DEV Community: TokenHub

How to use GPT-5 and Claude when your credit card keeps getting declined

TokenHub — Mon, 22 Jun 2026 15:24:13 +0000

If you've tried to sign up for the OpenAI or Anthropic API from outside the usual card-friendly regions, you've probably hit this wall:

Card declined.
Card declined, again.
"Please use a different payment method."

It's not always about money. A huge share of developers — across MENA, Southeast Asia, Latin America, and honestly plenty of students and researchers in "supported" countries — simply cannot get a foreign credit card to work with OpenAI or Anthropic. Declines, region blocks, USD billing friction, bank rejections. The models exist, the docs are open, but the payment gate is closed.

This post is about a workaround that doesn't involve sketchy resold accounts: an OpenAI-compatible API gateway that accepts USDT top-ups as a first-class payment path.

The problem isn't the API. It's the billing.

Most "OpenAI is blocked in my country" complaints are really payment problems, not network problems. The API endpoints are reachable. What fails is the subscription step — because it demands a US-issued card that your bank won't approve, or flags the transaction as suspicious.

So the question becomes: can you call GPT-5 / Claude / Gemini from a provider that takes a payment method you can actually use?

One endpoint, USDT on arrival

Vynex API is a unified LLM gateway — one OpenAI-compatible /v1 endpoint that routes to GPT-5.x, Claude 4.x, Gemini 3.x, DeepSeek, Qwen and GLM. The part that matters here: you can top up your balance with USDT (TRC20 or ERC20), and the credit applies automatically once the on-chain payment confirms. No foreign card required.

from openai import OpenAI

client = OpenAI(
    api_key="sk-...",  # your Vynex key
    base_url="https://llm-api.vynexcloud.com/v1",
)

# Works exactly like the OpenAI SDK — just point base_url at Vynex
resp = client.chat.completions.create(
    model="gpt-5.4",
    messages=[{"role": "user", "content": "Hello!"}],
)
print(resp.choices[0].message.content)

# Same call, Claude — change one field
resp = client.chat.completions.create(
    model="claude-sonnet-4-6",
    messages=[{"role": "user", "content": "Hello!"}],
)

If your existing code already uses the openai SDK, migration is literally changing base_url. Streaming, function/tool calling, and structured output all work.

Why USDT specifically

Stablecoins solve the cross-border payment problem cleanly for a few reasons:

No issuing bank in the middle to decline you. USDT on TRC20 moves between wallets; there's no foreign-card authorization step.
Low fees. A TRC20 transfer costs roughly $1, vs. card processing fees and FX markups.
Available wherever crypto is available, which covers most of the regions where OpenAI cards fail.
Settles in minutes, so top-ups are near-instant.

This isn't a hack or a gray-market workaround — it's a legitimate payment path for a gateway that runs as a real registered business (Hong Kong company, official invoices on every payment, a data processing agreement available for teams).

When this actually helps

Your country's cards get declined by OpenAI/Anthropic
You don't have a USD-denominated card at all
You're a student or researcher without a corporate card
Your team needs proper invoices (VAT/reimbursement) that a crypto-friendly provider can still issue
You want one API key for GPT + Claude + Gemini without maintaining N billing relationships

What it doesn't solve

Being honest about the limits:

You still need a way to acquire USDT (an exchange, P2P, etc.). If crypto itself is restricted where you are, this path doesn't magically open it.
USDT volatility is low but not zero; the gateway locks the rate at top-up time so you pay a fixed amount.
This is about payment access, not about bypassing any provider's acceptable-use policy. Use the models for legitimate work.

Try it

If card declines have been blocking you, here's the shortest path:

Register: llm-api.vynexcloud.com/register
Top up with USDT (TRC20) from the wallet page — no card needed
Point your OpenAI SDK at https://llm-api.vynexcloud.com/v1
Call gpt-5.4, claude-sonnet-4-6, gemini-3.1-pro-preview, etc.

Pricing is transparent and per-token: llm-api.vynexcloud.com/pricing. Docs are at /docs.

If you've been stuck on the payment step, hopefully this unblocks you. Questions welcome in the comments.

Call GPT-5.5, Claude Opus 4.8, and Gemini 3.1 from one OpenAI-compatible endpoint

TokenHub — Mon, 22 Jun 2026 15:24:11 +0000

If you build with LLMs, you probably juggle multiple SDKs, API keys, and bills — one for OpenAI, one for Anthropic, one for Google. And every time you want to A/B-test a different model, you rewrite integration code.

There's a simpler pattern: one OpenAI-compatible endpoint that proxies every frontier model. You keep the official openai SDK, change the base_url, and switch models by changing the model parameter.

The idea

Vynex API exposes a single /v1 endpoint that speaks the OpenAI Chat Completions contract. Behind it: GPT, Claude, Gemini, DeepSeek, Qwen, and GLM. One key, one bill.

from openai import OpenAI

client = OpenAI(
    api_key="sk-...",
    base_url="https://llm-api.vynexcloud.com/v1",
)

# GPT-5.5
client.chat.completions.create(
    model="gpt-5.5",
    messages=[{"role": "user", "content": "Explain backpressure in 2 lines"}],
)

# Same call, different model — Claude Opus 4.8
client.chat.completions.create(
    model="claude-opus-4-8",
    messages=[{"role": "user", "content": "Explain backpressure in 2 lines"}],
)

# Gemini 3.1 Pro
client.chat.completions.create(
    model="gemini-3.1-pro-preview",
    messages=[{"role": "user", "content": "Explain backpressure in 2 lines"}],
)

No new client library. No per-provider abstraction layer. The /v1/chat/completions contract is preserved, so streaming, tool calling, and structured output all work the way you expect.

Why this matters in practice

1. A/B-testing models becomes a one-liner. Want to compare GPT-5.5 vs Claude Opus 4.8 on your prompt? Change one string. No separate SDK init, no different auth header format.

2. Fallback chains. If one model is rate-limited or down, fall back to another family without touching your call shape:

models = ["gpt-5.5", "claude-opus-4-8", "gemini-3.1-pro-preview"]
for m in models:
    try:
        return client.chat.completions.create(model=m, messages=msgs)
    except Exception:
        continue

3. Streaming works everywhere:

stream = client.chat.completions.create(
    model="claude-sonnet-4-6",
    messages=msgs,
    stream=True,
)
for chunk in stream:
    print(chunk.choices[0].delta.content or "", end="")

4. Tool/function calling is identical to OpenAI's schema.

Cost transparency

Per-token pricing (input/output per 1M tokens), no seat fees:

Model	Input $/1M	Output $/1M
`gpt-5.4-mini`	$0.25	$1.50
`deepseek/deepseek-v3.2`	$0.23	$0.34
`claude-haiku-4-5-20251001`	$1.00	$5.00
`gpt-5.5`	$1.25	$7.50
`claude-opus-4-8`	$5.00	$25.00

Full list on the pricing page. The cheap open models (deepseek-v3.2 at ~$0.23/M) are useful for high-volume classification and extraction where you don't need a frontier model.

cURL (no SDK needed)

curl https://llm-api.vynexcloud.com/v1/chat/completions \
  -H "Authorization: Bearer $VYNEX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5.4",
    "messages": [{"role": "user", "content": "Hello"}]
  }'

Who is this for

Teams that want one integration instead of six
Anyone building model-eval or fallback tooling
Developers in regions where direct access to some providers is restricted
People who want transparent per-token billing without negotiating enterprise contracts

Getting started

Create a key at llm-api.vynexcloud.com/register
Point your OpenAI client at https://llm-api.vynexcloud.com/v1
Call any model by name

SDK examples (Python, Node.js, cURL) are in the public repo.

This is a factual walkthrough of the API I use. Prices are per-token and listed on the pricing page; verify them there before relying on the numbers above.

Using one LLM API key across OpenAI-compatible clients, Claude Code, and terminal agents

TokenHub — Tue, 02 Jun 2026 16:32:48 +0000

If you test multiple LLM clients, the annoying part is rarely the first API call. It is the mess around it: keys, base URLs, model names, billing pages, and protocol differences.

TokenHub is a prepaid gateway that exposes one endpoint for common LLM workflows:

OpenAI SDKs with a custom base_url
Claude Code via ANTHROPIC_BASE_URL
Codex / Responses-compatible flows
OpenCode and DeepSeek-TUI style terminal tools

The core idea is simple:

One key. One endpoint. Multiple LLM protocols.

OpenAI-compatible chat completion

Set your TokenHub API key as TOKENHUB_KEY, then call the OpenAI-compatible endpoint:

curl https://llm.sandboxclaw.com/v1/chat/completions \
  -H "Authorization: Bearer $TOKENHUB_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "moonshot-v1-8k",
    "messages": [{"role": "user", "content": "Reply exactly ok"}],
    "max_tokens": 8
  }'

For SDKs, the important part is setting the base URL to:

https://llm.sandboxclaw.com/v1

Claude Code style setup

For tools that expect Anthropic-style environment variables, point the base URL at TokenHub and reuse the same key:

export ANTHROPIC_BASE_URL=https://llm.sandboxclaw.com
export ANTHROPIC_API_KEY=$TOKENHUB_KEY

claude --bare -p --model moonshot-v1-8k "Reply exactly ok"

When this is useful

This is useful when you are testing model-backed tools and do not want to keep switching between separate dashboards, vendor keys, and billing setups.

A few practical use cases:

Trying different models before committing to one provider
Running local terminal agents with one prepaid key
Giving a small team one endpoint for experiments
Keeping demo projects easy to configure

The current public model catalog includes chat, agent, and image options, with examples such as moonshot-v1-8k, kimi-k2.6, deepseek-chat, Claude-compatible models, Gemini-compatible models, and gpt-image-2.

Docs and quickstart:

https://tokenhub.sandboxclaw.com/docs/quickstart?utm_source=devto&utm_medium=article&utm_campaign=launch

Homepage:

https://tokenhub.sandboxclaw.com/?utm_source=devto&utm_medium=article&utm_campaign=launch