Synthetic

Synthetic exposes Anthropic-compatible endpoints. FluffBuzz registers it as the synthetic provider and uses the Anthropic Messages API.

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

Getting started

Get an API key

Obtain a SYNTHETIC_API_KEY from your Synthetic account, or let the onboarding wizard prompt you for one.

Run onboarding

fluffbuzz onboard --auth-choice synthetic-api-key

Verify the default model

After onboarding the default model is set to:

synthetic/hf:MiniMaxAI/MiniMax-M2.5

FluffBuzz’s Anthropic client appends /v1 to the base URL automatically, so use https://api.synthetic.new/anthropic (not /anthropic/v1). If Synthetic changes its base URL, override models.providers.synthetic.baseUrl.

Config example

{
  env: { SYNTHETIC_API_KEY: "sk-..." },
  agents: {
    defaults: {
      model: { primary: "synthetic/hf:MiniMaxAI/MiniMax-M2.5" },
      models: { "synthetic/hf:MiniMaxAI/MiniMax-M2.5": { alias: "MiniMax M2.5" } },
    },
  },
  models: {
    mode: "merge",
    providers: {
      synthetic: {
        baseUrl: "https://api.synthetic.new/anthropic",
        apiKey: "${SYNTHETIC_API_KEY}",
        api: "anthropic-messages",
        models: [
          {
            id: "hf:MiniMaxAI/MiniMax-M2.5",
            name: "MiniMax M2.5",
            reasoning: false,
            input: ["text"],
            cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
            contextWindow: 192000,
            maxTokens: 65536,
          },
        ],
      },
    },
  },
}

Built-in catalog

All Synthetic models use cost 0 (input/output/cache).

Model ID	Context window	Max tokens	Reasoning	Input
`hf:MiniMaxAI/MiniMax-M2.5`	192,000	65,536	no	text
`hf:moonshotai/Kimi-K2-Thinking`	256,000	8,192	yes	text
`hf:zai-org/GLM-4.7`	198,000	128,000	no	text
`hf:deepseek-ai/DeepSeek-R1-0528`	128,000	8,192	no	text
`hf:deepseek-ai/DeepSeek-V3-0324`	128,000	8,192	no	text
`hf:deepseek-ai/DeepSeek-V3.1`	128,000	8,192	no	text
`hf:deepseek-ai/DeepSeek-V3.1-Terminus`	128,000	8,192	no	text
`hf:deepseek-ai/DeepSeek-V3.2`	159,000	8,192	no	text
`hf:meta-llama/Llama-3.3-70B-Instruct`	128,000	8,192	no	text
`hf:meta-llama/Llama-4-Maverick-17B-128E-Instruct-FP8`	524,000	8,192	no	text
`hf:moonshotai/Kimi-K2-Instruct-0905`	256,000	8,192	no	text
`hf:moonshotai/Kimi-K2.5`	256,000	8,192	yes	text + image
`hf:openai/gpt-oss-120b`	128,000	8,192	no	text
`hf:Qwen/Qwen3-235B-A22B-Instruct-2507`	256,000	8,192	no	text
`hf:Qwen/Qwen3-Coder-480B-A35B-Instruct`	256,000	8,192	no	text
`hf:Qwen/Qwen3-VL-235B-A22B-Instruct`	250,000	8,192	no	text + image
`hf:zai-org/GLM-4.5`	128,000	128,000	no	text
`hf:zai-org/GLM-4.6`	198,000	128,000	no	text
`hf:zai-org/GLM-5`	256,000	128,000	yes	text + image
`hf:deepseek-ai/DeepSeek-V3`	128,000	8,192	no	text
`hf:Qwen/Qwen3-235B-A22B-Thinking-2507`	256,000	8,192	yes	text

Model refs use the form synthetic/<modelId>. Use fluffbuzz models list --provider synthetic to see all models available on your account.

Model allowlist

If you enable a model allowlist (agents.defaults.models), add every Synthetic model you plan to use. Models not in the allowlist will be hidden from the agent.

Base URL override

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

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

Remember that FluffBuzz appends /v1 automatically.

Model selection

Provider rules, model refs, and failover behavior.

Configuration reference

Full config schema including provider settings.

Synthetic dashboard and API docs.

Overview

Concepts and configuration

Providers

Synthetic

Getting started

Config example

Built-in catalog

Model selection

Configuration reference

Synthetic

​Getting started

​Config example

​Built-in catalog

​Related

Model selection

Configuration reference

Synthetic

Getting started

Config example

Built-in catalog

Related