Content Engine

AI-powered content creation as a service. Generate scripts, images, and videos from any topic.

This is an MCP server accessible via Streamable HTTP transport. Any MCP-compatible client can connect to it directly — no proprietary CLI or binary required. Free tools work without credentials. Paid tools use the x402 protocol for per-request USDC payments.

Connection

Content Engine is a standard MCP server. Connect using any MCP client that supports Streamable HTTP transport.

MCP endpoint: https://content-engine-x402.fly.dev/mcp

Server discovery: https://content-engine-x402.fly.dev/.well-known/mcp.json

No special binary, CLI tool, or SDK is required. The server follows the MCP specification and works with any compliant client.

Required Environment Variables

Variable	Required	Description
CONTENT_ENGINE_URL	Yes	MCP server URL. Default: https://content-engine-x402.fly.dev
WALLET_PRIVATE_KEY	For paid tools	Private key for an EVM wallet holding USDC on Base. Used by the x402 client library to sign payment authorizations. Only needed if calling paid tools. Free tools work without it.

Important: WALLET_PRIVATE_KEY gives the x402 client library the ability to sign USDC transfer authorizations. This key should be for a dedicated agent wallet with limited funds — not a primary wallet. See the Payment section for details on how funds are protected.

Payment — How It Works

Paid tools use the x402 payment protocol for USDC payments on the Base network (EIP-155 chain 8453).

The agent controls every payment

No funds are ever auto-debited. The payment flow is:

1. Agent calls a paid tool (e.g. create_script)
2. Server responds with HTTP 402 Payment Required containing the exact USDC amount, recipient wallet, and network
3. The agent's x402 client library reads the 402 response and presents the payment for authorization — the agent decides whether to sign
4. If the agent authorizes, the client signs a USDC transfer for the exact amount specified and retries the request with the signed payment proof
5. Server verifies the payment, settles the transaction on-chain, and processes the request

Each payment is explicit, per-request, and for an exact amount. The server cannot withdraw funds, charge more than the stated amount, or initiate payments. The agent (or its x402 client) must actively sign each transaction.

What the agent needs

To make paid calls, the agent's HTTP client must support x402. The recommended approach:

import { wrapFetch } from "@x402/fetch";
import { createWalletClient, http } from "viem";
import { privateKeyToAccount } from "viem/accounts";
import { base } from "viem/chains";

// Create wallet from the dedicated agent wallet key
const account = privateKeyToAccount(process.env.WALLET_PRIVATE_KEY);
const wallet = createWalletClient({ account, chain: base, transport: http() });

// Wrap fetch — paid requests are handled via 402 → sign → retry
const x402fetch = wrapFetch(fetch, wallet, "eip155:8453");

The wrapped fetch handles the 402 challenge-response cycle. Free tools work with plain fetch — no wallet needed.

Cost control

• Call get_quote (free) before any paid tool to see the exact USDC price and per-stage breakdown
• Call get_pricing (free) to see all current rates
• Call get_queue_status (free) to check daily budget remaining
• Use a dedicated wallet with limited USDC to cap total exposure
• Use sandbox mode to test without any payment (see below)

Typical Pricing

Pricing is dynamic — costs vary based on video duration, narration, and effects.

Operation	Typical Cost (USDC)	Varies By
Script generation	$0.10–$0.20	Prompt complexity
Image generation	$0.15	Fixed per image
Video generation	$0.50–$2.00	Duration, shots, talking heads
Full pipeline (60s)	$1.50–$2.00	Duration, narration, effects
Publishing	$0.10–$0.15	Fixed

Always call get_quote with your parameters for the exact price.

Sandbox Mode (Free Testing)

Test the full API flow without payment, wallet, or USDC. Send Authorization: Bearer sandbox with any paid request to receive a mock response with the real cost quote attached.

# Get a quote (always free, no auth needed)
curl -X POST https://content-engine-x402.fly.dev/agent/quote 
  -H "Content-Type: application/json" 
  -d '{"operation":"script","duration_seconds":60}'

# Test a paid endpoint in sandbox mode (no payment, no wallet needed)
curl -X POST https://content-engine-x402.fly.dev/agent/script 
  -H "Content-Type: application/json" 
  -H "Authorization: Bearer sandbox" 
  -d '{"topic":"How AI is changing music production"}'

Sandbox mode returns: - The exact USDC price you would pay - A per-stage cost breakdown showing which AI services are used - The response structure your agent should expect from real calls - Mock IDs (content_id, jobId, transactionId) matching the real format

Sandbox mode does not create content, charge USDC, require a wallet, or count toward rate limits.

Available Tools

Free (no payment or credentials required)

Tool	Description
get_pricing	Live USDC pricing for all operations
get_quote	Exact cost quote with per-stage breakdown for specific parameters
get_queue_status	Queue position, active jobs, daily budget remaining
get_content	Full content item details including video URL and metadata
get_content_status	Lightweight status poll (pipeline stage + completion %)

Paid (x402 USDC — agent approves each payment)

Tool	Description
create_script	Generate AI video script from topic. Returns content_id for tracking.
create_image	Generate image from text prompt via Runway ML. Supports style and aspect ratio.
create_video	Generate video from a completed script. Requires content_id from create_script.
run_full_pipeline	End-to-end: script + video from a single topic. Fastest path to finished video.
publish_content	Publish to YouTube, X, TikTok, Instagram, LinkedIn.

Typical Workflow

Quick path

get_quote(operation="full_pipeline") → run_full_pipeline → poll get_content_status → get_content

Step-by-step path

1. get_quote operation="script" — See exact price
2. create_script topic="..." — Generate script, save returned content_id
3. get_content_status content_id="..." — Poll until complete
4. get_quote operation="video" — See exact price for video
5. create_video content_id="..." — Generate video
6. get_content_status content_id="..." — Poll until ready (1–5 min)
7. get_content content_id="..." — Retrieve video URL and metadata

Important Notes

• Video generation takes 1–5 minutes. Always poll get_content_status rather than assuming instant completion.
• The content_id (UUID) returned by creation tools is the key for all subsequent operations.
• Pricing is dynamic — always call get_quote before paid operations to see the exact cost.
• Use sandbox mode (Authorization: Bearer sandbox) to test without spending USDC.
• Use a dedicated agent wallet with limited funds — do not use a primary wallet.