To use Claude Fable 5, install the OpenAI SDK (any language), point base_url at https://api.aigateway.sh/v1 with an sk-aig-... key, and set model="anthropic/claude-fable-5". That's it — no provider account, no separate billing. Anthropic's model is served through AIgateway's OpenAI-compatible endpoint so every existing OpenAI integration (Cursor, LangChain, Vercel AI SDK) works unchanged.
Sign in at aigateway.sh with GitHub or Google, open the dashboard, and copy an sk-aig-... key. No credit card required to claim a key — every new account gets $5 signup credit (spendable on a curated edge-tier shortlist including Kimi K2.6) so you can test end-to-end before you top up.
Every OpenAI client library ships with a base_url (Python) or baseURL (Node) field. Set it to https://api.aigateway.sh/v1 and drop in your sk-aig-... key. Nothing else in your application code needs to change — the request and response schemas are OpenAI-identical.
On your chat.completions.create call (or images, embeddings, audio — whichever endpoint matches the text modality), pass model="anthropic/claude-fable-5". AIgateway handles provider auth, billing, retries, and transformation so Anthropic-specific quirks don't leak into your code.
# pip install aigateway-py openai
# aigateway-py: sub-accounts, evals, replays, jobs, webhook verify.
# openai SDK: chat/embeddings/images/audio — drop-in compat per our SDK's own guidance.
from openai import OpenAI
client = OpenAI(
base_url="https://api.aigateway.sh/v1",
api_key="sk-aig-...",
)
r = client.chat.completions.create(
model="anthropic/claude-fable-5",
messages=[{"role": "user", "content": "Explain vector databases in two sentences."}],
)
print(r.choices[0].message.content)// npm i aigateway-js openai
// aigateway-js: sub-accounts, evals, replays, jobs, webhook verify.
// openai SDK: chat/embeddings/images/audio — drop-in compat.
import OpenAI from "openai";
const client = new OpenAI({
baseURL: "https://api.aigateway.sh/v1",
apiKey: process.env.AIGATEWAY_KEY,
});
const r = await client.chat.completions.create({
model: "anthropic/claude-fable-5",
messages: [{ role: "user", content: "Explain vector databases in two sentences." }],
});
console.log(r.choices[0].message.content);No. AIgateway provides a unified sk-aig-... key that routes to Anthropic on your behalf. You only need an AIgateway account.
Yes — Claude Fable 5 supports OpenAI-standard function calling through the tools parameter on chat.completions.create. Parallel tool calls are supported.
Claude Fable 5 supports a 1,000,000-token context window. Output is capped at 128,000 tokens per response.
Every new AIgateway account gets $5 in signup credit (no card) — spendable on a curated edge-tier shortlist (Kimi K2.6, FLUX-2 Klein, Whisper Turbo, Aura 2, Gemma 4 vision, BGE-M3, Llama Guard 3). Claude Fable 5 is covered if it's on that shortlist; otherwise a $5 top-up unlocks the full catalog at pass-through pricing. Topups never expire.
Yes — anything that speaks OpenAI's API shape works. Set base_url to https://api.aigateway.sh/v1, paste your AIgateway key, and set the model string. Cursor, Cline, Continue, LangChain, LlamaIndex, Vercel AI SDK all supported.