Seth

Reliable and debug-friendly Ethereum client

Goals

• Be a thin, debuggable and battle tested wrapper on top of go-ethereum
• Decode all transaction inputs/outputs/logs for all ABIs you are working with, automatically
• Simple synchronous API
• Do not handle nonces on the client side, trust the server
• Do not wrap bind generated contracts, small set of additional debug API
• Resilient: should execute transactions even if there is a gas spike or an RPC outage (failover)
• Well tested: should provide a suite of e2e tests that can be run on testnets to check integration

Examples

Check examples folder

Lib is providing a small amount of helpers for decoding handling that you can use with vanilla go-ethereum generated wrappers

// Decode waits for transaction and decode all the data/errors
Decode(tx *types.Transaction, txErr error) (*DecodedTransaction, error)

// NewTXOpts returns a new sequential transaction options wrapper,
// sets opts.GasPrice and opts.GasLimit from seth.toml or override with options
NewTXOpts(o ...TransactOpt) *bind.TransactOpts

// NewCallOpts returns a new call options wrapper
NewCallOpts(o ...CallOpt) *bind.CallOpts

By default, we are using the root key 0, but you can also use keys from keyfile.toml

// NewCallKeyOpts returns a new sequential call options wrapper from the key N
NewCallKeyOpts(keyNum int, o ...CallOpt) *bind.CallOpts

// NewTXKeyOpts returns a new transaction options wrapper called from the key N
NewTXKeyOpts(keyNum int, o ...TransactOpt) *bind.TransactOpts

Start Geth in a separate terminal, then run the examples

make GethSync
cd examples
go test -v

Setup

We are using nix

Enter the shell

nix develop

Building contracts

We have go-ethereum and foundry tools inside nix shell

make build

Testing

To run tests on a local network, first start it

make AnvilSync

Or use latest Geth

make GethSync

You can use default hardhat key ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 to run tests

Run the decode tests

make network=Anvil root_private_key=ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 test
make network=Geth root_private_key=ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 test

Check other params in seth.toml, select any network and use your key for testnets

User facing API tests are here

make network=Anvil root_private_key=ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 test_api
make network=Geth root_private_key=ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 test_api

CLI tests

make network=Anvil root_private_key=ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 test_cli
make network=Geth root_private_key=ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 test_cli

Tracing tests

make network=Anvil root_private_key=ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 test_trace
make network=Geth root_private_key=ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 test_trace

Config

env vars

Some crucial data is stored in env vars, create .envrc and use source .envrc, or use direnv

export SETH_LOG_LEVEL=info # global logger level
export SETH_CONFIG_PATH=seth.toml # path to the toml config
export SETH_KEYFILE_PATH=keyfile.toml # keyfile path for using multiple keys
export NETWORK=Geth # selected network
export ROOT_PRIVATE_KEY=ac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 # root private key

alias seth="go run cmd/seth/seth.go" # useful alias for keyfile CLI

If SETH_KEYFILE_PATH is not set then client will create X ephemeral keys (60 by default, configurable) and won't return any funds.

Use SETH_KEYFILE_PATH for testnets/mainnets and ephemeral mode only when testing against simulated network.

seth.toml

Set up your ABI directory (relative to seth.toml)

abi_dir = "contracts/abi"

Setup your BIN directory (relative to seth.toml)

bin_dir = "contracts/bin"

Decide whether you want to read keyfile or use ephemeral keys. In the first case you have two options:

• read it from the filesystem

# If empty Seth will not try to load any keyfiles. You can either set it to 'file' to load keyfiles from
# a file (providing path to it in 'keyfile_path') or to 'base64_env' to load it from Base64-ed environment variable
# 'SETH_KEYFILE_BASE64'
keyfile_source = "file"

# If keyfile_source is set to 'file' this should be a path to a file with keyfiles
keyfile_path = "keyfile.toml"

• read it from environment variable SETH_KEYFILE_BASE64 (keyfile needs to be base64-ed)

keyfile_source = "base64_env"

If you want to use ephemeral keys, you can set the number of keys to be generated:

# Set number of ephemeral keys to be generated (0 for no ephemeral keys). Each key will receive a proportion of native tokens from root private key's balance with the value equal to `(root_balance / ephemeral_keys_number) - transfer_fee * ephemeral_keys_number`. Using ephemeral keys together with keyfile will result in an error.
ephemeral_addresses_number = 10

You cannot use both keyfile and ephemeral keys at the same time. Trying to do so will cause configuration error.

You can enable auto-tracing for all transactions meeting configured level, which means that every time you use Decode() we will decode the transaction and also trace all calls made within the transaction, together with all inputs, outputs, logs and events. Three tracing levels are available:

• all - trace all transactions
• reverted - trace only reverted transactions (that's default setting used if you don't set tracing_level)
• none - don't trace any transactions Example:

tracing_level = "reverted"

Additionally you can also enable saving all decoding/tracing information to JSON files with:

trace_to_json = true

That option should be used with care, when tracing_level is set to all as it will generate a lot of data.

If you want to check if the RPC is healthy on start, you can enable it with:

check_rpc_health_on_start = false

It will execute a simple check of transferring 10k wei from root key to root key and check if the transaction was successful.

You can add more networks like this:

[[Networks]]
name = "Fuji"
chain_id = "43113"
transaction_timeout = "30s"
# gas limit should be explicitly set only if you are connecting to a node that's incapable of estimating gas limit itself (should only happen for very old versions)
# gas_limit = 9_000_000
# hardcoded gas limit for sending funds that will be used if estimation of gas limit fails
transfer_gas_fee = 21_000
# legacy transactions
gas_price = 1_000_000_000
# EIP-1559 transactions
eip_1559_dynamic_fees = true
gas_fee_cap = 25_000_000_000
gas_tip_cap = 1_800_000_000
urls_secret = ["..."]
# if set to true we will dynamically estimate gas for every transaction (explained in more detail below)
gas_price_estimation_enabled = true
# how many last blocks to use, when estimating gas for a transaction
gas_price_estimation_blocks = 1000
# priority of the transaction, can be "fast", "standard" or "slow" (the higher the priority, the higher adjustment factor and buffer will be used for gas estimation) [default: "standard"]
gas_price_estimation_tx_priority = "slow"

If you want to save addresses of deployed contracts, you can enable it with:

save_deployed_contracts_map = true

If you want to re-use previously deployed contracts you can indicate file name in seth.toml:

contract_map_file = "deployed_contracts_mumbai.toml"

Both features only work for live networks. Otherwise, they are ignored, and nothing is saved/read from for simulated networks.

CLI

Multiple keys manipulation (keyfile.toml)

To use multiple keys in your tests you can create a keyfile.toml using CLI

Set up the alias, see .envrc configuration above

alias seth="go run cmd/seth/seth.go"

Create a new keyfile with 10 new accounts funded from the root key (KEYS env var)

seth -n Geth keys split -a 10

Run the tests, then return funds back, when needed

seth -n Geth keys return

Update the balances

seth -n Geth keys update

Remove the keyfile

seth -n Geth keys remove

Manual gas price estimation

In order to adjust gas price for a transaction, you can use seth gas command

seth -n Fuji gas -b 10000 -tp 0.99

This will analyze last 10k blocks and give you 25/50/75/99th/Max percentiles for base fees and tip fees

-tp 0.99 requests the 99th tip percentile across all the transaction in one block and calculates 25/50/75/99th/Max across all blocks

Bulk tracing

You can trace multiple transactions at once using seth trace command. Example:

SETH_CONFIG_PATH=seth.toml go run cmd/seth/seth.go -n=Geth trace -f reverted_transactions.json

You need to pass a file with a list of transaction hashes to trace. The file should be a JSON array of transaction hashes, like this:

[
  "0x...",
  "0x...",
  "0x...",
  ...
]

(Note that currently Seth automatically creates reverted_transactions_<network>_<date>.json with all reverted transactions, so you can use this file as input for the trace command.)

Features

• Decode named inputs
• Decode named outputs
• Decode anonymous outputs
• Decode logs
• Decode indexed logs
• Decode old string reverts
• Decode new typed reverts
• EIP-1559 support
• Multi-keys client support
• CLI to manipulate test keys
• Simple manual gas price estimation
• Tuned gas prices for testnets (optimized for fast transaction times)
• Fail over client logic
• Decode collided event hashes
• Tracing support (4byte)
• Tracing support (callTracer)
• Tracing support (prestate)
• Tracing decoding
• Tracing tests
• More tests for corner cases of decoding/tracing
• Saving of deployed contracts mapping (address -> ABI_name) for live networks
• Reading of deployed contracts mappings for live networks
• Automatic gas estimator (experimental)
• Check if address has a pending nonce (transaction) and panic if it does

You can read more about how ABI finding and contract map works here and about contract store here here.

Autmoatic gas estimator

This section explains how to configure and understand the automatic gas estimator, which is crucial for executing transactions on Ethereum-based networks. Here’s what you need to know:

Configuration Requirements

Before using the automatic gas estimator, it's essential to set the default gas-related parameters for your network:

• Non-EIP-1559 Networks: Set the gas_price to define the cost per unit of gas if your network doesn't support EIP-1559.
• EIP-1559 Networks: If your network supports EIP-1559, set the following:
  • eip_1559_dynamic_fees: Enables dynamic fee structure.
  • gas_fee_cap: The maximum fee you're willing to pay per gas.
  • gas_tip_cap: An optional tip to prioritize your transaction within a block (although if it's set to 0 there's a high chance your transaction will take longer to execute as it will be less attractive to miners, so do set it).

These settings act as a fallback if the gas estimation fails. Additionally, always specify transfer_gas_fee for the fee associated with token transfers.

If you do not know if your network supports EIP-1559, but you want to give it a try it's recommended that you also set gas_price as a fallback. When we try to use EIP-1559 during gas price estimation, but it fails, we will fallback to using non-EIP-1559 logic. If that one fails as well, we will use hardcoded gas_price value.

How Gas Estimation Works

Gas estimation varies based on whether the network is a private Ethereum Network or a live network.

• Private Ethereum Networks: no estimation is needed. We always use hardcoded values.

For real networks, the estimation process differs for legacy transactions and those compliant with EIP-1559:

Legacy Transactions

1. Initial Price: Query the network node for the current suggested gas price.
2. Priority Adjustment: Modify the initial price based on gas_price_estimation_tx_priority. Higher priority increases the price to ensure faster inclusion in a block.
3. Congestion Analysis: Examine the last X blocks (as specified by gas_price_estimation_blocks) to determine network congestion, calculating the usage rate of gas in each block and giving recent blocks more weight.
4. Buffering: Add a buffer to the adjusted gas price to increase transaction reliability during high congestion.

EIP-1559 Transactions

1. Tip Fee Query: Ask the node for the current recommended tip fee.
2. Fee History Analysis: Gather the base fee and tip history from recent blocks to establish a fee baseline.
3. Fee Selection: Use the greater of the node's suggested tip or the historical average tip for upcoming calculations.
4. Priority and Adjustment: Increase the base and tip fees based on transaction priority (gas_price_estimation_tx_priority), which influences how much you are willing to spend to expedite your transaction.
5. Final Fee Calculation: Sum the base fee and adjusted tip to set the gas_fee_cap.
6. Congestion Buffer: Similar to legacy transactions, analyze congestion and apply a buffer to both the fee cap and the tip to secure transaction inclusion.

Understanding and setting these parameters correctly ensures that your transactions are processed efficiently and cost-effectively on the network.

Finally, gas_price_estimation_tx_priority is also used, when deciding, which percentile to use for base fee and tip for historical fee data. Here's how that looks:

		case Priority_Fast:
			baseFee = stats.GasPrice.Perc99
			historicalGasTipCap = stats.TipCap.Perc99
		case Priority_Standard:
			baseFee = stats.GasPrice.Perc50
			historicalGasTipCap = stats.TipCap.Perc50
		case Priority_Slow:
			baseFee = stats.GasPrice.Perc25
			historicalGasTipCap = stats.TipCap.Perc25

Adjustment factor

All values are multiplied by the adjustment factor, which is calculated based on gas_price_estimation_tx_priority:

	case Priority_Fast:
		return 1.2
	case Priority_Standard:
		return 1.0
	case Priority_Slow:
		return 0.8

For fast transactions we will increase gas price by 20%, for standard we will use the value as is and for slow we will decrease it by 20%.

Buffer percents

We further adjust the gas price by adding a buffer to it, based on congestion rate:

	case Congestion_Low:
		return 1.10, nil
	case Congestion_Medium:
		return 1.20, nil
	case Congestion_High:
		return 1.30, nil
	case Congestion_VeryHigh:
		return 1.40, nil

For low congestion rate we will increase gas price by 10%, for medium by 20%, for high by 30% and for very high by 40%.

We cache block header data in an in-memory cache, so we don't have to fetch it every time we estimate gas. The cache has capacity equal to gas_price_estimation_blocks and every time we add a new element, we remove one that is least frequently used and oldest (with block number being a constant and chain always moving forward it makes no sense to keep old blocks).

It's important to know that in order to use congestion metrics we need to fetch at least 80% of the requested blocks. If that fails, we will skip this part of the estimation and only adjust the gas price based on priority.

For both transaction types if any of the steps fails, we fallback to hardcoded values.

Experimental features

In order to enable an experimental feature you need to pass it's name in config. It's a global config, you cannot enable it per-network. Example:

# other settings before...
tracing_level = "reverted"
trace_to_json = false
experiments_enabled = ["slow_funds_return", "eip_1559_fee_equalizer"]

Here's what they do:

• slow_funds_return will work only in core and when enabled it changes tx priority to slow and increases transaction timeout to 30 minutes.
• eip_1559_fee_equalizer in case of EIP-1559 transactions if it detects that historical base fee and suggested/historical tip are more than 3 orders of magnitude apart, it will use the higher value for both (this helps in cases where base fee is almost 0 and transaction is never processed).