Claude Code

Route Claude Code (CLI and VS Code extension) through Exemplar by setting ANTHROPIC_BASE_URL to the Anthropic passthrough. There is no /gateway/claude or /gateway/claude-code route—Claude clients speak Anthropic Messages, so they use the same passthrough as the Anthropic SDK.

Setting	Value
`ANTHROPIC_BASE_URL`	`https://production-api.exemplar.dev/gateway/anthropic`
Auth	Org platform key `eis_…` via `ANTHROPIC_AUTH_TOKEN` (or `ANTHROPIC_API_KEY`)
Provider	Enable anthropic under AI Gateway → Management → Providers + Vault/Connectors credentials

Create the key under Tokens and API keys.

Claude Code is Anthropic passthrough, not Unified /gateway/v1 and not the Cursor adapter. Comparison: Choose your surface.

Do not point Claude Code at /gateway/v1 or /gateway/cursor. Those are OpenAI-compatible surfaces. Claude Code needs the Anthropic Messages API shape on /gateway/anthropic.

How the path works

You set the base to …/gateway/anthropic (no trailing /v1).
Claude Code / the Anthropic client appends /v1/messages (and related paths).
The gateway serves passthrough under /gateway/anthropic/v1/*, authenticates the org from eis_*, resolves upstream Anthropic credentials from Vault (or BYOK), and proxies the native request.


Claude Code
  → POST {ANTHROPIC_BASE_URL}/v1/messages
  → https://…/gateway/anthropic/v1/messages
  → Exemplar Anthropic passthrough → api.anthropic.com (or vaulted upstream)

Model path vs action path: Gateway owns LLM requests. For bash, filesystem, MCP, and prompt decisions, install Relay → Connect (or /exemplar-relay via exemplar-skills). You can use either or both.

Setup

Enable Anthropic on the org

AI Gateway → Management → Providers — enable anthropic and attach Connectors/Vault credentials (or plan to send X-Upstream-Authorization for one-off BYOK).

Create an org `eis_*` key

Tokens and API keys. Use this as ANTHROPIC_AUTH_TOKEN—not an Anthropic sk-ant-… key (unless you intentionally BYOK upstream separately).

Configure Claude Code

Global: ~/.claude/settings.json · Project: .claude/settings.json


{
  "env": {
    "ANTHROPIC_BASE_URL": "https://production-api.exemplar.dev/gateway/anthropic",
    "ANTHROPIC_AUTH_TOKEN": "eis_…",
    "ANTHROPIC_MODEL": "claude-sonnet-4-6",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "claude-opus-4-6",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "claude-sonnet-4-6",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "claude-haiku-4-5",
    "CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS": "1"
  }
}

Or in the shell before claude:


export ANTHROPIC_BASE_URL=https://production-api.exemplar.dev/gateway/anthropic
export ANTHROPIC_AUTH_TOKEN=eis_…
export ANTHROPIC_DEFAULT_SONNET_MODEL=claude-sonnet-4-6
claude

Smoke-test the passthrough


curl -sS https://production-api.exemplar.dev/gateway/anthropic/v1/messages \
  -H "Authorization: Bearer $EXEMPLAR_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-sonnet-4-6",
    "max_tokens": 64,
    "messages": [{"role": "user", "content": "ping"}]
  }'

A JSON Messages response means auth, allowlist, and upstream credentials are working before you debug the IDE.

Model aliases

Claude Code’s /model opus, /model sonnet, and /model haiku shortcuts read ANTHROPIC_DEFAULT_*_MODEL. Values must contain a recognizable Anthropic model id (for example claude-sonnet-4-6) so capability detection (thinking, tools) still works.

Variable	Maps
`ANTHROPIC_DEFAULT_OPUS_MODEL`	`opus`
`ANTHROPIC_DEFAULT_SONNET_MODEL`	`sonnet`
`ANTHROPIC_DEFAULT_HAIKU_MODEL`	`haiku`
`ANTHROPIC_MODEL`	Default model for the session

Use bare Anthropic ids on the passthrough (claude-sonnet-4-6). Do not use anthropic/claude-sonnet-4-6 here—that provider/model form is for the unified OpenAI-compatible API (/gateway/v1).

Prefer CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS=1 until you have verified beta headers against your allowlisted models. Experimental betas can attach parameters the upstream model rejects (400).

Auth notes

Platform tenant auth expects an eis_* key (Authorization: Bearer eis_… or X-API-Key / x-api-key).
Claude Code’s ANTHROPIC_AUTH_TOKEN should be that org key.
Upstream Anthropic credentials normally come from Connectors / Vault after you enable the provider. One-off BYOK: X-Upstream-Authorization: Bearer sk-ant-… on the request (advanced; not required for normal Claude Code setup).
Passthrough does not use Console failover routes (model-prefix resolve only). Rate limits still apply when a policy is effective — see Rate limits.

VS Code extension

The Claude Code VS Code extension uses the same CLI configuration. Install and configure the CLI first, then launch VS Code from a terminal that inherits those env vars (code .). GUI launches on macOS/Linux often miss shell env.

Claude Agent SDK

The Agent SDK speaks Anthropic Messages on the same passthrough. See Frameworks → Claude Agent SDK. Load project settings with setting_sources=["project"] if you keep gateway env in .claude/settings.json.

What belongs on Relay

Need	Surface
Route Claude model calls through Exemplar	This page (`ANTHROPIC_BASE_URL` → `/gateway/anthropic`)
Allow / ask / deny shell, paths, MCP, prompts	Relay Connect
Org MCP tools for Claude	Tools & MCP → Connect

Common mistakes

Mistake	Fix
Base URL set to `/gateway/v1` or `/gateway/cursor`	Use `/gateway/anthropic`
Base URL ends with `/v1` (`…/anthropic/v1`)	Drop `/v1`—the client adds it
Model id `anthropic/claude-…` in Claude Code	Use bare `claude-…` on passthrough
Anthropic `sk-ant-…` as the only key, no `eis_*`	Platform auth needs `eis_*`; put upstream key in Vault
Expecting shell/MCP deny from the gateway	Install Relay hooks

Choose your surface — when Claude vs Unified vs Cursor
Provider passthrough — Anthropic Messages base, Cursor adapter, OpenAI passthrough
Cursor IDE — Cursor’s OpenAI override via /gateway/cursor (different adapter)
Frameworks — Claude Agent SDK snippets
Relay Connect — IDE hooks for tool governance
Getting started — eis_* auth and Management setup