Set Up Your Claude API Key
Connect your own Anthropic API key to PromptCloak for direct, private communication with Claude. When using BYOK, your messages go straight from your device to Anthropic — our servers are never involved.
WHY BRING YOUR OWN KEY?
- 01Zero intermediaries. Requests bypass the PromptCloak backend entirely. Your data path is: Device → TLS 1.3 → Anthropic API.
- 02Premium models. Access Claude Sonnet 4 and Claude Haiku 4.5 — Anthropic's most capable models.
- 03Pay only for what you use. Anthropic charges per token with no monthly subscription beyond your PromptCloak plan.
- 04Keychain security. Your API key is stored with the same protection used by banking apps — never exposed to our servers.
Step-by-Step Guide
Create an Anthropic Account
Go to console.anthropic.com and create an account. You can sign up with your email address or Google account.
If you already have an Anthropic account, skip to step 2.
Add Billing Information
Navigate to Settings → Billing in the Anthropic Console. Add a payment method (credit card). Anthropic uses pay-as-you-go pricing — you're only charged for the tokens you actually use.
Approximate Pricing (as of March 2026)
A typical chat session uses ~2,000-5,000 tokens. Prices may vary — check console.anthropic.com for current rates.
Generate an API Key
In the Anthropic Console, go to Settings → API Keys. Click “Create Key”. Give it a descriptive name like “PromptCloak”.
Copy the key immediately. Anthropic only shows the full key once. It starts with sk-ant-.
Keep your API key secret. Anyone with your key can make requests charged to your account. If you suspect your key is compromised, revoke it immediately in the Anthropic Console and create a new one.
Open PromptCloak Settings
In PromptCloak, tap the gear icon to open Settings. Scroll to the Providers section.
Add Your Anthropic Key
Tap Anthropic in the Providers section. Paste your API key (the one starting with sk-ant-).
PromptCloak will run a lightweight test call to verify the key is valid. Once verified, you'll see a green connection status.
Select a Claude Model
Open the model selector (tap the model name in the chat toolbar, or use the /model slash command). You'll see Claude models marked with a [YOUR KEY] badge:
- Claude Sonnet 4 — Best for complex reasoning, coding, and detailed analysis
- Claude Haiku 4.5 — Fast and efficient for everyday conversations
Start Chatting
That's it. Your messages now go directly from your device to Anthropic's API over TLS 1.3. The PromptCloak backend is not involved. All privacy features (PII scrubbing, local storage, EXIF stripping) still apply.
Common Questions
Is my API key sent to PromptCloak servers?
No. Your API key is stored in the device Keychain and used exclusively for direct communication with Anthropic. It never touches our servers.
Can I use the same key on multiple devices?
Yes, but you'll need to enter it on each device separately. Keys are stored per-device in the Keychain and are not synced via iCloud.
Does Strict Mode PII scrubbing work with BYOK?
Yes. PII scrubbing runs on-device before messages are sent, regardless of whether you use our backend or BYOK.
What happens if my key expires or is revoked?
PromptCloak will show an error when trying to send messages. Go to Settings > Providers > Anthropic to update or replace your key.
Can I set spending limits?
Yes. In the Anthropic Console under Settings > Billing, you can set monthly spending limits to control costs.
Also available: OpenAI API Keys
PromptCloak also supports BYOK with OpenAI for GPT-4o, GPT-4o Mini, and o4 Mini. The setup process is similar — create a key at platform.openai.com, then add it in Settings → Providers → OpenAI.
Also available: Hermes Agent (Self-Hosted)
Run your own AI agent with memory, skills, and tools. Messages go directly from your device to your server — no third-party services in the path. See the Hermes setup guide for details.