ReplyWithCare API

Quick start

1. Create a ReplyWithCare account if you don't have one.
2. Email hello@replywithcare.com to be added to the Agency plan (API access lives there).
3. Once we confirm, go to Dashboard → API Keys and click Generate key. Copy the key immediately — we only show it once.
4. Send a POST request to the endpoint below.

Endpoint

All API requests must use HTTPS. Plain HTTP requests are rejected by Vercel before they reach the function.

Authentication

Send your API key in the Authorization header as a Bearer token. Keys look like rwc_live_… and are tied to your account.

Authorization: Bearer rwc_live_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Never embed your key in client-side code that ships to end users (a public website or a published mobile app). For Chrome extensions, store the key in chrome.storage.local after the user pastes it into your extension's settings.

Request body

JSON with the following fields:

Response

{
  "reply": "Thank you so much for the kind words, Maya — we're delighted...",
  "model": "gemini-2.5-flash",
  "requestId": "8b3c12d4-..."
}

requestId is unique per request. Include it in any support ticket so we can look up the call in our logs.

Examples

curl

curl -X POST https://replywithcare.com/api/v1/generate \
  -H "Authorization: Bearer rwc_live_xxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "review": "Great service! The team was so helpful and the coffee was perfect.",
    "tone": "grateful",
    "language": "en",
    "length": "medium"
  }'

JavaScript (fetch)

const res = await fetch('https://replywithcare.com/api/v1/generate', {
  method: 'POST',
  headers: {
    'Authorization': `Bearer ${process.env.RWC_API_KEY}`,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    review: 'Great service! The team was so helpful and the coffee was perfect.',
    tone: 'grateful',
    language: 'en',
  }),
});

if (!res.ok) {
  const err = await res.json();
  throw new Error(`${err.error}: ${err.message}`);
}

const { reply, requestId } = await res.json();
console.log(reply);

Python (requests)

import os, requests

resp = requests.post(
    "https://replywithcare.com/api/v1/generate",
    headers={"Authorization": f"Bearer {os.environ['RWC_API_KEY']}"},
    json={
        "review": "Great service! The team was so helpful and the coffee was perfect.",
        "tone": "grateful",
        "language": "en",
    },
    timeout=30,
)
resp.raise_for_status()
print(resp.json()["reply"])

Errors

Errors return a JSON body with a machine-readable error code and a human-readable message.

Quota

Agency accounts get 200 generations per day, shared across the in-app generator and the public API. Quota resets at midnight UTC. If you need a higher ceiling, contact us at hello@replywithcare.com and we'll discuss a custom plan.

CORS

The endpoint sets Access-Control-Allow-Origin: * so Chrome extensions and third-party web apps can call it directly from the browser. Auth is enforced entirely by the Bearer token — never expose the key to untrusted code.