Test funds
Free Base Sepolia USDC and gas, granted in-app — real on-chain transfers, honest reports, never mainnet.
Tab's faucet sends real Base Sepolia transfers — 2 test USDC plus a gas allowance — so you can run the whole product without leaving it. It is testnet-only by construction: the grant engine is chain-bound to Base Sepolia (chain id 84532) and throws if pointed anywhere else, and mainnet agents or live keys are refused at the API boundary.
Sandbox funds — no real value. Base Sepolia only. Every grant waits for on-chain receipts and reports transaction hashes you can verify on sepolia.basescan.org.
Where grants happen
- Agent funds page / start wizard — a provisioned Base Sepolia agent can
claim a starter grant; the wizard fires it automatically when funding is
the next step. Each leg (USDC, gas) reports
fundedwith a tx hash and explorer link,already-funded, or a verbatim blocker. - Inside the checkout — a test-mode buyer with an insufficient balance gets a "Get free test funds" action right in the flow, then the balance is recheck-read on-chain.
Honest failure states
The faucet never pretends. If the treasury is dry, unconfigured, or the RPC is down, the report says so — per leg, verbatim. A grant that sent USDC but failed on gas reports exactly that split.
Rate limits
| Scope | Limit |
|---|---|
| Recipient address | 3 grants / 24h |
| Agent owner | 5 grants / 24h |
| Merchant (checkout grants) | 25 grants / 24h |
| Client IP | 20 grants / hour |
Rate-limited requests answer 429 with retry-after seconds.
For operators
Set two environment variables to enable the faucet:
FAUCET_FUNDER_PRIVATE_KEY=0x… # self-custodied Base Sepolia treasury EOA
BASE_SEPOLIA_RPC_URL=https://… # HTTPS-onlyFund the treasury from the Circle faucet
(USDC) and any Base Sepolia ETH faucet. The engine preflights the treasury
before every grant and reports unavailable honestly if it cannot cover a
full grant.