Tx · build (calldata)

Every state-changing contract function as a POST /v1/tx/... endpoint that returns ready-to-sign calldata. See the calldata-builder pattern for the integration flow.

Every endpoint accepts:

• The function's args (decimal strings for bigints, booleans where applicable)
• An optional from to enable gas estimation

And returns a BuiltTx.

All endpoints are unauthenticated — the security comes from the signing step in your wallet, not from any API key. Authorization on the on-chain function (owner-only, oracle-only, creator-only) is enforced by the smart contract.

ERC-20

Path	Encodes	Caller
POST /v1/tx/erc20/approve	approve(spender, amount) on a token	Anyone needing to approve USDC/USDT before a hedge action

curl -X POST https://api.blockfinax.com/v1/tx/erc20/approve \
  -d '{ "chainId": 8453, "token": "0x...USDC...", "spender": "0x...Diamond...", "amount": "110000000" }'

Hedge (public)

Path	Encodes	Caller
POST /v1/tx/hedge/create-event	createEvent(...) (the 14-field tuple)	Anyone (underwriter)
POST /v1/tx/hedge/deposit	deposit(eventId, amount)	LPs
POST /v1/tx/hedge/buy-protection	buyProtection(eventId, notional, maxCost, deadline)	Hedgers
POST /v1/tx/hedge/claim-payout	claimPayout(positionId)	Hedger of that position
POST /v1/tx/hedge/claim-premiums	claimPremiums(depositId)	LP of that deposit
POST /v1/tx/hedge/withdraw-capital	withdrawCapital(depositId)	LP, after expiry

createEvent body

The full body (see the per-field reference below):

{
  "chainId": 8453,
  "name": "USD/GHS · Q2 wide",
  "underlying": "USD/GHS",
  "strike":     "11400000",
  "payoutCap":  "12000000",
  "premiumRate": "23000",
  "expiry":     "1782182400",
  "allowExternalLp": true,
  "initialLiquidity": "100000000000",
  "initialRate":      "11070000",
  "strikeAbove":      true,
  "paymentToken":     "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "signature":        "0x",
  "quoteTimestamp":   "0",
  "quoteNonce":       "0x0000000000000000000000000000000000000000000000000000000000000000"
}

field	type	notes
name	string	Human label for the event
underlying	string	E.g. USD/GHS. Used to look up the FX rate
strike	uint256 (1e6)	Strike rate (11.40 = "11400000")
payoutCap	uint256 (1e6)	Cap rate. Pass "0" for legacy single-strike events
premiumRate	uint256 (1e6)	Premium as fraction of notional (2.3% = "23000")
expiry	uint256	Unix seconds
allowExternalLp	bool	If false, only the creator can deposit
initialLiquidity	uint256 (payment-token decimals)	Seed capital
initialRate	uint256 (1e6)	Spot rate at creation
strikeAbove	bool	true = upward hedge / call spread
paymentToken	address	USDC or USDT on the target chain
signature	bytes	"0x" for self-priced; engine signature for attested
quoteTimestamp	uint256	"0" for self-priced; engine's timestamp otherwise
quoteNonce	bytes32	ethers.ZeroHash for self-priced; engine's nonce otherwise

Hedge (creator-only)

Path	Encodes
POST /v1/tx/hedge/set-pool-settings	setPoolSettings(eventId, poolOpen, allowExternalLp)
POST /v1/tx/hedge/withdraw-creator-earnings	withdrawCreatorEarnings(eventId)

Only the wallet that called createEvent for that event can successfully broadcast these. The API builds the calldata regardless.

Hedge (owner / admin)

Path	Encodes
POST /v1/tx/hedge/initialize-fees	initializeHedgeFees(creationFee, hedgerFeeRate, payoutFeeRate, lpProfitFeeRate, creatorLoyaltyRate)
POST /v1/tx/hedge/settle-event	settleEvent(eventId, settlementPrice) (oracle admin)
POST /v1/tx/hedge/pause	pause()
POST /v1/tx/hedge/unpause	unpause()
POST /v1/tx/hedge/activate-oracle-v2	activateOracleV2()
POST /v1/tx/hedge/set-oracle-admin	setOracleAdmin(admin)
POST /v1/tx/hedge/set-pricing-engine-signer	setPricingEngineSigner(signer)
POST /v1/tx/hedge/withdraw-platform-fees	withdrawPlatformFees(amount) (USDC)
POST /v1/tx/hedge/withdraw-platform-fees-by-token	withdrawPlatformFeesByToken(token, amount)
POST /v1/tx/hedge/rescue-eth	rescueETH(to)
POST /v1/tx/hedge/rescue-erc20	rescueERC20(token, to)
POST /v1/tx/hedge/set-allowed-payment-token	setAllowedPaymentToken(token, allowed)
POST /v1/tx/hedge/recover-expired-payouts	recoverExpiredPayouts(eventId)

These will only succeed if signed by the Diamond owner (or oracle admin for settleEvent).

Oracle

Path	Encodes	Caller
POST /v1/tx/oracle/submit-rate	submitRate(eventId, price)	Authorised oracles only
POST /v1/tx/oracle/add-oracle	addOracle(oracle)	Owner
POST /v1/tx/oracle/remove-oracle	removeOracle(oracle)	Owner
POST /v1/tx/oracle/set-required-signers	setRequiredSigners(required)	Owner
POST /v1/tx/oracle/set-tolerance-bps	setToleranceBps(bps)	Owner
POST /v1/tx/oracle/clear-stale-submissions	clearStaleSubmissions(eventId)	Owner

Ownership

Path	Encodes
POST /v1/tx/ownership/transfer-ownership	transferOwnership(newOwner)
POST /v1/tx/ownership/accept-ownership	acceptOwnership()

Two-step ownership handover. The current owner calls transfer, then the new owner must call accept to finalize.

Governance (Timelock)

Path	Encodes
POST /v1/tx/governance/diamond-cut	diamondCut(cuts, init, initData) (queues an upgrade)
POST /v1/tx/governance/execute-cut	executeCut(proposalId) (after ETA)
POST /v1/tx/governance/cancel-cut	cancelCut(proposalId)

diamondCut body shape:

{
  "chainId": 8453,
  "cuts": [
    { "facetAddress": "0x...", "action": 0, "functionSelectors": ["0xdeadbeef"] }
  ],
  "init": "0x0000000000000000000000000000000000000000",
  "initData": "0x"
}

action enum: 0 = Add, 1 = Replace, 2 = Remove (EIP-2535).