Mureka API Key

Every node in the Mureka pack that actually generates music needs an API key, and this is the node that holds yours. One text box, one output wire, and suddenly Mureka Song, Mureka Instrumental and Mureka Billing have something to authenticate with. It's the least exciting node in the pack and the first one you'll wire up, because without it every generation node just dies on a 401.

What it actually does

Mureka API Key is a credential holder with a single input: api_key, a plain STRING where you paste the key you generate on the Mureka API platform (platform.mureka.ai → API Keys → create one). Its one output, also called api_key, is typed as MUREKA_API_KEY - a custom type only this pack's generation and billing nodes will accept. You can't accidentally wire it into a CLIP Text Encode or a sampler; the type system won't let you.

Mechanically it's a typed pass-through. Nothing is stored, nothing leaves your machine, and the key only travels to Mureka when a downstream node actually makes an API call. The author spells this out in the README's security notice: the key is used only to call the Mureka API within the workflow, isn't saved or transmitted anywhere else, and shouldn't be committed to source control or shared with third parties. Practical translation: paste it in the node, keep it out of any workflow JSON you share, and don't post screenshots of the node with the key visible.

Where it fits

Standard flow: Mureka API Key → Mureka Song (or Mureka Instrumental) → Mureka Save. The key node also feeds Mureka Billing so you can check your credit balance before you spend anything. One key node can fan out to several consumers - feed both the generation node and the billing node from the same output and you're done.

Installing the pack

ComfyUI Manager → Install Custom Nodes → search "Mureka API" → install, restart. Or manually:

cd ComfyUI/custom_nodes
git clone https://github.com/leewinder/comfyui-mureka-api.git

No models to download and no heavy dependencies - this is a thin wrapper around a cloud API, not a local music model, so install really is a two-minute job. The actual requirement is the key itself, which costs nothing to create but unlocks generations that cost credits.

Troubleshooting

• Generation node complains the key input is missing: you forgot to wire this node's output into it.
• "Invalid API key": paste the whole thing - the keys are long, and truncating one is the classic mistake.
• Key visible in a workflow you're about to share: delete it first. Anyone with that file can spend your credits.

One thing that trips people up: the repo's dev setup mentions an authentication.json file holding your key. That's for running the author's test suite, not for ComfyUI. In the graph, the key lives in this node.

This is a small, single-maintainer pack - lee_winder announced it on r/comfyui in late 2025, and it hasn't attracted a big community since. It's also explicitly unaffiliated with Mureka, so if the API itself misbehaves, that's a Mureka support ticket, not a node bug.