Guide · Prove

Prove a transaction

A V5 proof carries the Merkle path from a transaction's block to the root, so you check it yourself. Proofs are free on the public routes, on the 16 EVM chains the layer reads per transaction.

Prove a transaction

The first ask builds the proof and can take about 10 seconds. Later asks for the same transaction are quick.

shell

curl https://coord.taifoon.dev/v1/proof/tx/8453/0x0f7f432e5fb3e650618387cdfbe99e94c105675f7729cc85a9a61b6c678500ff

Answer	What it means
`200`, `proof_state: "proven"`	The block is final and committed by the superroot named in super_root_hash; checks lists what was verified, blob is the proof.
`200`, `proof_state: "not_final"`	The block is not final on its chain yet. The proof is served; act on it only after finality.
`200`, `pending_proof: true`	The block is in range but its proof is still being built: retry after retry_after_seconds.
`404 chain_not_read`	The layer reads no RPC of that chain. The answer lists the chains it reads.
`503 producer_unavailable`	The proof was not served in time. Retry after 10 seconds.

Prove one log, or many blocks

One log of a transaction, by its index in the block (here log 527 of the same transaction):

shell

curl "https://coord.taifoon.dev/v1/proof/log/8453/0x0f7f432e5fb3e650618387cdfbe99e94c105675f7729cc85a9a61b6c678500ff?log_index=527"

Up to 256 blocks of one chain in one compact proof, anchored to the superroot:

shell

curl "https://coord.taifoon.dev/v1/proof/blocks/8453?blocks=51419742,51419743"

That a block sits under the current root:

shell

curl https://coord.taifoon.dev/v1/root/proof/8453/52174000

What a proof commits, level by level

Layer	What it holds
`superroot`	One hash over every chain the layer reads, recomputed every 10 seconds.
`chainHeaders[]`	The block: chainId, blockNumber, blockHash, the chain tree root and its twig count.
`superrootProof`	The siblings from that chain’s leaf up to the superroot.
`blockProof`	The block’s path in its chain’s block tree (depth 32, indexed by block number); 2,048 headers make one twig.
`event`	The ABI-encoded log, when you ask for one.
`finality`	Whether the block is final on its chain, and by which rule.

Check it yourself

Off chain, the check is a keccak walk from the block's leaf to the superroot, then a comparison with the published root. The walk, line by line, is in Onboard a protocol, and /proof runs the same check in your browser for any block.

shell

curl https://coord.taifoon.dev/v1/root/latest

On Base, three contracts take a V5 proof. Call them with the ABI Basescan shows for each address; there is no package to install.

Contract	What it does	Calls
TaifoonV5ProofVerifier `0x2D475a53eAA8F9AC78B69bD2429275a622C644f8`	Checks a block proof, or a transaction’s receipt against its block.	`verify(blob) · verifyWithReceipt(blob, receipt) · verifyEncoded(bytes)`
Taifoon Universal Operator (TUO V5) `0x785F4701C681dCBa8762FcfaF18db4048215c0ca`	Calls your contract only after the proof passes; each event executes once.	`executeVerifiedCallV5Strict(blob, receipt, vendor, calldata)`
TaifoonHeaderOracle `0xCff7404874ffb1Ab1Cc62631bfE097C391b6491d`	Holds anchored block hashes per chain.	`isProven(chainId, block, hash) · provenHashAt(chainId, block)`

The superroot anchor of the verifier is not set yet, so on chain it checks a proof against the root the caller passes. Compare that root with GET /v1/root/latest before you act on a proof. For a transaction, build the receipt inclusion from eth_getBlockReceipts (the header RLP, the receipt RLP and its trie nodes) and call verifyWithReceipt.