Attach a source to a flow and mint a session token
Sets the source wallet address and chain on an initiated flow and mints the capability sessionToken used to drive the rest of the lifecycle. No API key or token is required (the browser has neither at this point) — the endpoint is gated by the flow still being initiated and by CORS. At most one live token exists per flow at a time. When re-attaching from the signing state, the existing session token must be supplied to prove the caller is the original signer.
Authorizations
Bearer authentication header of the form Bearer <token>, where <token> is your auth token.
Headers
Flow session token issued at source attachment. Required when no JWT is provided. Format: dft_.
Path Parameters
ID of the environment
36^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$"95b11417-f18f-457f-8804-68e361f9164f"
UUID of the flow
36^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$"95b11417-f18f-457f-8804-68e361f9164f"
Body
fromAddress, fromChainId, and fromChainName are required when sourceType is 'wallet'. When sourceType is 'exchange', they are optional; pass exchangeProvider to generate the buy URL and create the exchange source record server-side. When sourceType is 'deposit_address', fromChainId and fromChainName are required; fromAddress is not accepted (use refundAddress instead to specify where funds should be returned if the deposit fails).
How a flow is funded — a connected wallet, a CEX, or a deposit address.
wallet, exchange, deposit_address Valid blockchain wallet address, must be an alphanumeric string (underscores allowed for chains like Midnight, hyphens allowed for chains using base64url-encoded addresses like TON)
255^[A-Za-z0-9_-]{18,100}$"0xbF394748301603f18d953C90F0b087CBEC0E1834"
50^(?=\S)[\p{L}\p{N}a-zA-Z _.,:!?&%@\/+\-'|]+(?<=\S)$"An example name"
ETH, EVM, FLOW, SOL, ALGO, STARK, COSMOS, BTC, ECLIPSE, SUI, SPARK, TRON, APTOS, TON, STELLAR, ALEO, TEMPO, MIDNIGHT Source exchange identifier
coinbase, kraken Valid blockchain wallet address, must be an alphanumeric string (underscores allowed for chains like Midnight, hyphens allowed for chains using base64url-encoded addresses like TON)
255^[A-Za-z0-9_-]{18,100}$"0xbF394748301603f18d953C90F0b087CBEC0E1834"
Response
Source attached; session token minted
Response from the source endpoint — carries the one-time capability session token plus the current flow state.
When the session token expires.
Opaque capability token for authenticating subsequent calls on this flow (quote/prepare/broadcast). Minted by the source endpoint and returned exactly once — store it immediately. At most one live token exists per flow at a time. Format: dft_.
"dct_A1B2C3..."
A single payment, deposit, or withdraw flow. Collapses the former Checkout and CheckoutTransaction into one resource.