Frequently asked questions
How does Denpex get access to my training logs?
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You have two options. (1) Paste logs into the web console, no install. (2) Install the single-file Python agent, which wraps your training command and ships the last 500 log lines on a non-zero exit. We never install a daemon or modify the training process.
Will adding Denpex slow down my training?
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No. The agent is completely passive during training. It only activates on job failure. Zero overhead on forward / backward passes, zero overhead during normal operation.
Can it diagnose failures that already happened?
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Yes. Paste logs from any past failure into the console. A free account gets 3 diagnoses per day with no credit card, instant result.
Do you store our training logs?
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No. The agent masks PII/PHI client-side before egress by default; in strict mode it ships only anonymized failure signatures, so raw logs never leave. Raw logs are processed in memory and never written to durable storage. For zero egress, DENPEX_LOCAL=1 runs the deterministic engine entirely on-host. Nothing leaves the cluster at all.
What if Denpex can't diagnose it?
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If no pattern match exists with ≥60% confidence, Denpex falls back to an LLM-inferred diagnosis, clearly marked. You always know the confidence level of your diagnosis.
Does it work with spot instances and preemptible GPUs?
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Yes. Spot preemption is classified separately from software failures. Denpex distinguishes between PREEMPTION events and actual training failures, so your metrics aren't polluted by cloud provider interruptions.
Do you support JAX/Flax and TPUs?
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Partially today, natively soon. The console and the AI fallback already accept JAX/Flax stack traces and XLA compiler errors, paste them like any other log and you'll get a diagnosis with a confidence level. Deterministic JAX/Flax pattern packs (pjit/sharding mismatches, XLA OOM, TPU runtime faults, host-callback deadlocks) and TPU-native telemetry are in progress on the public roadmap. If you're a university or national-lab team on JAX, tell us at /contact. JAX users get priority access to the packs as they land.
How does the team knowledge base work?
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Confirming a fix records it in your team's knowledge base against its failure class, scoped to your organisation. The next diagnosis of that class, for anyone on your team, leads with your confirmed fix and keeps the engine's recommendation underneath. Your corrected wording wins over the engine's if you edited it. Browse and search at /knowledge-base; the API is GET /api/kb/entries.
Can Denpex compare my current failed run against a previous successful one?
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Yes, by giving it both runs. Paste the artifacts from the last good run and the failing one at /diff (free, no account) or POST them to /api/diagnose/env-diff on Team and above. Driver, CUDA, NCCL, framework, packages and NCCL_* variables are diffed and each change is ranked by how strongly it correlates with the failure class. Fetching your last good run automatically is in build.
Can I self-host / run air-gapped?
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Yes. DENPEX_LOCAL=1 runs the canonical deterministic pipeline entirely on-host with zero egress: patterns, causal detectors, Xid routing, cross-rank cascade analysis, and encyclopedia retrieval. The signed bundle uses a Python 3.8+ bridge plus a prebuilt Node.js 18+ engine; it needs no server, internet connection, API key, pip package, or npm install. Only the hosted LLM fallback and live research are unavailable offline. White-label / OEM is available on Data Center.
Is there a free trial?
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Yes. Every free account gets 3 diagnoses per day with no credit card. Visitors with a qualifying work email can also request a 14-day Scale trial with up to 50 diagnoses per day. It requires no card and does not become a subscription automatically. Request it on the pricing page or redeem an invitation at /redeem.