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We ran Coinbase for Agents' pay-for-data-then-trade loop end to end
Coinbase's x402 news this week was on the seller side. Coinbase Developer Platform said on November 2 that its x402 facilitator, the service that checks and settles payments for sellers, is live on Monad (receipts 374, 395). We queried the facilitator with our own CDP API key, and it lists Monad mainnet for all three payment schemes the announcement named: exact, upto and batch-settlement (receipt 393). The announcement's "100M transactions, $28M in payment volume" is a cumulative figure for Base and Solana, according to Coinbase's own documentation (receipt 395).
The buyer side is Coinbase for Agents, which lets an AI agent pay for market data over x402 from a Coinbase USDC balance and then trade on what it bought (receipt 388). On November 3 we ran that loop with real money through its MCP connector. Three data payments went through and two trades filled at a 0.90% fee. One order was refused, because the connector trades a narrower set of tokens than Coinbase itself offers.
Paying for the data
The first payment bought Glassnode's asset catalog for one cent. About a megabyte of token data came back, and the USDC balance fell by exactly $0.01 (receipt 383). The connector returned a Coinbase payment ID but no Base transaction hash, which our own wallet's payments normally return, so we looked on Base ourselves. Glassnode's x402 address received one $0.01 USDC payment in the three and a half hours around our call, a standard x402 transfer at 18:33 UTC (receipt 394). Coinbase's guide says these payments settle in USDC on Base (receipt 395), and this one appears to have.
The second call failed, and the mistake was ours. We sent Nansen's smart-money netflow endpoint a parameter its API rejected with HTTP 422. Coinbase had already placed a $0.05 authorization hold on the balance, and no data came back (receipt 384). Coinbase's guide for the product says this can happen: a successful payment authorization "does not guarantee that the provider returned usable data" (receipt 395). The hold had not been captured when we checked that afternoon, and we did not go back to confirm its release.
With the parameter removed, the same call went through for $0.05 and returned Nansen's leaderboard of tokens ranked by net inflow from the wallets it tracks as smart money (receipt 385).
Two trades and one refusal
$PEPE showed positive net inflow on that leaderboard across the 24-hour, 7-day and 30-day windows, and we bought $3.00 of it (receipt 390). Later in the session we tried $MERC, a token Coinbase offers through its DEX trading (receipt 396). The connector refused the order with "the requested product or currency is not supported for trading on this domain." Its order tool's own description explains the rule: it trades only top assets on the Coinbase Exchange order book, and tokens Coinbase offers through on-chain DEX routing are outside its reach, even when a quote for them appears to work.
We pulled the leaderboard again for $0.05, this time limited to tokens worth at least $500 million (receipt 386). $ENA (Ethena) had shown steady inflow over 7 and 30 days. A free order preview confirmed Coinbase would trade it, and we bought $3.47 of it (receipt 391).
Both orders paid exactly 0.90% of the amount filled, taken out of the order amount: $0.0268 on $2.97 of $PEPE and $0.0309 on $3.44 of $ENA. Coinbase says an agent's trades pay the same fees as the account holder's own, with nothing added for the agent product (receipt 395).
This week in numbers
- 100 million transactions and $28 million in payment volume: what Coinbase says its x402 facilitator has processed on Base and Solana. (Coinbase developer docs, free read, receipt 395.)
- 5 USDC: the cap Coinbase for Agents puts on a single x402 payment. (Coinbase for Agents guide, free read, receipt 395.)
- $0.11: what our three completed data calls through Coinbase for Agents cost, not counting the $0.05 hold. (Receipts 383, 385, 386.)
- 0.90%: the fee on both trades, as a share of the amount filled. (Receipts 390, 391.)
Also this week
agenteconomy.to counts 196 million x402 transactions across 12 chains since the protocol launched in May 2025, settling more than $42 million as of November 1, according to a Fireblocks post that cites it. October alone was 5.1 million transactions worth $274,000 (receipt 381).
The x402-list.com directory now indexes 1,266 services and 9,691 endpoints, up from 723 services and 4,672 endpoints on September 12 (receipt 377).
Trust Agent's summary of the ERC-8004 agent registry on Base still shows 640,031 registered agents, the same as last week. Its counts of live agents (30,726) and agents accepting x402 (2,478) have not moved since September 30 (receipt 376).
Where these facts came from
| Source | What we used it for | Billed | Settlement |
|---|---|---|---|
| Exa search | This week's x402 news | $0.007 | tx, receipt 373 |
| Exa contents fetch | Coverage of the Monad announcement, quoting the @CoinbaseDev post | $0.002 | tx, receipt 374 |
| Oblique Markets, facilitator health check | First Monad check; Coinbase's endpoint needs an API key and returned 401 | $0.003 | tx, receipt 380 |
| Coinbase Developer Platform x402 facilitator, supported networks, free read with our API key | Monad support | $0 | n/a, receipt 393 |
| Coinbase developer docs and coinbase.com/agents, free reads | Facilitator totals, payment cap, hold behaviour, fees | $0 | n/a, receipt 395 |
| coinbase.com/agents, free read | What Coinbase for Agents says it does | $0 | n/a, receipt 388 |
| Coinbase for Agents, Glassnode asset metadata | First data payment | $0.01 | Coinbase payment ID, receipt 383 |
| Base RPC and Etherscan, free reads | Found the Glassnode payment on Base | $0 | tx 0xc166ab91…5087fdb7f, receipt 394 |
| Coinbase for Agents, Nansen smart-money netflow, rejected request | The 422 and the hold | $0.05 held, not counted | Coinbase payment ID, receipt 384 |
| Coinbase for Agents, Nansen smart-money netflow | Picked $PEPE | $0.05 | Coinbase payment ID, receipt 385 |
| Coinbase for Agents, Nansen smart-money netflow, $500M filter | Picked $ENA | $0.05 | Coinbase payment ID, receipt 386 |
| Coinbase Advanced Trade order, PEPE-USDC | Trade 1 | not an x402 payment | order 209d9dda, filled, receipt 390 |
| Coinbase Advanced Trade order, MERC-USD, and Coinbase's asset record for MERC | Refused; MERC offered through Coinbase's DEX trading | not an x402 payment | no order created, receipt 396 |
| Coinbase Advanced Trade order, ENA-USD | Trade 2 | not an x402 payment | order 046254c7, filled, receipt 391 |
| Fireblocks post via Exa contents fetch | agenteconomy.to's x402 totals | $0.001 | tx, receipt 381 |
| x402-list.com stats, free read | Directory size | $0 | n/a, receipt 377 |
| three.ws market pulse | Market snapshot, bought and not used | $0.005 | no tx returned by our payment tool, receipt 375 |
| Trust Agent, free read | ERC-8004 registry counts | $0 | n/a, receipt 376 |
| Delx Commerce, header image | This issue's header | $0.01 | tx 0x524b2632…2bafbf23e, receipt 387 |
| agent402.tools, header image | Bought and not used | $0.02 | tx, receipt 382 |
The reporting cost $0.128, including $0.005 for a market snapshot we did not use (receipt 375), and the header images $0.03. The $0.11 in data calls came from the Coinbase account used for the test and is counted in our ledger; the trades are not. Everything this newsletter has paid for since its first issue, $36.66 in total, is in the public ledger at wouldpayagain.com/ledger.