Synthetic Provider Setup

Synthetic provides endpoints that work with Anthropic's API format. OpenClaw makes this available through the official @openclaw/synthetic-provider plugin and communicates using the Anthropic Messages API.

Property	Value
Provider	`synthetic`
Auth	`SYNTHETIC_API_KEY`
API	Anthropic Messages
Base URL	`https://api.synthetic.new/anthropic`

Getting started

Install the plugin

openclaw plugins install @openclaw/synthetic-provider
openclaw gateway restart

Get an API key

You can obtain a SYNTHETIC_API_KEY from your Synthetic account, or the onboarding flow can request one from you.

Run onboarding

openclaw onboard --auth-choice synthetic-api-key

Verify the default model

The default model assigned during onboarding is:

synthetic/hf:MiniMaxAI/MiniMax-M3

Warning

Since OpenClaw's Anthropic client adds /v1 to the base URL on its own, use https://api.synthetic.new/anthropic rather than /anthropic/v1. Should Synthetic alter its base URL, set models.providers.synthetic.baseUrl to override it.

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

Given a Synthetic credential, OpenClaw pulls the current text model list from Synthetic's /openai/v1/models API. The Anthropic Messages API still handles inference. Models that appear in the listing, including compact variants and syn: aliases, work without any OpenClaw catalog update.

The live catalog provides context and output caps, image input, reasoning, tool compatibility, and token pricing based on usage. Those prices are approximate, not an actual subscription charge. Check Synthetic's current model list for what's available and its suggested aliases.

When offline catalog generation occurs, or when discovery responses are unavailable or unusable, the bundled seed models are used. Your chosen model stays as it is. If you override the inference base URL, OpenClaw bypasses Synthetic's fixed discovery URL, which keeps a proxy credential from being forwarded to Synthetic.

Tip

Model refs follow the pattern synthetic/<modelId>. Run openclaw models list --provider synthetic to see which models you have configured.

Model allowlist

When a model allowlist is enabled (agents.defaults.modelPolicy.allow), include every Synthetic model you intend to use. Any model left off the allowlist is not visible to the agent.

Base URL override

If Synthetic moves its API endpoint, change the base URL:

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

OpenClaw continues to append /v1 automatically.

Model providers, Provider rules, model refs, and failover behavior.
Configuration reference, Full config schema including provider settings.
Synthetic, Synthetic dashboard and API docs.