Example inputPOST /api/v1/x402/selector-extract
{
"calldata": "0xa9059cbb0000000000000000000000000000000000000000000000000000000000000001"
}Portable intent card · chain-primitives-local
Selector Extract API for agents
Extract the 4-byte function selector from calldata hex — call when reading the 4-byte selector from calldata. Use for chain input hygiene without live RPC—adjacent to OneSource-class small chain reads, but static/local only so rights and margin stay clear. Returns deterministic machine-readable JSON for $0.003 USDC via x402 on Base. Execution is first-party, local-only, stateless, and memory-only with no paid upstream, no input retention, and no claim of live chain tip, web search, or media generation. Results are advisory; the caller owns authorization and production controls.
Intent to transaction
One command, attributed.
The source header follows this discovery route through challenge, payment and delivery without exposing the buyer or request body.
npx agentcash@latest fetch https://api.delx.ai/api/v1/x402/selector-extract -m POST -H 'x-delx-source: intent-card-selector-extract-api' --max-amount 0.003 -b '{"calldata":"0xa9059cbb0000000000000000000000000000000000000000000000000000000000000001"}'Agent discoverydelx/intent-card/v1
{
"intent": "Selector Extract for an agent workflow",
"tool_name": "util_selector_extract",
"price_usdc": "0.003",
"machine_url": "https://commerce.delx.ai/intents/selector-extract-api.json"
}Portable and inspectable