x402 · Hedera testnet
Any API.
An MCP server.
Priced per tool.
Upload an API. We shape it into MCP tools and host the server. You price each tool on its own — free, paid, or a mix — and agents connect to the address and call it. Free tools need no account at all; paid ones settle on Hedera inside the request.
One connection
Add the address once. Tools published afterwards are callable without the client changing.
Any MCP client
streamable http{
"mcpServers": {
"tessera": { "url": "https://tessera-sage-pi.vercel.app/mcp" }
}
}The whole surface
- search_servicesfree
- describe_servicefree
- call_servicepriced per tool
- get_spend_authorityfree
- get_balancefree
Five tools, whatever the catalogue holds. Discovery is a call, not a list, so a thousand tools cost an agent no more context than ten.
One session
The same server, two tools. Only one of them costs anything, and the agent never held an API key.
Transcript
example- tools/call weather_nowfree tool · no account
- 200 OKdelivered, nothing charged
- tools/call ecb_reference_ratespaid tool
- 402 Payment Required0.0012 ℏ · pay to the seller
- X-PAYMENT: eyJzaWciOiJ…signed Hedera transfer
- 200 OKsettled + receipt on HCS
From API to paid tools
- 01Upload a spec
An OpenAPI URL is all we need. Nothing of yours has to change.
POST /api/mcp/publish
- 02We shape the tools
Operations become named, argument-flattened tools an agent can choose between.
64 operations → 10 tools
- 03You price each one
Free, paid, or a mix. There is no restriction either way.
free · 0.0009 ℏ / call
- 04Agents connect and pay
Free tools answer immediately. Paid ones settle to you on Hedera.
200 OK + receipt
Rate card