Create a loan (borrow)

curl --request POST \
  --url https://api-sandbox.circle.com/v1/borrow/loans \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "idempotencyKey": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "protocol": "morpho",
  "marketId": "<string>",
  "borrowAmount": "<string>",
  "collateralAmount": "<string>"
}
'

import requests

url = "https://api-sandbox.circle.com/v1/borrow/loans"

payload = {
    "idempotencyKey": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "protocol": "morpho",
    "marketId": "<string>",
    "borrowAmount": "<string>",
    "collateralAmount": "<string>"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    idempotencyKey: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    protocol: 'morpho',
    marketId: '<string>',
    borrowAmount: '<string>',
    collateralAmount: '<string>'
  })
};

fetch('https://api-sandbox.circle.com/v1/borrow/loans', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api-sandbox.circle.com/v1/borrow/loans",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'idempotencyKey' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    'protocol' => 'morpho',
    'marketId' => '<string>',
    'borrowAmount' => '<string>',
    'collateralAmount' => '<string>'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api-sandbox.circle.com/v1/borrow/loans"

	payload := strings.NewReader("{\n  \"idempotencyKey\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"protocol\": \"morpho\",\n  \"marketId\": \"<string>\",\n  \"borrowAmount\": \"<string>\",\n  \"collateralAmount\": \"<string>\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api-sandbox.circle.com/v1/borrow/loans")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"idempotencyKey\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"protocol\": \"morpho\",\n  \"marketId\": \"<string>\",\n  \"borrowAmount\": \"<string>\",\n  \"collateralAmount\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api-sandbox.circle.com/v1/borrow/loans")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"idempotencyKey\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"protocol\": \"morpho\",\n  \"marketId\": \"<string>\",\n  \"borrowAmount\": \"<string>\",\n  \"collateralAmount\": \"<string>\"\n}"

response = http.request(request)
puts response.read_body

{
  "data": {
    "id": "d4e5f6a7-8901-2345-def0-234567890123",
    "jobType": "borrow",
    "status": "received",
    "amount": "1000.00",
    "asset": "USD",
    "collateralAmount": "0.05",
    "collateralAsset": "CIRBTC",
    "toAddress": "0x5a0b4a11d3f9b2c1e8a7d6c5b4a39281f0e1d2c3",
    "loanId": "fc988ed5-c129-4f70-a064-e5beb7eb8e32",
    "oraclePrice": "67234.51",
    "createDate": "2026-06-20T14:20:00.000Z",
    "updateDate": "2026-06-20T14:20:00.000Z"
  }
}

{
  "code": 400,
  "message": "Bad request."
}

{
  "code": 401,
  "message": "Malformed authorization."
}

{
  "code": 3,
  "message": "Forbidden"
}

{
  "code": 409,
  "message": "Conflicts with another request."
}

POST

borrow

loans

Create a loan (borrow)

curl --request POST \
  --url https://api-sandbox.circle.com/v1/borrow/loans \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "idempotencyKey": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "protocol": "morpho",
  "marketId": "<string>",
  "borrowAmount": "<string>",
  "collateralAmount": "<string>"
}
'

import requests

url = "https://api-sandbox.circle.com/v1/borrow/loans"

payload = {
    "idempotencyKey": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "protocol": "morpho",
    "marketId": "<string>",
    "borrowAmount": "<string>",
    "collateralAmount": "<string>"
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    idempotencyKey: '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    protocol: 'morpho',
    marketId: '<string>',
    borrowAmount: '<string>',
    collateralAmount: '<string>'
  })
};

fetch('https://api-sandbox.circle.com/v1/borrow/loans', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api-sandbox.circle.com/v1/borrow/loans",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'idempotencyKey' => '3c90c3cc-0d44-4b50-8888-8dd25736052a',
    'protocol' => 'morpho',
    'marketId' => '<string>',
    'borrowAmount' => '<string>',
    'collateralAmount' => '<string>'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api-sandbox.circle.com/v1/borrow/loans"

	payload := strings.NewReader("{\n  \"idempotencyKey\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"protocol\": \"morpho\",\n  \"marketId\": \"<string>\",\n  \"borrowAmount\": \"<string>\",\n  \"collateralAmount\": \"<string>\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api-sandbox.circle.com/v1/borrow/loans")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"idempotencyKey\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"protocol\": \"morpho\",\n  \"marketId\": \"<string>\",\n  \"borrowAmount\": \"<string>\",\n  \"collateralAmount\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api-sandbox.circle.com/v1/borrow/loans")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"idempotencyKey\": \"3c90c3cc-0d44-4b50-8888-8dd25736052a\",\n  \"protocol\": \"morpho\",\n  \"marketId\": \"<string>\",\n  \"borrowAmount\": \"<string>\",\n  \"collateralAmount\": \"<string>\"\n}"

response = http.request(request)
puts response.read_body

{
  "data": {
    "id": "d4e5f6a7-8901-2345-def0-234567890123",
    "jobType": "borrow",
    "status": "received",
    "amount": "1000.00",
    "asset": "USD",
    "collateralAmount": "0.05",
    "collateralAsset": "CIRBTC",
    "toAddress": "0x5a0b4a11d3f9b2c1e8a7d6c5b4a39281f0e1d2c3",
    "loanId": "fc988ed5-c129-4f70-a064-e5beb7eb8e32",
    "oraclePrice": "67234.51",
    "createDate": "2026-06-20T14:20:00.000Z",
    "updateDate": "2026-06-20T14:20:00.000Z"
  }
}

{
  "code": 400,
  "message": "Bad request."
}

{
  "code": 401,
  "message": "Malformed authorization."
}

{
  "code": 3,
  "message": "Forbidden"
}

{
  "code": 409,
  "message": "Conflicts with another request."
}

Authorizations

Authorization

string

header

required

Bearer authentication header of the form Bearer <token>, where <token> is your auth token.

Body

application/json

Request to originate a new borrow position.

idempotencyKey

string<uuid>

required

Idempotency key (UUID v4) for this request. Reusing it with a different body returns 409 Conflict.

protocol

enum<string>

required

Lending protocol.

Available options:

morpho

marketId

string

required

Identifier of an active market from GET /v1/borrow/markets.

borrowAmount

string

required

Borrow amount, as a raw onchain uint256 base-unit amount (decimal-integer string). Must be positive.

collateralAmount

string

Collateral to post, as a raw onchain uint256 base-unit amount (decimal-integer string, no fractional part). Optional. Omit or send 0 to draw additional debt against an existing position without adding collateral. When supplied, must be zero or positive.

Response

Loan request (borrow) accepted. Poll the returned job to track its status.

data

object

An async onchain operation. Each job represents one of: borrow, repay, add collateral, wallet setup, owner change, or residual withdraw. Poll this resource until the job reaches a terminal status (completed, failed, or approval_rejected). Fields that do not apply to the current status or job type are omitted rather than returned as null.

Show child attributes

Example:

{
  "id": "b3d9d2d5-4c12-4946-a09d-953e82fae2b0",
  "jobType": "borrow",
  "status": "completed",
  "amount": "1000.00",
  "asset": "USD",
  "collateralAmount": "0.05",
  "collateralAsset": "CIRBTC",
  "toAddress": "0x5a0b4a11d3f9b2c1e8a7d6c5b4a39281f0e1d2c3",
  "loanId": "fc988ed5-c129-4f70-a064-e5beb7eb8e32",
  "transferId": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "oraclePrice": "67234.51",
  "userOpHash": "0x9f8e7d6c5b4a39281f0e1d2c3b4a5968778695a4b3c2d1e0f9a8b7c6d5e4f3a2",
  "txHash": "0x1a2b3c4d5e6f70819293a4b5c6d7e8f90a1b2c3d4e5f60718293a4b5c6d7e8f9",
  "createDate": "2026-06-20T14:20:00.000Z",
  "updateDate": "2026-06-20T14:22:00.000Z"
}

Core API

API overview

Core API for institutions

Cross-currency API

Reserve management API

Credit API

Digital Asset-Backed Borrowing

Partner Onboarding API

Crypto deposits API

Crypto payouts API

Create a loan (borrow)

Authorizations

Body

Response