Verify each voter is a real, unique person, and catch the same person trying to vote twice. $0.33 per voter, duplicates detected for free. 500 verifications free every month.
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Trusted by 2,000+ organizations worldwide.
What governance owes
A single human can spin up a hundred wallets, email addresses, or burner phones. None of that proves they're a hundred different humans. Didit binds the vote to a real face and a real document, and Face Search 1:N (free) catches the same person trying again. 500 verifications free every month.
Pick the checks you want, ID, liveness, face match, sanctions, address, age, phone, email, custom questions. Drag them into a flow in the dashboard, or post the same flow to our API. Branch on conditions, run A/B tests, no code required.
Embed natively with our Web, iOS, Android, React Native, or Flutter SDK. Redirect to a hosted page. Or just send your user a link, by email, SMS, WhatsApp, anywhere. Pick what fits your stack.
Didit hosts the camera, the lighting cues, the mobile hand-off, and accessibility. While the user is in the flow, we score 200+ fraud signals in real time and verify every field against authoritative data sources. Result in under two seconds.
Real-time signed webhooks keep your database in sync the moment a user is approved, declined, or sent to review. Poll the API on demand. Or open the console to inspect every session, every signal, and manage cases your way.
Didit · Unique voter
Voter · step 3 / 4
Face check vs cohort
Didit · Face Search 1:N
Didit · Privacy contract
Platform sees
Didit holds (encrypted)
Didit · Reusable KYC
Didit · Voter eligibility
Didit · Vote integrity
$ curl -X POST https://verification.didit.me/v3/session/ \
-H "x-api-key: $DIDIT_API_KEY" \
-d '{
"workflow_id": "wf_voter_enrol",
"vendor_data": "voter-12871",
"metadata": { "cohort_id": "round-2026-05" }
}'status: Approved.docs →$ curl https://verification.didit.me/v3/session/$SID/decision/ \
-H "x-api-key: $DIDIT_API_KEY"
# Returns:
{
"status": "Approved",
"face_search": { "matches": [] }
}You are integrating Didit anti-Sybil identity into a voting / governance / survey / airdrop / quadratic-funding platform. The recipe ensures each real human can be counted exactly once — no duplicates, no bots, no farmed accounts.
Two pillars:
1. Verify the voter is a real human with a real identity. ONE call to POST /v3/session/ with ID Verification + Liveness + Face Match.
2. Check the voter has not already been enrolled in this cohort. Face Search 1:N runs the voter's face against every previously-enrolled voter and returns a similarity score. Above threshold → duplicate, block.
Cost:
- Voter Know Your Customer (KYC) bundle: $0.33 per voter (Sessions API)
- Face Search 1:N: free (included)
- Re-vote / next round with Reusable KYC: free (the user proves uniqueness without re-doing KYC)
- First 500 verifications free every month, forever
PRE-REQUISITES
- Production API key from https://business.didit.me (sandbox key in 60s, no card).
- Webhook endpoint with HMAC SHA-256 verification using the X-Signature-V2 header and your webhook secret.
- A workflow_id from the Workflow Builder that bundles ID Verification + Passive Liveness + Face Match 1:1 + Face Search 1:N + your jurisdiction rules (age, country, sanctions).
STEP 1 — Enrol the voter with the Sessions API
POST https://verification.didit.me/v3/session/
Headers:
x-api-key: <your api key>
Content-Type: application/json
Body:
{
"workflow_id": "<wf id with KYC + Face Search 1:N>",
"vendor_data": "<your voter id, max 256 chars>",
"callback": "https://<your-app>/vote/enrolment/callback",
"metadata": {
"purpose": "vote_enrolment",
"cohort_id": "<your election / round / airdrop id>"
}
}
Response: 201 Created with the hosted session URL. Redirect the voter to it. Sub-2-second median verdict on completion.
STEP 2 — Read the signed webhook on enrolment completion
Didit POSTs to your callback. Session statuses are Title Case With Spaces:
Body (excerpted):
{
"session_id": "<uuid>",
"vendor_data": "<your voter id>",
"status": "Approved",
"id_verification": { "status": "Approved" },
"liveness": { "status": "Approved" },
"face": { "status": "Approved", "similarity_score": 0.94 },
"face_search": { "status": "Approved", "matches": [] }
}
Status enum (exact case): Approved | Declined | In Review | Resubmitted | Expired | Not Finished | Kyc Expired | Abandoned.
Verify the X-Signature-V2 header BEFORE reading the body — HMAC SHA-256 of the raw bytes with your webhook secret.
STEP 3 — Block duplicates
When face_search.matches is non-empty AND the top match's similarity is above your threshold (typical: 0.85), DO NOT add the voter to the cohort. The voter has likely been enrolled already, possibly under a different document or alias.
Recommended handling:
similarity ≥ 0.95 → block automatically, log the match
similarity 0.85–0.95 → route to manual review
similarity < 0.85 → enrol normally
STEP 4 — Privacy-preserving storage
The platform stores ONLY:
- voter_pid (pseudonymous identifier — a UUID, NOT the raw document number)
- unique (boolean)
- age_band (e.g. "18+", "25-34") — never the raw birth date unless your eligibility rule needs it
- region (e.g. "EU", "ES") — never the raw address
Documents, biometrics, and full names stay inside Didit, encrypted at rest. Default retention 5 years post-relationship; configurable per workflow.
STEP 5 — Read the decision on demand
GET https://verification.didit.me/v3/session/{sessionId}/decision/
Headers:
x-api-key: <your api key>
Returns the full decision JSON. Use this when the tally service needs to confirm a voter is still eligible at vote time.
STEP 6 — Reusable KYC for subsequent rounds
Once a voter is verified, the next vote / round / airdrop can reuse the verification at no extra cost. The user proves uniqueness with a selfie only — no document re-capture. Same workflow, different cohort id.
WEBHOOK EVENT NAMES
- Sessions: status changes flow through the standard session webhook.
- Verify X-Signature-V2 on every payload.
CONSTRAINTS
- Session statuses use Title Case With Spaces (Approved, In Review). Don't transform them.
- Face Search 1:N is scoped to YOUR cohort by default — Didit doesn't share faces across customers.
- Always check the duplicate score BEFORE recording the ballot, never after.
- The platform never sees the raw ID document or the raw face template — only the verdict and the pseudonymous PID.
- Default record retention is 5 years post-relationship per the EU AML package; extend per your governing body's rules.
Read the docs:
- https://docs.didit.me/sessions-api/create-session
- https://docs.didit.me/sessions-api/retrieve-session
- https://docs.didit.me/integration/webhooks
- https://docs.didit.me/core-technology/reusable-kyc/overview
Start free at https://business.didit.me — sandbox key in 60 seconds, 500 verifications free every month, no credit card.$0 / month. No credit card required.
Pay only for what you use. 25+ modules. Public per-module pricing, no monthly minimum fee.
Custom MSA & SLA. For large volumes and regulated programs.
Start free → pay only when a check runs → unlock Enterprise for a custom contract, SLA, or data residency.
Didit is infrastructure for identity and fraud, the platform we wished existed when we were building products ourselves: open, flexible, and developer-friendly, so it works as a real part of your stack instead of a black box you integrate around.
One API covers verifying people (KYC, know your customer), verifying businesses (KYB, know your business), screening crypto wallets (KYT, know your transaction), and monitoring transactions in real time, on a stack built to be:
The footprint underneath: 14,000+ document types in 48+ languages, 1,000+ data sources, and 200+ fraud signals on every session. The Didit infrastructure dynamically learns from every session and gets better every day.
A Sybil attack is when one human pretends to be many, by spinning up wallets, email addresses, burner phones, or fake IDs, to game a system that counts each account as one vote, one entry, one share.
It shows up everywhere voting or scarcity matter:
The only durable defence is to bind each vote to a real human. That's what this recipe ships.
They prove control of a resource, not control of a body.
A face plus a government document is harder. There is exactly one face per body, and one valid government ID per face per country. Forging at scale costs orders of magnitude more than spinning up a wallet.
The full flow normally takes under 30 seconds end-to-end, pick up the ID, snap the document, snap the selfie, done. That is the fastest in the market. Legacy KYC providers usually take more than 90 seconds for the same flow.
On the back end, Didit returns the result in under two seconds at p99, measured from the moment the user finishes the selfie to the moment your webhook fires. Mobile capture is tuned for slow phones and slow networks: progressive image compression, lazy software development kit load, and a one-tap hand-off from desktop to phone via QR code if the user starts on web.
When a voter enrols, Didit creates a privacy-preserving face template (a vector, not the image) and compares it against every other voter template in your cohort. The output is a list of matches, each with a similarity score from 0 to 1.
A typical policy:
The cohort is scoped to YOUR dataset, Didit does not share faces across customers. The template is encrypted at rest, never exposed to the voting platform, and falls under the privacy notice the user agreed to at enrolment.
Every session lands on one of seven clear statuses, so your code always knows what to do:
Approved, every check passed. Move the user forward.Declined, one or more checks failed. You can allow the user to resubmit the specific failed step (for example, re-take the selfie) without re-running the whole flow.In Review, flagged for compliance review. Open the case in the console, see every signal, decide approve or decline.In Progress, user is mid-flow.Not Started, link sent, user has not opened it yet. Send a reminder if it sits too long.Abandoned, user opened the link but did not finish in time. Re-engage or expire.Expired, the session link aged out. Create a new session.A signed webhook fires on every status change, so your database always stays in sync. Abandoned and declined sessions are free.
Production data is processed and stored in the European Union by default, on Amazon Web Services. Enterprise contracts can request alternative regions for jurisdictions whose regulators require it.
Encryption everywhere. AES-256 at rest across every database, object store, and backup. Transport Layer Security 1.3 in transit on every API call, webhook, and Business Console session. Biometric data is encrypted under a separate Customer Master Key.
Retention is yours to control. Default retention is indefinite (unlimited) unless you configure shorter, between 30 days and 10 years per application, and you can delete any individual session at any time from the dashboard or the API.
Certifications: SOC 2 Type 1 (Type 2 audit in progress), ISO/IEC 27001:2022, iBeta Level 1 PAD, and a public attestation from Spain''s Tesoro / SEPBLAC / CNMV that Didit''s remote identity verification is safer than verifying someone in person. Full report at /security-compliance.
Didit ships compliant by default for the regulators that matter to identity infrastructure:
Detailed memo, every certificate, every regulator letter: /security-compliance.
Three integration paths, pick whichever fits your stack:
Same dashboard, same billing, same pay-per-success price for all three. Step-by-step guide at docs.didit.me/integration/integration-prompt.
No. Once a voter is verified by Didit, Reusable KYC (free, included) lets them prove uniqueness on every subsequent round with a selfie only, no document re-capture.
In practice:
The credential is portable across every Didit-powered platform, aligned with eIDAS2 (the EU's digital-identity regulation). The voter owns the credential, they re-present it on demand, you never re-pay.
Every enrolment produces a signed receipt you can export to your audit log or your DAO's transparency portal:
session_id, Didit's verifiable identifier for the enrolmentvoter_pid, your pseudonymous voter idverdict, Approved, Declined, In Review, etc. (status enum: Approved, Declined, In Review, Resubmitted, Expired, Not Finished, Kyc Expired, Abandoned)cohort_id, which round / election / airdropsignature, X-Signature-V2 HMAC SHA-256 of the payload with your webhook secrettimestampPair with the on-chain attestation (if used) and you have a tamper-evident trail from "this real human enrolled" to "this ballot was cast". Default retention 5 years, extendable per your governing body's rules.
Four steps, one afternoon:
business.didit.me, sandbox key in 60 seconds, no credit cardPOST /v3/session/ to enrol voters and the signed webhook to receive verdictsstatus: Approved and face_search.matches is empty (or below your threshold)The Didit MCP (Model Context Protocol) server is included free, paste the integration prompt above into Claude Code, Cursor, Codex, Replit Agent, Devin, or Aider and the agent scaffolds the whole thing against the live /v3/ API.
One API for KYC, KYB, Transaction Monitoring, and Wallet Screening. Integrate in 5 minutes.