Claude Code

Claude Code reads an Anthropic-shaped API. Kyma serves one at /v1/messages, so Claude Code works against Kyma with two environment variables and no plugin, proxy or wrapper.

Setup

export ANTHROPIC_BASE_URL="https://api.kymaapi.com"
export ANTHROPIC_AUTH_TOKEN="ky-your-api-key"

claude

ANTHROPIC_BASE_URL takes the host without /v1. Claude Code appends the path itself, so https://api.kymaapi.com/v1 becomes /v1/v1/messages and every request 404s. This is the one thing people get wrong.

ANTHROPIC_AUTH_TOKEN sends your key as a bearer token. If you would rather use the header Anthropic’s own SDK sends, ANTHROPIC_API_KEY works identically and goes out as x-api-key. Either is fine; use one, not both.

Making it permanent

Environment variables last as long as your shell. To keep the setting, put it in ~/.claude/settings.json:

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://api.kymaapi.com",
    "ANTHROPIC_AUTH_TOKEN": "ky-your-api-key"
  }
}

The same block works per-project in .claude/settings.json, which is how you point one repository at Kyma and leave everything else alone. In the VS Code extension the equivalent setting is claudeCode.environmentVariables. In GitHub Actions, put both in the step’s env:. In the Agent SDK, pass them as options.env.

Choosing a model

Kyma serves these under Claude Code’s own naming, so /model and the ANTHROPIC_MODEL variable behave the way you expect:

export ANTHROPIC_MODEL="claude-sonnet-5"

Model	Good for
`claude-opus-5`	The hardest work — architecture, long refactors
`claude-opus-5-fast`	Opus quality when latency matters
`claude-sonnet-5`	The default. Most sessions want this
`claude-sonnet-4-6`	Previous generation, cheaper
`claude-haiku-4-5`	Quick edits, cheap loops, subagents

You are not limited to those. Anything in the catalogue that supports tool calling will drive Claude Code — kimi-k2.6, qwen-3-coder and glm-5.2 all return proper tool_use blocks through /v1/messages. Set ANTHROPIC_MODEL to any model id from the model list.

Anthropic does not support or audit third-party gateways, and says so plainly in their documentation. Running Claude Code against any gateway — Kyma included — is outside what their support covers. It works; it is simply not their problem if it does not.

Checking it worked

curl https://api.kymaapi.com/v1/messages \
  -H "Authorization: Bearer $ANTHROPIC_AUTH_TOKEN" \
  -H "anthropic-version: 2023-06-01" \
  -H "content-type: application/json" \
  -d '{
    "model": "claude-haiku-4-5",
    "max_tokens": 16,
    "messages": [{ "role": "user", "content": "say ok" }]
  }'

A 200 with a content array means Claude Code will work. A 404 almost always means /v1 was left on the end of ANTHROPIC_BASE_URL.

Model discovery

Claude Code can populate its /model picker from the gateway:

export CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY=1

Kyma’s /v1/models answers this in well under Claude Code’s timeout and issues no redirect, both of which it requires. Leave the variable unset and the picker falls back to its built-in list, which still works — you just type the model id instead of choosing it.

What is not there

/v1/messages/count_tokens is not implemented. It is optional in Anthropic’s API and Claude Code falls back to estimating locally, so the only effect is that the context figure in the status line is approximate rather than exact.

Cost

Claude Code is a heavy client — long contexts, many turns, large tool outputs. Two things matter more here than anywhere else: Prompt caching is on. Claude Code re-sends the system prompt and file context every turn, which is exactly the shape caching is for. Cached input bills at 10% of the input rate, and usage.cache_discount on every response tells you what it saved. Watch the model you picked. An Opus-class model on a long agentic session costs an order of magnitude more than Haiku on the same work. /model mid-session is cheap; discovering the bill afterwards is not.

Guides

Use Cases

Integrations

Setup

Making it permanent

Choosing a model

Checking it worked

Model discovery

What is not there

Cost

​Setup

​Making it permanent

​Choosing a model

​Checking it worked

​Model discovery

​What is not there

​Cost

Setup

Making it permanent

Choosing a model

Checking it worked

Model discovery

What is not there

Cost