BMAB Image Storage

This is one of the more obscure nodes in the pack - the README doesn't mention it by name at all, and the schema is just two required inputs and no outputs. What we can say with confidence comes from what those inputs actually are: images plus a client_id, and client_id is not a BMAB invention. It's ComfyUI's own concept, baked into the server since day one - every browser tab or API caller connects with a client_id so the backend knows which websocket to push progress and preview messages back to. This node leans on that same identifier.

What it's for

Read plainly, it takes a batch of images and a client_id and does something with them scoped to that specific client, rather than writing them to the local output/ folder the way SaveImage does. That's the right mental model if you're driving ComfyUI headlessly - from a script, a bot, or an app talking to the API - rather than clicking around the web UI yourself. In that world you often care less about a file landing on disk on the server and more about getting the result routed back to the specific caller that asked for it, especially if multiple clients are hitting the same ComfyUI instance concurrently. Marking it is_output_node: true (no data flows onward, it's a terminal step) fits that reading too - it's a sink for images, not a passthrough.

The inputs that matter

• images (IMAGE, required) - the batch you want stored/routed. Wire your final generated or post-processed images here.
• client_id (STRING, required) - the identifier tying this call to a specific connected session. If you're calling the ComfyUI API directly, this is the same client_id you'd include in your /prompt POST body; it isn't something you invent on the node itself.

There are no outputs, so this node ends the graph branch it sits on.

How to install it

ComfyUI Manager: search comfyui_bmab. Manual:

cd ComfyUI/custom_nodes
git clone https://github.com/portu-sim/comfyui_bmab.git
cd comfyui_bmab
pip install -r requirements.txt

No model downloads involved - this is pure plumbing, not an image-generation node.

Common issues & troubleshooting

You wired this expecting it to save a file locally, and nothing shows up in output/. That's expected - this isn't SaveImage. If you just want a file on disk, use BMAB's own BMAB Remote Access And Save node or core Save Image instead; reach for this one specifically when you're building an API-driven or scripted integration and need the result addressed back to a particular caller.

Leaving client_id blank or hardcoded. If you're testing from the ComfyUI web UI, your session already has a client_id assigned by the browser client, but this node's field expects you to supply one explicitly - it won't auto-fill from your active session. For anything beyond a quick manual test, generate or capture the real client_id your caller used when it submitted the prompt, rather than typing a placeholder.

We genuinely don't know the exact delivery mechanism past this point - whether it pushes over the existing websocket, writes to a per-client temp path, or something else entirely. The README is silent on it and there's no example workflow that exercises it. If you're building against this node for real, budget time to read the pack's Python source (comfyui_bmab) rather than assume behavior from the schema alone.