Graviton is a free, open-source toolkit for blackbox testing smart contracts written in TEAL, the language used for Algorand smart contracts. It is aimed at developers who want to check how their contracts behave from the outside, feeding in transactions and inspecting the results without reading every line of logic first. Graviton for Windows is available as a Windows build or installer, alongside builds for macOS, Linux and Docker.
The project is written in Python and maintained in the Algorand GitHub organization. Its latest version is v0.9.0, and the most recent code update was made in February 2025, more than a year ago. Review the repository's recent activity before building it into a long-term pipeline. The tool suits testers and Web3 developers who already know the basics of Algorand and want a dedicated testing layer.
What Blackbox Testing Means for Smart Contracts
Blackbox testing evaluates software by its inputs and outputs, without relying on knowledge of its internal code. Whitebox testing, by contrast, inspects the logic line by line. Both approaches have a place, but blackbox tests answer a practical question: does the contract do what it should when someone interacts with it?
For smart contracts, that question matters a great deal. A contract may be correct in its code and still reject a valid transaction because of an edge case, such as an unexpected amount or a particular sender condition. Blackbox tests catch these behavioral gaps by exercising the contract the way real users and applications will.
The trade-off is coverage. A blackbox suite only tests the scenarios you think to write, so it works best alongside careful scenario design and, where possible, code review.
How TEAL Contracts Decide Transactions
TEAL is the assembly-style language used to write Algorand smart contracts. Its programs run on a stack and return a result that determines whether a transaction is approved or rejected. Because the language works at a low level, a small mistake in a comparison or a stack operation can change the outcome in ways that are hard to spot by reading.
Testing helps here because the question is always the same: given this transaction, should it pass? A useful test set covers normal cases, boundary values such as zero or maximum amounts, and transactions that should fail. Writing the failing cases down is often as valuable as writing the passing ones.
Keep your scenarios readable. A test named for the rule it checks, such as rejecting a payment from an unauthorized sender, is easier to maintain than a long list of anonymous inputs.
Who Uses a Testing Toolkit Like Graviton, and When
Graviton fits developers who are building or maintaining TEAL contracts and want repeatable checks. A typical case is a team that updates a contract to add a feature and needs to confirm that existing behavior has not changed. Running the same blackbox suite after each edit is a simple way to catch regressions.
Another scenario is preparing for deployment. Before a contract handles real value, testers can run a set of edge cases and confirm that each one produces the expected approval or rejection. Teams that run builds on servers may also find the Docker option convenient for keeping environments identical.
Graviton is less suited to someone who only wants to learn the basics of Algorand. For that, broader tooling and tutorials may be a better starting point, and Graviton becomes more useful once you have a contract worth testing.
Key features
Blackbox testing of TEAL contracts
Built in Python
Windows build or installer
Free and open source
Supported coins
The documentation names Algorand as the network Graviton targets. Its focus is TEAL contracts intended for that chain, so the toolkit is most relevant to developers building on Algorand. It is not designed for other blockchains, and developers working elsewhere should look for tools built for their own ecosystems.
How to install Graviton on Windows
- 1
Find the release
Open the GitHub Releases page of the project and locate the latest release, currently v0.9.0. Download only from the official website or the project's GitHub repository, and choose the Windows build or installer rather than a source archive that requires a compiler setup.
- 2
Verify the file
Check the release notes for a SHA-256 checksum or a signature, and compare it with your download before running anything. If the release provides neither, treat that as a reason for extra caution and review the repository before proceeding.
- 3
Run the installer or extract the build
If you downloaded the installer, run it and follow the prompts, choosing a folder you can find easily later. If you received the Windows build instead, extract it to a dedicated folder so the files stay organized.
-
Confirm the program starts
Open Command Prompt or PowerShell, go to the folder where Graviton is installed, and launch it to confirm it starts correctly. Then read the documentation for the exact command syntax before writing your first test suite.
How to use Graviton
Graviton works best when you already have a TEAL contract and a clear idea of what it should approve or reject. The workflow below describes the general pattern; check the documentation for exact command syntax and options.
- Write or load the TEAL contract you want to test.
- Define scenarios with sample transactions, sender accounts, amounts and the expected result for each.
- Include edge cases such as zero amounts, unexpected senders and transactions that should be rejected.
- Run the test suite from the command line against the contract.
- Compare each outcome with the expected approval or rejection and note any mismatches.
- Adjust the contract or the scenarios, then run the suite again.
- Keep the test files under version control so you can rerun them after every change.
Use test accounts for all scenarios so your real assets are never involved.
Pros & cons
- Free and open source, with public source code on GitHub
- Focused on blackbox testing of TEAL smart contracts
- Windows build or installer available, plus macOS, Linux and Docker
- Built in Python, which makes scripting and automation straightforward
- Narrow scope, centered on Algorand and TEAL
- Latest code update dates to February 2025, so project activity should be checked
- Learning curve for developers who are new to TEAL and Algorand concepts
Is Graviton safe?
Graviton is a testing tool, not a wallet, so it does not hold funds. Still, download it only from the official website or the project's GitHub repository, never from mirror sites or links shared in chats. Check the SHA-256 checksum or signature when the release provides one, and do not run files that fail the check. The last code update is more than a year old, so review recent commits and open issues before using it in a sensitive pipeline. Use test accounts and test mnemonics only, never real seed phrases, and never enter a seed phrase on a third-party website. Check the latest version on the official website before you install.
- Official source only. Download from github.com/algorand/graviton. Ignore ads and lookalike domains.
- Check the SHA-256. Compare the installer hash with the value the developer publishes before running it.
- Never share your seed phrase. No developer, support agent or website — including CryptApps — will ever ask for it.
Alternatives
Algojig is the closest match among the similar programs, since it is also a tool for testing Algorand smart contracts. Graviton is the dedicated blackbox testing toolkit from Algorand's own GitHub organization, so it is a natural choice if you want that focus. AlgoKit takes a wider role as a command-line tool for building on Algorand, covering more of the development workflow than testing alone. Algoml sits earlier in the pipeline: it is a domain-specific language that compiles into TEAL, so it helps you write contracts rather than test them. Conduit is a data pipeline framework, while Remix Desktop and Tenderly CLI target other ecosystems and workflows. Pick Graviton when blackbox testing of TEAL is your main need.
Specifications
- Price
- Free
- Type
- Open source
- License
- —
- Latest version
- v0.9.0
- Last update
- 20 Feb 2025
- Windows support
- Yes (Windows build or installer)
- Source code
- github.com/algorand/graviton
Frequently asked questions
Yes. Graviton is listed as free and open source, and its source code is public on GitHub. You can download the Windows build or installer without paying, and you can read the code to see how tests are run. Check the repository's license file for the terms of reuse before you redistribute it or include it in a commercial product.
Yes. Graviton is available as a Windows build or installer, so you do not need to build it from source. The project also supports macOS, Linux and Docker, which lets you run the same tests on different machines.
It is reasonably safe when you download it from the project's GitHub repository and verify the release file. Graviton is a testing tool, not a wallet, but you should still check checksums or signatures and avoid using real seed phrases in test environments.
Blackbox testing checks a contract by its inputs and outputs, without relying on its internal code structure. For TEAL, that means supplying transaction scenarios and confirming whether the contract approves or rejects each one as expected. It can reveal behavior problems that reading the code alone might miss.
The documentation names Algorand as the network Graviton is built for. It is aimed at TEAL contracts on Algorand, so it is not a fit for Ethereum or other chains. If you test contracts on other networks, look for tools designed for those ecosystems.
AlgoKit is a broader command-line tool for developers building on Algorand, covering several parts of the workflow. Graviton has a narrower purpose: blackbox testing of TEAL smart contracts. Many developers may use both, with AlgoKit for project work and Graviton for test coverage.
The latest release is v0.9.0, and the most recent code update was made in February 2025. Check the GitHub repository's commit history and open issues to see current activity before you rely on it in a long-term project.
Verdict
Graviton for Windows suits Algorand developers who want a focused, free way to test TEAL smart contracts from the outside. It is open source, Python-based and available as a Windows build or installer. Its scope is narrow and its last code update came in February 2025, so review the repository before depending on it. If you are already writing TEAL and want repeatable behavior checks, it is worth a trial on a test network using test accounts.