U.CASH documentation

Every doc, one door

The network's documentation lives where its surfaces live. This is the map: payments, agents, SDKs, protocol specs and guides.

Payments

Pay

Merchant docs: checkouts, payment links, payouts, webhooks, invoices, test mode.

Open

Agents + 402

Agents API

The REST surface for priced resources, wallets, challenges and settlements.

Open

SDKs

SDK

JavaScript and Python packages plus two MCP servers: a hosted keyless buyer endpoint (mcp.u.cash) and the 86-tool stdio seller server.

Open

Protocol

402 + UCP

The vendor-neutral 402 spec and the UCP discovery profile.

Open

Plain text

llms.txt

The entire agents surface in one plain-text file, for LLMs.

Open

Machine spec

OpenAPI 3.1

Structured spec for tooling and SDK generation.

Open

Guides

Learn

Long-form guides across payments, shops, invoicing and operations.

Open

Status + stats

Status

Fleet health, uptime history and the public statistics dashboard.

Open

App catalog

Apps

Every app on the network with its lifecycle stage.

Open