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Flow Crescendo Previewnet

About Flow Crescendo Previewnet​

Flow Crescendo Previewnet is Flow's official testing and development network. It is intended to provide a staging and testing environment for dApp developers. It aims to balance similarity with Mainnet with being a productive development environment, resulting in the following key differences:

  • Crescendo Previewnet has significantly fewer validator nodes, resulting in a faster block rate compared to Mainnet
  • Crescendo Previewnet is configured with shorter epochs (about 12 hours, compared to 7 days on Mainnet)

Accessing Flow Crescendo Previewnet​

Flow Crescendo Previewnet is available for access at this URL:


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access.previewnet.nodes.onflow.org:9000

For example, to access the network using the Flow Go SDK:


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import "github.com/onflow/flow-go-sdk/client"
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func main() {
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flowAccessAddress := "access.previewnet.nodes.onflow.org:9000"
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flowClient, _ := client.New(flowAccessAddress, grpc.WithInsecure())
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// ...
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}

Generating Crescendo Key Pair​

You can generate a new key pair with the Flow CLI as follows:


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> flow keys generate
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🙏 If you want to create an account on Crescendo Previewnet with the generated keys use this link:
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https://previewnet-faucet.onflow.org/?key= cc1c3d72...
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🔴️ Store private key safely and don't share with anyone!
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Private Key 246256f3...
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Public Key cc1c3d72...

Note: By default, this command generates an ECDSA key pair on the P-256 curve. Keep in mind, the CLI is intended for development purposes only and is not recommended for production use. Handling keys using a Key Management Service is the best practice.

Account Creation and Token Funding Requests​

Accounts and tokens for testing can be obtained through the previewnet faucet. If you generated the keypair through the CLI, you can click on the URL provided to create an account and request crescendo FLOW tokens.

Important Smart Contract Addresses​

You can review all available core contracts deployed to the Crescendo to identify which ones you want to import.