Coding agents

Which model?

Model	ID	Note
Hippo Coding (recommended to start)	hippo-coding (= openhippo/Qwen3.8-27B)	Self-hosted in Augsburg, suitable for § 203 StGB, works with the starting credit
GLM 5.3	aki-io/glm5.3-754b	Partner model
DeepSeek V4.1	aki-io/deepseek-v4.1-flash-552b	Partner model

With these models we have had Claude Code and OpenCode complete multi-step tasks with tool calls. Partner models work only after your first top-up, otherwise 403 permission_denied, and are not intended for § 203 StGB, see Models.

Coding agents use a lot of tokens: set a budget on the key.

What the agent sends to the API

Coding agents send your prompts and the contents of your files (code, configuration, command output) to the API. With hippo-coding the processing stays on our hardware in Augsburg. With partner models it goes to the respective partner, see Data, security, compliance. Keep secrets out of files the agent reads.

Claude Code

Claude Code speaks the Anthropic Messages API.

Recommended: ~/.claude/settings.json

Put the settings into the env block of your user settings. They then apply in every project, and model switches with /model also end up at Open Hippo:

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://api.openhippo.io",
    "ANTHROPIC_AUTH_TOKEN": "hk_live_...",
    "ANTHROPIC_MODEL": "hippo-coding",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "hippo-coding",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "hippo-coding",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "hippo-coding",
    "CLAUDE_CODE_SUBAGENT_MODEL": "hippo-coding"
  }
}

Variable	Purpose
ANTHROPIC_BASE_URL	without /v1: Claude Code appends /v1/messages itself.
ANTHROPIC_AUTH_TOKEN	sends the key as Authorization: Bearer. Do not use ANTHROPIC_API_KEY.
ANTHROPIC_MODEL	Main model.
ANTHROPIC_DEFAULT_OPUS_MODEL, ANTHROPIC_DEFAULT_SONNET_MODEL	Target of the opus and sonnet aliases, e.g. with /model.
ANTHROPIC_DEFAULT_HAIKU_MODEL	Target of the haiku alias, also used for background tasks. Replaces the deprecated ANTHROPIC_SMALL_FAST_MODEL.
CLAUDE_CODE_SUBAGENT_MODEL	Default model for subagents.

If one of these variables is left empty, Claude Code requests a Claude model at that point, which we do not have (400). Names as per the Anthropic docs. Do not put the key into a project's .claude/settings.json; that file gets committed.

Alternative: environment variables

For a single try in the shell:

export ANTHROPIC_BASE_URL="https://api.openhippo.io"
export ANTHROPIC_AUTH_TOKEN="$OPENHIPPO_API_KEY"
export ANTHROPIC_MODEL="hippo-coding"
export ANTHROPIC_DEFAULT_OPUS_MODEL="hippo-coding"
export ANTHROPIC_DEFAULT_SONNET_MODEL="hippo-coding"
export ANTHROPIC_DEFAULT_HAIKU_MODEL="hippo-coding"
export CLAUDE_CODE_SUBAGENT_MODEL="hippo-coding"
claude

If both set the same variable, Anthropic says the value from settings.json applies.

Variant with a partner model (after your first top-up, otherwise 403 permission_denied): replace hippo-coding everywhere with e.g. aki-io/glm5.3-754b.

Check

1. Create an empty folder and start claude in it.
2. Type: Create a file hello.txt containing "Hello from Augsburg".
3. Claude Code proposes creating the file and asks for your permission. Afterwards hello.txt is in the folder.
4. The usage shows up in the console under Analytics or via GET /v1/usage.

Typical errors: 401 = wrong key or not set as ANTHROPIC_AUTH_TOKEN; 400 = a model name is wrong; 403 = partner model without a top-up. See Errors.

note

Anthropic officially supports Claude Code only with Claude models. Running it with other models through a gateway works in our tests but is outside Anthropic's support. If a model rejects Claude Code's experimental fields with 400, Anthropic names CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS=1 as the fix (Anthropic docs).

OpenCode

OpenCode connects to Open Hippo as an OpenAI-compatible provider. In opencode.json in your project, or globally in ~/.config/opencode/opencode.json:

{
  "$schema": "https://opencode.ai/config.json",
  "provider": {
    "openhippo": {
      "npm": "@ai-sdk/openai-compatible",
      "name": "Open Hippo",
      "options": {
        "baseURL": "https://api.openhippo.io/v1",
        "apiKey": "{env:OPENHIPPO_API_KEY}"
      },
      "models": {
        "hippo-coding": { "name": "Hippo Coding (Augsburg)" },
        "aki-io/glm5.3-754b": { "name": "GLM 5.3" },
        "aki-io/deepseek-v4.1-flash-552b": { "name": "DeepSeek V4.1" }
      }
    }
  }
}

{env:OPENHIPPO_API_KEY} reads the key from the environment. Then pick an "Open Hippo" model in OpenCode with /models. Format as per the OpenCode docs.

Cline

In Cline's settings:

Field	Value
API Provider	OpenAI Compatible
Base URL	https://api.openhippo.io/v1
API Key	your key (hk_live_...)
Model ID	e.g. hippo-coding

Field names as per the Cline docs. We have not tested Open Hippo with Cline yet. The model's context length is in the model list.