Coston
TestnetThe protocol-development testnet for the Flare ecosystem.
Testnet. Tokens on this network have no real value. Use it for development and integration testing, not for real assets.
Coston is Flare’s protocol testnet — the first hop in the four-network upgrade path that runs Songbird Testnet Coston, then Songbird Canary-Network, then Flare Testnet Coston2, and finally Flare Mainnet. It runs CFLR as its native currency and is where protocol-level changes are implemented before any of them reach a canary or production network.
Network
- Chain ID
- 16
- Namespace
- eip155:16
- Native currency
- CFLR
- Network family
- Flare
- RPC endpoint
https://coston-api.flare.network/ext/bc/C/rpc- Explorer
- Coston 1
Technical
- Consensus
- Snowman++ (BFT, from Avalanche’s Snow family)
- Fees
- CFLR
- EVM
- Ethereum-compatible addresses and typed transactions
- Role
- Protocol testnet — stage 1 of the Flare upgrade path
Where Coston sits in the upgrade path
Flare ships four EVM-compatible, permissionless networks, and Coston is the protocol-development entry point. The documented path for a protocol change is Coston first, then Songbird Canary-Network, then Flare Testnet Coston2, then Flare Mainnet. Application developers do not need Coston at all — their path is Coston2 to Flare Mainnet.
This distinction is the single most useful thing to know about Coston: it is not a general-purpose application testnet. Putting an application there means testing against a network that protocol work will reset.
Testing against Coston
Because Coston is where protocol changes land first, code written against it is being tested against something that is still moving. Any integration built here should be expected to need revisiting as the change propagates to Songbird, Coston2 and Flare Mainnet.
For day-to-day contract work, Coston2 (chain 114) is the network Flare recommends — its documentation describes Coston2 explicitly as the dApp development testnet.
Marketplace contracts on Coston
Verified addresses from this marketplace's chain configuration. Follow a link to inspect the contract on the block explorer.
- AuctionManager (Diamond)
0xa8a7c79ba52515C213598fD0D1e34aBDbA395B27- NFT Deployer
0xa619C50ffD2FC59Ef1E58275eF70024Dbf315768- Block Gas Token Issuer
0x68e5C5a6B59AD9493e19e8888808c10Fa9EA4ee1
On this marketplace
Coston is a protocol testnet with no real economic value in its native currency. Listings here are for development and integration testing; do not price them as if they were real assets.