Learn / x402 vs ACP: what's the difference?
x402 vs ACP: what's the difference?
x402 and ACP serve different buyers. x402's customer is a machine buying API calls and data in sub-dollar increments. ACP's customer is a human whose assistant is buying products — normal-sized purchases that happen to be arranged in chat.
Transaction profile
x402: millions of payments averaging well under $1, settled in USDC on-chain with ~$0.0001 fees. ACP: conventional cart-sized amounts settled mostly over card rails with standard consumer protections.
Integration surface
x402 lives in HTTP itself — a server adds a 402 response and payment verification. ACP lives in merchant commerce stacks — catalog, checkout, and payment-credential handling exposed to chat assistants (Stripe/OpenAI-driven).
How to choose
Selling to agents (APIs, data, tools, content) → x402. Selling to humans through their assistants (goods, bookings, subscriptions) → ACP. Many businesses will need both: x402 for their API, ACP for their storefront.
Frequently asked questions
Do x402 and ACP compete?
Rarely head-on — they cover different transaction sizes and buyer types. The overlap (agent-purchased digital subscriptions) is where the standards war is genuinely live.
Which should a SaaS company implement first?
If agents consume your API today, x402 first — it's a small server-side change with immediate metering revenue. Add ACP when assistant-driven signups become material.
Can ACP settle in stablecoins?
Increasingly yes as card networks add stablecoin support, but its center of gravity is existing card credentials.
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