Tester Agent

The Tester agent role, test synthesis, and in-container test execution.

The Tester Agent (◉)

The Tester verifies that the Coder’s modifications actually work in practice.

Unlike tools that rely on hypothetical code analysis, NIKI’s Tester generates test suites and executes real commands inside the sandbox container.

What the Tester Does

1. Test Generation: Writes unit and integration test cases targeting the new functionality, edge cases, and boundary conditions.
2. Containerized Execution: Runs the project’s real test runner (e.g. npm test, cargo test, pytest) inside the isolated container.
3. Execution Analysis: Captures stdout, stderr, exit codes, and duration.
4. Artifact Production: Formats the test run into a TestReport JSON artifact containing:
   • Total tests run, passed, and failed.
   • Captured failure traces.
   • Coverage assessment.

Cost Optimization Tip

Because the Tester’s primary job is generating standard test boilerplate and verifying test runner outputs, you can often use faster and more economical models here:

[agents.tester]
provider    = "openai"
model       = "gpt-4o-mini"
max_tokens  = 4096
temperature = 0.1