coverctl vs native commands (go test -cover, pytest --cov, nyc)

TL;DR

coverctl runs the native commands. The question is what happens to the result afterward.

	Native commands	coverctl
What runs the tests	`go test -cover`, `pytest --cov`, `nyc`, …	The same native commands, invoked by coverctl
What reads the result	You, in a terminal	The agent (via MCP) or you (via CLI)
Per-language	Yes, only one at a time	One uniform interface across 15 languages
Domain policy	None	First-class, in `.coverctl.yaml`
Agent integration	None	Native MCP
Pre-commit signal	You wire it up manually per-language	Built-in, MCP-native

Native commands are the substrate

coverctl does not replace go test -cover or pytest --cov. It runs them. Then it does three things native commands cannot:

Adds per-domain policy — you can require 90 % on internal/auth and 60 % on internal/utils in the same repo, declared once.
Speaks one language across many — same .coverctl.yaml works in a Go + Python + TypeScript monorepo. Native commands force you to wire each language’s coverage tool independently.
Exposes coverage as a tool an agent can call — through MCP. The native commands have no agent interface.

Use native commands directly when

You’re hacking on a one-language project and just want to see a number.
You’re not using an AI coding agent.
You don’t need per-domain enforcement.

Use coverctl when

Anything beyond the above. Especially:

Polyglot codebases where wiring N coverage tools is N times the work.
Teams using Claude Code / Cursor / Cline that want the agent to read coverage signals before commit.
Critical-path code that needs stricter coverage than utility code.

What you don’t lose

coverctl never hides the underlying tool. coverctl run -v shows exactly what go test invocation it produced; the same with pytest --cov, nyc, cargo llvm-cov, etc. If something fails, you can reproduce it with the native command directly. coverctl is a thin governance layer over a stable substrate, not a replacement.