Gasless intents

Most on-chain actions on Necter are gasless: you sign typed data in your wallet, and the Hub’s relayer sends the transaction and pays the gas. You never need Sepolia ETH to mine.

Action	Endpoint	Contract call relayed
Bond / top up collateral	POST /v1/subscriptions (returns the payload), POST /v1/subscriptions/{id}/bond, …/bond-payload	Staking.bondBySig with an EIP-2612 NECTA permit
Unbond	POST /v1/subscriptions/{id}/unbond	Staking.unbondBySig
Withdraw collateral	POST /v1/subscriptions/{id}/withdraw	Staking.withdrawBySig
Change payout address	POST /v1/subscriptions/{id}/payout	Staking.setPayoutBySig
Claim rewards	POST /v1/me/withdrawals/claims	ProjectVault.claimMany (anyone may claim; funds always go to the miner)
Faucet	POST /v1/faucet/drip	NectaFaucet.dripTo
Register a project	POST /v1/developers/projects/{id}/register	ProjectRegistry.registerBySig
Publish a consensus version	POST /v1/developers/projects/{id}/versions/{v}/publish	ProjectRegistry.publishVersionBySig

The one action that is not gasless is creating a project’s vault: the developer sends createVault from their own wallet, which needs a little Sepolia ETH. Vault

The two-step pattern

Endpoints that change on-chain state work in two steps:

1. Ask for the payload. Call the endpoint with no body (or {}, or the parameters it needs such as {"payout_address": "0x…"}). The Hub answers with a GaslessPayload:

   {
     "action": "unbond",
     "typed_data": { "types": { … }, "domain": { … }, "primaryType": "…", "message": { … } },
     "permit": null,
     "direct_tx": { "chain_id": 11155111, "to": "0x…", "data": "0x…" },
     "expires_at": 1791478000
   }

2. Sign and post it back. Sign typed_data with eth_signTypedData_v4 (and permit too when present), then post {"typed_data": …, "signature": "0x…", "permit": …, "permit_signature": "0x…"} to the same endpoint. The Hub checks the signer, relays the transaction and answers 202 with {"status": "queued" | "sent" | "confirmed" | "reverted" | "failed", "tx_hash": …}.

direct_tx is the equivalent ordinary transaction, for wallets that prefer to pay gas themselves.

What you are signing

Check what your wallet shows before you sign: the domain names the contract (verifyingContract, chain id 11155111) and the message names the subscription, amount, payout address or project. The miner apps validate every field (type strings, chain id, contract addresses from GET /, owner, deadline, amount) before asking you to sign, and never sign anything silently except a Sign-In with Ethereum message that passes every check.