What is an AI API relay, and why do I need one?

An AI API relay (also called an API reseller) resells access to large model APIs from providers like OpenAI, Anthropic (Claude), and Google (Gemini). You top up with the relay directly and start calling the API right away, skipping the friction of setting up an official account yourself.

Why are relay prices sometimes cheaper than official?

Not every relay is cheaper than the official price. What matters is the "multiplier" — for example, a 2x multiplier means a $1 official call costs you $2.

Are API relays safe to use?

A legitimate relay's reliability is close to the official API. Test with a small deposit first, spread usage across 2-3 relays as backup, and route sensitive data through the official API directly.

What does "minimum deposit" mean?

The minimum deposit is the smallest amount you can top up in a single transaction — for example, "pay-as-you-go, $10 minimum" means your first top-up has to be at least $10.

Claude Code with an API Relay: Setup, Picking a Provider, and Fixing Errors

Claude Code is Anthropic's official command-line coding agent, but official access assumes a working account and a reliable connection to Anthropic's endpoint. If either of those is a problem for you, the easiest workaround is routing it through an API relay. Here's how to set it up, what to look for in a provider, and how to debug the errors you'll actually hit.

How Claude Code talks to a relay

Under the hood, Claude Code just calls the Anthropic API. It supports overriding the endpoint and auth token via environment variables, so as long as your relay exposes an Anthropic-compatible interface, pointing the endpoint at the relay and swapping in its key is all it takes. Two variables do the work:

ANTHROPIC_BASE_URL: set to the API address your relay gives you;
ANTHROPIC_AUTH_TOKEN (or ANTHROPIC_API_KEY): set to the key the relay issued.

Exact variable names can vary slightly, so check the relay's own docs — any legitimate provider will publish a "Claude Code setup" page you can copy from directly. Set these in your shell config (.zshrc / .bashrc) to make them permanent, or export them for a single session.

What to look for in a relay for Claude Code specifically

Claude Code is a heavy, long-running workload, not the occasional one-off question — so the bar for picking a provider is higher:

Explicit Claude Code support: the provider's docs should have a dedicated Claude Code / Anthropic setup guide, not a generic OpenAI-format writeup you're trying to bend to fit;
Current, complete model coverage: Claude Code defaults to a fairly recent Claude model, so confirm the relay has that exact version available;
Stability over rock-bottom price: frequent dropouts or truncated responses seriously hurt coding productivity — a provider with a slightly higher multiplier but solid uptime is usually the better deal, as covered in what a billing multiplier actually is;
Transparent pricing: Claude Code burns through tokens fast, so check input/output multipliers up front and test with a small deposit before scaling up.

Debugging common errors

401 / authentication failed

Usually a wrong key, or the wrong variable name (using API_KEY when the provider expects ANTHROPIC_AUTH_TOKEN). Double-check the provider's docs for the exact variable name, and confirm the key has no stray whitespace and hasn't expired.

Connection timeouts / 5xx errors

Usually upstream instability or throttling on the relay's end. First confirm BASE_URL is correct; try again at a different time; if it stays flaky, that upstream isn't reliable enough and it's time to switch or fall back to a second provider.

Response quality drops noticeably

Watch for silent model substitution — you think you're on the flagship Claude model, but the backend has quietly routed you to something smaller and cheaper. It shows up as a sudden drop in coding ability. Switch providers the moment you see this; it's one of the worst things a relay can do.

"Model not found" / unsupported

Means the relay hasn't added the model version Claude Code defaults to yet. Either switch to a provider that already has it, or explicitly pin a model it does support per its docs.

The short version

Wiring Claude Code up to a relay is just two environment variables — the hard part is finding a provider that's stable, current on models, and doesn't silently swap models on you. Start small, and keep a backup provider ready. To find relays that explicitly support coding-agent workloads, browse the HowToken directory and filter by model, then test a couple with a small deposit. Before you commit, it's worth reading 7 things to check before choosing a relay.