curl --request POST \
  --url https://api.portalhq.io/api/v3/clients/me/integrations/cctp/transfers \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "sourceChain": "eip155:84532",
  "destinationChain": "eip155:43113",
  "amount": "0.09",
  "speed": "auto"
}
'

{
  "data": {
    "transferId": "cmuzgyc2105hw41rg2h19pomm",
    "sourceChain": "eip155:84532",
    "destinationChain": "eip155:43113",
    "amount": "0.09",
    "amountRaw": "90000",
    "speed": "fast",
    "minFinalityThreshold": 1000,
    "fees": {
      "protocol": "0.000012",
      "forwarding": "0.054181",
      "maxFee": "0.054193",
      "custodian": "0"
    },
    "totalDebit": "0.09",
    "amountOut": "0.035807",
    "minAmount": "0.05419",
    "sourceGas": {
      "payer": "user",
      "estimatedWei": "1237440000000"
    },
    "estimatedSeconds": 8,
    "sender": "0xa7f0c09f250b7f9cc73068c02ceb296a013c0c0c",
    "recipient": "0xa7f0c09f250b7f9cc73068c02ceb296a013c0c0c",
    "warnings": [],
    "ready": true,
    "checks": [
      {
        "id": "ROUTE_SUPPORTED",
        "ok": true
      },
      {
        "id": "AMOUNT_ABOVE_MINIMUM",
        "ok": true
      },
      {
        "id": "BALANCE",
        "ok": true
      },
      {
        "id": "RECIPIENT_ALLOWED",
        "ok": true
      },
      {
        "id": "SOURCE_GAS",
        "ok": true
      }
    ],
    "transactions": [
      {
        "to": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
        "data": "0x095ea7b30000000000000000000000008fe6b999dc680ccfdd5bf7eb0974218be2542daa0000000000000000000000000000000000000000000000000000000000015f90",
        "value": "0",
        "kind": "approve"
      },
      {
        "to": "0x8FE6B999Dc680CcFDD5Bf7EB0974218be2542DAA",
        "data": "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",
        "value": "0",
        "kind": "burn"
      }
    ]
  }
}

CCTP

Create a CCTP transfer

Quotes again with fresh fees, runs every preflight check and, when they all pass, stores the transfer as BUILT and returns what to sign. If any check fails, nothing is stored and the response is 400 with the id CCTP_PREFLIGHT_FAILED.

EVM source, EOA clients: sign transactions in order, waiting for each to be mined successfully before signing the next; stop if one fails. An approve comes first when the allowance is too low, then the burn, then one fee transfer for your custodian fee.
EVM source, Account Abstraction clients: sign userOperation, which already contains every call in transactions.
Solana source: transactions holds one Solana transaction with serializedTransaction, already partially signed by Circle’s event account and with any fee transfers inside. Sign and broadcast it with sol_signAndSendTransaction. Its blockhash expires after roughly a minute.

Sign and broadcast on the source chain, then call submit with the burn transaction hash (EOA), the user operation hash (Account Abstraction on an EVM source) or the Solana signature (Solana source).

With an Idempotency-Key, the same key and body return the same transfer: with freshly built transactions while it’s BUILT or ABANDONED, or its current state (without transactions) once it’s submitted. If Portal can’t confirm that an earlier burn for the transfer never landed, it returns 409 with the id CCTP_REBUILD_UNAVAILABLE instead of new transactions. The same key with a different body returns 409 with the id IDEMPOTENCY_KEY_REUSED.

POST

clients

integrations

cctp

transfers

curl --request POST \
  --url https://api.portalhq.io/api/v3/clients/me/integrations/cctp/transfers \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "sourceChain": "eip155:84532",
  "destinationChain": "eip155:43113",
  "amount": "0.09",
  "speed": "auto"
}
'

{
  "data": {
    "transferId": "cmuzgyc2105hw41rg2h19pomm",
    "sourceChain": "eip155:84532",
    "destinationChain": "eip155:43113",
    "amount": "0.09",
    "amountRaw": "90000",
    "speed": "fast",
    "minFinalityThreshold": 1000,
    "fees": {
      "protocol": "0.000012",
      "forwarding": "0.054181",
      "maxFee": "0.054193",
      "custodian": "0"
    },
    "totalDebit": "0.09",
    "amountOut": "0.035807",
    "minAmount": "0.05419",
    "sourceGas": {
      "payer": "user",
      "estimatedWei": "1237440000000"
    },
    "estimatedSeconds": 8,
    "sender": "0xa7f0c09f250b7f9cc73068c02ceb296a013c0c0c",
    "recipient": "0xa7f0c09f250b7f9cc73068c02ceb296a013c0c0c",
    "warnings": [],
    "ready": true,
    "checks": [
      {
        "id": "ROUTE_SUPPORTED",
        "ok": true
      },
      {
        "id": "AMOUNT_ABOVE_MINIMUM",
        "ok": true
      },
      {
        "id": "BALANCE",
        "ok": true
      },
      {
        "id": "RECIPIENT_ALLOWED",
        "ok": true
      },
      {
        "id": "SOURCE_GAS",
        "ok": true
      }
    ],
    "transactions": [
      {
        "to": "0x036CbD53842c5426634e7929541eC2318f3dCF7e",
        "data": "0x095ea7b30000000000000000000000008fe6b999dc680ccfdd5bf7eb0974218be2542daa0000000000000000000000000000000000000000000000000000000000015f90",
        "value": "0",
        "kind": "approve"
      },
      {
        "to": "0x8FE6B999Dc680CcFDD5Bf7EB0974218be2542DAA",
        "data": "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",
        "value": "0",
        "kind": "burn"
      }
    ]
  }
}

Authorizations

Authorization

string

header

required

Client API Key or Client Session Token (CST). Pass as a Bearer token in the Authorization header.

Headers

Idempotency-Key

string

Optional key to deduplicate retries. Scoped to the client. Up to 255 characters from A-Z, a-z, 0-9, -, ., _ and ~.

Maximum string length: 255

Body

application/json

Option 1
Option 2

Send exactly one of amount or amountOut. Unknown fields are rejected.

sourceChain

string

required

CAIP-2 id of the chain to send from, an EVM chain or Solana.

Pattern: ^(eip155:\d+|solana:[1-9A-HJ-NP-Za-km-z]{32})$

Example:

"eip155:11155111"

destinationChain

string

required

CAIP-2 id of the chain to send to, an EVM chain or Solana.

Pattern: ^(eip155:\d+|solana:[1-9A-HJ-NP-Za-km-z]{32})$

Example:

"eip155:84532"

amount

string

required

USDC to burn on the source chain, as a decimal string with up to 6 decimals (not base units).

Pattern: ^\d+(\.\d{1,6})?$

Example:

"0.1"

amountOut

string

USDC the recipient must receive (exact-out). Portal works out the amount to burn so the recipient gets at least this after fees (exactly this when Circle charges the full maxFee, as it does in practice).

Pattern: ^\d+(\.\d{1,6})?$

Example:

"0.045735"

speed

enum<string>

default:auto

auto and fast use Fast when the source chain offers it, otherwise Standard. standard always uses Standard.

Available options:

auto,

fast,

standard

recipient

string

Address to receive the USDC, validated against the destination chain. An EVM address for an EVM destination, or a Solana wallet address (not a token account) for a Solana destination, where Circle mints into the wallet's USDC token account. Defaults to the client's own address on the destination chain. Any other address must be on the environment's destination allowlist.

Required string length: 1 - 64

Response

Transfer built

data

Built transfer · object

When ROUTE_SUPPORTED fails, only sourceChain, destinationChain, ready and checks are returned.

Built transfer
Already submitted (idempotent replay)

Show child attributes

Overview

Enclave MPC API

Client API

Authentication API

Custodian API

Reseller API

Create a CCTP transfer

Authorizations

Headers

Body

Response