Execute broker MEP operation

Executes a buy or sell USD-MEP operation for a specific account.

MEP and the broker path segment

"Dólar MEP" is the legal route to buy or sell US dollars in Argentina through the securities market: buy a bond in pesos, sell the same bond in dollars. Allaria runs both legs.

broker in the path is an internal service name, not something you configure — see the Glossary.

POST/v1/broker/operations/mep/{account-id}/{side}

Request

Headers

Field	Type	Required	Description
Authorization	string	Yes	Access token in Bearer ACCESS_TOKEN format
Content-Type	string	Yes	Must be application/json

Path Parameters

Field	Type	Required	Description
account-id	integer	Yes	Account number to execute the operation on.
side	string	Yes	Operation side. Possible values: buy, sell (case-insensitive).

Not applicable: Query Parameters.

Body

amount unit depends on side

The amount field is denominated in different currencies depending on the operation side:

• buy: amount is in ARS (Argentine pesos). The system converts to USD using the MEP rate.
• sell: amount is in USD.

Field	Type	Required	Description
amount	number	Yes	Operation amount. ARS when side is buy; USD when side is sell.
estimated_price	number	Yes	Estimated MEP exchange rate (ARS per USD) at the moment the client confirms the operation.
tag	object	No	Optional key-value map for custom metadata (e.g. { "reference": "op-001" }).

Response

2XX Success

Field	Type	Description
id	string	Unique identifier of the executed MEP operation.
executed_at	string (ISO 8601 datetime)	Timestamp when the operation was executed.
estimated_price	number	MEP rate used to execute the operation (ARS per USD).

Error Codes

Status	Description
400	Bad Request — invalid or missing parameters, or side is not buy/sell
401	Unauthorized — invalid or missing access token
403	Forbidden — the token does not have permission to access this resource
500	Internal Server Error

Error structure:

{
  "code": "invalid_request",
  "description": "Invalid side: hold"
}

Code Example

cURL

curl -X POST https://b2b.allaria.dev/v1/broker/operations/mep/70104/buy \
  -H "Authorization: Bearer ACCESS_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 10000.00,
    "estimated_price": 1245.50,
    "tag": { "reference": "op-001" }
  }'

JavaScript

const accountId = 70104;
const side = 'buy';

const response = await fetch(
  `https://b2b.allaria.dev/v1/broker/operations/mep/${accountId}/${side}`,
  {
    method: 'POST',
    headers: {
      'Authorization': 'Bearer ACCESS_TOKEN',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      amount: 10000.00,
      estimated_price: 1245.50,
      tag: { reference: 'op-001' }
    })
  }
);
const data = await response.json();
console.log(data);

Python

import requests

account_id = 70104
side = 'buy'

response = requests.post(
  f'https://b2b.allaria.dev/v1/broker/operations/mep/{account_id}/{side}',
  headers={
    'Authorization': 'Bearer ACCESS_TOKEN',
    'Content-Type': 'application/json'
  },
  json={
    'amount': 10000.00,
    'estimated_price': 1245.50,
    'tag': { 'reference': 'op-001' }
  }
)
data = response.json()
print(data)

Node.js

const axios = require('axios');

const accountId = 70104;
const side = 'buy';

const response = await axios.post(
  `https://b2b.allaria.dev/v1/broker/operations/mep/${accountId}/${side}`,
  {
    amount: 10000.00,
    estimated_price: 1245.50,
    tag: { reference: 'op-001' }
  },
  {
    headers: {
      Authorization: 'Bearer ACCESS_TOKEN',
      'Content-Type': 'application/json'
    }
  }
);
console.log(response.data);

2XX Success

{
  "id": "3f1c2b4a-5d6e-4f7a-8b9c-0d1e2f3a4b5c",
  "executed_at": "2026-07-21T14:30:45.123456",
  "estimated_price": 1245.50
}