feat(python): add x402search ActionProvider

[x402-index]

Summary

Adds a native x402search ActionProvider that gives AgentKit agents natural language search across 14,000+ indexed API services.

Why

Coinbase Bazaar lists services. x402search searches them by capability. They are complementary — Bazaar is ls /apis, x402search is grep -r "token price" across all of them.

When an agent needs a data source, it calls search_apis("token price") and gets 88 matching APIs back — paid automatically, no human in the loop.

What

• New x402search action provider under action_providers/x402search/
• Single action: search_apis(query, limit)
• Payment handled automatically via existing x402_requests client (same pattern as the existing x402 provider)
• Cost: $0.01 USDC per query on Base mainnet (eip155:8453)
• No new dependencies — reuses x402 SDK already in the repo

Usage

from coinbase_agentkit.action_providers.x402search import x402search_action_provider

agentkit = AgentKit(AgentKitConfig(
    wallet_provider=CdpWalletProvider(cdp_config),
    action_providers=[x402search_action_provider()],
))

Related

• Ecosystem PR: site(ecosystem): add x402search — pay-per-search x402 API discovery x402#1698
• Live API: https://x402search.xyz
• Index: 14,098 API resources, $0.01 USDC/query

[cb-heimdall]

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