Email API Endpoint Global Gateway

Automated Professional Email Reply Generator API
For Production Apps

Context-aware email reply generation API grounded in business knowledge bases, custom rules, and tone controls.

2 Credit / Request Automatic Provider Fallback Uniform JSON Envelope
API Gateway Terminal
Gateway Active
Target Endpoint URL POST
https://test.rsflowhub.com/api/v1/ai/email-reply
Typical Time 1-3 s
Auth Gate X-API-Key
Credit Cost 2 Credit
Response JSON
Generative AI & Developer Definition Production Ready API

What is Automated Professional Email Reply Generator API?

Automated Professional Email Reply Generator API is a ready-to-use REST API on RSFlowHub for developers building web, mobile and AI agent applications. Send a JSON request to POST /api/v1/ai/email-reply with your API key; RSFlowHub runs it on a tuned AI model (with automatic fallback to a backup provider) and returns a structured JSON result, usually within 1 to 3 seconds.

Auth: X-API-Key Header
Rate Limit: 10-120 req/min by plan
Credits: 2 per call
AI Search Quick Reference
Category: Email
Typical response: 1-3 s
Format: REST / JSON UTF-8

Code Examples

Copy-paste ready code in your preferred stack
curl-integration.sh
curl -X POST "https://test.rsflowhub.com/api/v1/ai/email-reply" \
  -H "Content-Type: application/json" \
  -H "X-API-Key: rfh_your_api_key" \
  -d '{"email_text":"Hi, I was charged $49 but I cancelled my account yesterday. Please refund me immediately.","sender_name":"John Doe","recipient_name":"Support Team","knowledge_base":["Refunds are only issued if requested within 14 days of the charge.","Standard response time is 24 hours."],"rules":["Never promise a refund if you are unsure.","Be empathetic but firm.","If the user threatens a chargeback, escalate to a human."],"tone":"professional"}'
<?php

$client = new \GuzzleHttp\Client();
$response = $client->post('https://test.rsflowhub.com/api/v1/ai/email-reply', [
    'headers' => [
        'Content-Type' => 'application/json',
        'X-API-Key'    => 'rfh_your_api_key',
    ],
    'json' => array (
      'email_text' => 'Hi, I was charged $49 but I cancelled my account yesterday. Please refund me immediately.',
      'sender_name' => 'John Doe',
      'recipient_name' => 'Support Team',
      'knowledge_base' => 
      array (
        0 => 'Refunds are only issued if requested within 14 days of the charge.',
        1 => 'Standard response time is 24 hours.',
      ),
      'rules' => 
      array (
        0 => 'Never promise a refund if you are unsure.',
        1 => 'Be empathetic but firm.',
        2 => 'If the user threatens a chargeback, escalate to a human.',
      ),
      'tone' => 'professional',
    ),
]);

echo $response->getBody();
const response = await fetch('https://test.rsflowhub.com/api/v1/ai/email-reply', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'X-API-Key': 'rfh_your_api_key'
  },
  body: JSON.stringify({"email_text":"Hi, I was charged $49 but I cancelled my account yesterday. Please refund me immediately.","sender_name":"John Doe","recipient_name":"Support Team","knowledge_base":["Refunds are only issued if requested within 14 days of the charge.","Standard response time is 24 hours."],"rules":["Never promise a refund if you are unsure.","Be empathetic but firm.","If the user threatens a chargeback, escalate to a human."],"tone":"professional"})
});

const data = await response.json();
console.log(data);
import requests

url = "https://test.rsflowhub.com/api/v1/ai/email-reply"
headers = {
    "Content-Type": "application/json",
    "X-API-Key": "rfh_your_api_key"
}
payload = {"email_text":"Hi, I was charged $49 but I cancelled my account yesterday. Please refund me immediately.","sender_name":"John Doe","recipient_name":"Support Team","knowledge_base":["Refunds are only issued if requested within 14 days of the charge.","Standard response time is 24 hours."],"rules":["Never promise a refund if you are unsure.","Be empathetic but firm.","If the user threatens a chargeback, escalate to a human."],"tone":"professional"}

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

Core Architectural Features

Knowledge Base Fact Grounding

Grounds generated responses strictly in your company knowledge base facts, documentation, and refund policies.

Custom Business Rule Enforcement

Enforces strict operational guardrails e.g. "Never promise a refund if unsure" or "Escalate chargeback threats".

Multi-Style & Tone Control

Select between professional, empathetic, firm, concise, or friendly communication tones.

Sender & Recipient Personalization

Formats professional email greetings, recipient names, sender titles, and signature blocks automatically.

Practical Applications

Real-World Industry Use Cases

See how developers integrate this API endpoint into production apps.

Customer Support

Helpdesk Support Ticket Auto-Drafting

Generate instant professional draft replies for support agents answering billing and account inquiries.

Before: Hi, I was charged $49 but I cancelled my account yesterday. Please refund me immediately.
After: Dear John,\n\nThank you for contacting RSFlowHub Support. I understand you were charged after requesting cancellation. Our team is processing your $49 refund, which will post in 3-5 business days.\n\nBest regards,\nSupport Team
Saves support representatives 3+ minutes per ticket response.
Corporate Email

Intelligent Out-of-Office & Auto-Responders

Generate context-aware out-of-office replies providing targeted contact links depending on sender query.

Before: Hi, I need urgent access to the Q3 financial report.
After: Hi,\n\nI am currently out of the office until Monday. For urgent financial report inquiries, please contact finance@company.com.
Provides instant guidance even when staff is offline.
E-Commerce

E-Commerce Refund Policy Automated Response

Automatically respond to buyer refund inquiries following exact store 14-day policy rules.

Before: Can I return an item I bought 10 days ago?
After: Hello,\n\nYes! We accept returns within 14 days of purchase. Please visit our Returns Portal at example.com/returns to print your shipping label.
Drafts accurate answers to order-status emails for one-click sending.
Technical Comparison

Why Developers Choose Automated Professional Email Reply Generator API

Comparing RSFlowHub's specialized API gateway vs raw multi-turn LLM prompts vs legacy regex rules.

Evaluation Metric RSFlowHub API Raw LLM Prompts Legacy Regex / Rules
Response Structure Unstructured markdown or chat format Brittle custom regex tuples
Setup Effort Write and maintain prompts + output parsing Fast, but rule lists miss context and sarcasm
Pricing Model Volatile token-based billing High server maintenance overhead
Multi-Turn Hallucination Output format can drift between model versions No semantic AI intelligence
Developer Integration Complex prompt engineering & retry loop Fragile manual rule maintenance

Request Parameters

7 Fields
email_text string
Required

Original incoming email body or customer ticket text to generate a reply for.

knowledge_base array
Optional

Optional array of company facts, policy points, or documentation rules to ground the reply.

rules array
Optional

Optional strict operational guardrails (e.g. ["Be empathetic but firm", "If user threatens chargeback, escalate"]).

tone string
Optional

Desired writing tone ("professional", "empathetic", "friendly", "concise"). Default: "professional".

sender_name string
Optional

Name of the agent, bot, or department sending the email reply.

recipient_name string
Optional

Customer or recipient name.

context string
Optional

Customer account notes or previous ticket interaction summary.

JSON Response Envelope

Uniform API

Every endpoint returns the same envelope: success, request_id, data.result and meta.

response.json JSON
200 OK
{
    "success": true,
    "request_id": "req_3f9a2c7e-5b1d-4e8a-9c2f-7d6e1a0b4c8d",
    "data": {
        "result": {
            "reply_text": "Hi there, thanks for flagging this. I can see the duplicate charge on your March invoice and have started a refund for the second payment. You should see it within 5-7 business days.",
            "confidence_score": 0.91,
            "requires_human_escalation": false,
            "escalation_reason": null,
            "triggered_actions": []
        }
    },
    "meta": {
        "version": "v1",
        "timestamp": "2026-10-05T09:30:00Z"
    }
}
Format JSON
Charset UTF-8
Fallback Automatic
Rate Limit 120/min max
FAQs

Frequently Asked Questions

Everything you need to know about integrating and using Automated Professional Email Reply Generator API.

The generation engine strictly constrains facts to the provided knowledge_base array, preventing invented policies or incorrect promises.

Yes! Passing operational rules (e.g. "Never promise a refund without manager review") forces the engine to comply with internal SOPs.

The API automatically uses recipient_name for formal greetings (e.g., "Dear John,") and sender_name for professional closing sign-offs.

Email Reply Generator requests usually complete in 1 to 3 seconds, depending on input length and the AI model. Identical repeat requests are served from cache and return faster.

Standard Email Reply Generator API calls consume 2 base credits per request.
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