A Flask wrapper of Starknet state. Similar in purpose to Ganache.
Aims to mimic Starknet's Alpha testnet, but with simplified functionality.
- Install
- Disclaimer
- Run
- Interaction
- Dumping and Loading
- Hardhat Integration
- L1-L2 Postman Communication
- Block Explorer
- Lite Mode
- Restart
- Advancing time
- Contract debugging
- Devnet speed-up troubleshooting
- Development
pip install starknet-devnet
Works with Python versions >=3.7.2 and <3.10.
On Ubuntu/Debian, first run:
sudo apt install -y libgmp3-dev
On Mac, you can use brew
:
brew install gmp
- Devnet should not be used as a replacement for Alpha testnet. After testing on Devnet, be sure to test on testnet (alpha-goerli)!
- Specifying a block by its hash/number is not supported. All interaction is done with the latest block.
- Read more in interaction.
Installing the package adds the starknet-devnet
command.
usage: starknet-devnet [-h] [-v] [--host HOST] [--port PORT]
Run a local instance of Starknet Devnet
optional arguments:
-h, --help show this help message and exit
-v, --version Print the version
--host HOST Specify the address to listen at; defaults to 127.0.0.1 (use the address the program outputs on start)
--port PORT, -p PORT Specify the port to listen at; defaults to 5050
--load-path LOAD_PATH
Specify the path from which the state is loaded on
startup
--dump-path DUMP_PATH
Specify the path to dump to
--dump-on DUMP_ON Specify when to dump; can dump on: exit, transaction
--lite-mode Applies all optimizations by disabling some
features. These can be applied individually
by using other flags instead of this one.
--lite-mode-block-hash
Disables block hash calculation
--lite-mode-deploy-hash
Disables deploy tx hash calculation
--start-time START_TIME
Specify the start time of the genesis block
in Unix time
You can run starknet-devnet
in a separate shell, or you can run it in background with starknet-devnet &
.
Check that it's alive by running the following (address and port my vary if you specified a different one with --host
or --port
):
curl https://127.0.0.1:5050/is_alive
Devnet is available as a Docker image (shardlabs/starknet-devnet):
docker pull shardlabs/starknet-devnet:<TAG>
Image tags correspond to Devnet versions as on PyPI and GitHub, with the latest
tag used for the latest image. These images are built for linux/amd64. To use the arm64 versions, since 0.1.23
you can append -arm
to the tag. E.g.:
shardlabs/starknet-devnet:0.1.23
- image for the amd64 architectureshardlabs/starknet-devnet:0.1.23-arm
- image for the arm64 architecture
The server inside the container listens to the port 5050, which you need to publish to a desired <PORT>
on your host machine:
docker run -p [HOST:]<PORT>:5050 shardlabs/starknet-devnet
E.g. if you want to use your host machine's 127.0.0.1:5050
, you need to run:
docker run -p 127.0.0.1:5050:5050 shardlabs/starknet-devnet
You may ignore any address-related output logged on container startup (e.g. Running on all addresses
or Running on https://172.17.0.2:5050
). What you will use is what you specified with the -p
argument.
If you don't specify the HOST
part, the server will indeed be available on all of your host machine's addresses (localhost, local network IP, etc.), which may present a security issue if you don't want anyone from the local network to access your Devnet instance.
- Interact with Devnet as you would with the official Starknet Alpha testnet.
- The exact underlying API is not exposed for the same reason Alpha testnet does not expose it.
- To use Devnet with Starknet CLI, provide Devnet's URL to the
--gateway_url
and--feeder_gateway_url
options of Starknet CLI commands. - The following Starknet CLI commands are supported:
call
deploy
estimate_fee
get_block
(currently pending block is not supported)get_code
get_full_contract
get_state_update
get_storage_at
get_transaction
get_transaction_receipt
get_transaction_trace
invoke
(currently will fail for max_fee > 0)tx_status
- The following Starknet CLI commands are not supported:
get_contract_addresses
- If you're using the Hardhat plugin, see here on how to edit its config file to integrate Devnet.
Postman is a Starknet utility that allows testing L1 <> L2 interaction. To utilize this, you can use starknet-hardhat-plugin
, as witnessed in this example. Or you can directly interact with the two Postman-specific endpoints:
-
Load a
StarknetMockMessaging
contract. Theaddress
parameter is optional; if provided, theStarknetMockMessaging
contract will be fetched from that address, otherwise a new one will be deployed:POST /postman/load_l1_messaging_contract
- body:
{ "networkUrl": "https://localhost:8545", "address": "0x83D76591560d9CD02CE16c060c92118d19F996b3" }
networkUrl
- the URL of the L1 network you've run locally or that already exists; possibilities include, and are not limited to:
-
Flush. This will go through the new enqueued messages, sending them from L1 to L2 and from L2 to L1:
POST /postman/flush
- body: None
This method of L1 <> L2 communication testing differs from Starknet Alpha networks. Taking the L1L2Example.sol contract in the starknet documentation:
constructor(IStarknetCore starknetCore_) public {
starknetCore = starknetCore_;
}
The constructor takes an IStarknetCore
contract as argument, however for Devnet L1 <> L2 communication testing, this will have to be replaced with the MockStarknetMessaging.sol contract:
constructor(MockStarknetMessaging mockStarknetMessaging_) public {
starknetCore = mockStarknetMessaging_;
}
To preserve your Devnet instance for future use, there are several options:
- Dumping on exit (handles Ctrl+C, i.e. SIGINT, doesn't handle SIGKILL):
starknet-devnet --dump-on exit --dump-path <PATH>
- Dumping after each transaction (done in background, doesn't block):
starknet-devnet --dump-on transaction --dump-path <PATH>
- Dumping on request (replace
<HOST>
,<PORT>
and<PATH>
with your own):
curl -X POST https://<HOST>:<PORT>/dump -d '{ "path": <PATH> }' -H "Content-Type: application/json"
To load a preserved Devnet instance, run:
starknet-devnet --load-path <PATH>
To enable dumping and loading if running Devnet in a Docker container, you must bind the container path with the path on your host machine.
This example:
- Relies on Docker bind mount; try Docker volume instead.
- Assumes that
/actual/dumpdir
exists. If unsure, use absolute paths. - Assumes you are listening on
127.0.0.1:5050
.
If there is dump.pkl
inside /actual/dumpdir
, you can load it with:
docker run \
-p 127.0.0.1:5050:5050 \
--mount type=bind,source=/actual/dumpdir,target=/dumpdir \
shardlabs/starknet-devnet \
--load-path /dumpdir/dump.pkl
To dump to /actual/dumpdir/dump.pkl
on Devnet shutdown, run:
docker run \
-p 127.0.0.1:5050:5050 \
--mount type=bind,source=/actual/dumpdir,target=/dumpdir \
shardlabs/starknet-devnet \
--dump-on exit --dump-path /dumpdir/dump.pkl
A local block explorer (Voyager), as noted here, apparently cannot be set up to work with Devnet. Read more in this issue.
To improve Devnet performance, instead of calculating the actual hash of deployment transactions and blocks, sequential numbering can be used (0x0, 0x1, 0x2, ...).
Consider passing these CLI flags on Devnet startup:
--lite-mode
enables all of the optimizations described below (same as using all of the flags below)--lite-mode-deploy-hash
- disables the calculation of transaction hash for deploy transactions
--lite-mode-block-hash
- disables the calculation of block hash
- disables get_state_update functionality
Devnet can be restarted by making a POST /restart
request. All of the deployed contracts, blocks and storage updates will be restarted to the empty state. If you're using the Hardhat plugin, run await starknet.devnet.restart()
.
Block timestamp can be manipulated by seting the exact time or seting the time offset. Timestamps methods won't generate a new block, but they will modify the time of the following blocks. All values should be set in Unix time and seconds.
Sets the exact time of the next generated block. All blocks afterwards will keep a set offset.
POST /set_time
{
"time": TIME_IN_SECONDS
}
Warning: block time can be set in the past and lead to unexpected behaviour!
Increases the time offset for each generated block.
POST /increase_time
{
"time": TIME_IN_SECONDS
}
Devnet can be started with the --start-time
argument.
starknet-devnet --start-time START_TIME_IN_SECONDS
If your contract is using print
in cairo hints (it was compiled with the --disable-hint-validation
flag), Devnet will output those lines together with its regular server output. To filter out just your debugging print lines, redirect stderr to /dev/null when starting Devnet:
starknet-devnet 2> /dev/null
To enable printing with a dockerized version of Devnet set PYTHONUNBUFFERED=1
:
docker run -p 127.0.0.1:5050:5050 -e PYTHONUNBUFFERED=1 shardlabs/starknet-devnet
If you are not satisfied with your Devnet performance, consider the following:
- Make sure you are using the latest version of Devnet because new improvements are added regularly.
- Try using lite-mode.
- Using an installed Devnet should be faster than running it with Docker.
- If you are running Devnet with Docker on an ARM machine (e.g. M1), make sure you are using the appropriate image tag
- If Devnet has been running for some time, try restarting it (either by killing it or by using the restart functionality).
- Keep in mind that:
- The first transaction is always a bit slower due to lazy loading.
- Tools you use for testing (e.g. the Hardhat plugin) add their own overhead.
- Bigger contracts are more time consuming.
If you're a developer willing to contribute, be sure to have installed Poetry and all the dependency packages.
pip install poetry
poetry install
poetry run starknet-devnet
When running tests locally, do it from the project root:
poetry run pytest test/
or for a single file
poetry run pytest test/<TEST_FILE>
You don't need to build anything to be able to run locally, but if you need the *.whl
or *.tar.gz
artifacts, run
poetry build