---
summary: "Run KaijiBot with SGLang (OpenAI-compatible self-hosted server)"
read_when:
  - You want to run KaijiBot against a local SGLang server
  - You want OpenAI-compatible /v1 endpoints with your own models
title: "SGLang"
---

# SGLang

SGLang can serve open-source models via an **OpenAI-compatible** HTTP API.
KaijiBot can connect to SGLang using the `openai-completions` API.

KaijiBot can also **auto-discover** available models from SGLang when you opt
in with `SGLANG_API_KEY` (any value works if your server does not enforce auth)
and you do not define an explicit `models.providers.sglang` entry.

## Quick start

1. Start SGLang with an OpenAI-compatible server.

Your base URL should expose `/v1` endpoints (for example `/v1/models`,
`/v1/chat/completions`). SGLang commonly runs on:

- `http://127.0.0.1:30000/v1`

2. Opt in (any value works if no auth is configured):

```bash
export SGLANG_API_KEY="sglang-local"
```

3. Run onboarding and choose `SGLang`, or set a model directly:

```bash
kaijibot onboard
```

```json5
{
  agents: {
    defaults: {
      model: { primary: "sglang/your-model-id" },
    },
  },
}
```

## Model discovery (implicit provider)

When `SGLANG_API_KEY` is set (or an auth profile exists) and you **do not**
define `models.providers.sglang`, KaijiBot will query:

- `GET http://127.0.0.1:30000/v1/models`

and convert the returned IDs into model entries.

If you set `models.providers.sglang` explicitly, auto-discovery is skipped and
you must define models manually.

## Explicit configuration (manual models)

Use explicit config when:

- SGLang runs on a different host/port.
- You want to pin `contextWindow`/`maxTokens` values.
- Your server requires a real API key (or you want to control headers).

```json5
{
  models: {
    providers: {
      sglang: {
        baseUrl: "http://127.0.0.1:30000/v1",
        apiKey: "${SGLANG_API_KEY}",
        api: "openai-completions",
        models: [
          {
            id: "your-model-id",
            name: "Local SGLang Model",
            reasoning: false,
            input: ["text"],
            cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
            contextWindow: 128000,
            maxTokens: 8192,
          },
        ],
      },
    },
  },
}
```

## Troubleshooting

- Check the server is reachable:

```bash
curl http://127.0.0.1:30000/v1/models
```

- If requests fail with auth errors, set a real `SGLANG_API_KEY` that matches
  your server configuration, or configure the provider explicitly under
  `models.providers.sglang`.

## Proxy-style behavior

SGLang is treated as a proxy-style OpenAI-compatible `/v1` backend, not a
native OpenAI endpoint.

- native OpenAI-only request shaping does not apply here
- no `service_tier`, no Responses `store`, no prompt-cache hints, and no
  OpenAI reasoning-compat payload shaping
- hidden KaijiBot attribution headers (`originator`, `version`, `User-Agent`)
  are not injected on custom SGLang base URLs
