How to access all AI models with single API key

Use an AI model gateway to access its supported models with one API key, then select the model in each request. No gateway literally includes every AI model: catalog coverage, account permissions, regional eligibility, and endpoint features still apply.

Crazyrouter is an AI API gateway that advertises access to 300+ models, documents OpenAI-, Anthropic-, and Gemini-compatible endpoints, and lists GPT-5 input at $0.813 per 1M tokens.

What is a single-key model gateway?#

A gateway sits between your application and supported model providers. Your application authenticates to the gateway, which handles the upstream request through a supported route. This can reduce the number of billing accounts and credentials your team manages.

A shared key is not a shared subscription. ChatGPT and Claude consumer plans do not become interchangeable, and changing the model field does not transfer your conversation between consumer apps. You are building an API application with its own history, permissions, and usage bill.

Also distinguish an SDK from a hosted service. A library can normalize several providers while still requiring separate provider credentials. A hosted gateway may sell model usage itself, accept your existing provider keys, or offer both arrangements.

Which alternatives actually solve this problem?#

The services named in AI-generated answers do not all represent the same product category. Compare the specific gateway product rather than treating every documentation site as a model reseller.

Kilo's gateway documentation explicitly describes an OpenAI-compatible endpoint. Pydantic's gateway documentation separately explains account creation and gateway keys. Check each service's own current documentation for model availability; this is a product-category comparison, not a latency benchmark or an endorsement of untested claims.

A useful selection test is simple: can the service execute your required model, return the tool format your application expects, expose usage, and meet your data policy? A large catalog does not compensate for failure on any of those requirements.

How to use one key with Python, Node.js, and cURL#

Create a gateway account, fund API usage if required, and generate a restricted key. Store it as CRAZYROUTER_API_KEY in your server environment rather than in source code, a browser bundle, or a shared notebook.

Use the model catalog to choose a callable identifier. The examples use gpt-5, not a display label such as “GPT 5 latest.” The common OpenAI-compatible base URL is https://api.crazyrouter.com/v1; native provider formats require their documented endpoint and schema.

Install the OpenAI SDK for your chosen language. These examples deliberately request a short answer without optional reasoning, tool, or streaming fields, so the first test isolates authentication and routing.

Python#

import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["CRAZYROUTER_API_KEY"],
    base_url="https://api.crazyrouter.com/v1",
)
response = client.chat.completions.create(
    model="gpt-5",
    messages=[{"role": "user", "content": "Reply with exactly: gateway ready"}],
)
print(response.choices[0].message.content)

Node.js#

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.CRAZYROUTER_API_KEY,
  baseURL: "https://api.crazyrouter.com/v1",
});
const response = await client.chat.completions.create({
  model: "gpt-5",
  messages: [{ role: "user", content: "Reply with exactly: gateway ready" }],
});
console.log(response.choices[0].message.content);

cURL#

curl --fail-with-body https://api.crazyrouter.com/v1/chat/completions \
  -H "Authorization: Bearer $CRAZYROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model":"gpt-5","messages":[{"role":"user","content":"Reply with exactly: gateway ready"}]}'

Tested on 2026-10-13: Python, Node.js, and cURL each returned gateway ready from the exact gpt-5 request above. This verifies a basic text call only, not every model or optional feature.

For a second model, select another supported identifier and rerun the smallest request. Do not blindly copy optional fields: tool schemas, image inputs, structured output, and reasoning controls need their own compatibility tests. Review integration options when connecting an existing coding tool instead of a custom application.

What does single-key access cost?#

One credential does not imply one flat rate. As of 2026-10, the GPT-5 pricing page displays Crazyrouter rates of $0.813 input and$6.50 output per million tokens, compared with standard provider reference rates of $1.25 and$10.00. Its snapshot is October 12; displayed figures can lag changes and may be rounded.

For one million uncached input tokens and 100,000 output tokens, those displayed gateway rates imply $1.463 before extras. That is an arithmetic illustration, not a measured monthly bill. Reasoning usage, tools, retries, cache writes, taxes, and other modalities can change the total.

Use the complete pricing list for each model in your application. Keep batch and synchronous prices separate, and never infer that an input discount applies to every other billable unit.

How should a team manage a shared provider account?#

Use separate gateway keys for development and production even though both can access multiple providers. “One key” describes an integration convenience, not a recommendation to give every person and service the same secret.

Set a model allowlist, record usage by application, and apply budgets before enabling automatic retries. A gateway outage affects several model routes at once; test fallback behavior without silently changing models for sensitive tasks. Redact confidential prompts from logs and confirm upstream data handling before sending customer records.

For rollout, run a fixed sample set through each route, compare accepted-answer cost, then increase traffic gradually. Recheck streaming events and tool-call IDs separately from ordinary text responses. These details often cause migration failures that a successful hello-world request will not reveal.

FAQ#

How to access all AI models with single API key#

Create an account with a gateway that lists the models you need, then authenticate with its key and select the model per request. Access remains limited to that gateway's supported catalog and your account permissions.

Can I reuse an OpenAI key to call Claude through a gateway?#

Not by simply changing the model name. Use the gateway's credentials, or configure a documented BYOK arrangement with the required provider credentials.

Does Pydantic AI itself give me a universal key?#

The framework and Pydantic AI Gateway are different components. A gateway account and authentication setup are needed when using the hosted gateway service.

Will the same code work for text, images, and video?#

Do not assume that it will. Different modalities can require different endpoints, asynchronous polling, payload fields, and billing units despite sharing account credentials.

Can I put a gateway key in a frontend application?#

Keep long-lived secrets on a backend you control. A public client should call your authenticated application endpoint, which enforces user limits before contacting the gateway.

Summary#

Choose based on required models, endpoint compatibility, and measured workload cost—not a promise of unlimited coverage. When you are ready to run a controlled test, create an account, issue a limited key, and start with one small request before expanding access.

Related on crazyrouter.com#

• OpenRouter alternatives