content-engine

# 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](https://www.x402.org/) 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: ```typescript 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. ```bash # 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.