omerozan16/pathfinder

A Starknet full node written in Rust

Welcome to Pathfinder

A StarkNet full node giving you a safe view into StarkNet.

Pathfinder is currently in alpha so expect some rough edges but it is already usable today!

Features

• access the full StarkNet state history
  • includes contract code and storage, and transactions
• verifies state using L1
  • calculates the StarkNet state's Patricia-Merkle Trie root on a block-by-block basis and confirms it against L1
  • this means the contract code and storage are now locally verified
• Ethereum-like RPC API
• run StarkNet functions without requiring a StarkNet transaction
  • executed against the local state

Feedback

We appreciate any feedback, especially during this alpha period. This includes any documentation issues, feature requests and bugs that you may encounter.

For help or to submit bug reports or feature requests, please open an issue or alternatively visit the StarkNet discord channel.

Installation (from source)

If you'd like to just run the node, please consider skipping ahead to docker instructions. The following are instructions on how to build from source.

Prerequisites

Currently only supports Linux. Windows and MacOS support is planned. We need access to a full Ethereum node operating on the network matching the StarkNet network you wish to run. Currently this is either Goerli or Mainnet.

⚠️	If using Infura as an L1 provider, you will need access to their archive node facilities. This is because pathfinder requires access to the full log history.

Before you start, make sure your system is up to date with Curl and Git available:

sudo apt update
sudo apt upgrade
sudo apt install curl git

Install Rust

pathfinder requires Rust version 1.64 or later. The easiest way to install Rust is by following the official instructions.

If you already have Rust installed, verify the version:

cargo --version # must be 1.63 or higher

To update your Rust version, use the rustup tool that came with the official instructions:

rustup update

Install Python

pathfinder requires Python version 3.8 (in particular, cairo-lang 0.10.2a0 seems incompatible with Python 3.10).

sudo apt install python3 python3-venv python3-dev

Verify the python version. Some Linux distributions only supply an outdated python version, in which case you will need to lookup a guide for your distribution.

python3 --version # must be 3.8

Install build dependencies

pathfinder compilation need additional libraries to be installed (C compiler, linker, other deps)

sudo apt install build-essential libgmp-dev pkg-config libssl-dev

Clone pathfinder

Checkout the latest pathfinder release by cloning this repo and checking out the latest version tag. Take care not to be on our main branch as we do actively develop in it.

The remainder of the installation documentation assumes you are in the checkout directory.

Python setup

Create a python virtual environment in the py folder.

# Enter the `<repo>/py` directory
cd py
# Create the virtual environment and activate it
python3 -m venv .venv
source .venv/bin/activate

Next install the python tooling and dependencies

PIP_REQUIRE_VIRTUALENV=true pip install --upgrade pip
PIP_REQUIRE_VIRTUALENV=true pip install -e .[dev]

Finally, run our python tests to make sure you were succesful.

# This should run the tests (and they should pass).
pytest

Compiling pathfinder

You should now be able to compile pathfinder by running (from within the pathfinder repo):

cargo build --release --bin pathfinder

Updating pathfinder

Updating a pathfinder node from source is fairly straight forward and is a simpler variant of the installation and compilation described above.

pathfinder repository

Start by updating the pathfinder repository to the desired version. From within your pathfinder folder:

git fetch
git checkout <version-tag>

where <version-tag> is the desired pathfinder version. To display a list of all available versions, run

git tag

Python dependencies

Next, update the python dependencies. First enable your python virtual environment (if you are using one). For our example installation this would be:

source ./py/.venv/bin/activate

and then update:

PIP_REQUIRE_VIRTUALENV=true pip install -e py/.[dev]

Build and run pathfinder

Re-compile pathfinder:

cargo build --release --bin pathfinder

and you should now be able to run your pathfinder node as described in the next section.

Running the node

Ensure you have activated the python virtual environment you created in the python setup step. For the pathfinder environment this is done by running:

source py/.venv/bin/activate

If you are already in another virtual environment, you can exit it by running deactivate and then activating the pathfinder one.

This step is always required when running pathfinder.

Finally, you can start the node:

cargo run --release --bin pathfinder -- <pathfinder options>

Note the extra "--" which separate the Rust cargo command options from the options for our node. For more information on these options see the Configuration section.

It may take a while to first compile the node on the first invocation if you didn't do the compilation step.

pathfinder runs relative to the current directory. This means things like the database will be created and searched for within the current directory.

Configuration

The pathfinder node options can be configured via the command line as well as environment variables.

The command line options are passed in after the after the cargo run options, as follows:

cargo run --release --bin pathfinder -- <pathfinder options>

Using --help will display the pathfinder options, including their environment variable names:

# with built from source
cargo run --release --bin pathfinder -- --help

# with docker images (0.2.0 onwards)
docker run --rm eqlabs/pathfinder

Pending Support

Block times on mainnet can be prohibitively long for certain applications. As a work-around, StarkNet added the concept of a pending block which is the block currently under construction. This is supported by pathfinder, and usage is documented in the JSON-RPC API with various methods accepting "block_id"="pending".

Note that pending support is disabled by default and must be enabled by setting poll-pending=true in the configuration options.

Logging

Logging can be configured using the RUST_LOG environment variable. We recommend setting it when you invoke the run command:

RUST_LOG=<log level> cargo run --release --bin pathfinder ...

The following log levels are supported, from most to least verbose:

trace
debug
info  # default
warn
error

At the more verbose log levels (trace, debug), you may find the logs a bit noisy as our dependencies also add their own logging to the mix. You can restrict the logs to only pathfinder specific ones using RUST_LOG=pathfinder=<level> instead. For example:

RUST_LOG=pathfinder=<log level> cargo run --release --bin pathfinder ...

Network Selection

The StarkNet network can be selecting with the --network configuration option.

If --network is not specified, network selection will default to match your Ethereum endpoint:

• StarKNet mainnet for Ethereum mainnet,
• StarkNet testnet for Ethereum Goerli

Custom networks & gateway proxies

You can specify a custom network with --network custom and specifying the --gateway-url, feeder-gateway-url and chain-id options. Note that chain-id should be specified as text e.g. SN_GOERLI.

This can be used to interact with a custom StarkNet gateway, or to use a gateway proxy.

Running with Docker

The pathfinder node can be run in the provided Docker image. Docker image is the easiest way which does not involve a lot of python setup. The following assumes you have docker installed and ready to go.

The example uses $HOME/pathfinder as the volume directory where persistent files used by pathfinder will be stored. It is easiest to create the volume directory as the user who is running the docker command. If the directory gets created by docker upon startup, it might be unusable for creating files.

# ensure the directory has been created before invoking docker
mkdir -p $HOME/pathfinder
docker run \
  --rm \
  -p 9545:9545 \
  --user "$(id -u):$(id -g)" \
  -e RUST_LOG=info \
  -e PATHFINDER_ETHEREUM_API_URL="https://goerli.infura.io/v3/<project-id>" \
  -v $HOME/pathfinder:/usr/share/pathfinder/data \
  eqlabs/pathfinder

Updating the docker image

When pathfinder detects there has been a new release, it will log a message similar to:

WARN New pathfinder release available! Please consider updating your node! release=0.1.8-alpha

You can try pulling the latest docker image to update it:

docker pull eqlabs/pathfinder

There is a chance of seeing the release notification before a new docker image is available for download, so just wait a minutes and then retry.

Available images

Our images are updated on every pathfinder release. This means that the :latest docker image does not track our main branch here, but instead matches the latest pathfinder release.

Building the container image yourself

Building the container image from source code is necessary only in special cases or development. You can build the image by running:

docker build -t pathfinder .

Docker compose

Create the folder pathfinder where your `docker-compose.yaml is

mkdir -p pathfinder

# replace the value by of PATHFINDER_ETHEREUM_API_URL by the HTTP(s) URL pointing to your Ethereum node's endpoint
cp example.pathfinder-var.env pathfinder-var.env

docker-compose up -d

To check if it's running well use docker-compose logs -f.

JSON-RPC API

You can interact with StarkNet using the JSON-RPC API. Pathfinder supports the official StarkNet RPC API and in addition supplements this with its own pathfinder specific extensions such as pathfinder_getProof.

Currently pathfinder supports both v0.1 and v0.2.1 versions of the StarkNet JSON-RPC specification. v0.1 will be supported until the ecosystem has moved onto the next version. The path of the URL used to access the JSON-RPC server determines which version of the API is served:

• the v0.1.0 API is exposed on the /rpc/v0.1 path
• the v0.2.1 API is exposed on the / and /rpc/v0.2 paths
• the pathfinder extension API is exposed on /rpc/pathfinder/v0.1

Note that the pathfinder extension is versioned separately from the StarkNet specification itself.

API v0.1.0

Pathfinder supports version v0.1.0 of the StarkNet JSON-RPC specification, with the following changes:

• The starknet_protocolVersion method is not implemented. This method will be removed from the specification in its next version as its semantics and usage was questionable. We decided to not implement it.
• To be able to represent L1 handler transactions introduced in Starknet 0.10.0, we use the L1_HANDLER_TXN type from v0.2.1-rc1 of the JSON-RPC specification.
• To be able to represent DEPLOY_ACCOUNT transactions introduced in Starknet 0.10.1, we use the DEPLOY_ACCOUNT_TXN type from v0.2.1-rc1 of the JSON-RPC specification.

When browsing the specification project, please be aware of the following pitfalls:

• It uses git tags for release versions. The link above should take you to the version supported by pathfinder.
• The master branch is an active development branch and may contain unreleased specification changes.
• The playground link listed there does not link to the specific version, but instead reflects the master branch. Here is a corrected playground link.

Transaction write API v0.1.0

Pathfinder also support's submitting StarkNet transaction's to the StarkNet gateway. Here are links to the specification and the playground.

Note that:

• mainnet requires an additional token parameter to submit deploy and declare transactions
• starknet_addInvokeTransaction allows an optional nonce parameter to support version 1 invoke transactions. To keep compatibility with existing clients using positional parameters the nonce parameter is the last in the list.
• starknet_addDeployTransaction and starknet_addDeclareTransaction allow an optional abi property within the contract definition JSON object.

API v0.2.1-rc1

Pathfinder supports v0.2.1 of the Starknet JSON-RPC specification, with the following deviations:

• starknet_estimateFee does not support estimating DEPLOY_ACCOUNT transactions.

Use the playground link to check the list of methods and the parameters.

Transaction write API v0.2.1-rc1

Here are links to the specification and the playground.

Note that:

• mainnet requires an additional token parameter to submit deploy and declare transactions

pathfinder extension API

You can find the API specification here.

Monitoring API

Pathfinder has a monitoring API which can be enabled with the --monitor-address configuration option.

Health

/health provides a method to check the health status of your pathfinder node, and is commonly useful in Kubernetes docker setups. It returns a 200 OK status if the node is healthy.

Readyness

pathfinder does several things before it is ready to respond to RPC queries. In most cases this startup time is less than a second, however there are certain scenarios where this can be considerably longer. For example, applying an expensive database migration after an upgrade could take several minutes (or even longer) on testnet. Or perhaps our startup network checks fail many times due to connection issues.

/ready provides a way of checking whether the node's JSON-RPC API is ready to be queried. It returns a 503 Service Unavailable status until all startup tasks complete, and then 200 OK from then on.

Metrics

/metrics provides a Prometheus metrics scrape endpoint. Currently the following metrics are available:

RPC related counters

• rpc_method_calls_total,
• rpc_method_calls_failed_total,

You must use the label key method to retrieve a counter for a particular RPC method, for example:

rpc_method_calls_total{method="starknet_getStateUpdate"}
rpc_method_calls_failed_total{method="starknet_chainId"}

Python subprocess related counters

• extpy_processes_launched_total incremented each time python subprocess is launched
• extpy_processes_exited_total with labels, incremented each time python subprocess exits normally
• extpy_processes_failed_total incremented each time python subprocess exits abnormally

Feeder Gateway and Gateway related counters

• gateway_requests_total
• gateway_requests_failed_total

Labels:

• method, to retrieve a counter for a particular sequencer request type
• tag
  • works with: get_block, get_state_update
  • valid values:
    • pending
    • latest
• reason
  • works with: gateway_requests_failed_total
  • valid values:
    • decode
    • starknet
    • rate_limiting

Valid examples:

gateway_requests_total{method="get_block"}
gateway_requests_total{method="get_block", tag="latest"}
gateway_requests_failed_total{method="get_state_update"}
gateway_requests_failed_total{method="get_state_update", tag="pending"}
gateway_requests_failed_total{method="get_state_update", tag="pending", reason="starknet"}
gateway_requests_failed_total{method="get_state_update", reason="rate_limiting"}

These will not work:

• gateway_requests_total{method="get_transaction", tag="latest"}, tag is not supported for that method
• gateway_requests_total{method="get_transaction", reason="decode"}, reason is only supported for failures.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Questions / FAQ

Questions are welcome! If you have any questions regarding Pathfinder, feel free to ask them using Newton.

FAQ

• How do I run a Pathfinder node?

• Why should I run a Pathfinder node?

• What resources are required to run a Pathfinder node?

• Are there rewards for running a Pathfinder node?

• How do I connect my wallet to my Pathfinder node?

• How do I interact with my Pathfinder node?

• My Alchemy dashboard usage is low?

• How to select the network my Pathfinder node runs on?

• How do I see my Pathfinder logs?

• How do I move my Pathfinder node to another server / disk?

• Error compiling Pathfinder (rust)

• Python issues with Pathfinder

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

If you would like to contribute to the py/ parts, which interface with cairo-lang, please include a mention that you agree to relicense the python parts as necessary to abide with future cairo-lang license. See contributing.md for more information.