Overview
Blockchain Link is a self-serve flow designed for adding, validating, and activating EVM-compatible blockchains, with no R&D dependency.
Note: Blockchain Link is currently limited to local integration only, meaning that the blockchain can be enabled for a limited amount of customers rather than for a global integration (where all FB customers have access to the blockchains).
The integration process
- Test the Chain: in the Console, go to Settings > Blockchain Link to explore a new blockchain for your use case and initiate testing. Fireblocks evaluates chain compatibility and technical readiness.
- Pay for Integration: Once testing confirms the chain meets the requirements, you commit to the integration through the commercial agreement.
- Integration with E2E Tests: Fireblocks completes the full blockchain integration, running end-to-end tests to verify transaction signing, broadcasting, and monitoring work correctly.
Note: The validation step is free of charge for any blockchain. Proceeding to a full integration (steps 2–3 below) requires additional payment.
Supported capabilities
Blockchain Link includes the following features:
- Native Asset: full blockchain native asset support: sending, receiving, and balance tracking.
- ERC20 Token Self-Serve Listing: you can list ERC20-compatible tokens on your integrated chain without R&D involvement.
- Contract Calls: the ability to interact with smart contracts deployed on the integrated blockchain.
Additional capabilities, such as WalletConnect integration, tokenization, and NFTs, are tested and approved separately. Contact your Customer Success Manager or Sales Engineer if you require these capabilities.
Chain ID duplications limitation
The ability to integrate a blockchain with the same chain ID as another blockchain already supported in the Fireblocks system is blocked, in order to prevent replay attacks.
Integration testing requirements
The following details are required to test the integration:
Node requirements
To integrate a blockchain through Blockchain Link, the RPC node you provide (for both Mainnet and Testnet) must support the following JSON-RPC endpoints, and meet a few additional operating requirements.
Required RPC endpoints
| Endpoint | Purpose | Reference |
| eth_getBlockByNumber | Retrieve a block by its number | ethereum.org |
| eth_getBlockByNumber (with 'pending') or parity_pendingTransactions | Retrieve pending block / mempool transaction data | ethereum.org · OpenEthereum |
| eth_blockNumber | Get the number of the most recent block | ethereum.org |
| eth_getBlockReceipts or parity_getBlockReceipts | Get all transaction receipts for a block | ethereum.github.io/execution-apis · OpenEthereum |
| eth_getTransactionByHash | Retrieve transaction details by hash | ethereum.org |
| eth_sendRawTransaction | Broadcast a signed transaction to the network | ethereum.org |
| eth_getTransactionCount or parity_nextNonce | Get the next nonce for an address | ethereum.org · OpenEthereum |
| eth_getBalance | Get the native asset balance of an address | ethereum.org |
| eth_estimateGas | Estimate gas required for a transaction | ethereum.org |
| eth_gasPrice | Get the current network gas price | ethereum.org |
| eth_getLogs | Retrieve event logs matching a filter | ethereum.org |
| web3_clientVersion | Get the node's client software version | ethereum.org |
| eth_getTransactionReceipt | Get the receipt of a mined transaction | ethereum.org |
| debug_traceBlockByNumber or trace_block (not mandatory) | Trace all transactions in a block | Geth docs · OpenEthereum trace module |
| debug_traceTransaction or trace_transaction(not mandatory) | Trace the execution of a single transaction | Geth docs · OpenEthereum trace module |
Note: debug_* methods are exposed by Geth-family clients, while trace_*/parity_* methods are exposed by OpenEthereum/Nethermind/Erigon-family clients. Your node only needs to support the variant matching its client implementation.
Your node can also support internal transactions (traces), which are native asset transfers executed by smart contracts during the execution of a blockchain transaction. This is what the debug_trace*/trace_* endpoints above are used for. Note that for local integrations via Blockchain Link the trace fields are optional.
Additional node criteria
- Endpoints must be available to Fireblocks without throttling or rate limiting.
- The node must support a request-per-second rate no lower than the blockchain's maximum transactions-per-second.
- The RPC connection must use HTTPS.
- The node must support at least 1,000 requests per minute (RPM).
Node authentication method
If your node does not require authentication, select None. Otherwise, select one of the following supported methods: Basic auth Bearer token, or Custom header.
Chain identity
You must provide the full set of blockchain identity details (blockchain name, native asset name, chain ID, network ID, and related metadata).
If the chain is a public chain, the blockchain name, base asset name, chain ID, and network ID you provide must match the details listed on Chainlist.
- Wallet derivation will be based on the SLIP-0044 architecture. Wallet derivation paths will be calculated using 1 for testnet blockchains and 60 for mainnet blockchains.
- The address structure must be compatible with the Ethereum address format (0x prefix).
Network & connectivity
You must provide connectivity details for both Mainnet and Testnet; this input determines how wallet addresses are derived.
- Production workspaces support Mainnet blockchains.
- Testnet workspaces support Testnet blockchains.
As part of the integration form, you must also answer:
- Is fee/gas required? Indicates whether transactions on this blockchain require a fee (e.g., Ethereum, Polygon).
- Is the blockchain PoA? Specifies whether the blockchain uses a Proof-of-Authority consensus mechanism.
- Does it have a layered fee? For Layer 2 blockchains, this indicates whether an associated Layer 1 fee is required for transaction submission (e.g., Optimism, Base).
Notes:
- Tokens cannot be used to pay transaction fees; only the chain's base asset can be used for this purpose.
- The fee model must be fully aligned with the original forked blockchain's fee model.
Explorer
Fireblocks uses this to link transactions directly to the explorer. Note that for local integrations via blockchain link, the explorer fields are optional.
Base asset funds for validation purposes
As part of the integration process, you must provide base token funds to a Fireblocks wallet in order to validate the integration. Ensure the funds cover at least 10 transactions, including the transferred amount and fees.
Blockchain Link is currently in the Early Availability (EA) phase. Contact your Customer Success Manager (CSM) to obtain early access.