Synthetic exposes Anthropic-compatible endpoints. Apus provides it through the official @openclaw/synthetic-provider plugin and uses the Anthropic Messages API.

Getting started

```bash
apus plugins install @openclaw/synthetic-provider
```

Installation applies to a running Gateway automatically; otherwise it takes effect
on the next startup. See [Apply changes and inspect](/plugins/manage-plugins#apply-changes-and-inspect).

Get a `SYNTHETIC_API_KEY` from your Synthetic account, or let onboarding
prompt you for one.

```bash
apus onboard --auth-choice synthetic-api-key
```

Onboarding sets the default model to `synthetic/hf:MiniMaxAI/MiniMax-M3`.
Confirm it is registered:

```bash
apus models list --provider synthetic
```

Config example

{
  env: { vars: { SYNTHETIC_API_KEY: "sk-..." } },
  agents: {
    defaults: {
      model: { primary: "synthetic/hf:MiniMaxAI/MiniMax-M3" },
      models: { "synthetic/hf:MiniMaxAI/MiniMax-M3": { alias: "MiniMax M3" } },
    },
  },
  models: {
    mode: "merge",
    providers: {
      synthetic: {
        baseUrl: "https://api.synthetic.new/anthropic",
        apiKey: "${SYNTHETIC_API_KEY}",
        api: "anthropic-messages",
        models: [
          {
            id: "hf:MiniMaxAI/MiniMax-M3",
            name: "MiniMax M3",
            reasoning: true,
            input: ["text", "image"],
            cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
            contextWindow: 262144,
            maxTokens: 65536,
          },
        ],
      },
    },
  },
}

Model discovery

With a Synthetic credential, Apus discovers current text models from Synthetic's /openai/v1/models API. Inference still uses the Anthropic Messages API. Newly advertised models, including small models and syn: aliases, do not need an Apus catalog update.

The live catalog supplies context and output limits, image input, reasoning, tool support, and usage-based token prices. Those prices are estimates, not a subscription bill. See Synthetic's current model list for availability and its recommended aliases.

Offline catalog generation and unavailable or unusable discovery responses use the bundled seed models. Your selected model is not changed automatically. When you override the inference base URL, Apus skips Synthetic's fixed discovery URL so a proxy credential is not sent to Synthetic.

If you enable a model allowlist (`agents.defaults.modelPolicy.allow`), add every
Synthetic model you plan to use. Models not in the allowlist are hidden
from the agent.

If Synthetic changes its API endpoint, override the base URL:

```json5
{
  models: {
    providers: {
      synthetic: {
        baseUrl: "https://new-api.synthetic.new/anthropic",
      },
    },
  },
}
```

Apus still appends `/v1` automatically.

Related

Provider rules, model refs, and failover behavior.

Full config schema including provider settings.

Synthetic dashboard and API docs.