BigPlayer Checkpoint Picker

BigPlayer Checkpoint Picker is the module that answers "which of my checkpoints would do this prompt best?" and lets the LLM decide. It reads the shared session from BigPlayer Natural Language Root and outputs checkpoint_name - constrained to the checkpoints installed in your ComfyUI - plus a comments field explaining the pick.

The mechanism is the reason to trust this node at all. When the root assembles the request, the allowed checkpoint list is resolved from your actual models/checkpoints folder, baked into the JSON schema as an enum, and then validated again locally after the response. The LLM physically cannot return a checkpoint you don't own - no hallucinated "realvisXL" that you never downloaded. If you have zero checkpoints installed, the node refuses to run outright ("requires at least one available checkpoint"), because there's nothing honest to pick from.

The LLM's instructions lean on that constraint: "choose exactly one checkpoint from the allowed list" and "you may need to do research on the available checkpoints if you are unsure about their capabilities." With Grok, that research is a real web-search tool scoped to civitai, huggingface, and github - the places checkpoint capabilities actually live.

Wiring it in

checkpoint_name feeds into a Load Checkpoint node. comments is worth reading: it explains why the LLM chose that model, so you can veto with information instead of vibes. If it picks a checkpoint you don't want for a project, don't fight the node - don't wire the output, or say so in your prose.

One distinction that trips people up: this node recommends a checkpoint for a job, while BigPlayer Checkpoint State (the state-indication node) tells the LLM what's already loaded. They're complementary. The natural workflow is to give the root your current state via Checkpoint State, let Checkpoint Picker suggest the alternative for a new request, and decide which one wins.

Install and troubleshooting

Pack install: ComfyUI Manager, search "BigPlayer Prompting", or git clone https://github.com/josh-ent/comfyui-bigplayer-llm-nodes into ComfyUI/custom_nodes, then restart. Deps are httpx and pydantic; no model downloads, but the root needs a Grok API key.

If you get an "unknown checkpoint" validation error, the response named a checkpoint that left your folder or was renamed - or the cached session predates a change to your checkpoint list. Turn assume_determinism off on the provider node and re-run to rebuild the list.