Gas Quotes

Overview

Use the Gas API to calculate relayer fees and obtain the cryptographic signatures required by the CashmereCCTP contracts. Quotes are deterministic for the current block state and expire 100 seconds after issuance.

`GET /getEcdsaSig_native`

Generates an ECDSA signature for EVM contracts (transfer, transferWithPermit, transferV2, transferV2WithPermit).

GET https://gas.cashmere.exchange/getEcdsaSig_native

Query Parameters

Name	Type	Required	Description
`localDomain`	number	✅	Origin Circle domain (Ethereum = `0`, Arbitrum = `3`, etc.).
`destinationDomain`	number	✅	Target Circle domain.
`isV2`	boolean	✅	`true` for CCTP v2 flows (`transferV2*`), `false` for legacy v1.
`isNative`	boolean	✅	`true` if relayer fee + gas drop will be paid in the origin’s native token.

Example

curl "https://gas.cashmere.exchange/getEcdsaSig_native\
?localDomain=0\
&destinationDomain=3\
&isV2=true\
&isNative=false"

{
  "fee": "1500000",
  "deadline": "1729281534",
  "signature": "0x8b6aa1…1f9d",
  "isNative": false,
  "cctpVersion": 2
}

Response Fields

Field	Description
`fee`	Relayer fee (USDC, 6 decimals when `isNative=false`, native units otherwise).
`deadline`	UNIX timestamp that the contracts enforce (`now + 100s`).
`signature`	ECDSA signature over `(localDomain, destinationDomain, fee, deadline, isNative, cctpVersion)`.
`isNative`	Echo of the query flag.
`cctpVersion`	`1` or `2`, matching the target function.

Gas drops are not returned explicitly. When isNative=false, include your desired gasDropAmount in TransferParams and pass the same value to the contract.

`GET /getEd25519Sig_native`

Generates an Ed25519 signature for Solana, Aptos, or Sui transfers.

GET https://gas.cashmere.exchange/getEd25519Sig_native

Query Parameters

Name	Type	Required	Description
`localDomain`	number	✅	Origin domain.
`destinationDomain`	number	✅	Target domain.
`isNative`	boolean	✅	`true` for native fee flows.
`version`	number	❌	Set to `2` when calling Solana `transfer_v2`.

Example

curl "https://gas.cashmere.exchange/getEd25519Sig_native\
?localDomain=5\
&destinationDomain=0\
&isNative=false\
&version=2"

{
  "signature": "0x6c80e3…d4",
  "message": "0x0200000000000000000000000000000000000000000000000000000000000000e0fb080000000000",
  "publicKey": "0x93ab6f…af",
  "destinationDomain": "0",
  "fee": "590000",
  "deadline": "1729281534",
  "isNative": false,
  "version": 2
}

Message Layout

BCS-encoded fields (in order):

Optional version (u8).
Optional localDomain (u32) when isNative is provided.
destinationDomain (u32).
fee (u64).
deadline (u64).
Optional isNative (bool).

Reproduce this byte order on-chain before verifying the signature.

Token Pricing

GET https://gas.cashmere.exchange/tokenPrices

Returns a JSON map of { domainId: priceInUsd } pulled from Redis.

WebSocket Updates

GET wss://gas.cashmere.exchange/subscribe

{ "type": "fees", "data": { <sourceChain>: { fee: { <dest>: { native, usd } }, gas: { native, usd } } } }
{ "type": "tokenPrices", "data": { <domainId>: "<price>" } }

Use the socket to keep frontends in sync without repeatedly polling the REST endpoints.

Failure Modes

HTTP Status	Description
`400`	Missing or invalid query parameters.
`500`	Redis cache is incomplete (`MISSING_PRICE_DATA`) or an internal error occurred.

Retries are usually safe after a brief delay if the issue is cache-related.

Welcome

Overview

Products

Developer Resources

API Reference

Overview

`GET /getEcdsaSig_native`

Query Parameters

Example

Response Fields

`GET /getEd25519Sig_native`

Query Parameters

Example

Message Layout

Token Pricing

WebSocket Updates

Failure Modes

​Overview

​GET /getEcdsaSig_native

​Query Parameters

​Example

​Response Fields

​GET /getEd25519Sig_native

​Query Parameters

​Example

​Message Layout

​Token Pricing

​WebSocket Updates

​Failure Modes

Overview

`GET /getEcdsaSig_native`

Query Parameters

Example

Response Fields

`GET /getEd25519Sig_native`

Query Parameters

Example

Message Layout

Token Pricing

WebSocket Updates

Failure Modes