Add Synthetic provider support

docs/concepts/model-providers.md

@@ -143,6 +143,34 @@ Moonshot uses OpenAI-compatible endpoints, so configure it as a custom provider:
 }
 ```
 
+### Synthetic
+
+Synthetic provides Anthropic-compatible models behind the `synthetic` provider:
+
+- Provider: `synthetic`
+- Auth: `SYNTHETIC_API_KEY`
+- Example model: `synthetic/hf:MiniMaxAI/MiniMax-M2.1`
+- CLI: `clawdbot onboard --auth-choice synthetic-api-key`
+
+```json5
+{
+  agents: {
+    defaults: { model: { primary: "synthetic/hf:MiniMaxAI/MiniMax-M2.1" } }
+  },
+  models: {
+    mode: "merge",
+    providers: {
+      synthetic: {
+        baseUrl: "https://api.synthetic.new/anthropic",
+        apiKey: "${SYNTHETIC_API_KEY}",
+        api: "anthropic-messages",
+        models: [{ id: "hf:MiniMaxAI/MiniMax-M2.1", name: "MiniMax M2.1" }]
+      }
+    }
+  }
+}
+```
+
 ### MiniMax
 
 MiniMax is configured via `models.providers` because it uses custom endpoints:

docs/gateway/configuration.md

@@ -1819,6 +1819,48 @@ Notes:
 - Model ref: `moonshot/kimi-k2-0905-preview`.
 - Use `https://api.moonshot.cn/v1` if you need the China endpoint.
 
+### Synthetic (Anthropic-compatible)
+
+Use Synthetic's Anthropic-compatible endpoint:
+
+```json5
+{
+  env: { SYNTHETIC_API_KEY: "sk-..." },
+  agents: {
+    defaults: {
+      model: { primary: "synthetic/hf:MiniMaxAI/MiniMax-M2.1" },
+      models: { "synthetic/hf:MiniMaxAI/MiniMax-M2.1": { alias: "MiniMax M2.1" } }
+    }
+  },
+  models: {
+    mode: "merge",
+    providers: {
+      synthetic: {
+        baseUrl: "https://api.synthetic.new/anthropic",
+        apiKey: "${SYNTHETIC_API_KEY}",
+        api: "anthropic-messages",
+        models: [
+          {
+            id: "hf:MiniMaxAI/MiniMax-M2.1",
+            name: "MiniMax M2.1",
+            reasoning: false,
+            input: ["text"],
+            cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+            contextWindow: 192000,
+            maxTokens: 65536
+          }
+        ]
+      }
+    }
+  }
+}
+```
+
+Notes:
+- Set `SYNTHETIC_API_KEY` or use `clawdbot onboard --auth-choice synthetic-api-key`.
+- Model ref: `synthetic/hf:MiniMaxAI/MiniMax-M2.1`.
+- Base URL should omit `/v1` because the Anthropic client appends it.
+
 ### Local models (LM Studio) — recommended setup
 
 See [/gateway/local-models](/gateway/local-models) for the current local guidance. TL;DR: run MiniMax M2.1 via LM Studio Responses API on serious hardware; keep hosted models merged for fallback.

docs/providers/models.md

@@ -26,6 +26,7 @@ model as `provider/model`.
 - [Anthropic (API + Claude CLI)](/providers/anthropic)
 - [OpenRouter](/providers/openrouter)
 - [Moonshot AI (Kimi)](/providers/moonshot)
+- [Synthetic](/providers/synthetic)
 - [OpenCode Zen](/providers/opencode)
 - [Z.AI](/providers/zai)
 - [GLM models](/providers/glm)

docs/providers/synthetic.md

@@ -0,0 +1,98 @@
+---
+summary: "Use Synthetic's Anthropic-compatible API in Clawdbot"
+read_when:
+  - You want to use Synthetic as a model provider
+  - You need a Synthetic API key or base URL setup
+---
+# Synthetic
+
+Synthetic exposes Anthropic-compatible endpoints. Clawdbot registers it as the
+`synthetic` provider and uses the Anthropic Messages API.
+
+## Quick setup
+
+1) Set `SYNTHETIC_API_KEY` (or run the wizard below).
+2) Run onboarding:
+
+```bash
+clawdbot onboard --auth-choice synthetic-api-key
+```
+
+The default model is set to:
+
+```
+synthetic/hf:MiniMaxAI/MiniMax-M2.1
+```
+
+## Config example
+
+```json5
+{
+  env: { SYNTHETIC_API_KEY: "sk-..." },
+  agents: {
+    defaults: {
+      model: { primary: "synthetic/hf:MiniMaxAI/MiniMax-M2.1" },
+      models: { "synthetic/hf:MiniMaxAI/MiniMax-M2.1": { alias: "MiniMax M2.1" } }
+    }
+  },
+  models: {
+    mode: "merge",
+    providers: {
+      synthetic: {
+        baseUrl: "https://api.synthetic.new/anthropic",
+        apiKey: "${SYNTHETIC_API_KEY}",
+        api: "anthropic-messages",
+        models: [
+          {
+            id: "hf:MiniMaxAI/MiniMax-M2.1",
+            name: "MiniMax M2.1",
+            reasoning: false,
+            input: ["text"],
+            cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+            contextWindow: 192000,
+            maxTokens: 65536
+          }
+        ]
+      }
+    }
+  }
+}
+```
+
+Note: Clawdbot's Anthropic client appends `/v1` to the base URL, so use
+`https://api.synthetic.new/anthropic` (not `/anthropic/v1`). If Synthetic changes
+its base URL, override `models.providers.synthetic.baseUrl`.
+
+## Model catalog
+
+All models below use cost `0` (input/output/cache).
+
+| Model ID | Context window | Max tokens | Reasoning | Input |
+| --- | --- | --- | --- | --- |
+| `hf:MiniMaxAI/MiniMax-M2.1` | 192000 | 65536 | false | text |
+| `hf:moonshotai/Kimi-K2-Thinking` | 256000 | 8192 | true | text |
+| `hf:zai-org/GLM-4.7` | 198000 | 128000 | false | text |
+| `hf:deepseek-ai/DeepSeek-R1-0528` | 128000 | 8192 | false | text |
+| `hf:deepseek-ai/DeepSeek-V3-0324` | 128000 | 8192 | false | text |
+| `hf:deepseek-ai/DeepSeek-V3.1` | 128000 | 8192 | false | text |
+| `hf:deepseek-ai/DeepSeek-V3.1-Terminus` | 128000 | 8192 | false | text |
+| `hf:deepseek-ai/DeepSeek-V3.2` | 159000 | 8192 | false | text |
+| `hf:meta-llama/Llama-3.3-70B-Instruct` | 128000 | 8192 | false | text |
+| `hf:meta-llama/Llama-4-Maverick-17B-128E-Instruct-FP8` | 524000 | 8192 | false | text |
+| `hf:MiniMaxAI/MiniMax-M2` | 192000 | 65536 | false | text |
+| `hf:moonshotai/Kimi-K2-Instruct-0905` | 256000 | 8192 | false | text |
+| `hf:openai/gpt-oss-120b` | 128000 | 8192 | false | text |
+| `hf:Qwen/Qwen3-235B-A22B-Instruct-2507` | 256000 | 8192 | false | text |
+| `hf:Qwen/Qwen3-Coder-480B-A35B-Instruct` | 256000 | 8192 | false | text |
+| `hf:Qwen/Qwen3-VL-235B-A22B-Instruct` | 250000 | 8192 | false | text + image |
+| `hf:zai-org/GLM-4.5` | 128000 | 128000 | false | text |
+| `hf:zai-org/GLM-4.6` | 198000 | 128000 | false | text |
+| `hf:deepseek-ai/DeepSeek-V3` | 128000 | 8192 | false | text |
+| `hf:Qwen/Qwen3-235B-A22B-Thinking-2507` | 256000 | 8192 | true | text |
+
+## Notes
+
+- Model refs use `synthetic/<modelId>`.
+- If you enable a model allowlist (`agents.defaults.models`), add every model you
+  plan to use.
+- See [Model providers](/concepts/model-providers) for provider rules.

docs/start/wizard.md

@@ -84,6 +84,8 @@ Tip: `--json` does **not** imply non-interactive mode. Use `--non-interactive` (
    - **API key**: stores the key for you.
    - **MiniMax M2.1**: config is auto-written.
    - More detail: [MiniMax](/providers/minimax)
+   - **Synthetic (Anthropic-compatible)**: prompts for `SYNTHETIC_API_KEY`.
+   - More detail: [Synthetic](/providers/synthetic)
    - **Moonshot (Kimi K2)**: config is auto-written.
    - More detail: [Moonshot AI](/providers/moonshot)
    - **Skip**: no auth configured yet.
@@ -214,6 +216,17 @@ clawdbot onboard --non-interactive \
   --gateway-bind loopback
 ```
 
+Synthetic example:
+
+```bash
+clawdbot onboard --non-interactive \
+  --mode local \
+  --auth-choice synthetic-api-key \
+  --synthetic-api-key "$SYNTHETIC_API_KEY" \
+  --gateway-port 18789 \
+  --gateway-bind loopback
+```
+
 OpenCode Zen example:
 
 ```bash

src/agents/model-auth.test.ts

@@ -236,4 +236,28 @@ describe("getApiKeyForModel", () => {
       }
     }
   });
+
+  it("resolves Synthetic API key from env", async () => {
+    const previousSynthetic = process.env.SYNTHETIC_API_KEY;
+
+    try {
+      process.env.SYNTHETIC_API_KEY = "synthetic-test-key";
+
+      vi.resetModules();
+      const { resolveApiKeyForProvider } = await import("./model-auth.js");
+
+      const resolved = await resolveApiKeyForProvider({
+        provider: "synthetic",
+        store: { version: 1, profiles: {} },
+      });
+      expect(resolved.apiKey).toBe("synthetic-test-key");
+      expect(resolved.source).toContain("SYNTHETIC_API_KEY");
+    } finally {
+      if (previousSynthetic === undefined) {
+        delete process.env.SYNTHETIC_API_KEY;
+      } else {
+        process.env.SYNTHETIC_API_KEY = previousSynthetic;
+      }
+    }
+  });
 });

src/agents/model-auth.ts

@@ -148,6 +148,7 @@ export function resolveEnvApiKey(provider: string): EnvApiKeyResult | null {
     openrouter: "OPENROUTER_API_KEY",
     moonshot: "MOONSHOT_API_KEY",
     minimax: "MINIMAX_API_KEY",
+    synthetic: "SYNTHETIC_API_KEY",
     mistral: "MISTRAL_API_KEY",
     opencode: "OPENCODE_API_KEY",
   };

src/agents/models-config.providers.ts

@@ -32,6 +32,177 @@ const MOONSHOT_DEFAULT_COST = {
   cacheWrite: 0,
 };
 
+const SYNTHETIC_BASE_URL = "https://api.synthetic.new/anthropic";
+const SYNTHETIC_DEFAULT_MODEL_ID = "hf:MiniMaxAI/MiniMax-M2.1";
+const SYNTHETIC_DEFAULT_COST = {
+  input: 0,
+  output: 0,
+  cacheRead: 0,
+  cacheWrite: 0,
+};
+const SYNTHETIC_MODELS = [
+  {
+    id: SYNTHETIC_DEFAULT_MODEL_ID,
+    name: "MiniMax M2.1",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 192000,
+    maxTokens: 65536,
+  },
+  {
+    id: "hf:moonshotai/Kimi-K2-Thinking",
+    name: "Kimi K2 Thinking",
+    reasoning: true,
+    input: ["text"],
+    contextWindow: 256000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:zai-org/GLM-4.7",
+    name: "GLM-4.7",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 198000,
+    maxTokens: 128000,
+  },
+  {
+    id: "hf:deepseek-ai/DeepSeek-R1-0528",
+    name: "DeepSeek R1 0528",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:deepseek-ai/DeepSeek-V3-0324",
+    name: "DeepSeek V3 0324",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:deepseek-ai/DeepSeek-V3.1",
+    name: "DeepSeek V3.1",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:deepseek-ai/DeepSeek-V3.1-Terminus",
+    name: "DeepSeek V3.1 Terminus",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:deepseek-ai/DeepSeek-V3.2",
+    name: "DeepSeek V3.2",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 159000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:meta-llama/Llama-3.3-70B-Instruct",
+    name: "Llama 3.3 70B Instruct",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:meta-llama/Llama-4-Maverick-17B-128E-Instruct-FP8",
+    name: "Llama 4 Maverick 17B 128E Instruct FP8",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 524000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:MiniMaxAI/MiniMax-M2",
+    name: "MiniMax M2",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 192000,
+    maxTokens: 65536,
+  },
+  {
+    id: "hf:moonshotai/Kimi-K2-Instruct-0905",
+    name: "Kimi K2 Instruct 0905",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 256000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:openai/gpt-oss-120b",
+    name: "GPT OSS 120B",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:Qwen/Qwen3-235B-A22B-Instruct-2507",
+    name: "Qwen3 235B A22B Instruct 2507",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 256000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:Qwen/Qwen3-Coder-480B-A35B-Instruct",
+    name: "Qwen3 Coder 480B A35B Instruct",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 256000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:Qwen/Qwen3-VL-235B-A22B-Instruct",
+    name: "Qwen3 VL 235B A22B Instruct",
+    reasoning: false,
+    input: ["text", "image"],
+    contextWindow: 250000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:zai-org/GLM-4.5",
+    name: "GLM-4.5",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 128000,
+  },
+  {
+    id: "hf:zai-org/GLM-4.6",
+    name: "GLM-4.6",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 198000,
+    maxTokens: 128000,
+  },
+  {
+    id: "hf:deepseek-ai/DeepSeek-V3",
+    name: "DeepSeek V3",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:Qwen/Qwen3-235B-A22B-Thinking-2507",
+    name: "Qwen3 235B A22B Thinking 2507",
+    reasoning: true,
+    input: ["text"],
+    contextWindow: 256000,
+    maxTokens: 8192,
+  },
+] as const;
+
 function normalizeApiKeyConfig(value: string): string {
   const trimmed = value.trim();
   const match = /^\$\{([A-Z0-9_]+)\}$/.exec(trimmed);
@@ -180,6 +351,22 @@ function buildMoonshotProvider(): ProviderConfig {
   };
 }
 
+function buildSyntheticProvider(): ProviderConfig {
+  return {
+    baseUrl: SYNTHETIC_BASE_URL,
+    api: "anthropic-messages",
+    models: SYNTHETIC_MODELS.map((model) => ({
+      id: model.id,
+      name: model.name,
+      reasoning: model.reasoning,
+      input: [...model.input],
+      cost: SYNTHETIC_DEFAULT_COST,
+      contextWindow: model.contextWindow,
+      maxTokens: model.maxTokens,
+    })),
+  };
+}
+
 export function resolveImplicitProviders(params: {
   agentDir: string;
 }): ModelsConfig["providers"] {
@@ -202,5 +389,12 @@ export function resolveImplicitProviders(params: {
     providers.moonshot = { ...buildMoonshotProvider(), apiKey: moonshotKey };
   }
 
+  const syntheticKey =
+    resolveEnvApiKeyVarName("synthetic") ??
+    resolveApiKeyFromProfiles({ provider: "synthetic", store: authStore });
+  if (syntheticKey) {
+    providers.synthetic = { ...buildSyntheticProvider(), apiKey: syntheticKey };
+  }
+
   return providers;
 }

src/agents/models-config.test.ts

@@ -348,11 +348,13 @@ describe("models config", () => {
       const previousGithub = process.env.GITHUB_TOKEN;
       const previousMinimax = process.env.MINIMAX_API_KEY;
       const previousMoonshot = process.env.MOONSHOT_API_KEY;
+      const previousSynthetic = process.env.SYNTHETIC_API_KEY;
       delete process.env.COPILOT_GITHUB_TOKEN;
       delete process.env.GH_TOKEN;
       delete process.env.GITHUB_TOKEN;
       delete process.env.MINIMAX_API_KEY;
       delete process.env.MOONSHOT_API_KEY;
+      delete process.env.SYNTHETIC_API_KEY;
 
       try {
         vi.resetModules();
@@ -381,6 +383,9 @@ describe("models config", () => {
         else process.env.MINIMAX_API_KEY = previousMinimax;
         if (previousMoonshot === undefined) delete process.env.MOONSHOT_API_KEY;
         else process.env.MOONSHOT_API_KEY = previousMoonshot;
+        if (previousSynthetic === undefined)
+          delete process.env.SYNTHETIC_API_KEY;
+        else process.env.SYNTHETIC_API_KEY = previousSynthetic;
       }
     });
   });
@@ -451,6 +456,42 @@ describe("models config", () => {
     });
   });
 
+  it("adds synthetic provider when SYNTHETIC_API_KEY is set", async () => {
+    await withTempHome(async () => {
+      vi.resetModules();
+      const prevKey = process.env.SYNTHETIC_API_KEY;
+      process.env.SYNTHETIC_API_KEY = "sk-synthetic-test";
+      try {
+        const { ensureClawdbotModelsJson } = await import("./models-config.js");
+        const { resolveClawdbotAgentDir } = await import("./agent-paths.js");
+
+        await ensureClawdbotModelsJson({});
+
+        const modelPath = path.join(resolveClawdbotAgentDir(), "models.json");
+        const raw = await fs.readFile(modelPath, "utf8");
+        const parsed = JSON.parse(raw) as {
+          providers: Record<
+            string,
+            {
+              baseUrl?: string;
+              apiKey?: string;
+              models?: Array<{ id: string }>;
+            }
+          >;
+        };
+        expect(parsed.providers.synthetic?.baseUrl).toBe(
+          "https://api.synthetic.new/anthropic",
+        );
+        expect(parsed.providers.synthetic?.apiKey).toBe("SYNTHETIC_API_KEY");
+        const ids = parsed.providers.synthetic?.models?.map((model) => model.id);
+        expect(ids).toContain("hf:MiniMaxAI/MiniMax-M2.1");
+      } finally {
+        if (prevKey === undefined) delete process.env.SYNTHETIC_API_KEY;
+        else process.env.SYNTHETIC_API_KEY = prevKey;
+      }
+    });
+  });
+
   it("fills missing provider.apiKey from env var name when models exist", async () => {
     await withTempHome(async () => {
       vi.resetModules();

src/auto-reply/reply/directive-handling.ts

@@ -350,6 +350,7 @@ const MODEL_PICK_PROVIDER_PREFERENCE = [
   "openai",
   "openai-codex",
   "minimax",
+  "synthetic",
   "google",
   "zai",
   "openrouter",

src/cli/program.test.ts

@@ -202,6 +202,29 @@ describe("cli program", () => {
     );
   });
 
+  it("passes synthetic api key to onboard", async () => {
+    const program = buildProgram();
+    await program.parseAsync(
+      [
+        "onboard",
+        "--non-interactive",
+        "--auth-choice",
+        "synthetic-api-key",
+        "--synthetic-api-key",
+        "sk-synthetic-test",
+      ],
+      { from: "user" },
+    );
+    expect(onboardCommand).toHaveBeenCalledWith(
+      expect.objectContaining({
+        nonInteractive: true,
+        authChoice: "synthetic-api-key",
+        syntheticApiKey: "sk-synthetic-test",
+      }),
+      runtime,
+    );
+  });
+
   it("passes zai api key to onboard", async () => {
     const program = buildProgram();
     await program.parseAsync(

src/cli/program.ts

@@ -264,7 +264,7 @@ export function buildProgram() {
     .option("--mode <mode>", "Wizard mode: local|remote")
     .option(
       "--auth-choice <choice>",
-      "Auth: setup-token|claude-cli|token|openai-codex|openai-api-key|openrouter-api-key|moonshot-api-key|codex-cli|antigravity|gemini-api-key|zai-api-key|apiKey|minimax-api|minimax-api-lightning|opencode-zen|skip",
+      "Auth: setup-token|claude-cli|token|openai-codex|openai-api-key|openrouter-api-key|moonshot-api-key|synthetic-api-key|codex-cli|antigravity|gemini-api-key|zai-api-key|apiKey|minimax-api|minimax-api-lightning|opencode-zen|skip",
     )
     .option(
       "--token-provider <id>",
@@ -289,6 +289,7 @@ export function buildProgram() {
     .option("--gemini-api-key <key>", "Gemini API key")
     .option("--zai-api-key <key>", "Z.AI API key")
     .option("--minimax-api-key <key>", "MiniMax API key")
+    .option("--synthetic-api-key <key>", "Synthetic API key")
     .option("--opencode-zen-api-key <key>", "OpenCode Zen API key")
     .option("--gateway-port <port>", "Gateway port")
     .option("--gateway-bind <mode>", "Gateway bind: loopback|lan|tailnet|auto")
@@ -334,6 +335,7 @@ export function buildProgram() {
               | "openai-api-key"
               | "openrouter-api-key"
               | "moonshot-api-key"
+              | "synthetic-api-key"
               | "codex-cli"
               | "antigravity"
               | "gemini-api-key"
@@ -357,6 +359,7 @@ export function buildProgram() {
             geminiApiKey: opts.geminiApiKey as string | undefined,
             zaiApiKey: opts.zaiApiKey as string | undefined,
             minimaxApiKey: opts.minimaxApiKey as string | undefined,
+            syntheticApiKey: opts.syntheticApiKey as string | undefined,
             opencodeZenApiKey: opts.opencodeZenApiKey as string | undefined,
             gatewayPort:
               typeof opts.gatewayPort === "string"

src/commands/auth-choice-options.test.ts

@@ -106,4 +106,16 @@ describe("buildAuthChoiceOptions", () => {
 
     expect(options.some((opt) => opt.value === "moonshot-api-key")).toBe(true);
   });
+
+  it("includes Synthetic auth choice", () => {
+    const store: AuthProfileStore = { version: 1, profiles: {} };
+    const options = buildAuthChoiceOptions({
+      store,
+      includeSkip: false,
+      includeClaudeCliIfMissing: true,
+      platform: "darwin",
+    });
+
+    expect(options.some((opt) => opt.value === "synthetic-api-key")).toBe(true);
+  });
 });

src/commands/auth-choice-options.ts

@@ -20,7 +20,8 @@ export type AuthChoiceGroupId =
   | "moonshot"
   | "zai"
   | "opencode-zen"
-  | "minimax";
+  | "minimax"
+  | "synthetic";
 
 export type AuthChoiceGroup = {
   value: AuthChoiceGroupId;
@@ -53,6 +54,12 @@ const AUTH_CHOICE_GROUP_DEFS: {
     hint: "M2.1 (recommended)",
     choices: ["minimax-api", "minimax-api-lightning"],
   },
+  {
+    value: "synthetic",
+    label: "Synthetic",
+    hint: "Anthropic-compatible (multi-model)",
+    choices: ["synthetic-api-key"],
+  },
   {
     value: "google",
     label: "Google",
@@ -167,6 +174,7 @@ export function buildAuthChoiceOptions(params: {
   options.push({ value: "openai-api-key", label: "OpenAI API key" });
   options.push({ value: "openrouter-api-key", label: "OpenRouter API key" });
   options.push({ value: "moonshot-api-key", label: "Moonshot AI API key" });
+  options.push({ value: "synthetic-api-key", label: "Synthetic API key" });
   options.push({
     value: "antigravity",
     label: "Google Antigravity (Claude Opus 4.5, Gemini 3, etc.)",

src/commands/auth-choice.test.ts

@@ -102,6 +102,67 @@ describe("applyAuthChoice", () => {
     expect(parsed.profiles?.["minimax:default"]?.key).toBe("sk-minimax-test");
   });
 
+  it("prompts and writes Synthetic API key when selecting synthetic-api-key", async () => {
+    tempStateDir = await fs.mkdtemp(path.join(os.tmpdir(), "clawdbot-auth-"));
+    process.env.CLAWDBOT_STATE_DIR = tempStateDir;
+    process.env.CLAWDBOT_AGENT_DIR = path.join(tempStateDir, "agent");
+    process.env.PI_CODING_AGENT_DIR = process.env.CLAWDBOT_AGENT_DIR;
+
+    const text = vi.fn().mockResolvedValue("sk-synthetic-test");
+    const select: WizardPrompter["select"] = vi.fn(
+      async (params) => params.options[0]?.value as never,
+    );
+    const multiselect: WizardPrompter["multiselect"] = vi.fn(async () => []);
+    const prompter: WizardPrompter = {
+      intro: vi.fn(noopAsync),
+      outro: vi.fn(noopAsync),
+      note: vi.fn(noopAsync),
+      select,
+      multiselect,
+      text,
+      confirm: vi.fn(async () => false),
+      progress: vi.fn(() => ({ update: noop, stop: noop })),
+    };
+    const runtime: RuntimeEnv = {
+      log: vi.fn(),
+      error: vi.fn(),
+      exit: vi.fn((code: number) => {
+        throw new Error(`exit:${code}`);
+      }),
+    };
+
+    const result = await applyAuthChoice({
+      authChoice: "synthetic-api-key",
+      config: {},
+      prompter,
+      runtime,
+      setDefaultModel: true,
+    });
+
+    expect(text).toHaveBeenCalledWith(
+      expect.objectContaining({ message: "Enter Synthetic API key" }),
+    );
+    expect(result.config.auth?.profiles?.["synthetic:default"]).toMatchObject({
+      provider: "synthetic",
+      mode: "api_key",
+    });
+
+    const authProfilePath = path.join(
+      tempStateDir,
+      "agents",
+      "main",
+      "agent",
+      "auth-profiles.json",
+    );
+    const raw = await fs.readFile(authProfilePath, "utf8");
+    const parsed = JSON.parse(raw) as {
+      profiles?: Record<string, { key?: string }>;
+    };
+    expect(parsed.profiles?.["synthetic:default"]?.key).toBe(
+      "sk-synthetic-test",
+    );
+  });
+
   it("sets default model when selecting github-copilot", async () => {
     tempStateDir = await fs.mkdtemp(path.join(os.tmpdir(), "clawdbot-auth-"));
     process.env.CLAWDBOT_STATE_DIR = tempStateDir;

src/commands/auth-choice.ts

@@ -43,14 +43,18 @@ import {
   applyMinimaxHostedConfig,
   applyMinimaxHostedProviderConfig,
   applyMinimaxProviderConfig,
+  applySyntheticConfig,
+  applySyntheticProviderConfig,
   applyOpencodeZenConfig,
   applyOpencodeZenProviderConfig,
   applyZaiConfig,
   MINIMAX_HOSTED_MODEL_REF,
+  SYNTHETIC_DEFAULT_MODEL_REF,
   setAnthropicApiKey,
   setGeminiApiKey,
   setMinimaxApiKey,
   setOpencodeZenApiKey,
+  setSyntheticApiKey,
   setZaiApiKey,
   writeOAuthCredentials,
   ZAI_DEFAULT_MODEL_REF,
@@ -641,6 +645,28 @@ export async function applyAuthChoice(params: {
       agentModelOverride = ZAI_DEFAULT_MODEL_REF;
       await noteAgentModel(ZAI_DEFAULT_MODEL_REF);
     }
+  } else if (params.authChoice === "synthetic-api-key") {
+    const key = await params.prompter.text({
+      message: "Enter Synthetic API key",
+      validate: (value) => (value?.trim() ? undefined : "Required"),
+    });
+    await setSyntheticApiKey(String(key).trim(), params.agentDir);
+    nextConfig = applyAuthProfileConfig(nextConfig, {
+      profileId: "synthetic:default",
+      provider: "synthetic",
+      mode: "api_key",
+    });
+    if (params.setDefaultModel) {
+      nextConfig = applySyntheticConfig(nextConfig);
+      await params.prompter.note(
+        `Default model set to ${SYNTHETIC_DEFAULT_MODEL_REF}`,
+        "Model configured",
+      );
+    } else {
+      nextConfig = applySyntheticProviderConfig(nextConfig);
+      agentModelOverride = SYNTHETIC_DEFAULT_MODEL_REF;
+      await noteAgentModel(SYNTHETIC_DEFAULT_MODEL_REF);
+    }
   } else if (params.authChoice === "apiKey") {
     const key = await params.prompter.text({
       message: "Enter Anthropic API key",
@@ -805,6 +831,8 @@ export function resolvePreferredProviderForAuthChoice(
       return "google";
     case "antigravity":
       return "google-antigravity";
+    case "synthetic-api-key":
+      return "synthetic";
     case "minimax-cloud":
     case "minimax-api":
       return "minimax";

src/commands/models/list.ts

@@ -727,6 +727,7 @@ export async function modelsStatusCommand(
     "openrouter",
     "zai",
     "mistral",
+    "synthetic",
   ];
   for (const provider of envProbeProviders) {
     if (resolveEnvApiKey(provider)) providersFromEnv.add(provider);

src/commands/onboard-auth.test.ts

@@ -9,11 +9,15 @@ import {
   applyAuthProfileConfig,
   applyMinimaxApiConfig,
   applyMinimaxApiProviderConfig,
+  applySyntheticConfig,
+  applySyntheticProviderConfig,
   applyOpencodeZenConfig,
   applyOpencodeZenProviderConfig,
   applyOpenrouterConfig,
   applyOpenrouterProviderConfig,
   OPENROUTER_DEFAULT_MODEL_REF,
+  SYNTHETIC_DEFAULT_MODEL_ID,
+  SYNTHETIC_DEFAULT_MODEL_REF,
   writeOAuthCredentials,
 } from "./onboard-auth.js";
 
@@ -260,6 +264,56 @@ describe("applyMinimaxApiProviderConfig", () => {
   });
 });
 
+describe("applySyntheticConfig", () => {
+  it("adds synthetic provider with correct settings", () => {
+    const cfg = applySyntheticConfig({});
+    expect(cfg.models?.providers?.synthetic).toMatchObject({
+      baseUrl: "https://api.synthetic.new/anthropic",
+      api: "anthropic-messages",
+    });
+  });
+
+  it("sets correct primary model", () => {
+    const cfg = applySyntheticConfig({});
+    expect(cfg.agents?.defaults?.model?.primary).toBe(
+      SYNTHETIC_DEFAULT_MODEL_REF,
+    );
+  });
+
+  it("merges existing synthetic provider models", () => {
+    const cfg = applySyntheticProviderConfig({
+      models: {
+        providers: {
+          synthetic: {
+            baseUrl: "https://old.example.com",
+            apiKey: "old-key",
+            api: "openai-completions",
+            models: [
+              {
+                id: "old-model",
+                name: "Old",
+                reasoning: false,
+                input: ["text"],
+                cost: { input: 1, output: 2, cacheRead: 0, cacheWrite: 0 },
+                contextWindow: 1000,
+                maxTokens: 100,
+              },
+            ],
+          },
+        },
+      },
+    });
+    expect(cfg.models?.providers?.synthetic?.baseUrl).toBe(
+      "https://api.synthetic.new/anthropic",
+    );
+    expect(cfg.models?.providers?.synthetic?.api).toBe("anthropic-messages");
+    expect(cfg.models?.providers?.synthetic?.apiKey).toBe("old-key");
+    const ids = cfg.models?.providers?.synthetic?.models.map((m) => m.id);
+    expect(ids).toContain("old-model");
+    expect(ids).toContain(SYNTHETIC_DEFAULT_MODEL_ID);
+  });
+});
+
 describe("applyOpencodeZenProviderConfig", () => {
   it("adds allowlist entry for the default model", () => {
     const cfg = applyOpencodeZenProviderConfig({});

src/commands/onboard-auth.ts

@@ -16,6 +16,9 @@ export const MOONSHOT_DEFAULT_MODEL_ID = "kimi-k2-0905-preview";
 const MOONSHOT_DEFAULT_CONTEXT_WINDOW = 256000;
 const MOONSHOT_DEFAULT_MAX_TOKENS = 8192;
 export const MOONSHOT_DEFAULT_MODEL_REF = `moonshot/${MOONSHOT_DEFAULT_MODEL_ID}`;
+const SYNTHETIC_BASE_URL = "https://api.synthetic.new/anthropic";
+export const SYNTHETIC_DEFAULT_MODEL_ID = "hf:MiniMaxAI/MiniMax-M2.1";
+export const SYNTHETIC_DEFAULT_MODEL_REF = `synthetic/${SYNTHETIC_DEFAULT_MODEL_ID}`;
 // Pricing: MiniMax doesn't publish public rates. Override in models.json for accurate costs.
 const MINIMAX_API_COST = {
   input: 15,
@@ -41,6 +44,175 @@ const MOONSHOT_DEFAULT_COST = {
   cacheRead: 0,
   cacheWrite: 0,
 };
+const SYNTHETIC_DEFAULT_COST = {
+  input: 0,
+  output: 0,
+  cacheRead: 0,
+  cacheWrite: 0,
+};
+
+const SYNTHETIC_MODEL_CATALOG = [
+  {
+    id: SYNTHETIC_DEFAULT_MODEL_ID,
+    name: "MiniMax M2.1",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 192000,
+    maxTokens: 65536,
+  },
+  {
+    id: "hf:moonshotai/Kimi-K2-Thinking",
+    name: "Kimi K2 Thinking",
+    reasoning: true,
+    input: ["text"],
+    contextWindow: 256000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:zai-org/GLM-4.7",
+    name: "GLM-4.7",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 198000,
+    maxTokens: 128000,
+  },
+  {
+    id: "hf:deepseek-ai/DeepSeek-R1-0528",
+    name: "DeepSeek R1 0528",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:deepseek-ai/DeepSeek-V3-0324",
+    name: "DeepSeek V3 0324",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:deepseek-ai/DeepSeek-V3.1",
+    name: "DeepSeek V3.1",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:deepseek-ai/DeepSeek-V3.1-Terminus",
+    name: "DeepSeek V3.1 Terminus",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:deepseek-ai/DeepSeek-V3.2",
+    name: "DeepSeek V3.2",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 159000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:meta-llama/Llama-3.3-70B-Instruct",
+    name: "Llama 3.3 70B Instruct",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:meta-llama/Llama-4-Maverick-17B-128E-Instruct-FP8",
+    name: "Llama 4 Maverick 17B 128E Instruct FP8",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 524000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:MiniMaxAI/MiniMax-M2",
+    name: "MiniMax M2",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 192000,
+    maxTokens: 65536,
+  },
+  {
+    id: "hf:moonshotai/Kimi-K2-Instruct-0905",
+    name: "Kimi K2 Instruct 0905",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 256000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:openai/gpt-oss-120b",
+    name: "GPT OSS 120B",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:Qwen/Qwen3-235B-A22B-Instruct-2507",
+    name: "Qwen3 235B A22B Instruct 2507",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 256000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:Qwen/Qwen3-Coder-480B-A35B-Instruct",
+    name: "Qwen3 Coder 480B A35B Instruct",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 256000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:Qwen/Qwen3-VL-235B-A22B-Instruct",
+    name: "Qwen3 VL 235B A22B Instruct",
+    reasoning: false,
+    input: ["text", "image"],
+    contextWindow: 250000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:zai-org/GLM-4.5",
+    name: "GLM-4.5",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 128000,
+  },
+  {
+    id: "hf:zai-org/GLM-4.6",
+    name: "GLM-4.6",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 198000,
+    maxTokens: 128000,
+  },
+  {
+    id: "hf:deepseek-ai/DeepSeek-V3",
+    name: "DeepSeek V3",
+    reasoning: false,
+    input: ["text"],
+    contextWindow: 128000,
+    maxTokens: 8192,
+  },
+  {
+    id: "hf:Qwen/Qwen3-235B-A22B-Thinking-2507",
+    name: "Qwen3 235B A22B Thinking 2507",
+    reasoning: true,
+    input: ["text"],
+    contextWindow: 256000,
+    maxTokens: 8192,
+  },
+] as const;
 
 const MINIMAX_MODEL_CATALOG = {
   "MiniMax-M2.1": { name: "MiniMax M2.1", reasoning: false },
@@ -97,6 +269,22 @@ function buildMoonshotModelDefinition(): ModelDefinitionConfig {
   };
 }
 
+type SyntheticCatalogEntry = (typeof SYNTHETIC_MODEL_CATALOG)[number];
+
+function buildSyntheticModelDefinition(
+  entry: SyntheticCatalogEntry,
+): ModelDefinitionConfig {
+  return {
+    id: entry.id,
+    name: entry.name,
+    reasoning: entry.reasoning,
+    input: [...entry.input],
+    cost: SYNTHETIC_DEFAULT_COST,
+    contextWindow: entry.contextWindow,
+    maxTokens: entry.maxTokens,
+  };
+}
+
 export async function writeOAuthCredentials(
   provider: OAuthProvider,
   creds: OAuthCredentials,
@@ -166,6 +354,19 @@ export async function setMoonshotApiKey(key: string, agentDir?: string) {
   });
 }
 
+export async function setSyntheticApiKey(key: string, agentDir?: string) {
+  // Write to the multi-agent path so gateway finds credentials on startup
+  upsertAuthProfile({
+    profileId: "synthetic:default",
+    credential: {
+      type: "api_key",
+      provider: "synthetic",
+      key,
+    },
+    agentDir: agentDir ?? resolveDefaultAgentDir(),
+  });
+}
+
 export const ZAI_DEFAULT_MODEL_REF = "zai/glm-4.7";
 export const OPENROUTER_DEFAULT_MODEL_REF = "openrouter/auto";
 
@@ -343,6 +544,83 @@ export function applyMoonshotConfig(cfg: ClawdbotConfig): ClawdbotConfig {
   };
 }
 
+export function applySyntheticProviderConfig(
+  cfg: ClawdbotConfig,
+): ClawdbotConfig {
+  const models = { ...cfg.agents?.defaults?.models };
+  models[SYNTHETIC_DEFAULT_MODEL_REF] = {
+    ...models[SYNTHETIC_DEFAULT_MODEL_REF],
+    alias:
+      models[SYNTHETIC_DEFAULT_MODEL_REF]?.alias ?? "MiniMax M2.1",
+  };
+
+  const providers = { ...cfg.models?.providers };
+  const existingProvider = providers.synthetic;
+  const existingModels = Array.isArray(existingProvider?.models)
+    ? existingProvider.models
+    : [];
+  const syntheticModels = SYNTHETIC_MODEL_CATALOG.map(
+    buildSyntheticModelDefinition,
+  );
+  const mergedModels = [
+    ...existingModels,
+    ...syntheticModels.filter(
+      (model) => !existingModels.some((existing) => existing.id === model.id),
+    ),
+  ];
+  const { apiKey: existingApiKey, ...existingProviderRest } =
+    (existingProvider ?? {}) as Record<string, unknown> as { apiKey?: string };
+  const resolvedApiKey =
+    typeof existingApiKey === "string" ? existingApiKey : undefined;
+  const normalizedApiKey = resolvedApiKey?.trim();
+  providers.synthetic = {
+    ...existingProviderRest,
+    baseUrl: SYNTHETIC_BASE_URL,
+    api: "anthropic-messages",
+    ...(normalizedApiKey ? { apiKey: normalizedApiKey } : {}),
+    models: mergedModels.length > 0 ? mergedModels : syntheticModels,
+  };
+
+  return {
+    ...cfg,
+    agents: {
+      ...cfg.agents,
+      defaults: {
+        ...cfg.agents?.defaults,
+        models,
+      },
+    },
+    models: {
+      mode: cfg.models?.mode ?? "merge",
+      providers,
+    },
+  };
+}
+
+export function applySyntheticConfig(cfg: ClawdbotConfig): ClawdbotConfig {
+  const next = applySyntheticProviderConfig(cfg);
+  const existingModel = next.agents?.defaults?.model;
+  return {
+    ...next,
+    agents: {
+      ...next.agents,
+      defaults: {
+        ...next.agents?.defaults,
+        model: {
+          ...(existingModel &&
+          "fallbacks" in (existingModel as Record<string, unknown>)
+            ? {
+                fallbacks: (existingModel as { fallbacks?: string[] })
+                  .fallbacks,
+              }
+            : undefined),
+          primary: SYNTHETIC_DEFAULT_MODEL_REF,
+        },
+      },
+    },
+  };
+}
+
 export function applyAuthProfileConfig(
   cfg: ClawdbotConfig,
   params: {

src/commands/onboard-non-interactive.ts

@@ -41,6 +41,7 @@ import {
   applyMoonshotConfig,
   applyOpencodeZenConfig,
   applyOpenrouterConfig,
+  applySyntheticConfig,
   applyZaiConfig,
   setAnthropicApiKey,
   setGeminiApiKey,
@@ -48,6 +49,7 @@ import {
   setMoonshotApiKey,
   setOpencodeZenApiKey,
   setOpenrouterApiKey,
+  setSyntheticApiKey,
   setZaiApiKey,
 } from "./onboard-auth.js";
 import {
@@ -316,6 +318,25 @@ export async function runNonInteractiveOnboarding(
       mode: "api_key",
     });
     nextConfig = applyMoonshotConfig(nextConfig);
+  } else if (authChoice === "synthetic-api-key") {
+    const resolved = await resolveNonInteractiveApiKey({
+      provider: "synthetic",
+      cfg: baseConfig,
+      flagValue: opts.syntheticApiKey,
+      flagName: "--synthetic-api-key",
+      envVar: "SYNTHETIC_API_KEY",
+      runtime,
+    });
+    if (!resolved) return;
+    if (resolved.source !== "profile") {
+      await setSyntheticApiKey(resolved.key);
+    }
+    nextConfig = applyAuthProfileConfig(nextConfig, {
+      profileId: "synthetic:default",
+      provider: "synthetic",
+      mode: "api_key",
+    });
+    nextConfig = applySyntheticConfig(nextConfig);
   } else if (
     authChoice === "minimax-cloud" ||
     authChoice === "minimax-api" ||

src/commands/onboard-types.ts

@@ -12,6 +12,7 @@ export type AuthChoice =
   | "openai-api-key"
   | "openrouter-api-key"
   | "moonshot-api-key"
+  | "synthetic-api-key"
   | "codex-cli"
   | "antigravity"
   | "apiKey"
@@ -53,6 +54,7 @@ export type OnboardOptions = {
   geminiApiKey?: string;
   zaiApiKey?: string;
   minimaxApiKey?: string;
+  syntheticApiKey?: string;
   opencodeZenApiKey?: string;
   gatewayPort?: number;
   gatewayBind?: GatewayBind;

src/config/io.ts

@@ -49,6 +49,7 @@ const SHELL_ENV_EXPECTED_KEYS = [
   "ZAI_API_KEY",
   "OPENROUTER_API_KEY",
   "MINIMAX_API_KEY",
+  "SYNTHETIC_API_KEY",
   "ELEVENLABS_API_KEY",
   "TELEGRAM_BOT_TOKEN",
   "DISCORD_BOT_TOKEN",