Coal - Payments for AI agents

# Coal

Coal gives AI agents a real checkout.

Discover merchants through the decentralized 0G Storage catalog, pay autonomously in USDC on Base via x402 (Coinbase) or OKX APP (v2 envelope), and download purchased products — all without a human in the loop.

Receipts are anchored on 0G Chain, allowing any third party to independently verify payments without trusting Coal itself.

The MCP server is fully multi-tenant: every user supplies their own wallet key through the `X-Coal-Agent-Key` header, meaning the server never stores long-lived private keys or custody secrets.

Agents are gasless by default — Coal covers operator gas costs.

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## MCP Tools (13)

### Discovery & Marketplace

* `discover_merchants`
Browse the marketplace as a Markdown product grid

* `search_products`
Search and filter by product name, price, or tags

* `get_merchant_profile`
Retrieve merchant metadata and payout addresses

* `query_merchant_memory`
Natural-language merchant Q&A powered by TEE-backed 0G Compute

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### Payments & Checkout

* `check_paywall`
Check whether an address has already paid

* `create_checkout`
Create a Coal checkout session *(requires API key)*

* `get_checkout_status`
Retrieve checkout session state and payment status

* `pay_merchant`
Send USDC on Base using ERC-3009 gasless transfers

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### Verification & Delivery

* `verify_receipt`
Verify the complete proof trail:

1. Base transaction
2. 0G Storage receipt
3. 0G Chain anchor

* `download_product`
Verify on-chain payment and return a signed download URL

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### Infrastructure & Agent Utilities

* `get_0g_health`
Check live 0G mainnet status

* `agent_wallet_status`
View derived wallet address and USDC balance

* `setup_instructions`
Print the full integration and setup guide

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## Live Demos

* Claude paying $0.10 for an ebook end-to-end
`https://agent.usecoal.xyz`

* x402 paywall demo
`https://oracle.usecoal.xyz/api/price/ETH`

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## Stack

* Dual-protocol support:

* Coinbase x402
* OKX APP

* Base USDC settlement

* 0G Storage receipts

* 0G Chain receipt anchoring

* 0G Compute Sealed Inference for policy execution

* ERC-3009 gasless payment flow

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