Kaktoos: open-source tool verifies AI-written API integrations against OpenAPI contracts
richocolate · reddit · 2026-09-10
An indie developer open-sourced Kaktoos to address a blind spot in AI coding agents: when the agent writes both integration code and its tests, passing tests don't prove the code matches the real API.
Workflow: AI agent → integration code → Kaktoos (executes against OpenAPI contract + live API) → structured failures → agent fixes.
Features:
- Executes multi-step API workflows;
- Verifies responses against OpenAPI (missing required fields, wrong types, unexpected status/content-type);
- Exposes verification via MCP so coding agents can call it;
- Runs the same checks in GitHub Actions.
The author is experimenting with whether independent verification matters for AI-generated code and seeks feedback on scenario-definition cost, coverage vs existing tests, and CI adoption.
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