x402 is an open standard that lets websites/APIs charge money directly over HTTP, so an app or AI agent can pay automatically and then continue the request.
In simple terms, x402 turns HTTP into a paywall + checkout cart for agents, it can also be understood as “payments over HTTP” for the agent economy.
A server can reply 402 Payment Required with machine-readable terms;
- the client/agent pays (usually stablecoin)
- retries the request with proof
- gets the resource.
The details on how it works (simple flow):
1. An agent calls an API like normal.
2. The server replies HTTP 402 Payment Required plus machine-readable payment terms (what to pay, where, which chain/asset).
3. The agent sends the onchain payment (often stablecoins).
4. The agent retries the request with proof/signature; the server verifies and returns the data.
No accounts, no API keys, no subscriptions. Agents pay for using.
I believe there is a huge use case for this as this is where value likely accrues.
The meta-take: if agents become economic actors, payments will be a huge part of any protocol. And I think this is also what Solana sees.
We’re increasingly seeing that AI agents are moving from just chatting → doing
So, the missing gap was autonomous settlement: paying for data, tools, inference, bandwidth, storage, and real-world services without humans clicking “confirm.”
The x402 whitepaper is explicit that it’s designed for agentic + M2M payments with instant/low-fee settlement using stablecoins like USDC.
Big players behind this and pushing it
1) @coinbase + @Cloudflare (focuses on distribution)
Coinbase and Cloudflare launched the x402 Foundation, and Cloudflare added x402 support to its Agents SDK and MCP server ecosystem. They’re trying to make “agent pays for tool” a default developer pattern, not just a niche crypto thing.
And in the most recent AMA @jessepollak mentioned payments and distribution being one of the key focus for @base.
2) Solana’s pitch for @x402 is focused on micropayments needing cheap + fast finality
Solana is openly positioning itself as an ideal settlement layer for x402 because of very low fees and fast finality and they’re already quoting meaningful usage growth (including “over 500,000 weekly transactions” and ~10,000% monthly growth).
Dune-tracked activity has already gone up massively:
- ~500,000 x402 transactions in Oct to 1.7M today
- A record $332,000 daily volume in Oct, though volume has gone much smaller now
This will only continue to grow being the only agentic crossover combining both web2 and web3 tech.
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