Anthropic: get an API key and write fiction with it on your phone

Claude models have a reputation for stable long-form prose, so many writers make this their main continuation provider; it does text and vision only — pair another provider for images and speech. This page is the BYOK quick answer for Anthropic: key steps, direct console and pricing links, and the app-side notes that matter. Verified 2026-07-18.

Two links up front: get your key at the official console and check rates on the official pricing page. Prices and free quotas move; the official pages are authoritative.

What does it power inside Foreverse?

The factory preset declares 2 modality flags for Anthropic. The models actually available come from the live catalog fetched in-app — catalogs move fast, and the flag only means the protocol wiring is ready.

ModalityUsed for
TextContinuation · roleplay chat · agent
VisionImage understanding in chat

How do I get a Anthropic API key?

  1. Sign up at console.anthropic.com (it now lands on the same developer console as platform.claude.com).
  2. Add a card or prepaid credits under Settings → Billing — a fresh key is rejected until billing exists.
  3. Go to Settings → API keys → Create Key; you can set an expiration while you're at it.
  4. The sk-ant- key is shown exactly once — copy it on the spot.

Key in hand: three steps to connect

  1. Open the app's Settings → AI models & services and find Anthropic in the list (one of 62 presets, with logo and search).
  2. Paste the key and tap the connectivity test — it fires one real request to verify key and network, and pulls back the model list while it's at it.
  3. Enable the models you want, then set per-modality defaults (text, image, speech, and video each get their own); continuation, chat, and listening route through them from then on.

The one universal host pitfall: the API host must include its full version prefix (this provider's exact form is in the notes below) — the app never appends /v1 for you.

Anthropic-specific notes

The preset host is https://api.anthropic.com/v1 using Anthropic's native protocol. Claude.ai Pro/Max subscriptions are a separate billing track — they include no API credit. Prompt-cache hits and discounts show up in the app's request records.

FAQ

Does Anthropic have a free tier?

No free tier: usage is priced per token and billing must be configured first. Small trial credits appear occasionally — check the console.

Where does the key live once I paste it into the app?

It's stored on your device only, under system-level encryption — never uploaded or synced to any Foreverse server. Requests go straight from your phone to the provider's official endpoint with zero markup. To revoke access, delete the key in the provider's console.

Anthropic API Key — Get One and Plug It into Foreverse (BYOK)