:
      - kind
      - searchInformation
      - items
      properties:
        kind:
          type: string
          const: customsearch#search
        url:
          type: object
        queries:
          type: object
          additionalProperties: true
        context:
          type: object
        searchInformation:
          type: object
          properties:
            searchTime:
              type: number
            formattedSearchTime:
              type: string
            totalResults:
              type: string
            formattedTotalResults:
              type: string
        items:
          type: array
          items:
            type: object
            properties:
              kind:
                type: string
                const: customsearch#result
              title:
                type: string
              htmlTitle:
                type: string
              link:
                type: string
              displayLink:
                type: string
              snippet:
                type: string
              htmlSnippet:
                type: string
              formattedUrl:
                type: string
              htmlFormattedUrl:
                type: string
              pagemap:
                type: object
                additionalProperties: true
              image:
                type: object
                additionalProperties: true
  securitySchemes:
    bearer:
      type: http
      scheme: bearer
    oauth:
      type: oauth2
      description: OAuth 2.1 for the remote MCP server only (authorization code + PKCE S256; app-api.serpkite.com is the authorization server).
      flows:
        authorizationCode:
          authorizationUrl: https://app-api.serpkite.com/oauth/authorize
          tokenUrl: https://app-api.serpkite.com/oauth/token
          refreshUrl: https://app-api.serpkite.com/oauth/token
          scopes:
            mcp: Use the SerpKite MCP tools, billed to your account
            offline_access: Stay connected with refresh tokens