Guide
Connecting your API key
Black Hole's builder is free to use with your own AI provider account. You connect a key once, pick a model from that provider, and every build runs on your account at your provider's rates. Black Hole adds no markup to those calls and takes no credits for them.
Why bring your own key
Running a strong model is the expensive part of an AI builder. Rather than hide that behind a subscription everyone has to pay, Black Hole lets you choose: either subscribe to Pro and use the hosted Power and Max modes, or connect a key and pay your provider directly. Heavy users with an existing provider account almost always pay less with their own key. People who do not want another account to manage prefer Pro.
Supported providers
| Provider | Where to get a key | Key format |
|---|---|---|
| OpenAI | platform.openai.com → API keys | sk-… |
| Anthropic | console.anthropic.com → API keys | sk-ant-… |
| Google AI Studio | aistudio.google.com → Get API key | AIza… |
| Mistral | console.mistral.ai → API keys | Alphanumeric string |
| OpenRouter | openrouter.ai → Keys | sk-or-… |
| DeepSeek | platform.deepseek.com → API keys | sk-… |
| Together | api.together.xyz → Settings → API keys | Alphanumeric string |
| Custom endpoint | Any OpenAI-compatible server you run | Whatever your server expects |
Connecting a key
- Open the model picker above the message box and choose Add your own key.
- Pick the provider. For a custom endpoint, enter its base URL and pick the API format it speaks.
- Paste the key and give the connection a label — useful when you keep separate work and personal keys.
- Save. Black Hole immediately makes a real call to the provider to verify the key and to fetch the list of models your account can actually use. If the key is wrong, expired, or has no billing attached, you see the provider's own error message straight away.
- Choose a model from that list, and start building.
Verification is a real call
How your key is stored
Keys are encrypted with AES-256-GCM before they touch the database. The encryption key lives only in the server environment and is never present in the browser, in the page source, or in any response Black Hole sends you. What is stored is opaque ciphertext with an authentication tag, so a modified record fails to decrypt rather than decrypting to something else.
- The key is decrypted only inside the server process, only for the duration of one build.
- The interface only ever shows a hint — the last four characters — so you can tell two keys apart.
- No support process, log line, or error message reveals a full key.
- Row-level security means your connection rows are readable only by your own account.
What it costs you
You are billed by your provider for the tokens each build consumes, exactly as if you had called their API yourself. A typical single-page build is a few cents on a mid-tier model and more on a frontier model. Black Hole shows the usage it recorded for each connection so you can compare it against your provider's dashboard.
Keeping costs down
- Use a mid-tier model for drafts and switch to a frontier model for the final pass.
- Correct specific sections rather than asking for full rebuilds.
- Set a spending limit in your provider's dashboard — Black Hole cannot exceed a limit set there.
Removing a key
Delete the connection in the model picker and the encrypted record is removed. If you suspect a key has been exposed anywhere, revoke it in your provider's dashboard as well — that is the only action that invalidates a key everywhere, including copies outside Black Hole.
Prefer not to manage a key?
Pro includes Black Hole's hosted Power and Max modes with no provider account required. Details on the pricing page and in Credits and plans.