Install Claude Code: Windows, macOS, and Linux, an API key without a subscription, and payment with Bancontact

Installing Claude Code takes one line, but it is not the same everywhere: curl -fsSL https://claude.ai/install.sh | bash in the macOS, Linux, or WSL terminal, irm https://claude.ai/install.ps1 | iex in PowerShell, and a line install.cmd in the Windows Command Prompt. The real question comes at first launch: who pays for the requests? A Pro, Max, Team, Enterprise, or Console account lets you sign in (the free Claude.ai plan does not include Claude Code). Without a subscription, an API key is sufficient: six variables, including ANTHROPIC_BASE_URL without /v1 and ANTHROPIC_AUTH_TOKEN, followed by a quick look at /status. The Kunavo balance can be paid for by card, Apple Pay, Google Pay, Link, or, in Belgium, Bancontact, starting at $10, with no subscription.

Where this information comes from: the commands and variables are drawn from the official Claude Code documentation (installation, environment variables, connecting to a gateway), which we reviewed on October 3, 2026; Kunavo prices and payment methods were checked on October 3, 2026. According to Anthropic's list of supported countries (checked on October 3, 2026), Claude.ai and the API are available in France, Belgium, Switzerland, Luxembourg, and Canada, as well as Morocco, Tunisia, Algeria, Senegal, and Côte d’Ivoire. The same guide is available in English and, for Flanders, in Dutch.

Which command to type: it depends on the window

# macOS, Linux, WSL
curl -fsSL https://claude.ai/install.sh | bash

# Windows PowerShell
irm https://claude.ai/install.ps1 | iex

:: Invite de commandes Windows (CMD)
curl -fsSL https://claude.ai/install.cmd -o install.cmd && install.cmd && del install.cmd

The first three lines install the native version, which Anthropic recommends: a standalone binary stored in ~/.local/bin (%USERPROFILE%\.local\bin on Windows), which downloads updates in the background and applies them at the next startup. Once installation is complete, close the terminal and reopen one: the terminal used for installation does not yet know about the new PATH.

On Windows, using the wrong window is the number-one cause of failure, and the message says so unambiguously. The token '&&' is not a valid statement separator: you pasted the CMD line into PowerShell. 'irm' is not recognized as an internal or external command: the opposite is true. On a French-language Windows system, this second message may appear translated; the cause does not change. The other messages are in the error table at the end of the guide.

Requirements

Windows: what old tutorials say and what is true

Many French-language tutorials date back to the early versions of Claude Code. Here are their most common instructions, checked against the current installation documentation and the troubleshooting page (reviewed on October 3, 2026):

If you install Git for Windows, Claude Code uses Git Bash and keeps the PowerShell tool alongside it. Sometimes it cannot find bash.exe; in that case, specify its path in the CLAUDE_CODE_GIT_BASH_PATH variable within the env block of ~/.claude/settings.json (the documentation gives C:\Program Files\Git\bin\bash.exe as an example). One last pitfall: the “Windows PowerShell (x86)” shortcut launches a 32-bit version, which Claude Code does not support.

Native or WSL: the choice depends on where your projects live:

On the WSL side, everything happens inside the Linux distribution: that is where you paste the curl … | bash line, and where you then type claude. If launched from PowerShell or CMD, it would not see this installation.

Homebrew, WinGet, apt, or npm

Package managers work, with one trade-off: Claude Code is not updated automatically through them. For Homebrew and WinGet, the CLAUDE_CODE_PACKAGE_MANAGER_AUTO_UPDATE=1 variable tells Claude Code to update itself; without it, you must do so yourself:

# Homebrew (macOS)
brew install --cask claude-code
brew upgrade claude-code              # pas de mise à jour automatique

# WinGet (Windows)
winget install Anthropic.ClaudeCode
winget upgrade Anthropic.ClaudeCode   # pas de mise à jour automatique

On Debian, Ubuntu, Fedora, RHEL, and Alpine, Anthropic also publishes signed apt, dnf, and apk repositories that are updated with the rest of the system; instructions are on the installation page.

That leaves npm, which is convenient if Node.js is already part of your toolkit. The package requires Node.js 22 at minimum. On an older version, npm merely issues an EBADENGINE warning and completes, because the package installs the same native binary, which does not need Node.js to run. Two rules: no sudo npm install -g, and update with @latest, because npm update -g stays within the original version range and may leave you behind.

node -v                                       # v22 ou plus récent
npm install -g @anthropic-ai/claude-code      # jamais avec sudo

# mise à jour : avec @latest, pas avec npm update -g
npm install -g @anthropic-ai/claude-code@latest

Verify the installation and repair the PATH

claude --version   # affiche le numéro de version, suivi de (Claude Code)
claude doctor      # diagnostic de l’installation et des réglages, sans ouvrir de session

A version number returned means it is installed. claude doctor goes further without starting a session: installation status, errors in settings files, and the result of the latest update. When something is wrong, this is the first command to run.

command not found: claude on macOS or Linux, claude “not recognized” on Windows: the program is installed, but the shell does not know where to find it. Opening a new window is usually enough. Otherwise, add ~/.local/bin to PATH in ~/.zshrc or ~/.bashrc. On Windows, the official troubleshooting page gives these three PowerShell steps:

# 1. Le dossier d'installation est-il déjà dans le PATH ?
$env:PATH -split ';' | Select-String '\.local\\bin'

# 2. Aucun résultat ? Ajoutez-le au PATH de l'utilisateur, puis ouvrez une nouvelle fenêtre
$currentPath = [Environment]::GetEnvironmentVariable('PATH', 'User')
[Environment]::SetEnvironmentVariable('PATH', "$currentPath;$env:USERPROFILE\.local\bin", 'User')

# 3. Dans la nouvelle fenêtre : deux chemins = deux installations concurrentes
where.exe claude

Installed via npm, and PowerShell responds with npm.ps1 cannot be loaded? Its execution policy blocks npm scripts. Switch to the native installer, or allow local scripts for your account only:

Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser

Who pays for requests: Claude subscription or API key

The choice is made not during installation but at first launch, and it remains reversible. A key defined in the environment takes precedence over a saved claude.ai connection, which remains dormant; remove the variable, and the connection takes over again at the next launch.

With a Claude subscription

Nothing to configure: claude in the project directory, then sign in through the browser. One exception is an ANTHROPIC_API_KEY that happens to be present in your environment. Claude Code then asks once whether it should use it; a refusal is remembered, and the key is subsequently ignored without a message, making it seem as though the variable is not being read. To change this choice: /config → Use custom API key.

Without a subscription: the Kunavo API key

Pointing Claude Code somewhere other than Anthropic is a supported configuration. The official list of environment variables identifies ANTHROPIC_BASE_URL as the way to route requests through a proxy or gateway. Kunavo responds using the Anthropic Messages API format, so you can keep the official Claude Code without an extension or modified version.

1. Open an account: Kunavo sign-up.
2. Fund the balance in Billing, $10 minimum (payment methods below).
3. Generate a key at /app/keys. It starts with sk-kn- and is shown only when it is created: copy it immediately.
4. Enter the six variables below.

Why pin four models? Claude Code's aliases track Anthropic's releases. According to the model configuration documentation (checked on October 3, 2026), for an API account, the default setting and opus currently point to Opus 5.5, while sonnet points to Sonnet 5.5, which Kunavo does not serve: without ANTHROPIC_DEFAULT_SONNET_MODEL, /model sonnet, the execution phase of opusplan, and subagents configured with sonnet return a 404. The opus alias is pinned to Opus 5.5 (claude-opus-5-5), which requires Claude Code v2.1.280 or later; if you have an older version, run claude update. A newly released model may also not be available on Kunavo the same day. With full model names, every request goes to a served model at a known price. The gateway protocol documentation (checked on October 3, 2026) confirms the point about background tasks: with Claude Haiku 4.5, they cost little.

Where to enter the variables

The recommended version, to merge with the file’s existing content if there is any (add only the env block):

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://api.kunavo.com",
    "ANTHROPIC_AUTH_TOKEN": "sk-kn-...",
    "ANTHROPIC_MODEL": "claude-sonnet-5",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "claude-opus-5-5",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "claude-sonnet-5",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "claude-haiku-4-5"
  }
}

The same values in the shell on macOS and Linux:

export ANTHROPIC_BASE_URL=https://api.kunavo.com   # le domaine seul, sans /v1
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

For a quick test in a PowerShell window:

# Valable uniquement dans cette fenêtre PowerShell
$env:ANTHROPIC_BASE_URL = "https://api.kunavo.com"
$env:ANTHROPIC_AUTH_TOKEN = "sk-kn-..."
$env:ANTHROPIC_MODEL = "claude-sonnet-5"
$env:ANTHROPIC_DEFAULT_OPUS_MODEL = "claude-opus-5-5"
$env:ANTHROPIC_DEFAULT_SONNET_MODEL = "claude-sonnet-5"
$env:ANTHROPIC_DEFAULT_HAIKU_MODEL = "claude-haiku-4-5"
claude

And for the VS Code extension, in the editor’s user settings (command Preferences: Open User Settings (JSON)):

{
  "claudeCode.environmentVariables": [
    { "name": "ANTHROPIC_BASE_URL", "value": "https://api.kunavo.com" },
    { "name": "ANTHROPIC_AUTH_TOKEN", "value": "sk-kn-..." },
    { "name": "ANTHROPIC_MODEL", "value": "claude-sonnet-5" },
    { "name": "ANTHROPIC_DEFAULT_OPUS_MODEL", "value": "claude-opus-5-5" },
    { "name": "ANTHROPIC_DEFAULT_SONNET_MODEL", "value": "claude-sonnet-5" },
    { "name": "ANTHROPIC_DEFAULT_HAIKU_MODEL", "value": "claude-haiku-4-5" }
  ]
}

The Claude desktop app is an exception: it reads neither ANTHROPIC_BASE_URL nor settings.json. A variable changed in the shell that still has no effect? First look for the same variable in a settings.json, which takes precedence.

Prices per million tokens from the Kunavo catalog, alongside Anthropic’s public price listed on claude.com/pricing (read on October 3, 2026):

To switch to Opus for the duration of a task: /model opus during the session (the alias pinned to claude-opus-5-5), or claude --model claude-opus-5-5 at startup. The monthly budget based on your usage, and the threshold at which the subscription becomes more advantageous, are quantified in the price of Claude Code. The Claude token cost calculator calculates it for your own volumes, and the pricing page lists all models.

Verify with /status

The first sign, even before /status: with ANTHROPIC_AUTH_TOKEN in place, Claude Code starts without a login screen. If this screen appears, no key was read, often because it exists only in the project settings (.claude/settings.json or .claude/settings.local.json). In an interactive session, this env block is applied only after the first-launch assistant and the folder trust prompt. Move the key to your shell or to ~/.claude/settings.json.

Once in the session, /status opens on the Status tab. Here’s how to read it, according to the gateway documentation (read on October 3, 2026):

Were you already signed in with a subscription? Claude Code may then report two active authentication sources at startup, in a warning that ends with auth may not work as expected. This is the key used for requests; /logout removes the old connection and makes the warning disappear.

To find out whether a problem comes from Kunavo or your configuration, test without Claude Code. The documentation provides a request limited to a single output token, which costs a fraction of a cent. The two commands below take the address and key from the shell: if they are defined only in settings.json, they would not be visible here.

curl -sS -w '\n%{http_code}\n' -X POST "$ANTHROPIC_BASE_URL/v1/messages" \
  -H "Authorization: Bearer $ANTHROPIC_AUTH_TOKEN" \
  -H "anthropic-version: 2023-06-01" \
  -H "content-type: application/json" \
  -d '{"model": "claude-sonnet-5", "max_tokens": 1, "messages": [{"role": "user", "content": "."}]}'

Invoke-RestMethod -Method Post -Uri "$env:ANTHROPIC_BASE_URL/v1/messages" `
  -Headers @{ "Authorization" = "Bearer $env:ANTHROPIC_AUTH_TOKEN"; "anthropic-version" = "2023-06-01" } `
  -ContentType "application/json" `
  -Body '{"model": "claude-sonnet-5", "max_tokens": 1, "messages": [{"role": "user", "content": "."}]}'

A JSON object starting with {"id":"msg_, or in PowerShell an object whose id starts with msg_: the address and key work. A 401: the key is rejected.

What changes with an API key

• Remote Control and voice dictation disappear. Both rely on a claude.ai account and remain unavailable as long as ANTHROPIC_AUTH_TOKEN is defined. Remote Control is also disabled as soon as ANTHROPIC_BASE_URL points to a host other than Anthropic.
• Fast mode (/fast) appears disabled, because its verification requires a claude.ai connection or an Anthropic key, not a simple bearer token.
• MCP tool search is disabled by default when ANTHROPIC_BASE_URL points outside Anthropic.
• /context displays estimates. Kunavo does not offer /v1/messages/count_tokens, and in that case Claude Code counts based on the number of characters (gateway protocol documentation).

For everything else (reading and writing code, tools, sub-agents, MCP servers, hooks, prompt caching), nothing changes. The technical details, in English, are in the Claude Code integration documentation.

Paying from France or Belgium

Two payment channels not to confuse. A Claude subscription purchased on the web can be paid for only by credit or debit card (Anthropic billing FAQ, read on October 3, 2026); subscriptions purchased in the mobile app are billed through the App Store or Google Play. The amounts on claude.com/pricing exclude taxes.

Kunavo balance, by contrast, is topped up on a Stripe checkout page. The price is set in US dollars, but from France or Belgium Stripe shows you the amount in euros, at a rate guaranteed for 24 hours that includes 2 to 4% in conversion fees charged to you (Stripe documentation on Adaptive Pricing, read on October 3, 2026). You can pay in dollars to avoid these fees, but your bank will then apply its own exchange rate, and Bancontact is available only in euros. Available payment methods:

• French CB card? According to the Stripe documentation on Cartes Bancaires (read on October 3, 2026), more than 95% of CB cards are co-badged with Visa or Mastercard. They therefore go through checkout as Visa or Mastercard, and a basic debit card will do.
• Bancontact is offered to buyers located in Belgium. Stripe sends you to the Bancontact website or app to authorize the payment, and the result is known immediately (Stripe documentation on Bancontact, read on October 3, 2026).
• Pay by Bank, payment from your online bank, is not offered from France or Belgium: checkout displays it only to buyers located in the United Kingdom, Ireland, and Finland. The Stripe documentation on Pay by Bank (read on October 3, 2026) classifies it as a private preview for France and does not mention Belgium.
• From Switzerland or Canada, the amount is displayed in Swiss francs or Canadian dollars, with card and Link, plus Apple Pay and Google Pay, which rely on a card.

Not offered: PayPal, SEPA direct debit, Klarna, reserved for buyers located in the United States (paying in dollars is not enough).

1. Sign up for Kunavo; no card is required at this stage.
2. In Billing, choose the amount: $10 minimum. Higher amounts qualify for a bonus ($100 paid, $110 credited; $1.000 paid, $1.200 credited; $5.000 paid, $6.250 credited).
3. On the Stripe page, select the payment method; the amount in euros is displayed before confirmation. With Bancontact, confirm in the app or with the card.
4. Create the key at /app/keys and place it in ANTHROPIC_AUTH_TOKEN.

The balance is prepaid: no monthly fees, no expiration date, and a failed request is not charged. Automatic top-ups require a saved card or Link. Bancontact does not support recurring payments with Stripe, so each Bancontact top-up must be initiated manually. Kunavo does not issue VAT invoices, whether French, Belgian, or from any other country; top-up history can be viewed in Billing. Finally, these payment methods are used only for the Kunavo API balance and do not pay for a Claude Pro or Max subscription. All other options, including the App Store and Google Play, are reviewed in paying for Claude without a bank card.

Common errors

Getting started in a project

In a repository that Claude Code discovers, start with /init: it explores the code and writes a CLAUDE.md documenting the test commands and conventions it finds. Review and trim this file, since it is reloaded in every session. To change the subject, /clear starts a blank conversation; to continue a long task, /compact summarizes its history.

API key limits

• You pay based on usage, not for a Claude Pro or Max plan. For several hours of Claude Code per day, every day, the subscription often wins; for irregular use, token-based billing is more flexible, and quiet months cost nothing. Figures are in Claude Code pricing.
• No Remote Control or voice dictation while the key is active.
• Kunavo capacity is shared, with no reserved quota or contractual commitment; if you need that, contract directly with Anthropic.
• Bancontact allows only manual top-ups; automatic top-ups use a saved card or Link.
• Euro amounts include Stripe’s conversion fees, and Kunavo does not issue VAT invoices.

Frequently asked questions