验证任何 人脸。
无需用户进行任何操作。

# Didit Liveness — integrate in 5 minutes

You are integrating Didit's Liveness (presentation-attack detection) module
into <my_stack>. Follow these steps exactly. Every URL, header, and enum
value below is canonical — do not paraphrase or "improve" them.

## 1. Provision an account
- Sign up: https://business.didit.me (no credit card required).
- Or provision programmatically: POST https://apx.didit.me/auth/v2/programmatic/register/
  (returns an API key bound to the workspace + application).

## 2. Two integration paths — pick one

### Path A — Workflow Builder (hosted UI)
Best when you want Didit to handle camera, motion prompts, low-light
fallback, mobile handoff, and accessibility for you.

1. Create a workflow that contains the LIVENESS feature:
   POST https://verification.didit.me/v3/workflows/
   Authorization header:  x-api-key: <your-api-key>
   Body: workflow_label, features array with the single entry
         { feature: "LIVENESS" }   (UPPERCASE — strict enum)
   Optional config: liveness_method ("PASSIVE" | "FLASHING" | "ACTIVE_3D")
   and per-warning threshold overrides.

2. Create a verification session for an end user:
   POST https://verification.didit.me/v3/session/
   Body: workflow_id (from step 1), vendor_data (your own user id).
   Response: session_url — redirect the user to it.

3. Listen for webhook callbacks (see "Webhooks" below).

### Path B — Standalone server-to-server API
Best when you already have a selfie image (mobile SDK capture, native
onboarding app, reseller pipeline). Standalone is single-frame
PASSIVE only — for ACTIVE_3D or FLASHING you must use Path A.

POST https://verification.didit.me/v3/passive-liveness/
Content-Type: multipart/form-data
Body fields:
  - image        (required, file — single selfie)
  - vendor_data  (optional string, your user id)

Response: JSON report with liveness score, method, and warnings array.

## 3. Webhooks (Path A only — Path B returns synchronously)
- Register a webhook destination once via
  POST https://verification.didit.me/v3/webhook/destinations/
  Body: url, subscribed_events: ["session.verified", "session.review_started",
                                  "session.declined"]
- Response includes secret_shared_key — store it.
- Every webhook delivery carries an X-Signature-V2 header you MUST verify
  before trusting the payload.  HMAC-SHA256 verification MUST run against the raw body bytes (the raw payload as Didit sent it) BEFORE any JSON parsing — re-serialising the parsed body changes whitespace and key order, which invalidates the signature.Algorithm:
    1. sortKeys(payload) recursively
    2. shortenFloats (truncate trailing zeros after the decimal point)
    3. JSON.stringify the result
    4. HMAC-SHA256 with the secret_shared_key
    5. Hex-encode, compare to the X-Signature-V2 header.

## 4. Reading the report (both paths return the same shape)
The liveness object includes:
- status: "Approved" | "Declined" | "In Review" | "Not Finished"
- method: "PASSIVE" | "FLASHING" | "ACTIVE_3D"
- score: number 0-100 (normalized liveness score)
- reference_image: signed URL to the captured selfie (expires in 1 hour)
- video_url: signed URL to the capture video, present only for FLASHING
  and ACTIVE_3D (expires in 1 hour)
- age_estimation: { age, age_range } when enabled in the workflow
- warnings: Array<{ risk, log_type, short_description, long_description }>

Auto-decline risks (always enforced by Didit, not configurable):
- NO_FACE_DETECTED
- LIVENESS_FACE_ATTACK
- FACE_IN_BLOCKLIST

Configurable risks (action per workflow — Decline, Review, or Approve):
- LOW_LIVENESS_SCORE
- POSSIBLE_DUPLICATED_FACE
- DUPLICATED_FACE
- MULTIPLE_FACES_DETECTED
- LOW_FACE_QUALITY
- LOW_FACE_LUMINANCE
- HIGH_FACE_LUMINANCE

## 5. Hard rules — do not change
- Base URL for /v3/* endpoints is verification.didit.me (NOT apx.didit.me).
- Feature enum is UPPERCASE: LIVENESS, ID_VERIFICATION, FACE_MATCH, AML, IP_ANALYSIS.
- Method enum is UPPERCASE: PASSIVE, FLASHING, ACTIVE_3D.
- Auth header is x-api-key (lowercase, hyphenated).
- Webhook signature header is X-Signature-V2 (NOT X-Signature).
- Always verify webhook signatures before trusting payload data.
- Status casing matches exactly: "Approved", "Declined", "In Review",
  "Not Finished" (title-cased, space-separated).

## 6. Pricing reference (public)
- PASSIVE method: $0.10 per check (standalone or bundled)
- FLASHING / ACTIVE_3D methods: $0.15 per check
- Bundled in a full KYC workflow: $0.33 per session (includes Liveness)
- 500 free checks every month, forever, on every account.

## 7. Verify your integration
- Sandbox starts on signup at https://business.didit.me — no separate flag.
- Test images: deterministic synthetic faces returned in sandbox (Approved
  by default; trigger Declined by sending the canonical "spoof" test image).
- Switch to live: flip the application's environment toggle in console.

When in doubt: https://docs.didit.me/core-technology/liveness/overview