# Sproto Studio

> AI generation studio for agents. Image, video, music, 3D asset, and avatar generation, payable per-call via x402 USDC on Base — no API keys, no accounts required.

Sproto Studio is an MCP-server-fronted, x402-payable AI media generation service running on Base. Agents discover tools and pricing at one URL, pay per-call in USDC (or $BITCOIN), and receive generated images, videos, music, 3D models, and avatars. The same tools are usable by humans via the website and by AI assistants via MCP.

## Quick start for agents

If you can make signed x402 payments, you can use Sproto Studio with no account. The flow:

1. `GET https://sproto.studio/api/mcp/tools` — returns the full tool manifest with USDC/$BITCOIN pricing and the payment receiver address. No auth required.
2. `POST https://sproto.studio/api/mcp/tools` with `{ "tool": "<name>", "arguments": {...} }`. First request returns HTTP 402 with `accepts[]` listing acceptable payment assets.
3. Sign an x402 payment for the cost of the tool (Permit2 / EIP-3009 / EIP-7702 depending on asset), send it as `PAYMENT-SIGNATURE` header (V2) or `X-Payment` (V1 compat), retry the POST.
4. Receive the generated asset URL in the response.

Bearer-token flow (`SPROTO_API_TOKEN`) is also supported for credit-based billing — see `/api/mcp/tools` → metadata → auth.

## Endpoints

| URL | Method | Purpose | Auth |
|---|---|---|---|
| `https://sproto.studio/api/mcp/tools` | GET | Tool + pricing discovery (manifest) | none |
| `https://sproto.studio/api/mcp/tools` | POST | Execute tool with x402 or Bearer payment | x402 sig or Bearer |
| `https://sproto.studio/.well-known/agent.json` | GET | ERC-8004 agent registration | none |
| `https://sproto.studio/.well-known/x402` | GET | x402 discovery pointer | none |

## Payment

- **Settlement network:** Base (`eip155:8453`)
- **Facilitator:** `https://api.cdp.coinbase.com/platform/v2/x402` (Coinbase CDP V2)
- **Primary asset:** USDC — `0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913`
- **Secondary asset:** $BITCOIN (HarryPotterObamaSonic10Inu) — `0x2a06a17cbc6d0032cac2c6696da90f29d39a1a29`
- **Receiver:** see `settlement.payTo` in the live `/api/mcp/tools` manifest (canonical source)

## Tools and rate card

Authoritative rate card is the live `/api/mcp/tools` manifest. Snapshot at time of writing:

- `sproto_generate_image` — $0.35 USDC
- `sproto_generate_video` (Veo 3.1 fast) — $1.50 USDC
- `sproto_generate_wan_video` (WAN 2.2) — $0.80 USDC
- `sproto_generate_seedance_video` (Seedance 2.0 + audio) — $3.00 USDC
- `sproto_grok_imagine_video` — $1.50 USDC
- `sproto_generate_music` (Beatoven) — $0.60 USDC
- `sproto_generate_3d_asset` (Hunyuan3D v3) — $1.75 USDC
- `sproto_generate_avatar` (image → 3D pipeline) — $3.00 USDC

Free tools (no payment required): credit balance, status checks, character lookup, preset retrieval, Roblox upload status, NFT collection search.

## MCP server

Open-source MCP server published in this repo. Compatible with Claude Desktop, Cursor, VS Code, ChatGPT, Goose, and any MCP host. Two variants:

- `mcp-server/index.ts` — classic stdio MCP (text-only, universal).
- `mcp-server/apps-server.ts` — MCP Apps (SEP-1865) interactive UI via sandboxed iframes.

Install: `npx tsx mcp-server/index.ts` after setting `SPROTO_API_TOKEN` (from sproto.studio/profile → API tab) or `AGENT_WALLET_KEY` (autonomous x402 autopay).

## For autonomous agents

- Set `AGENT_WALLET_KEY` on the MCP server. The server auto-retries 402 responses by signing $BITCOIN or USDC payments from that wallet.
- Fund the agent wallet with USDC (Base) and/or $BITCOIN (Base) for autonomous operation.
- For session-key permissions on smart wallets, see `src/skills/agent-x402.md` — supports ERC-7715 grants for time-bounded spending caps.

## Skills documentation

The `src/skills/` directory contains protocol-level skill documentation:

- `agent-x402.md` — autonomous agent payment flow, EIP-712 signing, ERC-7715 session keys.
- `bitcoin-iap.md` — $BITCOIN in-app-purchase flow for human users.
- `nft-gating.md` — gating tools/access on NFT ownership.
- `avatar-pipeline.md` — image → 3D avatar generation chain.
- `bitcoin-trading.md` — $BITCOIN price/trading integration.

## Source

- Open source repo: [link to be added when published]
- License: TBD
- MCP server: `mcp-server/` in repo
- Backend route: `src/app/api/mcp/tools/route.ts`
- x402 library code: `src/lib/x402-bitcoin.ts`
- Agent wallet helpers: `src/lib/agent-wallet.ts`

## Contact and status

- Site: https://sproto.studio
- API status: `GET /api/mcp/tools` (200 = up; manifest changes mean rate-card moved)
- Issues / contributions: see linked GitHub repo when published