Connect Claude Code to an LLM gateway

An LLM gateway is a proxy your organization runs between Claude Code and the model provider. When your organization uses one, Claude Code authenticates to the gateway with a credential your organization issues instead of your personal claude.ai login. This page is for developers running Claude Code through a gateway their organization operates. It covers two paths: checking whether your administrator already configured it for you, and configuring it yourself when they haven’t.

To deploy a gateway for your organization, see Roll out an LLM gateway
For what Claude Code sends to a gateway, see the gateway protocol reference

Check for an existing configuration

Administrators can distribute the gateway address and credential through managed settings, device management, or an apiKeyHelper, so Claude Code picks them up at startup with nothing for you to set. To check whether your organization already did this:

Start Claude Code

Run claude. If it opens to the login screen instead of a session, no gateway credential was distributed; configure it yourself below.

Check the Status tab

If Claude Code started a session without showing the login screen, run /status, which opens on the Status tab, and check two lines:

Anthropic base URL: this line only appears when a gateway address is set. If it isn’t there, Claude Code isn’t pointed at the gateway; configure it yourself below.
Auth token or API key: a line naming ANTHROPIC_AUTH_TOKEN, ANTHROPIC_API_KEY, or an apiKeyHelper confirms a gateway credential is active. A Login method line naming a claude.ai account instead means the credential wasn’t distributed; set it yourself.

Send a test message

Close the /status menu and send any prompt in Claude Code. A normal response from Claude, with no error, confirms the gateway connection works.

If both lines in the /status menu look right but the message to Claude fails, see the troubleshooting table.

Configure Claude Code yourself

To configure Claude Code for the gateway yourself, you need from your gateway team:

The gateway’s base URL
A credential: a key or token string, or a command that fetches one
- If your gateway team didn’t say which kind of credential it is, the credential variable section below covers what to try

The sections below cover the configuration in order:

Set the credential variable and set the base URL: the two variables every gateway connection needs
Verify the connection: confirm it works before persisting anything
Configure each surface: if you are using a surface besides the Claude Code CLI, such as VS Code, see how to configure it with your gateway credentials
Additional configuration: variables some gateways need beyond the base URL and credential, such as a custom header, a credential helper, model discovery, a provider-format base URL, or turning off traffic outside the gateway path. Set these only if your administrator named them or your network restricts egress

Set the credential variable

To authenticate Claude Code to the gateway, set your credential in an environment variable. Which variable depends on what your gateway team told you:

Set the credential in	Use when
`ANTHROPIC_AUTH_TOKEN`	Your gateway team said “bearer token” or “Authorization header”
`ANTHROPIC_API_KEY`	Your gateway team said “API key” or “x-api-key”
`apiKeyHelper`	The credential rotates or comes from a vault

If you weren’t told which kind, use ANTHROPIC_AUTH_TOKEN; the verification request below shows how to tell if you need to switch.

Set the base URL and credential

Set the gateway’s base URL and the credential variable you picked above as environment variables. The examples use ANTHROPIC_AUTH_TOKEN; swap it for ANTHROPIC_API_KEY if that’s the variable you picked. You can set them in your shell, which lasts for one terminal session, or in a Claude Code settings file, which persists everywhere Claude Code runs. For your first connection, start with shell exports and run the verification request before moving the values to a settings file.

Set as shell environment variables

Replace the values with the ones your gateway team gave you:

Bash or Zsh
PowerShell

export ANTHROPIC_BASE_URL=https://llm-gateway.example.com
export ANTHROPIC_AUTH_TOKEN=sk-gateway-key

$env:ANTHROPIC_BASE_URL = "https://llm-gateway.example.com"
$env:ANTHROPIC_AUTH_TOKEN = "sk-gateway-key"

Shell exports apply only to that terminal session and programs started from it. An editor launched from the dock or Start menu won’t see them. To make the values persist across new terminals, add the same lines to your shell profile, such as ~/.zshrc, ~/.bashrc, or your PowerShell $PROFILE. If you export the gateway only in your shell, it doesn’t reliably reach background agents hosted by the supervisor; see how each background session sources its gateway. Use a settings file for any gateway that background agents must always route through.

Set in a settings file

To make the configuration apply everywhere Claude Code runs, including background agents, set the variables in the env block of a settings file instead of relying on your shell. Settings files have different scopes:

~/.claude/settings.json applies to all your projects. On Windows the path is %USERPROFILE%\.claude\settings.json
.claude/settings.local.json applies to one project. Claude Code adds it to your gitignore when it creates the file; if you create it yourself, add it to your gitignore manually first so you don’t accidentally commit your credential

Don’t put the credential in a project’s .claude/settings.json. That file is committed and shared with everyone who clones the repository.

The env block looks the same in either file:

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://llm-gateway.example.com",
    "ANTHROPIC_AUTH_TOKEN": "sk-gateway-key"
  }
}

When both a shell export and a settings-file env block set the same variable, the settings-file value applies. Run /status to see which base URL and credential source Claude Code is using.

Verify the connection

With the variables exported in your shell, send a one-token request to the gateway directly. This confirms the URL and credential work before you open Claude Code, so a failure points at the gateway rather than your configuration. The commands below read the shell variables, so they need the shell exports even if you also put the values in a settings file.

Bash or Zsh
PowerShell

curl -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-4-6", "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-4-6", "max_tokens": 1, "messages": [{"role": "user", "content": "."}]}'

If your gateway expects keys in the x-api-key header, replace the Authorization header with x-api-key: $ANTHROPIC_API_KEY in the Bash command, or the "Authorization" hashtable entry with "x-api-key" = "$env:ANTHROPIC_API_KEY" in the PowerShell command. A JSON response that starts with {"id":"msg_ and includes a "content":[...] field means the gateway is reachable and the credential works. An error naming an unknown model still proves the URL and credential work, since the gateway authenticated the request before rejecting the model name; you don’t need to find a model your gateway serves for this test. A 401 means the credential was rejected: if you guessed the variable, switch to the other one and re-export.

Confirm in Claude Code

Start claude from the same shell so it inherits the exports, send a message, and run /status. On the Status tab, the Anthropic base URL line should show your gateway address, which confirms requests are routing there; if the line isn’t there, the variable didn’t reach the session. An Auth token or API key line naming the variable you set confirms the gateway credential is active rather than a saved claude.ai login. If the message fails, or /status doesn’t show the gateway URL, see the troubleshooting table below.

How the credential variable maps to a header

Each variable sends the credential in a different HTTP header: ANTHROPIC_AUTH_TOKEN in Authorization: Bearer, ANTHROPIC_API_KEY in x-api-key, and apiKeyHelper in both. A credential in the wrong variable reaches the gateway in a header it doesn’t read, and the request fails with 401. If the verification request returned 401, switch to the other variable and try again. A gateway credential variable takes precedence over a saved claude.ai login or Console key. Your claude.ai login stays saved and unused while the variable is set; unset the variable and Claude Code goes back to it. With ANTHROPIC_AUTH_TOKEN, the variable takes precedence immediately. With ANTHROPIC_API_KEY, you are prompted once in interactive mode to approve the key before it takes over. Run /status to confirm which credential source is active. If startup shows an auth-conflict warning naming two sources, see the first row of the troubleshooting table for which one to drop. To clear a saved login so only the gateway credential remains, run /logout.

Configure each surface

The CLI reads the environment variables and settings files above. The other surfaces are the VS Code extension, the desktop app, GitHub Actions, the Agent SDK, and the cloud surfaces such as Slack and the web; the sections below cover whether those settings reach each one.

VS Code extension

Set the gateway variables for the VS Code extension in claudeCode.environmentVariables, in VS Code’s own user settings opened with the Preferences: Open User Settings (JSON) command. The extension checks credentials from this setting before launching, so it’s the reliable place for the gateway credential; values in ~/.claude/settings.json reach the spawned process but not the extension’s own login check.

{
  "claudeCode.environmentVariables": [
    { "name": "ANTHROPIC_BASE_URL", "value": "https://llm-gateway.example.com" },
    { "name": "ANTHROPIC_AUTH_TOKEN", "value": "sk-gateway-key" }
  ]
}

Desktop app

The desktop app reads gateway routing from its third-party inference configuration, not from ANTHROPIC_BASE_URL or settings.json. That configuration can come from your organization or from a form in the app itself:

Distributed by an administrator: if your organization has deployed the configuration, the desktop app routes through the gateway with no setup on your part
Configured locally: for devices without an administrator-distributed configuration, open Help → Troubleshooting → Enable Developer Mode, which restarts the app with a Developer menu. Then open Developer → Configure Third-Party Inference and enter your gateway base URL. An administrator-distributed configuration takes precedence and makes this form read-only

With the gateway configuration active, the desktop app runs sessions on your local machine only: the environment picker doesn’t offer SSH sessions or Anthropic-hosted cloud environments, and Remote Control is unavailable. To use Claude Code on a remote host through the gateway, run the CLI on that host with ANTHROPIC_BASE_URL and the gateway credential set there. If the desktop app shows Gateway was unreachable, the app couldn’t reach the configured base URL at startup; check the URL and network path with the curl test above.

GitHub Actions

Claude Code GitHub Actions reads ANTHROPIC_BASE_URL and ANTHROPIC_CUSTOM_HEADERS from the workflow’s env block. Pass the credential as the action’s anthropic_api_key input; the action sets it as ANTHROPIC_API_KEY, so it reaches the gateway in the x-api-key header. For an x-api-key gateway, set the base URL in env and pass the gateway key as the input:

env:
  ANTHROPIC_BASE_URL: https://llm-gateway.example.com

steps:
  - uses: anthropics/claude-code-action@v1
    with:
      anthropic_api_key: ${{ secrets.GATEWAY_API_KEY }}

For a bearer-token gateway, pass the same secret twice: as the anthropic_api_key input and as ANTHROPIC_AUTH_TOKEN in the workflow env block. The action requires anthropic_api_key, CLAUDE_CODE_OAUTH_TOKEN, or workload identity federation before it launches Claude Code, and it doesn’t read ANTHROPIC_AUTH_TOKEN, so the input is there only to satisfy that launch check. The env variable is what puts the key in the Authorization header the gateway reads; the copy in x-api-key is ignored:

env:
  ANTHROPIC_BASE_URL: https://llm-gateway.example.com
  ANTHROPIC_AUTH_TOKEN: ${{ secrets.GATEWAY_API_KEY }}

steps:
  - uses: anthropics/claude-code-action@v1
    with:
      anthropic_api_key: ${{ secrets.GATEWAY_API_KEY }}

For the action’s other authentication options, including CLAUDE_CODE_OAUTH_TOKEN and workload identity federation, see Claude Code GitHub Actions and the action’s README.

Agent SDK

The Agent SDK has no gateway-specific options; it passes environment variables to the Claude Code process it spawns. Each SDK accepts an env option that sets the spawned process’s environment, and the TypeScript and Python SDKs treat it differently:

TypeScript: the spawned process inherits the parent environment by default, but setting options.env replaces the environment entirely. Spread process.env into it to keep your gateway variables.
Python: ClaudeAgentOptions(env=...) merges on top of the inherited environment, so gateway variables set in the parent process carry through without spreading.

const result = query({
  prompt: "...",
  options: {
    env: {
      ...process.env,
      ANTHROPIC_BASE_URL: "https://llm-gateway.example.com",
      ANTHROPIC_AUTH_TOKEN: process.env.GATEWAY_KEY,
    },
  },
})

options = ClaudeAgentOptions(
    env={
        "ANTHROPIC_BASE_URL": "https://llm-gateway.example.com",
        "ANTHROPIC_AUTH_TOKEN": os.environ["GATEWAY_KEY"],
    }
)

Slack, web, and Remote Control

Claude Code in Slack and Claude Code on the web are Anthropic-hosted products that always use Anthropic’s API; they aren’t part of a gateway deployment. Gateway variables set in a cloud session’s environment configuration are not applied. If your traffic must stay on the gateway, don’t enable these surfaces for those users. Remote Control and voice dictation both rely on a claude.ai identity: Remote Control to pair a live session with your account, and voice dictation to reach the claude.ai transcription endpoint. They are unavailable while ANTHROPIC_API_KEY, ANTHROPIC_AUTH_TOKEN, or an apiKeyHelper is active. As of v2.1.196, Remote Control is also disabled while ANTHROPIC_BASE_URL points at a non-Anthropic host, so signing in with claude.ai isn’t enough on its own. To restore either feature, log in with claude.ai and unset the gateway variables that feature checks. The Remote Control section of claude doctor names the credential variable to unset.

Voice dictation: unset the gateway credential
Remote Control: unset the gateway credential and ANTHROPIC_BASE_URL

Additional configuration

These settings cover cases beyond the base URL and credential. Set them only if your administrator’s instructions, your network’s egress rules, or the troubleshooting table call for one.

Send additional headers

Some gateways route or tag requests using a custom header in addition to the credential, for example a tenant identifier or a routing key. To send one, set ANTHROPIC_CUSTOM_HEADERS with one Name: Value pair per line. The example below adds a routing header named X-Org-Route:

Bash or Zsh
PowerShell

export ANTHROPIC_CUSTOM_HEADERS="X-Org-Route: prod"

$env:ANTHROPIC_CUSTOM_HEADERS = "X-Org-Route: prod"

You can also set ANTHROPIC_CUSTOM_HEADERS in the env block of a settings file. Use \n between pairs there, since JSON strings can’t span multiple lines:

{
  "env": {
    "ANTHROPIC_CUSTOM_HEADERS": "X-Org-Route: prod\nX-Tenant: example"
  }
}

Add gateway models to the model picker

Model discovery queries the gateway for its model list at startup and adds those names to the /model picker alongside the built-in entries. Enable it if your gateway serves model names that aren’t in Claude Code’s built-in list and you want to select them from the picker. If the built-in models are what you use, you don’t need discovery; your administrator may also have already enabled it through managed settings. To enable it, set CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY=1 in your shell or in the env block of ~/.claude/settings.json. Discovery requires Claude Code v2.1.129 or later. Discovered models appear as additional /model entries labeled From gateway. To confirm discovery ran, start claude --debug and look for the [gatewayDiscovery] lines: a success logs how many models were cached, and a 404, timeout, or redirect is recorded there too. For when discovery runs, what it filters, and the response format gateways serve, see the model discovery reference.

Rotate credentials with apiKeyHelper

An apiKeyHelper is a command Claude Code runs to fetch your gateway credential, instead of reading it from a static environment variable. Use a helper when the credential expires on a schedule, comes from a vault or SSO command, or your administrator told you to configure one. If your credential is a fixed string you set once, the credential variable is all you need and you can skip this section. The helper is any shell command that prints the current credential to stdout. Claude Code runs it through your system shell, so on Windows it can be an executable or a PowerShell invocation. Write the script, make it executable, and reference it from apiKeyHelper in your settings file:

Bash or Zsh
PowerShell

For example, a script that reads from a vault:

#!/bin/bash
vault kv get -field=api_key secret/llm-gateway/claude-code

Reference its path in ~/.claude/settings.json:

{
  "apiKeyHelper": "~/bin/get-gateway-key.sh"
}

For example, a script that reads from a vault:

vault kv get -field=api_key secret/llm-gateway/claude-code

Reference the PowerShell invocation in %USERPROFILE%\.claude\settings.json, escaping the backslashes in the JSON string:

{
  "apiKeyHelper": "powershell -NoProfile -File C:\\scripts\\get-gateway-key.ps1"
}

Claude Code caches the helper’s output for five minutes by default and re-runs it when a request returns HTTP 401. To change the cache lifetime, set CLAUDE_CODE_API_KEY_HELPER_TTL_MS in milliseconds, for example CLAUDE_CODE_API_KEY_HELPER_TTL_MS=900000 for 15 minutes. The helper’s value is sent in both the Authorization and x-api-key headers, so it works whichever header your gateway reads.

Turn off traffic outside the gateway path

The gateway carries model requests, but Claude Code also sends nonessential background traffic outside the gateway path, to Anthropic and to third-party services such as GitHub: version checks, telemetry, error reports, release notes, and similar requests. On a network that only allows egress to the gateway, these requests fail and can appear as blocked connections in your egress monitoring. To turn that traffic off, set CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC=1 alongside the gateway variables, in the same shell exports or settings-file env block:

Bash or Zsh
PowerShell

export CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC=1

$env:CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC = "1"

Setting the variable has these effects and limits:

It disables auto-updates, so plan for another update path, such as your package manager or managed distribution.
It suppresses the fast mode availability check. Unless a previous check already enabled fast mode on the machine, /fast reports that fast mode is unavailable.
It turns off gateway model discovery, even though discovery queries the gateway itself. Previously discovered models stay available from the local cache, but the list isn’t refreshed.
The WebFetch tool’s domain safety check isn’t affected and still calls api.anthropic.com. Turn it off separately with skipWebFetchPreflight: true in settings if your network blocks that host.
For each telemetry stream and the variable that controls it, see telemetry services.

Route to a cloud provider through a gateway

These configurations point Claude Code at a gateway through a provider-specific base URL variable in place of ANTHROPIC_BASE_URL. Amazon Bedrock and Google Cloud’s Agent Platform gateways accept those providers’ native request formats; Microsoft Foundry and Claude Platform on AWS gateways accept the Anthropic Messages format and differ only in which base URL variable reaches them. Use one only if your gateway team specifically named Amazon Bedrock, Google Cloud’s Agent Platform, Microsoft Foundry, or the Claude Platform on AWS. If the verification request above returned JSON, you can skip this section. Set the block for the provider your gateway team named. The skip-auth variables tell Claude Code not to sign requests with provider credentials, since the gateway holds those. If the gateway needs its own token, add ANTHROPIC_AUTH_TOKEN after the block, except for Microsoft Foundry, which uses ANTHROPIC_FOUNDRY_API_KEY as shown. A Microsoft Foundry gateway that expects a bearer token can use ANTHROPIC_FOUNDRY_AUTH_TOKEN instead; it takes precedence over ANTHROPIC_FOUNDRY_API_KEY when both are set. ANTHROPIC_FOUNDRY_AUTH_TOKEN requires Claude Code v2.1.203 or later.

Amazon Bedrock

Bash or Zsh
PowerShell

export ANTHROPIC_BEDROCK_BASE_URL=https://llm-gateway.example.com/bedrock
export CLAUDE_CODE_SKIP_BEDROCK_AUTH=1
export CLAUDE_CODE_USE_BEDROCK=1

$env:ANTHROPIC_BEDROCK_BASE_URL = "https://llm-gateway.example.com/bedrock"
$env:CLAUDE_CODE_SKIP_BEDROCK_AUTH = "1"
$env:CLAUDE_CODE_USE_BEDROCK = "1"

Google Cloud’s Agent Platform

Bash or Zsh
PowerShell

export ANTHROPIC_VERTEX_BASE_URL=https://llm-gateway.example.com/vertex
export ANTHROPIC_VERTEX_PROJECT_ID=your-gcp-project-id
export CLAUDE_CODE_SKIP_VERTEX_AUTH=1
export CLAUDE_CODE_USE_VERTEX=1
export CLOUD_ML_REGION=us-east5

$env:ANTHROPIC_VERTEX_BASE_URL = "https://llm-gateway.example.com/vertex"
$env:ANTHROPIC_VERTEX_PROJECT_ID = "your-gcp-project-id"
$env:CLAUDE_CODE_SKIP_VERTEX_AUTH = "1"
$env:CLAUDE_CODE_USE_VERTEX = "1"
$env:CLOUD_ML_REGION = "us-east5"

Microsoft Foundry

Put the gateway’s credential in ANTHROPIC_FOUNDRY_API_KEY; it is sent to the gateway as the x-api-key header. A gateway that expects a bearer token can take ANTHROPIC_FOUNDRY_AUTH_TOKEN instead. Claude Code sends that value as the Authorization: Bearer header, and it takes precedence over ANTHROPIC_FOUNDRY_API_KEY when both are set. Requires Claude Code v2.1.203 or later. For a gateway that injects its own Authorization header, set CLAUDE_CODE_SKIP_FOUNDRY_AUTH=1 and leave both credential variables unset. Claude Code then sends requests without an Azure credential and preserves the Authorization header you supply, for example through ANTHROPIC_CUSTOM_HEADERS. Before v2.1.203, CLAUDE_CODE_SKIP_FOUNDRY_AUTH without an API key left the Microsoft Foundry client unable to send requests.

Bash or Zsh
PowerShell

export ANTHROPIC_FOUNDRY_BASE_URL=https://llm-gateway.example.com/foundry
export ANTHROPIC_FOUNDRY_API_KEY=sk-gateway-key
export CLAUDE_CODE_USE_FOUNDRY=1

$env:ANTHROPIC_FOUNDRY_BASE_URL = "https://llm-gateway.example.com/foundry"
$env:ANTHROPIC_FOUNDRY_API_KEY = "sk-gateway-key"
$env:CLAUDE_CODE_USE_FOUNDRY = "1"

Claude Platform on AWS

See Claude Platform on AWS for the workspace ID.

Bash or Zsh
PowerShell

export ANTHROPIC_AWS_BASE_URL=https://llm-gateway.example.com/anthropic-aws
export ANTHROPIC_AWS_WORKSPACE_ID=wrkspc_01ABCDEFGHIJKLMN
export CLAUDE_CODE_SKIP_ANTHROPIC_AWS_AUTH=1
export CLAUDE_CODE_USE_ANTHROPIC_AWS=1

$env:ANTHROPIC_AWS_BASE_URL = "https://llm-gateway.example.com/anthropic-aws"
$env:ANTHROPIC_AWS_WORKSPACE_ID = "wrkspc_01ABCDEFGHIJKLMN"
$env:CLAUDE_CODE_SKIP_ANTHROPIC_AWS_AUTH = "1"
$env:CLAUDE_CODE_USE_ANTHROPIC_AWS = "1"

Troubleshoot gateway errors

These are the most common errors when running Claude Code through a gateway, with the gateway-side cause and the fix:

Error	Cause	Fix
A startup warning naming two credential sources and ending in `auth may not work as expected`. Older versions show `Auth conflict: Both a token (SOURCE) and an API key (SOURCE) are set` instead.	A gateway credential and a saved login are both active; the variable is used for requests, but the stale login can cause unexpected auth behavior	Unset the variable to use the saved login, or run `/logout` to use the gateway credential
`401` errors naming an invalid or unrecognized token	The credential isn’t one the gateway issued, or it’s in a header the gateway doesn’t read	Confirm the variable matches your credential kind in the credential table, and regenerate the key at the gateway if it was revoked
`Your apiKeyHelper script is failing`	The command in the `apiKeyHelper` setting exited with an error, timed out, or printed nothing, so requests carry a placeholder key	Run the command directly to see why it fails, and re-authenticate with your credential provider if it reports an expired session; see the error reference
`Unable to connect to API (ConnectionRefused)` when nothing answers at the address, `Unable to connect to API (FailedToOpenSocket)` when the hostname doesn’t resolve, or `(ECONNREFUSED)` from npm installs, often after a silent pause while Claude Code retries with backoff	Nothing answered at the base URL: the address is wrong, or a VPN or firewall blocks the path to the gateway	Run the curl test above, which fails immediately with the same cause, and confirm the URL and network path with your gateway team
`API returned an empty or malformed response (HTTP 200)`	The gateway or an intermediate proxy returned a non-API response, often an HTML error or login page	Test with the curl request above; fix the gateway route that returns non-JSON
`400` errors naming `context_management`, `Extra inputs are not permitted`, or other unrecognized fields	The gateway forwards requests to an upstream that rejects fields Claude Code sends to Anthropic-format endpoints	Set `CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS=1`, which suppresses most pre-release fields; see feature pass-through. Some betas aren’t gated by this flag; for those, set the matching `CLAUDE_CODE_USE_*` provider variable so Claude Code sends only what that provider accepts
`400` errors naming `thinking` or `adaptive`, such as `Input tag 'adaptive' found`	The upstream model build doesn’t accept adaptive reasoning, which Claude Code requests for Claude 4.6 and later models	Upgrade the gateway’s upstream. On Opus 4.6 and Sonnet 4.6, `CLAUDE_CODE_DISABLE_ADAPTIVE_THINKING=1` works instead. The model configuration capability variables apply only to the provider configurations, such as `CLAUDE_CODE_USE_BEDROCK` and `CLAUDE_CODE_USE_VERTEX`, not behind an `ANTHROPIC_BASE_URL` gateway
`400` errors stating a context or token limit in the gateway’s own words, such as `ContextWindowExceededError` or `prompt token count of N exceeds the limit of M`	The gateway enforces a smaller context than the model’s native window and rewrites the upstream error, so the automatic compact-and-retry, which matches Anthropic’s `prompt is too long` wording, doesn’t fire	Run `/compact` to recover the session. To prevent it, set `CLAUDE_CODE_AUTO_COMPACT_WINDOW` to the gateway’s limit; the value is clamped to at least 100,000 tokens and at most the model’s context window, so a gateway limit below 100,000 can’t be matched and `/compact` remains the recovery there. Also set `CLAUDE_CODE_MAX_OUTPUT_TOKENS` below the gateway model’s output limit
Models missing from the `/model` picker	Gateway model names aren’t in Claude Code’s built-in list	Enable gateway model discovery or add names with the model configuration variables
`/fast` reports `Fast mode unavailable due to network connectivity issues` while inference requests work	The fast mode availability check goes directly to `api.anthropic.com` and doesn’t follow `ANTHROPIC_BASE_URL`, so blocked direct egress fails the check. The same message appears on an open network when the check presents a gateway-issued key from `ANTHROPIC_API_KEY` or an `apiKeyHelper` and Anthropic rejects it	Allowlist `api.anthropic.com` if egress is blocked, or set a skip variable; for a rejected gateway key only the skip variables help. See use fast mode behind proxies and LLM gateways
`/fast` reports `Fast mode has been disabled by your organization` in a session authenticated with `ANTHROPIC_AUTH_TOKEN`, even though the organization has fast mode enabled	The availability check requires a claude.ai login or an Anthropic API key; with only a bearer token, Claude Code treats fast mode as disabled without sending the check	Set `CLAUDE_CODE_SKIP_FAST_MODE_ORG_CHECK=1`; see use fast mode behind proxies and LLM gateways
Claude Code asks you to log in even though the curl test succeeds	The CLI has no credential of its own: a reachable base URL isn’t one, and an `env` block in a project’s `.claude/settings.json` or `.claude/settings.local.json` applies only after the first-run wizard and trust prompt	Set `ANTHROPIC_AUTH_TOKEN` somewhere Claude Code reads before first-run setup: a shell export, the `env` block in `~/.claude/settings.json`, or managed settings
`ANTHROPIC_API_KEY` is set but ignored, with no prompt	The key needs a one-time approval in interactive sessions, and a previously declined key is ignored without asking again	Enable it under `/config` with the `Use custom API key` option
`This machine's managed settings require a first-party login`	Managed settings include `forceLoginMethod` or `forceLoginOrgUUID`, which on Claude Code v2.1.146 and later cannot coexist with `ANTHROPIC_API_KEY`, `ANTHROPIC_AUTH_TOKEN`, or `apiKeyHelper`	Your administrator must remove `forceLoginMethod` and `forceLoginOrgUUID` from managed settings to use gateway credentials, or remove the gateway credential to use first-party login. The two cannot be combined
`403` with an HTML body such as `403 Forbidden`, when the gateway’s own logs show no request received	A web application firewall or reverse proxy in front of the gateway blocked the request body before it reached the gateway. Claude Code prompts include XML-style tags and source code that match cross-site-scripting body rules, so a short curl test passes while a real session doesn’t	Exempt the gateway’s `/v1/messages` path from request-body inspection. On AWS WAF this is the `CrossSiteScripting_Body` managed rule; on nginx with ModSecurity it is the equivalent OWASP CRS body rules
Certificate or TLS errors such as `SSL certificate verification failed` or `Self-signed certificate detected`, when the curl test succeeds	Claude Code’s runtime isn’t trusting the same certificate authority that `curl` uses. Common behind corporate TLS-inspection proxies	Set `NODE_EXTRA_CA_CERTS` to the CA bundle path; see CA certificate store

If Claude Code prompts you to log in repeatedly after removing gateway configuration, the cause is usually credential storage rather than the gateway; see authentication errors.

LLM gateways overview: what a gateway is and how it interacts with claude.ai subscriptions
Roll out an LLM gateway for your organization: the admin-facing checklist for deploying and distributing gateway configuration
Gateway protocol reference: what Claude Code sends to a gateway, including the headers and fields the gateway must forward
Settings: where settings files live and how the env block is read
Authentication: how credential variables, apiKeyHelper, and OAuth login interact

Setup and access

Deployment

Gateways

Usage and costs

Plugin distribution

Security and data

Adoption

Connect Claude Code to an LLM gateway

Check for an existing configuration

Configure Claude Code yourself

Set the credential variable

Set the base URL and credential

Set as shell environment variables

Set in a settings file

Verify the connection

Confirm in Claude Code

How the credential variable maps to a header

Configure each surface

VS Code extension

Desktop app

GitHub Actions

Agent SDK

Slack, web, and Remote Control

Additional configuration

Send additional headers

Add gateway models to the model picker

Rotate credentials with apiKeyHelper

Turn off traffic outside the gateway path

Route to a cloud provider through a gateway

Amazon Bedrock

Google Cloud’s Agent Platform

Microsoft Foundry

Claude Platform on AWS

Troubleshoot gateway errors

​Check for an existing configuration

​Configure Claude Code yourself

​Set the credential variable

​Set the base URL and credential

​Set as shell environment variables

​Set in a settings file

​Verify the connection

​Confirm in Claude Code

​How the credential variable maps to a header

​Conflicts with an existing login

​Configure each surface

​VS Code extension

​Desktop app

​GitHub Actions

​Agent SDK

​Slack, web, and Remote Control

​Additional configuration

​Send additional headers

​Add gateway models to the model picker

​Rotate credentials with apiKeyHelper

​Turn off traffic outside the gateway path

​Route to a cloud provider through a gateway

​Amazon Bedrock

​Google Cloud’s Agent Platform

​Microsoft Foundry

​Claude Platform on AWS

​Troubleshoot gateway errors

​Related resources

Check for an existing configuration

Configure Claude Code yourself

Set the credential variable

Set the base URL and credential

Set as shell environment variables

Set in a settings file

Verify the connection

Confirm in Claude Code

How the credential variable maps to a header

Conflicts with an existing login

Configure each surface

VS Code extension

Desktop app

GitHub Actions

Agent SDK

Slack, web, and Remote Control

Additional configuration

Send additional headers

Add gateway models to the model picker

Rotate credentials with apiKeyHelper

Turn off traffic outside the gateway path

Route to a cloud provider through a gateway

Amazon Bedrock

Google Cloud’s Agent Platform

Microsoft Foundry

Claude Platform on AWS

Troubleshoot gateway errors

Related resources