Breadcrumb is the Plausible of LLM tracing. Self-hosted, open source, and built for developers who just want to understand what their agents are actually doing without the enterprise bloat of LangFuse or LangSmith. Three lines to get your app traced. An LLM watches every trace and automatically flags issues: wrong tool calls, looping agents, oversized models and cost spikes, all before you even know something's wrong. Ask questions about your traces in plain English and get charts back.
Hey everyone! AI agents are surprisingly easy to build. Understanding what they're doing is another story.
I recently had a complex coding agent where subagents silently stopped passing responses to each other. An error somewhere in the chain, but instead of failing loudly, the agents just worked around it. Output looked almost right. I only found it by accident after hours of debugging. With many, many tool calls and nested agents, you're mostly blind. You can't fix what you can't see.
Breadcrumb gives you visibility into what your agents are actually doing. An LLM watches every trace and automatically surfaces issues like this: silent failures, agent loops, wrong tool calls, cost spikes, before you spend hours hunting them down. There's also an explore tab where you ask questions about your traces in plain English and get real charts back. Open beta is live today. One click Railway deploy, fully self-hosted and open source. A hosted version is planned (sign up here https://breadcrumb.sh/docs/setup...).
Really like this, debugging agents gets painful fast once things get complex.
The “silent failure” issue is spot on, things look right but something breaks underneath. Visibility here feels super valuable.
Curious how this scales with lots of nested agents and traces?
Also big +1 on self-hosted + privacy.
Thanks you so much!!! I was always wondering where do I spend most of the money. Thanks also for contributing to privacy and opensource.
About Breadcrumb on Product Hunt
“Open-source LLM tracing for agent visibility”
Breadcrumb launched on Product Hunt on March 26th, 2026 and earned 176 upvotes and 7 comments, placing #20 on the daily leaderboard. Breadcrumb is the Plausible of LLM tracing. Self-hosted, open source, and built for developers who just want to understand what their agents are actually doing without the enterprise bloat of LangFuse or LangSmith. Three lines to get your app traced. An LLM watches every trace and automatically flags issues: wrong tool calls, looping agents, oversized models and cost spikes, all before you even know something's wrong. Ask questions about your traces in plain English and get charts back.
Breadcrumb was featured in Open Source (68.3k followers), Analytics (171.4k followers), Developer Tools (511k followers) and GitHub (41.2k followers) on Product Hunt. Together, these topics include over 109.6k products, making this a competitive space to launch in.
Who hunted Breadcrumb?
Breadcrumb was hunted by Joshua Knauber. A “hunter” on Product Hunt is the community member who submits a product to the platform — uploading the images, the link, and tagging the makers behind it. Hunters typically write the first comment explaining why a product is worth attention, and their followers are notified the moment they post. Around 79% of featured launches on Product Hunt are self-hunted by their makers, but a well-known hunter still acts as a signal of quality to the rest of the community. See the full all-time top hunters leaderboard to discover who is shaping the Product Hunt ecosystem.
Want to see how Breadcrumb stacked up against nearby launches in real time? Check out the live launch dashboard for upvote speed charts, proximity comparisons, and more analytics.
Joshua Knauber
Hey everyone! AI agents are surprisingly easy to build. Understanding what they're doing is another story.
I recently had a complex coding agent where subagents silently stopped passing responses to each other. An error somewhere in the chain, but instead of failing loudly, the agents just worked around it. Output looked almost right. I only found it by accident after hours of debugging. With many, many tool calls and nested agents, you're mostly blind.
You can't fix what you can't see.
Breadcrumb gives you visibility into what your agents are actually doing. An LLM watches every trace and automatically surfaces issues like this: silent failures, agent loops, wrong tool calls, cost spikes, before you spend hours hunting them down. There's also an explore tab where you ask questions about your traces in plain English and get real charts back.
Open beta is live today. One click Railway deploy, fully self-hosted and open source.
A hosted version is planned (sign up here https://breadcrumb.sh/docs/setup...).
Give it a try here http://demo.breadcrumb.sh/!
Would love to hear what you're building and what you're struggling with when debugging your agents!