> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lasso.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# Supported Methods

> Complete reference of Ethereum JSON-RPC methods supported by Lasso

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 |

<Warning>
  Large `eth_getLogs` queries may be limited by provider block range caps (typically 2,000-10,000 blocks). See [provider capabilities](/configuration/capabilities) for block range limits.
</Warning>

### 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)                |

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

## 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

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

**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.

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

### 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:

```bash theme={null}
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}'
```