Supported Networks

Mainnet networks

Network	Chain ID	Chain Selector	Type
Ethereum Mainnet	`1`	`5009297550715157269`	Mainnet
Arbitrum One	`42161`	`4949039107694359620`	Mainnet
Avalanche	`43114`	`6433500567565415381`	Mainnet
Polygon	`137`	`4051577828743386545`	Mainnet
Base	`8453`	`15971525489660198786`	Mainnet

Testnet networks

Network	Chain ID	Chain Selector	Type
Ethereum Sepolia	`11155111`	`16015286601757825753`	Testnet
Arbitrum Sepolia	`421614`	`3478487238524512106`	Testnet
Avalanche Fuji	`43113`	`14767482510784806043`	Testnet
Polygon Amoy	`80002`	`16281711391670634445`	Testnet
Base Sepolia	`84532`	`10344971235874465080`	Testnet

Discovering networks at runtime

Go SDK

import (
    "context"
    "fmt"
    "os"

    crec "github.com/smartcontractkit/crec-sdk"
)

client, err := crec.NewClient(
    os.Getenv("CREC_BASE_URL"),
    os.Getenv("CREC_API_KEY"),
)
if err != nil { return err }

networks, hasMore, err := client.ListNetworks(ctx)
if err != nil { return err }
_ = hasMore

for _, n := range networks {
    netType := "unknown"
    if n.Type != nil {
        netType = string(*n.Type) // "mainnet" | "testnet"
    }
    defaultCL := "—"
    if n.DefaultConfidenceLevel != nil {
        defaultCL = string(*n.DefaultConfidenceLevel) // e.g. "finalized"
    }
    fmt.Printf("%-25s  family=%-6s  type=%-7s  chain_id=%-10s  selector=%s  default_cl=%s\n",
        n.Name, n.ChainFamily, netType, n.ChainId, n.ChainSelector, defaultCL)
}

REST

curl https://cre-connect.api.chain.link/v1/networks \
  -H "Authorization: Apikey $CREC_API_KEY" \

Response:

{
  "data": [
    {
      "id": "320efa6d-af83-4dae-89f1-5a124404a54d",
      "name": "Ethereum Sepolia",
      "chain_selector": "16015286601757825753",
      "chain_id": "11155111",
      "chain_family": "evm",
      "type": "testnet",
      "default_confidence_level": "finalized",
      "created_at": 1775503594,
      "updated_at": 1775503594
    }
  ],
  "has_more": false
}

Network record fields

Each Network record exposes the fields you need to wire into other CRE Connect resources:

Field	Used by	Notes
`id`	Diagnostic / display	Internal UUID for the network row.
`name`	UI / logs	Human-readable name (e.g. "Ethereum Mainnet").
`chain_selector`	`wallets`, `watchers`, `operations`	The CCIP chain selector: pass to every chain-aware request.
`chain_id`	EIP-712 domain (`chainId`)	Pass into `eip712.Domain` for typed-data signing.
`chain_family`	Application logic	Currently `"evm"`; future families may include `"solana"`.
`type`	Application logic	`"mainnet"` or `"testnet"`. Optional; absent on environments that haven't classified the network.
`default_confidence_level`	Watcher / event defaults	The confidence level the backend uses when none is supplied (e.g. `"finalized"`). Optional. See Confidence Levels.
`created_at` / `updated_at`	Diagnostic	Unix seconds.

Where chain selectors are required

Resource	Field	Notes
`CreateWallet`	`chain_selector`	The chain on which the Smart Account is deployed.
`Watchers.CreateWithService` / `Watchers.CreateWithABI`	`ChainSelector`	The chain whose logs the watcher subscribes to.
`Operation` (via SDK)	`ChainSelector` argument to `ExecuteOperation`	The chain on which the operation will be broadcast.
`events.SearchEvents`	`chain_selector` filter (optional)	Narrow historical search to one chain.

Network-level confidence levels (latest, safe, finalized) are configured per network and surfaced via default_confidence_level. See Confidence Levels for the semantic and latency trade-offs. Operation status events can progress through Multi-Event Finality as the underlying block matures.

Authentication: uses ListNetworks as the canonical smoke test.
REST API Reference: /networks endpoint contract.
Confidence Levels: pick the right finality for your workload.
Multi-Event Finality: understand progressive operation confirmations.

Supported Networks

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