The one door that asks for nothing — no key, no card, no form:
Puter.js — anthropic/claude-opus-5-5 straight in a browser page. The caller pays for their own calls, so you can run a public demo and never see a bill.
That is also the answer to @pei49102 above: stop waiting on the AWS form.
Two clouds that hand you a real key with credit 
Vertex gives $300 for 90 days · Foundry gives $200 on a new account. Both carry Opus 5.5.
Check the map before you build 
modelavailability.com — Opus 5.5 region by region across Bedrock, Foundry and Vertex, updated daily.
Cheaper shelf for this month 
34 providers · 635 endpoints · one key — our own board.
The code — Puter in a page, and the Hermes config Mohamed asked for
import { puter } from '@heyputer/puter.js';
const r = await puter.ai.chat("explain vector databases like I'm 15", {
model: "anthropic/claude-opus-5-5"
});
For Hermes, LibreChat, Open WebUI or the OpenAI SDK — Cloudflare speaks the OpenAI wire format, so it is three lines:
base_url : https://api.cloudflare.com/client/v4/accounts/<ACCOUNT_ID>/ai/v1
api_key : <CLOUDFLARE_API_TOKEN>
model : anthropic/claude-opus-5.5
Cloudflare’s model page — 10,000 neurons a day, 1M-token context. Bedrock has an OpenAI-compatible endpoint too.
If you want the key from Vertex or Foundry — the exact steps
Vertex: Opus 5.5 docs → enable the model in Model Garden → claude-opus-5-5 → the $300 trial covers it, card required but not charged.
Foundry: model catalog page → deploy → the $200 new-account credit covers it.
Bedrock: the credits route, not the Activate form that never gets reviewed.
!