Is Claude Code free? What's free, what isn't, and what a month costs

The Claude Code CLI is free to install. Running it is not. Every action Claude Code takes — reading a file, proposing an edit, running a command, checking the result — is a model call that someone pays for. Anthropic gives new API accounts a small amount of free credit to test with, but there is no free tier beyond that grant — once it is spent, every call is billed.

What that costs you depends entirely on which of two payment routes you take — a claude.ai subscription or an API key billed per token — and they suit very different usage patterns. The cheapest way to run it without a subscription is a pay-as-you-go key: on Kunavo every Claude model is 30% under Anthropic's list, from a $10 top-up with no monthly fee, and the setup is a few environment variables (below). Here is the actual arithmetic.

What's free and what isn't

The one free way in is a guest pass. Eligible Pro and Max subscribers can share passes that give someone new to Claude's paid plans a seven-day Pro trial, Claude Code included; senders find them with the /passes command. Passes are limited and can expire, so they are a way to try Claude Code, not a way to keep using it for free (Anthropic's guest pass article, read 2026-10-10). The Free plan itself does not include Claude Code.

Codex is the opposite case: ChatGPT's Free plan includes Codex in the desktop app, with limits. The side-by-side is in is Codex free.

The two ways to pay

The two don't stack, and it matters which one is active: while a credential variable such as ANTHROPIC_AUTH_TOKEN or ANTHROPIC_API_KEY is set, Claude Code uses it instead of a saved claude.ai login. Your subscription stays parked and unused, its limits stop applying, and usage bills to the key. Unset the variable and Claude Code goes back to the subscription. Run /status to see which is live right now.

What a real month costs

Cost tracks agentic steps, not calendar days. Claude Code resends the system prompt, the conversation and fresh file context on every step, so a step is bigger than a chat message — around 25,000 input and 1,200 output tokens is typical. At Kunavo rates on claude-sonnet-5:

Those are unoptimised numbers — no prompt caching, everything on the mainline model. Light or exploratory use lands in single-digit dollars a month; the row that hurts is sustained daily agentic work, which is exactly where the per-token rate compounds. Run your own numbers in the cost calculator, or see Claude Code pricing for the subscription tiers, the full per-model rate table and the break-even between the two routes. The “At Anthropic list” column above comes from Anthropic's official API pricing, which carries the current per-token list price for every Claude model next to what the same model costs here.

The cheapest way to run it

Claude Code reads ANTHROPIC_BASE_URL natively, so it works against any endpoint serving the Anthropic Messages API — no plugin, no patched binary, no proxy to babysit. That is the supported route to a lower per-token rate:

export ANTHROPIC_BASE_URL=https://api.kunavo.com
export ANTHROPIC_AUTH_TOKEN=sk-kn-...
export ANTHROPIC_MODEL=claude-sonnet-5
export ANTHROPIC_DEFAULT_OPUS_MODEL=claude-opus-5-5
export ANTHROPIC_DEFAULT_SONNET_MODEL=claude-sonnet-5
export ANTHROPIC_DEFAULT_HAIKU_MODEL=claude-haiku-4-5

Same models, same CLI, about 30% off list on the mainline model. Keep the model lines: Claude Code's built-in default and its opus and sonnet aliases follow Anthropic's newest models, and if Kunavo does not serve one yet, the request returns 404. The sonnet alias asks for Sonnet 5.5, which Kunavo does not serve, so /model sonnet, the execution phase of opusplan and subagents set to sonnet return a 404 unless ANTHROPIC_DEFAULT_SONNET_MODEL pins it. The opus pin is Opus 5.5, which needs Claude Code v2.1.280 or later — run claude update on an older install. Pay-as-you-go from a $10 top-up, no monthly fee, and the balance doesn't expire — so a quiet month genuinely costs nothing. Full walkthrough in the Claude Code setup guide. If you are already on a plan and keep hitting its window, what happens when you hit a Claude limit does the break-even arithmetic for keeping the plan and adding a key for the hours it has stopped serving.

Four levers that actually move the number

1. Keep the Haiku line. Without ANTHROPIC_DEFAULT_HAIKU_MODEL=claude-haiku-4-5, Claude Code's haiku alias asks for a model id Kunavo does not serve (Haiku 5.5 from v2.1.293), so /model haiku and subagents set to haiku return 404. With it, the calls Claude Code makes on its own for summaries and titles run on the cheapest model ($0.70 / $3.50 per 1M) instead of the main one — the Anthropic Claude API price list has the per-model rates this trades between, official and discounted side by side.
2. Start fresh tasks. Context is resent every step, so one long-running session is quadratically expensive. A new task is a small context again.
3. Let prompt caching work. Cached input bills at 10% of the input rate. On a loop that resends a stable prefix every step that's the single biggest saving available (how it works).
4. Cap the key. Give the editor its own key with a spend limit in the dashboard. A runaway loop becomes a capped one instead of a surprise.

Things people get wrong about this

“Claude Code is open source, so it's free”

The client being free to install says nothing about the model calls. The CLI is the cheap part; inference is the cost.

“My Claude Pro subscription covers the API”

It doesn't. Subscriptions and API keys are separate products with separate billing — claude.ai handles one, console.anthropic.com the other. Pro funds Claude Code through the subscription route only, not through a key.

“There must be a free tier if I use a small model”

Cheaper, not free. claude-haiku-4-5 at $0.70 / $3.50 per 1M is a fraction of Sonnet, but it still bills.

“A gateway means I can use it without paying Anthropic”

You're still paying for inference — just at a different rate, to a different party. What changes is the price and the billing model, not whether it costs money.

Frequently asked questions