Agent loops for coding agents
An agent loop is a prompt that keeps a coding agent working through one check-and-fix cycle until a condition you can measure is true: the build is green, coverage clears a target, an audit comes back clean. Each loop below is ready to paste into Claude Code, Cursor, or any agent with tools, with an iteration cap, stop rules, and the MCP servers that help it run.
Write, repair, and harden tests until the suite says what you need it to say.
- Testing
Coverage Until Threshold
Measure test coverage, write meaningful tests for the least covered code, and repeat until the project clears your coverage target without padding.
Up to 8 iterationsOpen loop - Testing
Flaky Test Hunter
Re-run your test suite to expose flaky tests, find the root cause of each one, fix it, and prove the fix with a long streak of consecutive passes.
Up to 6 iterationsOpen loop - Testing
TDD Red-Green Loop
Build a feature test first: write one failing test per acceptance criterion, make it pass with minimal code, refactor, and move on to the next one.
Up to 12 iterationsOpen loop - Testing
Bug Repro Until Fixed
Turn a bug report or error event into a failing regression test, fix the code until that test passes, and confirm nothing else in the suite broke.
Up to 8 iterationsOpen loop
What makes a good agent loop
- A settings block. Commands, targets, and limits sit at the top of the prompt, so you adapt a loop to your project by editing a few lines instead of rewriting it.
- One small change per pass. The agent runs a check, fixes one cause, and checks again. Small steps keep each change reviewable and stop one bad edit from snowballing.
- A stop condition the agent can verify. Exit codes, coverage numbers, and audit counts are things the agent can read from command output, so it knows when it is done instead of guessing.
- Hard limits and safety rules. Every loop has an iteration cap, a rule for when it is stuck, and a list of things it must never do, such as force-pushing, silencing tests, or touching production.
- The right tools. Loops run best when the agent can reach your repository, CI, browser, or database directly. Each loop page lists matching MCP servers from the directory, ranked by trust score.