Signature proofs

A signature proof is cryptographic evidence that a wallet belongs to your account, without moving funds and without an on-chain transaction. CBPay builds a structured, human-readable anti-phishing envelope (title, purpose, wallet, nonce and validity window), the wallet signs it with EIP-191 (Ethereum) or TIP-191 (TRON), and anyone can verify the result on a public link — no authentication required. Two ways to produce a proof:

Flow	Who signs	Use it when
Server-side	CBPay signs with your segregated wallet (custody `cbpay`)	The wallet is custodied by CBPay and you need an attestation on demand
Wallet link	The owner signs in their own wallet (MetaMask, TronLink…)	You need to prove ownership of an external wallet you don’t custody

Every proof expires 10 minutes after it is issued (expires_at). A proof attests a moment in time; if a counterparty needs a fresh one, create a new signature.

The anti-phishing envelope

CBPay never signs a free-form message. Both flows build the same structured envelope, so the signer always sees what is being attested, which wallet signs it and until when it is valid:

CBPay Signature Proof
Domain: https://api.qbank.cl/platform
Purpose: wallet_ownership
Wallet: 0x71C7656EC7ab88b098defB751B7401B5f6d8976F
Nonce: 9f2c4a7d1e5b48c0a3f69d2e7b1c4a58
Issued: 2026-08-20T14:03:22Z
Expires: 2026-08-20T14:13:22Z
Statement: I control this wallet

The wallet_link purpose adds an Account: line with your masked account id. A signature whose envelope is expired, not yet valid, or bound to a different wallet is rejected.

1. Server-side signature (segregated wallet)

Sign with a segregated wallet custodied by CBPay (custody: cbpay). Because this flow produces a signature with a custodied key, it requires KYC approved and an OTP challenge.

Create the OTP challenge

Ask for a one-time code for the sign_message action and verify it to get an X-OTP-Token (see OTP).

Request the signature

curl -X POST https://api.qbank.cl/platform/v1/segregated-wallets/b7e3f1a2-4c5d-4e6f-8a9b-0c1d2e3f4a5b/signatures \
  -H "Authorization: Bearer <token>" \
  -H "X-OTP-Token: <otp-token>" \
  -H "Content-Type: application/json" \
  -d '{
    "purpose": "wallet_ownership",
    "statement": "I control this wallet"
  }'

purpose is wallet_ownership or treasury_attestation. statement is an optional free-text line (max 140 runes) embedded in the envelope.

201

{
  "proof_id": "c41d8f2e-9a3b-4c7d-ae1f-5b6c8d0e2f4a",
  "wallet_id": "b7e3f1a2-4c5d-4e6f-8a9b-0c1d2e3f4a5b",
  "chain": "eth",
  "address": "0x71C7656EC7ab88b098defB751B7401B5f6d8976F",
  "purpose": "wallet_ownership",
  "statement": "I control this wallet",
  "envelope": "CBPay Signature Proof\nDomain: https://api.qbank.cl/platform\nPurpose: wallet_ownership\nWallet: 0x71C7656EC7ab88b098defB751B7401B5f6d8976F\nNonce: 9f2c4a7d1e5b48c0a3f69d2e7b1c4a58\nIssued: 2026-08-20T14:03:22Z\nExpires: 2026-08-20T14:13:22Z\nStatement: I control this wallet",
  "message_hash": "4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b",
  "signature": "9f2c4a7d1e5b48c0a3f69d2e7b1c4a589f2c4a7d1e5b48c0a3f69d2e7b1c4a589f2c4a7d1e5b48c0a3f69d2e7b1c4a589f2c4a7d1e5b48c0a3f69d2e7b1c1b",
  "proof_code": "G9f2c4a7d1e5b48c0a3f69d2e7b1c4a58c41d8f2e9a3b4c7dae",
  "verify_url": "https://api.qbank.cl/platform/v1/public/signature-proofs/G9f2c4a7d1e5b48c0a3f69d2e7b1c4a58c41d8f2e9a3b4c7dae",
  "status": "signed",
  "issued_at": "2026-08-20T14:03:22Z",
  "signed_at": "2026-08-20T14:03:22Z",
  "expires_at": "2026-08-20T14:13:22Z"
}

Share the public link

Send verify_url to the counterparty. They open it without credentials and see the proof, its status and the signature.

Every signature also triggers a security email to the account owner and a wallet_signature_created webhook.

List, detail and revoke

# List proofs of the wallet
curl "https://api.qbank.cl/platform/v1/segregated-wallets/b7e3f1a2-4c5d-4e6f-8a9b-0c1d2e3f4a5b/signatures?page=1&page_size=50" \
  -H "Authorization: Bearer <token>"

# All proofs of the account (paginated, from/to filters)
curl "https://api.qbank.cl/platform/v1/signature-proofs?from=2026-08-01&to=2026-08-20" \
  -H "Authorization: Bearer <token>"

# Detail
curl "https://api.qbank.cl/platform/v1/signature-proofs/c41d8f2e-9a3b-4c7d-ae1f-5b6c8d0e2f4a" \
  -H "Authorization: Bearer <token>"

# Revoke (the public link keeps working and shows status revoked)
curl -X POST "https://api.qbank.cl/platform/v1/signature-proofs/c41d8f2e-9a3b-4c7d-ae1f-5b6c8d0e2f4a/revoke" \
  -H "Authorization: Bearer <token>"

2. Link an external wallet (MetaMask / TronLink)

To prove ownership of a wallet you hold the keys to (not custodied by CBPay), complete a signed challenge:

Create the challenge

curl -X POST https://api.qbank.cl/platform/v1/wallet-links/challenges \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{ "chain": "eth", "address": "0x71C7656EC7ab88b098defB751B7401B5f6d8976F" }'

201

{
  "link_id": "d52e9c41-7b3a-4e8f-b2d6-1a9c5e7f3b8d",
  "chain": "eth",
  "address": "0x71C7656EC7ab88b098defB751B7401B5f6d8976F",
  "nonce": "9f2c4a7d1e5b48c0a3f69d2e7b1c4a58",
  "envelope": "CBPay Signature Proof\nDomain: https://api.qbank.cl/platform\nPurpose: wallet_link\nWallet: 0x71C7656EC7ab88b098defB751B7401B5f6d8976F\nAccount: ae8c…\nNonce: 9f2c4a7d1e5b48c0a3f69d2e7b1c4a58\nIssued: 2026-08-20T14:03:22Z\nExpires: 2026-08-20T14:13:22Z",
  "status": "pending",
  "expires_at": "2026-08-20T14:13:22Z"
}

Sign the envelope in the wallet

Show the envelope text to the owner and ask them to sign it exactly as shown with the wallet at address (MetaMask personal_sign for eth, TronLink for tron). The challenge expires in 10 minutes.

Submit the signature

curl -X POST https://api.qbank.cl/platform/v1/wallet-links/verify \
  -H "Authorization: Bearer <token>" \
  -H "Content-Type: application/json" \
  -d '{
    "link_id": "d52e9c41-7b3a-4e8f-b2d6-1a9c5e7f3b8d",
    "signature": "9f2c4a7d1e5b48c0a3f69d2e7b1c4a589f2c4a7d1e5b48c0a3f69d2e7b1c4a589f2c4a7d1e5b48c0a3f69d2e7b1c4a589f2c4a7d1e5b48c0a3f69d2e7b1c1b"
  }'

200

{
  "link_id": "d52e9c41-7b3a-4e8f-b2d6-1a9c5e7f3b8d",
  "chain": "eth",
  "address": "0x71C7656EC7ab88b098defB751B7401B5f6d8976F",
  "status": "linked",
  "linked_at": "2026-08-20T14:05:10Z",
  "proof_id": "c41d8f2e-9a3b-4c7d-ae1f-5b6c8d0e2f4a",
  "verify_url": "https://api.qbank.cl/platform/v1/public/signature-proofs/G9f2c4a7d1e5b48c0a3f69d2e7b1c4a58c41d8f2e9a3b4c7dae"
}

A successful verification creates a signature proof (purpose: wallet_link) and fires the wallet_linked webhook. List and revoke links:

curl "https://api.qbank.cl/platform/v1/wallet-links" -H "Authorization: Bearer <token>"
curl -X DELETE "https://api.qbank.cl/platform/v1/wallet-links/d52e9c41-7b3a-4e8f-b2d6-1a9c5e7f3b8d" -H "Authorization: Bearer <token>"

3. Public verification

Anyone with the link can verify a proof — no account, no token:

curl "https://api.qbank.cl/platform/v1/public/signature-proofs/G9f2c4a7d1e5b48c0a3f69d2e7b1c4a58c41d8f2e9a3b4c7dae"

200

{
  "proof_code": "G9f2c4a7d1e5b48c0a3f69d2e7b1c4a58c41d8f2e9a3b4c7dae",
  "status": "signed",
  "valid": true,
  "chain": "eth",
  "address": "0x71C7656EC7ab88b098defB751B7401B5f6d8976F",
  "purpose": "wallet_ownership",
  "statement": "I control this wallet",
  "issued_at": "2026-08-20T14:03:22Z",
  "signed_at": "2026-08-20T14:03:22Z",
  "expires_at": "2026-08-20T14:13:22Z",
  "message_hash": "4a5b6c7d8e9f0a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b",
  "signature": "9f2c4a7d1e5b48c0a3f69d2e7b1c4a589f2c4a7d1e5b48c0a3f69d2e7b1c4a589f2c4a7d1e5b48c0a3f69d2e7b1c4a589f2c4a7d1e5b48c0a3f69d2e7b1c1b",
  "verified_live": true
}

valid is true only when the proof is signed, not revoked, not expired and the signature still matches the envelope (verified_live re-checks the cryptography on every call). An unknown or malformed code returns 404 not_found.

Status

Status	Meaning	Terminal?
`pending`	Challenge created, waiting for the owner’s signature (wallet link only)	No — expires in 10 min
`signed`	Proof signed and valid	No — can be revoked or expire
`revoked`	The account revoked the proof	Yes
`expired`	The 10-minute window elapsed	Yes

Errors

HTTP	Code	Solution
400	`invalid_json` / `invalid_payload`	Malformed body; check the JSON
400	`invalid_purpose`	Use `wallet_ownership` or `treasury_attestation`
400	`invalid_statement`	Statement exceeds 280 characters
400	`unsupported_chain`	Chain must be `eth` or `tron`
400	`invalid_address`	Address doesn’t match the chain format
403	`verification_required`	The account needs KYC approved
403	`otp_required` / `otp_invalid`	Create and verify an OTP challenge, send `X-OTP-Token`
404	`not_found`	Wrong wallet/link/proof id, or unknown proof code
409	`custody_transferred`	The wallet was exported; it no longer signs server-side
409	`challenge_consumed`	The challenge was already used; create a new one
409	`proof_not_signable`	The proof is not in a signable state
410	`challenge_expired`	The 10-minute challenge window elapsed; create a new one
422	`sign_rejected`	The statement doesn’t fit the envelope (max 140 runes)
422	`signature_mismatch`	The signature doesn’t match the address/envelope
429	`too_many_attempts`	Public verification rate limit; wait and retry
502	`signer_unavailable` / `verification_failed`	Transient signing/verification failure; retry

Webhooks

Subscribe to these events (see Webhooks):

wallet_signature_created

{
  "proof_id": "c41d8f2e-9a3b-4c7d-ae1f-5b6c8d0e2f4a",
  "account_id": "ae8c5f21-3b7d-4a9e-c6f2-8d1b4e6a9c3f",
  "wallet_id": "b7e3f1a2-4c5d-4e6f-8a9b-0c1d2e3f4a5b",
  "chain": "eth",
  "address": "0x71C7656EC7ab88b098defB751B7401B5f6d8976F",
  "purpose": "wallet_ownership",
  "proof_code": "G9f2c4a7d1e5b48c0a3f69d2e7b1c4a58c41d8f2e9a3b4c7dae",
  "verify_url": "https://api.qbank.cl/platform/v1/public/signature-proofs/G9f2c4a7d1e5b48c0a3f69d2e7b1c4a58c41d8f2e9a3b4c7dae"
}

wallet_linked

{
  "link_id": "d52e9c41-7b3a-4e8f-b2d6-1a9c5e7f3b8d",
  "account_id": "ae8c5f21-3b7d-4a9e-c6f2-8d1b4e6a9c3f",
  "chain": "eth",
  "address": "0x71C7656EC7ab88b098defB751B7401B5f6d8976F",
  "proof_id": "c41d8f2e-9a3b-4c7d-ae1f-5b6c8d0e2f4a"
}

FAQ

Does a signature proof move funds or cost gas?

No. Signing a message is purely cryptographic: no on-chain transaction, no network fee, no balance change.

How long is a proof valid?

10 minutes from issued_at. After that the public link shows the proof as expired. Create a new signature when a fresh attestation is needed.

Can I revoke a proof?

Yes — POST /v1/signature-proofs/{proofID}/revoke. The public link keeps working and reports status: revoked, so past verifications remain auditable.

Why was my statement rejected?

The envelope accepts up to 140 runes of statement. Requests over 280 characters fail with invalid_statement; between 141 and 280 the envelope rejects them with sign_rejected.

Getting Started

Concepts

Integration flows

Products

Integration

Resources

Signature proofs

The anti-phishing envelope

1. Server-side signature (segregated wallet)

List, detail and revoke

2. Link an external wallet (MetaMask / TronLink)

3. Public verification

Status

Errors

Webhooks

FAQ

​The anti-phishing envelope

​1. Server-side signature (segregated wallet)

​List, detail and revoke

​2. Link an external wallet (MetaMask / TronLink)

​3. Public verification

​Status

​Errors

​Webhooks

​FAQ

The anti-phishing envelope

1. Server-side signature (segregated wallet)

List, detail and revoke

2. Link an external wallet (MetaMask / TronLink)

3. Public verification

Status

Errors

Webhooks

FAQ