Fund a wallet in live mode

In sandbox you fund wallets from the faucet. In live, funds come from actual money sources — cards, bank accounts, crypto wallets, or hosted on-ramp sessions. This guide covers the full spectrum.

Funding options at a glance

Source	Best for	Settlement time
Card (Stripe, Adyen)	Small amounts, immediate funding	Instant
Bank (US ACH)	Large amounts, low fees	1-3 business days
Bank (EU SEPA)	Euro funding	1-2 business days
Bank (LATAM Pix / SPEI)	Brazilian / Mexican flows	Minutes
Crypto wallet	Pre-existing stablecoin	On-chain confirmation (seconds-minutes)
Hosted on-ramp (Coinbase, Stripe, Crossmint)	Consumer-facing signup-to-funded	Variable

Step 1 — Register a funding source

curl -X POST https://api.getsly.ai/v1/funding/sources \
  -H "Authorization: Bearer pk_live_..." \
  -d '{
    "account_id": "acc_...",
    "type": "bank_account_us",
    "provider": "plaid",
    "public_token": "public-sandbox-abc123"
  }'

Source types and required fields

`type`	`provider`	Required conditional fields
`card`	`stripe`, `adyen`	`setup_token`
`bank_account_us`	`plaid`, `stripe`	`public_token` or `link_id`
`bank_account_eu`	`plaid`, `stripe`	`public_token`
`bank_account_latam`	`belvo`	`link_id`
`crypto_wallet`	`circle` (custodial)	`wallet_address`, `network`

Non-custodial crypto wallets don’t require registration — agents can send directly to their Sly wallet address.

Step 2 — Verify the source

Bank accounts typically require verification (micro-deposits or identity check):

curl -X POST https://api.getsly.ai/v1/funding/sources/fsr_.../verify \
  -H "Authorization: Bearer pk_live_..."

For Plaid-linked banks, verification happens in the link flow. For manual bank entry, micro-deposits arrive in 1-2 business days; the user confirms the amounts in your UI, which submits back to this endpoint. Source status transitions: unverified → verified | blocked.

Step 3 — Initiate funding

Once verified:

curl -X POST https://api.getsly.ai/v1/funding/transactions \
  -H "Authorization: Bearer pk_live_..." \
  -d '{
    "source_id": "fsr_...",
    "wallet_id": "wal_...",
    "amount_cents": 50000,
    "currency": "USD",
    "idempotency_key": "fund-2026-04-23-001"
  }'

Amount is in minor units (amount_cents) — 50000 = $500.00 USD. Avoid float precision issues. Response:

{
  "id": "fx_...",
  "status": "pending",
  "source_id": "fsr_...",
  "wallet_id": "wal_...",
  "amount_cents": 50000,
  "currency": "USD",
  "estimated_settlement": "2026-04-26T00:00:00Z",
  "fees": { "provider": 125, "sly": 0, "total": 125 }
}

Step 4 — Watch settlement

curl https://api.getsly.ai/v1/funding/transactions/fx_... \
  -H "Authorization: Bearer pk_live_..."

Status: pending → processing → completed | failed. Or subscribe to funding.transaction.completed webhook.

Hosted on-ramp (consumer-facing)

For consumer flows where the end-user completes funding in a branded Sly-hosted page — useful when you don’t want to build card/bank capture UI yourself.

Coinbase on-ramp (fiat → USDC → your wallet)

curl -X POST https://api.getsly.ai/v1/funding/onramp-session \
  -H "Authorization: Bearer pk_live_..." \
  -d '{
    "wallet_id": "wal_...",
    "default_amount_usd": 100,
    "supported_payment_methods": ["card", "ach"],
    "return_url": "https://yourapp.example/funded"
  }'

Returns { session_token, session_url }. Redirect the user; they complete funding in Coinbase’s flow; the wallet is credited on confirmation.

Stripe crypto on-ramp

Similar pattern, different provider:

curl -X POST https://api.getsly.ai/v1/funding/stripe-onramp-session \
  -H "Authorization: Bearer pk_live_..." \
  -d '{
    "wallet_id": "wal_...",
    "default_amount_usd": 100
  }'

Crossmint order (card → USDC, web + mobile friendly)

curl -X POST https://api.getsly.ai/v1/funding/crossmint-order \
  -H "Authorization: Bearer pk_live_..." \
  -d '{
    "wallet_id": "wal_...",
    "amount_usd": 100,
    "return_url": "https://yourapp.example/funded"
  }'

Off-ramp (USDC → fiat)

The inverse — move from a Sly wallet out to a bank:

curl -X POST https://api.getsly.ai/v1/funding/offramp-session \
  -H "Authorization: Bearer pk_live_..." \
  -d '{
    "wallet_id": "wal_...",
    "amount_usd": 500,
    "destination_bank_account_id": "bank_..."
  }'

For a Plaid / Belvo link flow embedded in your UI:

curl -X POST https://api.getsly.ai/v1/funding/widget-sessions \
  -H "Authorization: Bearer pk_live_..." \
  -d '{
    "provider": "plaid",
    "account_id": "acc_...",
    "products": ["auth", "transactions"]
  }'

Returns a short-lived session token. Pass it to the Plaid Link SDK client-side.

Estimate fees before funding

curl -X POST https://api.getsly.ai/v1/funding/estimate-fees \
  -H "Authorization: Bearer pk_live_..." \
  -d '{
    "source_type": "card",
    "amount_cents": 50000,
    "currency": "USD",
    "destination_currency": "USDC"
  }'

Returns provider fee, Sly fee, FX spread, and total — useful for displaying to end users.

Cross-currency funding

Funding a USDC wallet from a USD bank account = on-ramp + FX.

curl -X POST https://api.getsly.ai/v1/funding/conversion-quote \
  -H "Authorization: Bearer pk_live_..." \
  -d '{
    "from_currency": "USD",
    "to_currency": "USDC",
    "amount_cents": 50000
  }'

Use the returned quote_id on the funding transaction to lock in the rate.

List providers + supported pairs

curl https://api.getsly.ai/v1/funding/providers \
  -H "Authorization: Bearer pk_live_..."

curl https://api.getsly.ai/v1/funding/conversion-rates \
  -H "Authorization: Bearer pk_live_..."

Endpoints

Endpoint	Purpose
`POST /v1/funding/sources`	Register source
`GET /v1/funding/sources`	List sources
`POST /v1/funding/sources/:id/verify`	Trigger verification
`POST /v1/funding/transactions`	Initiate funding
`GET /v1/funding/transactions/:id`	Transaction status
`POST /v1/funding/widget-sessions`	Plaid/Belvo link session
`POST /v1/funding/onramp-session`	Coinbase on-ramp
`POST /v1/funding/stripe-onramp-session`	Stripe on-ramp
`POST /v1/funding/crossmint-order`	Crossmint order
`POST /v1/funding/offramp-session`	Off-ramp (USDC → fiat)
`POST /v1/funding/estimate-fees`	Fee preview
`POST /v1/funding/conversion-quote`	FX quote
`GET /v1/funding/providers`	List providers
`GET /v1/funding/conversion-rates`	List supported currency pairs

Common pitfalls

Forgetting idempotency_key on funding transactions — retries create duplicate debits
Rounding in amount — always use amount_cents, never floats
Stale quotes — FX quotes expire in ~30 seconds; re-quote before large moves
Unverified source — sources in unverified state can’t fund; verify first
Provider-specific KYC — some providers require additional KYC beyond Sly’s; check the source’s verification_status

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Fund a wallet in live mode

Funding options at a glance

Step 1 — Register a funding source

Source types and required fields

Step 2 — Verify the source

Step 3 — Initiate funding

Step 4 — Watch settlement

Hosted on-ramp (consumer-facing)

Coinbase on-ramp (fiat → USDC → your wallet)

Stripe crypto on-ramp

Crossmint order (card → USDC, web + mobile friendly)

Off-ramp (USDC → fiat)

Embedded widget session

Estimate fees before funding

Cross-currency funding

List providers + supported pairs

Endpoints

Common pitfalls

​Funding options at a glance

​Step 1 — Register a funding source

​Source types and required fields

​Step 2 — Verify the source

​Step 3 — Initiate funding

​Step 4 — Watch settlement

​Hosted on-ramp (consumer-facing)

​Coinbase on-ramp (fiat → USDC → your wallet)

​Stripe crypto on-ramp

​Crossmint order (card → USDC, web + mobile friendly)

​Off-ramp (USDC → fiat)

​Embedded widget session

​Estimate fees before funding

​Cross-currency funding

​List providers + supported pairs

​Endpoints

​Common pitfalls

Funding options at a glance

Step 1 — Register a funding source

Source types and required fields

Step 2 — Verify the source

Step 3 — Initiate funding

Step 4 — Watch settlement

Hosted on-ramp (consumer-facing)

Coinbase on-ramp (fiat → USDC → your wallet)

Stripe crypto on-ramp

Crossmint order (card → USDC, web + mobile friendly)

Off-ramp (USDC → fiat)

Embedded widget session

Estimate fees before funding

Cross-currency funding

List providers + supported pairs

Endpoints

Common pitfalls