Gambit

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What Gambit is

Gambit is an open-source mutation testing tool for Solidity projects. It evaluates how well a test suite or formal specification detects faults by generating altered contract versions, called mutants, and checking which are caught. Gambit finds valid mutation points by traversing a program’s abstract syntax tree, then applies predefined syntax transformations. A declarative configuration language lets users target and customize mutations for particular parts of a program. Results can be reviewed in a dashboard that summarizes mutant verification and computes a specification score. Gambit can work with the Certora Prover to evaluate formal specifications; that workflow generates mutants and submits a verification job for each to Certora’s server. The command line provides `mutate` to generate mutants and `summary` to present them. A compatible Solidity compiler binary, `solc`, is required for the project being mutated. The tool supports Solidity and is described as usable with any Solidity project. It runs on Linux, macOS, and Windows, though prebuilt binaries are listed for Linux x86-64 and Mac; Windows and Linux ARM users must build from source. Function-call and swap-arguments-function mutation operators are disabled.

Who it suits

Gambit suits Solidity developers who want to assess tests or formal specifications by checking which generated contract faults they detect. It can be used on any Solidity project, with a compatible `solc` binary.

What it does well

Evaluates both test suites and formal specifications.
Lets users target mutations with declarative configuration.
Includes a dashboard with mutant results and a specification score.
MIT-licensed open-source project.

What to know first

Requires a compatible `solc` binary.
Windows and Linux ARM users must build from source.
Function-call and swap-arguments-function operators are disabled.

Limits

Function-call and swap-arguments-function mutation operators are disabled. Windows and Linux ARM users must build Gambit from source.

Getting started

Visit https://www.certora.com/gambit.
Install or build Gambit for your platform; prebuilt binaries are available for Linux x86-64 and Mac.
Provide a compatible `solc` binary for the Solidity project.
Use `mutate` to generate mutants, configuring mutation targets if needed.
Run the mutants against a test suite or formal specification and use `summary` or the dashboard to review results.

Verdict

Gambit provides a configurable way to evaluate Solidity tests and formal rules against generated mutants. Its compiler requirement and source-build needs on some platforms are worth checking before adoption.

Questions

Does Gambit cost anything?

Gambit is listed as free, with a free plan and no free trial.

Which languages does it support?

The supported language listed is Solidity.

Which platforms are available?

Gambit is listed for Linux, macOS, and Windows. Prebuilt binaries are available for Linux x86-64 and Mac; Windows and Linux ARM users must build from source.

Is Gambit open source?

Yes. The project’s GitHub repository identifies its license as MIT.

Does it work with the Certora Prover?

Yes. Gambit mutations can be used with the Certora Prover to evaluate formal specifications as well as tests. That workflow submits a verification job for each mutant to Certora’s server.

What does Gambit need to mutate a project?

It requires a compatible Solidity compiler binary, `solc`, for the project being mutated.

Facts from Gambit's own pages

Certora Prover integration: Gambit mutations can be used with the Certora Prover to evaluate formal specifications as well as tests. · certora.com, 7 Oct 2026
Command line: Gambit provides `mutate` to generate mutants and `summary` to summarize generated mutants. · github.com, 7 Oct 2026
Commands: Gambit provides mutate for generating mutants and summary for presenting generated mutants in a human-readable format. · github.com, 7 Oct 2026
Compiler requirement: Gambit uses the Solidity compiler `solc` and requires a compatible binary for the project being mutated. · github.com, 7 Oct 2026
Dashboard: Gambit results can be viewed in a dashboard that summarizes mutant verification results and computes a specification score. · certora.com, 7 Oct 2026
Formal specifications: Gambit mutants can be used to evaluate both tests and formal specifications. · certora.com, 7 Oct 2026
How it works: Gambit introduces faults called mutants into selected contracts and measures whether a test suite detects them. · certora.com, 7 Oct 2026
Installation: Prebuilt binaries are available for Linux x86-64 and Mac; Windows and Linux ARM users must build from source. · github.com, 7 Oct 2026
Intended users: The maker describes Gambit as usable on any Solidity project. · certora.com, 7 Oct 2026
License: The Gambit GitHub repository identifies its license as MIT. · github.com, 7 Oct 2026
Maker: Gambit is built and maintained as an open-source project by the Certora team. · certora.com, 7 Oct 2026
Mutant detection: Gambit measures how well a test suite detects generated mutants, with more detected mutants indicating a stronger suite. · certora.com, 7 Oct 2026
Mutant generation: Gambit applies predefined syntax transformations to Solidity source code to generate program variants called mutants. · github.com, 7 Oct 2026
Mutation generation: Gambit traverses a Solidity program’s abstract syntax tree to identify valid mutation points and generate variable mutants. · certora.com, 7 Oct 2026
Mutation limits: The README lists function-call mutation and swap-arguments-function mutation as disabled operators. · github.com, 7 Oct 2026
Mutation points: Gambit traverses a Solidity program's abstract syntax tree to identify valid mutation points. · certora.com, 7 Oct 2026
Mutation selection: Users can customize and localize mutations to specific program parts using a declarative configuration language. · certora.com, 7 Oct 2026
Other tools: The maker describes Gambit as usable with Solidity testing and verification tools generally, and with any Solidity project. · certora.com, 7 Oct 2026
Platforms: Prebuilt binaries are available for Linux x86-64 and Mac; Windows and Linux ARM users must build from source. · github.com, 7 Oct 2026
Prover integration: Gambit is integrated with Certora Prover for evaluating the strength of verification rules. · certora.com, 7 Oct 2026
Prover workflow: Using the mutation verifier generates mutants and submits a verification job for each mutant to Certora's server. · docs.certora.com, 7 Oct 2026
Purpose: Gambit is an open source Solidity mutation testing tool that evaluates and strengthens a testing suite. · certora.com, 7 Oct 2026
Results: The Gambit dashboard summarizes mutant verification results and computes a score to evaluate a specification. · certora.com, 7 Oct 2026
Support: Certora's documentation says product questions can be directed to its Help Desk channel on Discord. · docs.certora.com, 7 Oct 2026

Where Gambit stands on Freedom251

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