Underwing

Credit for AI agents, on Solana

Back an AI agent's spending. Earn a share when it pays back.

Agents need money for paid tools and APIs. Backers cover a small USDC allowance, the agent pays a fixed weekly fee, and every repayment and default is on the agent's public page.

Browse agents Request an allowance
Fee calculator Hatchling
Agent pays / week
1.00
To backers
0.90
Underwing
0.10

Every agent starts at Hatchling, up to 50 USDC.

How the money moves

Four legs of one route, all of them on the record.

Follow an allowance from the owner's request to the agent's public page.

  1. 01

    The owner asks

    An agent's owner requests a USDC allowance for named tools and APIs, and sets the weekly fee the agent will pay.

  2. 02

    Backers cover it

    Backers put up the USDC behind the allowance. Their cover stands first in line if the agent misses a week.

  3. 03

    The agent works and pays

    The agent spends on its tools, then pays the fixed fee each week. The fee goes to its backers.

  4. 04

    Every week is recorded

    Each repayment, late payment and default goes on the agent's public page, for anyone to check.

Earned, not granted

Allowances start small and grow with a clean history.

Each clean week moves an agent closer to the next tier, so a bigger allowance always sits on a record you can read.

    A default returns the agent to Hatchling and the count starts again.

    Where each fee goes

    Most of every fee goes to the backers.

    The agent's weekly fee is fixed when the allowance is set. Underwing keeps a slice of each fee paid, and the rest is shared among the agent's backers in proportion to their cover.

    Backers Underwing

    The register

    Listed agents

    All agents

    Questions

    What can an allowance pay for?

    Paid tools and APIs an agent needs to do its work: search, data, model calls, scraping, and pay-per-request services such as x402 endpoints. The owner names them in the request, and they show on the agent's page.

    When can I back an agent?

    Backing opens when the USDC vault goes live on Solana. Agent pages, requests and the public record are open now, so you can follow an agent before you back it.

    What happens if an agent doesn't repay?

    The backers' cover pays for that week, the default goes on the agent's public page, and the agent drops back to the Hatchling tier.

    Who sets the fee?

    The owner, when they request the allowance: a fixed amount per week, between 0.5% and 10% of the allowance. It is shown on the agent's page before anyone backs it.

    What does Underwing keep?

    A slice of every fee the agent pays, shown above. Nothing is charged to backers on top of that.

    Running an agent that needs a budget?

    Start at Hatchling with a small allowance and grow it one clean week at a time.

    Request an allowance