DFlow Proof

Proof is DFlow's identity-verification primitive for Solana wallets. Stripe Identity verifies the person once; Proof links that verified identity to one or more wallet addresses. Builders query a public endpoint to check status.

There are two reasons to integrate it:

Self-gating your own app — any product that needs identity-based KYC (jurisdiction-gated DeFi, regulated token sales, identity-attested access, etc.) can use Proof as a ready-made primitive.
Kalshi PM trading on DFlow — DFlow's Trading API requires Proof for Kalshi prediction-market buys. This skill is also where the matching error handling lives.

Prerequisites

DFlow docs MCP (https://pond.dflow.net/mcp) — install per the repo README. This skill is the recipe; the MCP is the reference. Look up the deep-link signing code, the full parameter list, and user-journey diagrams via search_d_flow / query_docs_filesystem_d_flow — don't guess.
dflow CLI (optional, only relevant for Kalshi-trading use) — install per the repo README.

Part I — Proof as a generic primitive (self-gating)

Use this path when you need KYC for your own app, independent of Kalshi.

Check verification status

GET https://proof.dflow.net/verify/{address} → { "verified": boolean }. Public, no auth. Use it to gate features, to decide whether to show a "Verify me" CTA, or to short-circuit a restricted action.

Redirect the user to verify (deep link)

If the wallet isn't verified, redirect the user to Proof's hosted flow. The deep link carries a signed ownership proof so Proof can link the wallet to the verified identity automatically:

URL: https://dflow.net/proof?wallet=<addr>&signature=<sig>&timestamp=<ms>&redirect_uri=<url>
Optional: email, projectId.
Signature: user signs the exact message Proof KYC verification: {timestamp} (Unix ms, 13 digits) with their wallet; base58-encode the bytes.
Full signing snippet and parameter table → docs MCP, or read directly: /build/proof/partner-integration.

Handle the return

User lands back on your redirect_uri. Re-query /verify/{address} to confirm status. If verified: true, proceed; otherwise, surface an appropriate "verification pending / failed" message.

Part II — Kalshi PM trading (Trading API enforcement)

DFlow's Trading API enforces Proof only on Kalshi PM buys. Not sells, not redemptions, not spot, not quotes.

Three patterns, each maps to a user intent:

Proactive UX gate — at session start, call /verify/{address}, cache the result, and conditionally show the "Buy" button. Best UX; same primitive as Part I.
Reactive fallback — if the proactive check was skipped or is stale, /order will reject unverified buys with unverified_wallet_not_allowed (API) / PROOF_NOT_VERIFIED (CLI). Both error envelopes carry details.deepLink — redirect the user straight to it, then retry the buy after they return verified. (The CLI auto-opens the browser itself and prints the deepLink for headless environments.)
Quote-before-KYC — omit userPublicKey from GET /order to preview pricing without verification. Lets unverified users see what a buy would cost before committing to KYC.

What to ASK the user (and what NOT to ask)

Ask if missing:

What are they using Proof for? Self-gating their own app / Kalshi PM trading / both.

Self-gating → only /verify/{address} + deep-link flow matters. Skip trade-API error handling.
Kalshi trading → same flow, plus handle unverified_wallet_not_allowed / PROOF_NOT_VERIFIED + details.deepLink at /order time.
Both → superset of the Kalshi path.

Wallet pubkey — the address to verify / check.
App's callback URL (redirect_uri) — where Proof sends the user after verification.
Web or native mobile — changes the redirect_uri guidance (universal / app links for mobile; see Gotchas).

Do NOT ask about:

API key — /verify/{address} is public, no auth. Proof itself has no API key concept.
RPC / signing for trading — that's dflow-kalshi-trading. This skill just does the verification piece.

Gotchas (the docs MCP won't volunteer these)

Proof is enforced on Kalshi PM buys, not spot swaps. Don't state "all DFlow trades need KYC" — they don't.
Buys only, not sells or redemptions. Even on Kalshi, selling an outcome token or redeeming a winner needs no KYC.
Proof doesn't verify age. Stripe Identity captures name, address, email, and government-issued ID, but Proof does not currently check or expose date-of-birth. Don't use Proof for age gating — you won't get what you need.
Enforced on both dev and prod. Many agents assume dev is unprotected; it isn't.
Proof is usable outside Kalshi. Don't default to thinking "Proof = Kalshi KYC" — any builder who needs identity-gating can use it. Same primitive, same endpoint.
Redirect URI scheme restrictions. Proof only redirects to https:, chrome-extension:, and moz-extension: URLs. Custom schemes (myapp://callback) fail silently — no redirect, no error. Native mobile → universal links (iOS) / app links (Android), which are https: URLs that deep-link into the app.
The public endpoint is booleanized. /verify/{address} returns { verified: true | false }. There's no pending / failed / unverified distinction — everything non-verified collapses to false. If you need those states for UX, infer them from your own session state (did the user come back from Proof?), not from the public check.
Cache true, not false. Once verified, a wallet stays verified; caching avoids the per-trade check. But unverified is volatile — never cache it, because it flips the moment the user completes the flow.
For Kalshi buys, DFlow is authoritative. /order checks verification server-side internally, so you don't need your own backend re-check just to gate a buy — the API won't let an unverified wallet through either way. Client-side caching is fine purely as a UX hint (to hide the Buy button).
For self-gating your own app, verify server-side. If your backend is the thing enforcing a KYC-gated feature (not DFlow's API), don't trust a client's cached status. Re-query /verify/{address} from your backend before unlocking the gated action.
Embedded wallets work. Privy, Turnkey, etc., as long as the wallet supports signMessage.
One verified identity → unlimited wallets. No cap. A user who verified on wallet A can link wallet B, C, D, and onward without re-doing ID + liveness — just a fresh ownership signature from each new wallet.
Free + Stripe Identity under the hood. No fee to builders or users. Users complete Stripe's document + liveness flow.
Proof is not geoblocking. KYC ≠ jurisdictional restriction. Kalshi PM trading requires both — geoblocking logic lives inline in dflow-kalshi-trading, not here.

When something doesn't fit

Defer to the docs MCP for full reference — specifically:

/build/proof/partner-integration — deep-link code (signature generation, URL building), caching sample, handling edge cases (signature expiration, user cancellation, network errors), security guidance.
/build/proof/user-journeys — diagrams for new-direct, new-from-partner, and returning-user flows.
/build/proof-api/verify-address — the single public endpoint's reference.
/build/faqs — Proof + embedded wallets, Proof + dev endpoints, redirect debugging.

Sibling skills

dflow-kalshi-trading — places the actual orders that require Proof. Geoblocking policy also lives here.
dflow-kalshi-portfolio — view positions / P&L (no Proof required for reading).
dflow-spot-trading — non-Kalshi swaps; no Proof required, ever.

dflow-proof-kyc

SKILL.mdskills/dflow-proof-kyc/SKILL.md