curl --request PATCH \
  --url https://mercy-pay.com/api/v1/subscriptions/{id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "plan": "plan_c7d2e9f13a4b4c5d8e6f1a2b3c4d5e6f"
}
'

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://mercy-pay.com/api/v1/subscriptions/{id}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PATCH",
  CURLOPT_POSTFIELDS => json_encode([
    'plan' => 'plan_c7d2e9f13a4b4c5d8e6f1a2b3c4d5e6f'
  ]),
  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;
}

const options = {
  method: 'PATCH',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({plan: 'plan_c7d2e9f13a4b4c5d8e6f1a2b3c4d5e6f'})
};

fetch('https://mercy-pay.com/api/v1/subscriptions/{id}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://mercy-pay.com/api/v1/subscriptions/{id}"

payload = { "plan": "plan_c7d2e9f13a4b4c5d8e6f1a2b3c4d5e6f" }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

{
  "data": {
    "id": "sub_4f2c8a1e0b7d4c559a3e6d1f8b2c7e90",
    "object": "subscription",
    "livemode": false,
    "created": "2026-11-07T10:00:00+00:00",
    "plan": {
      "id": "plan_9b1e4c2a6d3f4a5e8f6c2d9b1a7e3c48",
      "object": "plan",
      "livemode": false,
      "created": "2026-11-01T09:00:00+00:00",
      "name": "Abonnement Pro",
      "description": null,
      "amount": 5000,
      "currency": "XAF",
      "interval": "monthly",
      "interval_count": 1,
      "trial_period_days": 0,
      "status": "active",
      "portal_switchable": true,
      "metadata": null
    },
    "pending_plan": "plan_c7d2e9f13a4b4c5d8e6f1a2b3c4d5e6f",
    "payment_method": "mobile_money",
    "customer": "cus_c71d0e5a3b2f4e8a9c1d5f6a7b8c9d01",
    "customer_name": "Awa Ndiaye",
    "customer_email": "awa@example.com",
    "customer_phone": "237670000012",
    "customer_country": "CMR",
    "customer_provider": "MTN_MOMO_CMR",
    "status": "active",
    "current_period_start": "2026-11-07T10:00:00+00:00",
    "current_period_end": "2026-12-07T10:00:00+00:00",
    "trial_ends_at": null,
    "next_billing_at": "2026-12-07T10:00:00+00:00",
    "cancel_at_period_end": false,
    "canceled_at": null,
    "paused_at": null,
    "resumes_at": null,
    "max_cycles": null,
    "cycles_billed": 1,
    "metadata": {
      "customer_id": "cus_1042"
    },
    "next_action": null
  }
}

{
  "error": {
    "type": "authentication_error",
    "code": "api_key_invalid",
    "message": "Clé API invalide.",
    "param": null,
    "doc_url": "https://docs.mercy-pay.com/developers/errors#api_key_invalid",
    "request_id": "req_01jc8x4m2v7t9qk3n5w6y8z0ab"
  }
}

{
  "error": {
    "type": "invalid_request_error",
    "code": "resource_not_found",
    "message": "Ressource introuvable.",
    "param": null,
    "doc_url": "https://docs.mercy-pay.com/developers/errors#resource_not_found",
    "request_id": "req_01jc8x4m2v7t9qk3n5w6y8z0ab"
  }
}

{
  "error": {
    "type": "invalid_request_error",
    "code": "validation_failed",
    "message": "Le champ amount est obligatoire.",
    "param": "amount",
    "doc_url": "https://docs.mercy-pay.com/developers/errors#validation_failed",
    "request_id": "req_01jc8x4m2v7t9qk3n5w6y8z0ab",
    "errors": {
      "amount": [
        "Le champ amount est obligatoire."
      ]
    }
  }
}

{
  "error": {
    "type": "rate_limit_error",
    "code": "rate_limited",
    "message": "Trop de requêtes.",
    "param": null,
    "doc_url": "https://docs.mercy-pay.com/developers/errors#rate_limited",
    "request_id": "req_01jc8x4m2v7t9qk3n5w6y8z0ab"
  }
}