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AI Content Generation API

AI Content Generation API

Generate long-form articles, product copy, and marketing assets with structured parameters and zero hallucinations.

POST https://rsflowhub.com/api/v1/ai/content-generation

3 credits per call
X-API-Key header
JSON in, JSON out

Try it in the playground API reference

POST /api/v1/ai/content-generation

{
    "prompt": "Write a launch announcement for our AI API platform for LinkedIn.",
    "tone": "professional",
    "format": "linkedin_post",
    "audience": "developers"
}

200 OK response.json

{
    "result": {
        "content": "Stay refreshed all day with our stainless steel insulated bottle, built to keep drinks ice-cold for a full 24 hours. Leak-proof, lightweight and tough enough for the gym, the office or the trail."
    }
}

Definition

What is the AI Content Generation API?

AI Content Generation API is a REST API on RSFlowHub for web, mobile and AI agent applications. Send a JSON request to POST /api/v1/ai/content-generation with your API key; RSFlowHub runs it on a tuned AI model, falls back to a backup provider if needed, and returns a structured JSON result, usually within 1 to 3 seconds.

Category: Content Generation
Endpoint: POST /api/v1/ai/content-generation
Authentication: X-API-Key header
Price: 3 credits per call
Rate limit: 10 to 120 requests / minute by plan
Typical response: 1 to 3 seconds
Format: JSON, UTF-8

Request parameters

Send these fields as a JSON body. An invalid or missing field returns a 422 error that names the field.

Field	Type	Required	Description
`prompt`	string	Required	Instruction or writing prompt (Max: 15,000 characters)
`tone`	string	Optional	Tone style such as "professional", "friendly", "persuasive" (Max: 50 chars)
`format`	string	Optional	Content format such as "blog_post", "social_caption", "email" (Max: 50 chars)
`audience`	string	Optional	Target audience for the content (e.g., "developers", "teenagers") (Max: 100 chars)

Code examples

Copy, replace rfh_your_api_key with your key and run. Prefer a client library? See the official SDKs.

request.sh

curl -X POST "https://rsflowhub.com/api/v1/ai/content-generation" \
  -H "Content-Type: application/json" \
  -H "X-API-Key: rfh_your_api_key" \
  -d '{"prompt":"Write a launch announcement for our AI API platform for LinkedIn.","tone":"professional","format":"linkedin_post","audience":"developers"}'

client.php

<?php

$client = new \GuzzleHttp\Client();
$response = $client->post('https://rsflowhub.com/api/v1/ai/content-generation', [
    'headers' => [
        'Content-Type' => 'application/json',
        'X-API-Key'    => 'rfh_your_api_key',
    ],
    'json' => array (
      'prompt' => 'Write a launch announcement for our AI API platform for LinkedIn.',
      'tone' => 'professional',
      'format' => 'linkedin_post',
      'audience' => 'developers',
    ),
]);

echo $response->getBody();

client.js

const response = await fetch('https://rsflowhub.com/api/v1/ai/content-generation', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'X-API-Key': 'rfh_your_api_key'
  },
  body: JSON.stringify({"prompt":"Write a launch announcement for our AI API platform for LinkedIn.","tone":"professional","format":"linkedin_post","audience":"developers"})
});

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

main.py

import requests

url = "https://rsflowhub.com/api/v1/ai/content-generation"
headers = {
    "Content-Type": "application/json",
    "X-API-Key": "rfh_your_api_key"
}
payload = {"prompt":"Write a launch announcement for our AI API platform for LinkedIn.","tone":"professional","format":"linkedin_post","audience":"developers"}

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

Response

Every RSFlowHub endpoint uses the same envelope, so one parser handles all of them. Failed calls are not charged.

response.json

{
    "success": true,
    "request_id": "req_3f9a2c7e-5b1d-4e8a-9c2f-7d6e1a0b4c8d",
    "data": {
        "result": {
            "content": "Stay refreshed all day with our stainless steel insulated bottle, built to keep drinks ice-cold for a full 24 hours. Leak-proof, lightweight and tough enough for the gym, the office or the trail."
        }
    },
    "meta": {
        "version": "v1",
        "timestamp": "2026-10-05T09:30:00Z"
    }
}

error.json

{
    "success": false,
    "request_id": "req_8c1d4e2a-7f3b-4a9c",
    "error": {
        "code": "VALIDATION_ERROR",
        "message": "The given data was invalid.",
        "details": {
            "prompt": [
                "This field is required."
            ]
        }
    },
    "meta": {
        "version": "v1",
        "timestamp": "2026-10-05T09:30:00Z"
    }
}

Envelope fields
Field	Type	Meaning
`success`	boolean	true when the call worked, false on any error.
`request_id`	string	Unique id for this call. Quote it when you contact support.
`data.result`	object	The result of this endpoint (see the example).
`error`	object	Only on failure: code, message and details per field.
`meta`	object	API version and server timestamp.

All error codes: Errors reference

Features

Multi-Format Content Synthesis

Generate blog articles, social media hooks, email newsletters, and ad copy from simple outline prompts.

Brand Tone & Voice Customization

Control writing tone (professional, casual, persuasive, technical) and target reading level dynamically.

Integrated SEO Optimization

Automatically inject primary and secondary keywords, generate meta titles, and structure clean H2/H3 subheadings.

Dynamic Model Routing with Fallback

Dynamically routes requests between OpenAI, Gemini and DeepSeek models for optimal creativity and speed.

Use cases

How teams use the AI Content Generation API in production.

E-Commerce

Automated E-Commerce Product Descriptions

Generate compelling, feature-rich product descriptions from raw vendor specs for catalog items.

Input: Product: Wireless Noise-Cancelling Earbuds, 40h battery, IPX7 waterproof, Bluetooth 5.3
Output: Elevate your audio experience with ultra-clear acoustics and 40-hour playtime designed for daily workouts.

Writes consistent copy across large product catalogs.

Marketing & SaaS

B2B Marketing & Thought Leadership

Transform technical whitepapers and release notes into developer blog posts and LinkedIn announcements.

Input: Release 2.4: provider fallback, circuit breaker and atomic credit holds.
Output: How we added automatic LLM provider failover with circuit breakers in production.

Accelerates go-to-market content publishing from weeks to minutes.

Sales & CRM

Personalized Outbound Email Sequences

Craft hyper-personalized cold outreach emails based on prospect industry, company size, and pain points.

Input: Prospect: CTO at FinTech, struggling with OpenAI downtime and fragmented billing.
Output: Reduce multi-provider downtime with one master API key and automatic model failover.

Personalises email replies instead of sending static templates.

AI Content Generation API vs building it yourself

The same job done three ways.

Topic	RSFlowHub API	Raw LLM prompts	Rules / regex
Output	Validated JSON fields	Free text you have to parse	Fixed patterns only
Setup	One POST request, no prompts	Write and maintain prompts and parsing	Write and maintain rule lists
Provider outage	Automatic fallback to a backup model	You build retries and a second vendor	Not applicable
Pricing	3 credits per call, failed calls free	Per token, per vendor	Your own servers and upkeep
Understands context	Yes, AI model	Yes, AI model	No, keywords only

Frequently asked questions

Does the Content Generation API support markdown and HTML output?

Yes. You can specify output_format as markdown or html to receive ready-to-render headings, lists, and bold text.

Can I specify custom keywords for SEO optimization?

Yes. Pass a keywords array in your payload and the AI will organically integrate them into headings and body text.

Which foundation models power the Content Generation endpoint?

Requests are dynamically routed between OpenAI, Gemini and DeepSeek models based on prompt complexity.

Is generated content stored or used to train public models?

No. RSFlowHub does not use your requests or outputs to train AI models, and generated copy is returned only to your account.

How many credits does each generation request consume?

Content generation consumes 3 base credits per request for standard lengths up to 1,000 words.

Start using the AI Content Generation API

Free plan with 100 credits/month + 1,000 bonus credits when you sign in before 23 Nov. Test it in the playground first, no code needed.

Get a free API key Try it now