# Which agent patterns loop most often?

Retry feedback with no bound on it, the same call retried again after a failure with nothing stopping it, is the single most common shape: it showed up in 25% of a study's 68 confirmed infinite-loop cases across 6,549 open-source agent repositories. Tool-call iteration without a bound is close behind at 23.5%, and multi-agent chat with no cap on turns is third at 20.6%.

Two more patterns cover most of what's left: a workflow loop with no effective bound at 13.2%, and one agent re-entering a message it already sent at 10.3%. Together the top three patterns account for most of the confirmed cases, ahead of the runner, delegation, or evaluator feedback loops that make up the remainder. That's a different cut of the same data from [why a retry limit doesn't always stop a loop](/answers/agent-loops-research/does-a-retry-limit-stop-an-agent-from-looping-forever): that finding is about where the bound is missing, this one is about what the repeating call itself looks like, and the same trace can be read both ways, [stuck with nothing ever throwing an error to flag it](/answers/failure-modes/why-does-an-agent-get-stuck-in-a-loop).

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Sources:
- "When Agents Do Not Stop: Uncovering Infinite Agentic Loops in LLM Agents" (arXiv:2607.01641): https://arxiv.org/abs/2607.01641 (fetched 2026-09-20)

Source: https://tessary.ai/answers/agent-loops-research/which-agent-patterns-loop-most-often
More on Agent loops research: https://tessary.ai/answers/agent-loops-research
From Tessary, agent reliability for AI agents in production: https://tessary.ai