Fee caps

Usage

$ beam fetch --max-fee <AMOUNT> <URL>

--max-fee auto-confirms only when the estimated total stays at or below the cap. The cap is denominated in the payment chain's units.

Examples

$ beam fetch --max-fee 0.001 https://paywall.example/article/123
$ beam --from agent --chain base fetch --max-fee 0.0005 https://api.example/expensive

What's counted in the cap

• For ERC20 payment offers: the transfer amount plus estimated gas (priced in the gas token, converted as needed).
• For native-asset payments: the transfer amount plus estimated gas.
• Beam rejects payments whose estimated gas alone exceeds the cap, even if the principal would fit. This protects against gas-spike attacks where the principal is small but the gas estimate is large.

Behavior

• If the estimated total fits inside the cap, Beam auto-confirms and proceeds.
• If it exceeds the cap, Beam fails the command with a normal CLI error and does not prompt — agent runs never block waiting for input.

Why it matters for agents

The combination of --max-fee + --allowed-chains + --from lets you run beam fetch as a non-interactive subprocess from any agent loop with predictable spend bounds.

beam --from agent --chain base fetch \
  --max-fee 0.001 \
  --allowed-chains base \
  https://paywall.example/api/data

If the paywall ever shifts to another chain or hikes the price, Beam fails instead of paying.