> ## Documentation Index > Fetch the complete documentation index at: https://technologychecker.io/docs/llms.txt > Use this file to discover all available pages before exploring further. # Validate churn signals API > Actively re-detect churn candidates in real time and get a reasoned verdict per domain. Billed per domain after completion; verdicts cached 48 hours. ## Frequently asked questions The confidence score is statistical — it grades a churn from detection history. This endpoint is definitive: it loads the site again right now with a browser and consent-banner clicks, so it sees more than the bulk crawl did. Use it on the handful of churns you are about to act on, not on the whole feed. `confirmed` — the technology is absent on a healthy re-detection, so the removal is genuine. `false_positive` — it is still there, so the churn was a prior crawl miss. `masked` — a header-detected origin web server is now behind a CDN or proxy, which is a detection change rather than a removal. `inconclusive` — the site was unreachable, blocked, or gave too little signal. Roughly 2 credits per domain in fetch mode and 5 in browser mode, charged after completion. An `inconclusive` result is never charged, because that is our side failing rather than yours. Verdicts are cached for 48 hours per domain and technology pair, so a repeat call returns the stored verdict with `cached: true` at no charge and with no re-crawl. Inconclusive results are never cached, so a retry genuinely re-runs. Up to 10 in `auto` or `browser` mode, and up to 100 in `fetch` mode. Fetch parallelises at roughly 1–3 seconds per item; browser takes 30–60 seconds each, which is why its cap is small enough to fit a synchronous response. Split larger browser batches on your side. It routes technologies with a reliable detection method to the fast fetch path and sends everything else straight to a browser. If a fetch result comes back weak it escalates to a browser once. That keeps the average cost near the fetch price while still settling the hard cases. ## OpenAPI ````yaml POST /v1/signals/churn/validate openapi: 3.1.0 info: title: TechnologyChecker API description: >- Discover technology stacks, track market trends, and enrich data with company intelligence. version: 1.0.0 contact: name: TechnologyChecker Support email: support@technologychecker.io url: https://technologychecker.io servers: - url: https://api.technologychecker.io description: Production security: - bearerAuth: [] tags: - name: Domain technologies description: Look up technologies detected on any domain - name: Technology data description: Search, look up, and get details on tracked technologies - name: Market intelligence description: Technology stats, trends, and market share - name: Company data description: Firmographic and company intelligence - name: Live detection description: Real-time technology detection with browser rendering - name: Signals description: >- Intent signals derived from technology state transitions: who adopted, who churned, who switched, and who has a gap in their stack. - name: Alerts description: >- Saved signal queries delivered to your webhook. Every signal you can query, you can subscribe to. - name: Audiences description: >- Saved groups of domains — uploaded lists or computed recipes — that you can profile, slice and monitor. - name: Lead lists description: >- Build and export targeted domain lists combining technology detection with company data. paths: /v1/signals/churn/validate: post: tags: - Signals summary: Validate churn signals API description: >- Actively re-detect churn candidates right now and return a reasoned verdict per item. The statistical accuracy layers grade a churn from history; this endpoint settles it by loading the site again with a browser and consent-banner clicks, so it sees more than the bulk crawl did. **Billing is per domain, charged after completion:** roughly 2 credits for a fetch-mode check and 5 for a browser-mode check. An `inconclusive` result is never charged. Verdicts are cached for 48 hours per `(domain, technology_id)` pair — a repeat call returns the stored verdict with `cached: true`, with no re-crawl and no charge. operationId: validateChurn requestBody: required: true content: application/json: schema: type: object required: - items properties: items: type: array minItems: 1 description: >- The churn candidates to re-check. Maximum 10 items in `auto` or `browser` mode, 100 in `fetch` mode. items: type: object required: - domain - technology_id properties: domain: type: string example: sandovalcountynm.gov technology_id: type: integer example: 300 mode: type: string enum: - auto - fetch - browser default: auto description: >- `auto` routes high-reliability technologies to a fast fetch and everything else straight to a browser, escalating weak fetch results once. `fetch` parallelises at roughly 1–3 seconds per item. `browser` takes 30–60 seconds per item. interact: type: boolean default: true description: Click consent banners so consent-gated tags fire. example: items: - domain: sandovalcountynm.gov technology_id: 300 mode: auto interact: true responses: '200': description: A verdict per submitted item content: application/json: schema: type: object properties: success: type: boolean example: true data: type: object properties: results: type: array items: type: object properties: domain: type: string example: sandovalcountynm.gov technology_id: type: integer example: 300 verdict: type: string enum: - confirmed - false_positive - masked - inconclusive description: >- `confirmed` — absent on a healthy re-detection, a genuine removal. `false_positive` — still detected live, so the churn was a prior crawl miss. `masked` — a header-detected origin web server is now behind a CDN or proxy, which is a detection change rather than a removal. `inconclusive` — unreachable, blocked or too little signal; never cached and never charged. example: confirmed still_detected: type: boolean example: false newly_detected: type: array items: type: string example: - Cloudflare mode_used: type: string enum: - fetch - browser example: browser cached: type: boolean description: >- The verdict came from the 48-hour cache; nothing was re-crawled or charged. example: false credits_charged: type: integer example: 5 reason: type: string credits_charged: type: integer description: Total charged for this request. example: 5 '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '402': $ref: '#/components/responses/PaymentRequired' '404': $ref: '#/components/responses/NotFound' '429': $ref: '#/components/responses/RateLimited' components: responses: BadRequest: description: Invalid or missing parameters content: application/json: schema: $ref: '#/components/schemas/ApiError' example: success: false error: code: VALIDATION_ERROR message: >- Provide exactly one scope: technology_id, technology or category_id. Unauthorized: description: Missing or invalid API key content: application/json: schema: $ref: '#/components/schemas/ApiError' PaymentRequired: description: Not enough credits, or the plan does not include this feature content: application/json: schema: $ref: '#/components/schemas/ApiError' example: success: false error: code: INSUFFICIENT_CREDITS message: Insufficient credits for this request. details: required: 1 available: 0 NotFound: description: Resource not found content: application/json: schema: $ref: '#/components/schemas/ApiError' RateLimited: description: Rate limit exceeded content: application/json: schema: $ref: '#/components/schemas/ApiError' schemas: ApiError: type: object properties: success: type: boolean example: false error: type: object properties: code: type: string example: UNAUTHORIZED message: type: string example: Missing or invalid API key securitySchemes: bearerAuth: type: http scheme: bearer description: >- API key in format `tapi_live_[32-char]` (live) or `tapi_test_[32-char]` (test) ````