Supported Methods

Lasso provides production-grade routing for stateless Ethereum JSON-RPC reads and subscriptions. This page lists all supported methods organized by category.

Read-Only Methods (HTTP + WebSocket)

All read-only methods support failover, circuit breakers, and performance-based routing.

Blocks & Transactions

Method	Description
`eth_blockNumber`	Returns the number of the most recent block
`eth_getBlockByNumber`	Returns information about a block by block number
`eth_getBlockByHash`	Returns information about a block by block hash
`eth_getBlockTransactionCountByNumber`	Returns the number of transactions in a block by block number
`eth_getBlockTransactionCountByHash`	Returns the number of transactions in a block by block hash
`eth_getTransactionByHash`	Returns information about a transaction by transaction hash
`eth_getTransactionReceipt`	Returns the receipt of a transaction by transaction hash
`eth_getTransactionByBlockHashAndIndex`	Returns information about a transaction by block hash and transaction index
`eth_getTransactionByBlockNumberAndIndex`	Returns information about a transaction by block number and transaction index
`eth_getUncleCountByBlockHash`	Returns the number of uncles in a block by block hash
`eth_getUncleCountByBlockNumber`	Returns the number of uncles in a block by block number
`eth_getUncleByBlockHashAndIndex`	Returns information about an uncle by block hash and uncle index
`eth_getUncleByBlockNumberAndIndex`	Returns information about an uncle by block number and uncle index

Account State

Method	Description
`eth_getBalance`	Returns the balance of an account at a given block
`eth_getTransactionCount`	Returns the number of transactions sent from an address (nonce)
`eth_getCode`	Returns the code at a given address
`eth_getStorageAt`	Returns the value from a storage position at a given address
`eth_getProof`	Returns the Merkle proof for account and storage values (EIP-1186)

Execution & Gas

Method	Description
`eth_call`	Executes a new message call immediately without creating a transaction
`eth_estimateGas`	Generates and returns an estimate of gas needed for transaction execution
`eth_gasPrice`	Returns the current gas price in wei
`eth_maxPriorityFeePerGas`	Returns a fee per gas value for EIP-1559 transactions
`eth_feeHistory`	Returns historical gas information for fee estimation

Logs & Events

Method	Description
`eth_getLogs`	Returns an array of logs matching a given filter object

Large eth_getLogs queries may be limited by provider block range caps (typically 2,000-10,000 blocks). See provider capabilities for block range limits.

Network Information

Method	Description
`eth_chainId`	Returns the chain ID (served locally, no upstream call)
`eth_protocolVersion`	Returns the current Ethereum protocol version
`eth_syncing`	Returns an object with sync status or false
`net_version`	Returns the current network ID
`net_listening`	Returns true if client is actively listening for network connections
`net_peerCount`	Returns number of peers currently connected to the client
`web3_clientVersion`	Returns the current client version
`web3_sha3`	Returns Keccak-256 hash of the given data

Subscription Methods (WebSocket Only)

These methods are only available over WebSocket connections and include automatic gap-filling on failover.

Method	Description
`eth_subscribe`	Create a subscription for events (newHeads, logs, newPendingTransactions)
`eth_unsubscribe`	Cancel an active subscription

Supported Subscription Types

Type	Parameters	Gap-Filling
`newHeads`	`["newHeads"]`	✅ Full backfill with `eth_getBlockByNumber`
`logs`	`["logs", {"address":"0x...", "topics":[...]}]`	✅ Full backfill with `eth_getLogs`
`newPendingTransactions`	`["newPendingTransactions"]`	❌ No gap-filling (ephemeral)

When a WebSocket provider fails, Lasso automatically detects gaps, backfills missing events via HTTP, and resumes the stream on a new provider.

Advanced & Non-Standard Methods

These methods are forwarded on a best-effort basis with no guarantees of availability.

Enhanced Batch Methods

Method	Description	Availability
`eth_getBlockReceipts`	Returns all transaction receipts for a block	Alchemy, Erigon, some providers

EIP-4844 (Blob Transactions)

Method	Description	Availability
`eth_getBlobBaseFee`	Returns the current blob base fee	Post-Dencun networks

Debug & Trace Methods

Debug and trace methods are expensive and rarely supported on hosted providers. Use provider override to target specific nodes.

Debug Methods:

debug_traceTransaction
debug_traceBlockByNumber
debug_traceBlockByHash
debug_traceCall
debug_getBadBlocks
debug_storageRangeAt
debug_getModifiedAccountsByNumber
debug_getModifiedAccountsByHash

Trace Methods (Parity/Erigon):

trace_block
trace_transaction
trace_call
trace_callMany
trace_rawTransaction
trace_replayBlockTransactions
trace_replayTransaction
trace_filter
trace_get

Chain-Specific:

arbtrace_* (Arbitrum)
optimism_* (Optimism)
Other L2-specific extensions

Blocked Methods

The following methods are explicitly blocked for security or architectural reasons:

Subscriptions Over HTTP

❌ eth_subscribe, eth_unsubscribe - Use WebSocket connections instead

Wallet & Signing

❌ Server-side key management is out of scope:

eth_sign
eth_signTransaction
eth_signTypedData, eth_signTypedData_v3, eth_signTypedData_v4
eth_sendTransaction
eth_accounts
All personal_* methods
All wallet_* methods (EIP-1193 client APIs)

Transaction Writes

❌ eth_sendRawTransaction - Currently blocked. Multi-provider routing requires nonce management and transaction deduplication.

Write support is planned for future releases with proper nonce queuing, sticky sessions, and idempotency tracking.

Stateful Filters

❌ Filter methods require sticky sessions and are incompatible with failover:

eth_newFilter
eth_newBlockFilter
eth_newPendingTransactionFilter
eth_getFilterChanges
eth_getFilterLogs
eth_uninstallFilter

Alternative: Use WebSocket subscriptions (eth_subscribe) for real-time events.

Transaction Pool

❌ Provider-specific internal state with no standardization:

txpool_content
txpool_inspect
txpool_status

Mining & Local Node Operations

❌ Not available on hosted providers:

eth_coinbase
eth_mining
eth_hashrate
eth_getWork
eth_submitWork
eth_submitHashrate

EIP Compatibility

EIP	Description	Support
EIP-1474	JSON-RPC API	✅ Full baseline method set
EIP-1898	Block Parameter Objects	✅ `blockHash`, `blockNumber`, `requireCanonical`
EIP-1186	State Proofs	✅ `eth_getProof`
EIP-1559	Fee Market	✅ `eth_maxPriorityFeePerGas`, `eth_feeHistory`
EIP-4844	Blob Transactions	⚠️ Pass-through, provider-specific
EIP-1193	Provider API	⚠️ Recognized, wallet methods blocked

Best Practices

Gas Estimation Consistency

eth_estimateGas and eth_call can vary across providers due to different node implementations and timing. For consistency:

Pin estimates to a single provider using ?provider=<id>
Use :priority strategy for consistent results
Add a 10-20% buffer on the client side

Large Log Queries

For eth_getLogs with large block ranges:

Query 2,000 blocks at a time
Filter aggressively using address and topics
Monitor for rate limit errors and back off
Use :priority strategy for consistency across pages

Non-Standard Method Availability

To check if a specific provider supports a non-standard method:

curl -X POST 'http://localhost:4000/rpc/ethereum?provider=alchemy_eth' \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","method":"eth_getBlockReceipts","params":["latest"],"id":1}'

HTTP API

WebSocket API

Management API

Reference

Supported Methods

Read-Only Methods (HTTP + WebSocket)

Blocks & Transactions

Account State

Execution & Gas

Logs & Events

Network Information

Subscription Methods (WebSocket Only)

Supported Subscription Types

Advanced & Non-Standard Methods

Enhanced Batch Methods

EIP-4844 (Blob Transactions)

Debug & Trace Methods

Blocked Methods

Subscriptions Over HTTP

Wallet & Signing

Transaction Writes

Stateful Filters

Transaction Pool

Mining & Local Node Operations

EIP Compatibility

Best Practices

Gas Estimation Consistency

Large Log Queries

Non-Standard Method Availability

​Read-Only Methods (HTTP + WebSocket)

​Blocks & Transactions

​Account State

​Execution & Gas

​Logs & Events

​Network Information

​Subscription Methods (WebSocket Only)

​Supported Subscription Types

​Advanced & Non-Standard Methods

​Enhanced Batch Methods

​EIP-4844 (Blob Transactions)

​Debug & Trace Methods

​Blocked Methods

​Subscriptions Over HTTP

​Wallet & Signing

​Transaction Writes

​Stateful Filters

​Transaction Pool

​Mining & Local Node Operations

​EIP Compatibility

​Best Practices

​Gas Estimation Consistency

​Large Log Queries

​Non-Standard Method Availability

Read-Only Methods (HTTP + WebSocket)

Blocks & Transactions

Account State

Execution & Gas

Logs & Events

Network Information

Subscription Methods (WebSocket Only)

Supported Subscription Types

Advanced & Non-Standard Methods

Enhanced Batch Methods

EIP-4844 (Blob Transactions)

Debug & Trace Methods

Blocked Methods

Subscriptions Over HTTP

Wallet & Signing

Transaction Writes

Stateful Filters

Transaction Pool

Mining & Local Node Operations

EIP Compatibility

Best Practices

Gas Estimation Consistency

Large Log Queries

Non-Standard Method Availability