Spec Kit
Puts the specification back in front of the code, which is the only way agent output stays reviewable.
Spec Kit is a toolkit for spec-driven development: write the spec first, let the agent implement against it, and review the diff against an artefact a human actually wrote. It is GitHub's answer to the real failure mode of agent-assisted work — not bad code, but code nobody can say is correct because there was never an agreed description of correct.
Best for: Teams moving from ad-hoc agent use to a process a reviewer can actually check
Deploy: Self-hostable
What to do about it
- Spec-driven development
- Reviewable code
- Open-source
What it is
Spec Kit is a toolkit for spec-driven development, which involves writing the specification first and then letting an agent implement against it.
The goal is to keep the specification in front of the code, making it reviewable.
This approach is meant to address the issue of code being generated without a clear description of what is correct.
Where it fits in a deployment stack
Tools like Spec Kit are used to manage the interaction between humans and agents in a development workflow.
They normally sit next to version control systems and code review tools, taking over the work of ensuring that the code generated by agents is correct and reviewable.
This category of tools solves the problem of agents producing code that is difficult for humans to understand or verify.
How to evaluate it
To evaluate Spec Kit, you need to consider how it handles the specification, implementation, and review process.
You should look at the artifacts it produces and how they can be used to verify the correctness of the generated code.
- Feed it a simple specification and inspect the generated code
- Measure the time it takes to generate code for a complex specification
- Inject errors into the specification and verify that the tool detects them
- Compare the generated code with a manually written version
- Verify that the tool produces a diff that can be reviewed by a human
- Check the tool's output for a specification with multiple possible implementations
What to verify before you commit
Before committing to using Spec Kit, you need to verify several aspects of the tool, including its licence, data handling, and operational cost.
You should also check how it behaves in case of failures and whether it locks you into a specific workflow or technology.
- Check the licence terms to ensure they are compatible with your project
- Verify how the tool handles sensitive data and whether it meets your security requirements
- Estimate the operational cost of using the tool, including any potential performance overhead
- Test the tool's failure behaviour and verify that it does not cause data loss or corruption
- Check for any potential lock-in, such as proprietary formats or dependencies
- Verify that the tool can be integrated with your existing workflow and tools
Where this fits in the FDE path
- FDE career path — the levels, the titles that map to them, and what changes at each step
- Interview guide — what the loop tests beyond coding
- Pay data — 223 postings — midpoint median $231,000, employer-published ranges only
- 922 live FDE roles — pulled daily from employers’ own job boards