Skip to content

Model selection

Any specific model recommendation goes stale in a month, so this page sticks to how to choose one for failure analysis and what to reach for locally versus remotely. Wire whatever you land on into the model registry.

What the app leans on

A model can be great at chat, tool-calling, or long agentic runs and still be a poor fit here. Three things decide it.

Screenshots. Test analysis feeds failure screenshots, and a model with weak visual understanding usually loses to a smaller one that can actually see. Pick a vision-capable model, or keep a text-only analysis model and point a dedicated vision model at transcription.

Format. The prompts ask for structured markdown. Models that wander off-format produce output that's hard to read and hard to reuse.

Reasoning that stops. More reasoning helps up to a point; models that overthink burn tokens and wall-clock without a better answer. Watch out for tokens-per-second here - a tiny model stuck in long reasoning loops is often slower end to end than a bigger model that thinks quickly and answers short. Judge by round-trip on a real failure, not the tps number.

Sampling settings

These carry across models and usually matter more than the model itself.

  • Temperature - trade determinism for enough variety to explain. Below ~0.2-0.3 reasoning models can collapse into repetitive chain-of-thought, so keep 0.2-0.3 for frontier models and 0.6-0.7 for reasoning ones (they calibrate inside the think block).
  • Top K - cap the candidate pool (~40-64) to cut off hallucinated identifiers.
  • Top P - dynamic pool by cumulative probability; 0.95 is conventional.
  • Min P - a relative floor instead of top_p/top_k; fine left off when the other two are set.
  • Repeat penalty - leave at 1.0. It's semantics-blind, and analysis reasons about the same failure and code blocks on purpose.
  • Max tokens - a hard generation cap; leave headroom, reasoning runs long.

Local

Run local models through LM Studio, oMLX, or Ollama (any OpenAI-compatible endpoint). Pick by the unified memory or VRAM you can spare. Quality drops first on the hardest task, project summaries.

HardwareReach forExpect
Small (≈8 GB)a small instruct modelfast test analysis, weak on report/project summaries
Mid (≈12-16 GB)a small-to-mid instruct or vision modelsolid across all three tasks
Large (24 GB+)a mid-size MoE or light-reasoning modelbest local quality, slower round-trip

Prefer instruct or lightly-reasoning models over heavy reasoners for this work, lean toward vision-capable ones for test analysis, and remember a fast small model you keep enabled beats a big one that keeps timing out.

Remote

Any OpenAI-compatible or Anthropic-format provider works; OpenRouter reaches many at once. Pick by what you're optimising for.

Optimising forReach for
Qualitya current frontier flagship
Cost and latencya small "mini" model - good enough for most failures
The middlea fast-tier model (the fast/haiku/flash class)
Zero budgeta free-tier model on OpenRouter

Combining models

You don't have to settle on one. Pair a cheap tier-1 with a strong top tier so only the hard cases escalate (cascade), or ensemble peer-quality models (fusion, council). See LLM routing.