StepFun

StepFun

Velaclaw includes a bundled StepFun provider plugin with two provider ids:

• stepfun for the standard endpoint
• stepfun-plan for the Step Plan endpoint

Standard and Step Plan are separate providers with different endpoints and model ref prefixes (stepfun/... vs stepfun-plan/...). Use a China key with the .com endpoints and a global key with the .ai endpoints.

Region and endpoint overview

Endpoint	China (.com)	Global (.ai)
Standard	https://api.stepfun.com/v1	https://api.stepfun.ai/v1
Step Plan	https://api.stepfun.com/step_plan/v1	https://api.stepfun.ai/step_plan/v1

Auth env var: STEPFUN_API_KEY

Built-in catalogs

Standard (stepfun):

Model ref	Context	Max output	Notes
stepfun/step-3.5-flash	262,144	65,536	Default standard model

Step Plan (stepfun-plan):

Model ref	Context	Max output	Notes
stepfun-plan/step-3.5-flash	262,144	65,536	Default Step Plan model
stepfun-plan/step-3.5-flash-2603	262,144	65,536	Additional Step Plan model

Getting started

Choose your provider surface and follow the setup steps.

Standard

Best for: general-purpose use via the standard StepFun endpoint.

1. Choose your endpoint region

   Auth choice	Endpoint	Region
   stepfun-standard-api-key-intl	https://api.stepfun.ai/v1	International
   stepfun-standard-api-key-cn	https://api.stepfun.com/v1	China

2. Run onboarding

   velaclaw onboard --auth-choice stepfun-standard-api-key-intl
   

   Or for the China endpoint:

   velaclaw onboard --auth-choice stepfun-standard-api-key-cn
   
3. Non-interactive alternative

   velaclaw onboard --auth-choice stepfun-standard-api-key-intl \
     --stepfun-api-key "$STEPFUN_API_KEY"
   
4. Verify models are available

   velaclaw models list --provider stepfun
   

Model refs

• Default model: stepfun/step-3.5-flash

Step Plan

Best for: Step Plan reasoning endpoint.

1. Choose your endpoint region

   Auth choice	Endpoint	Region
   stepfun-plan-api-key-intl	https://api.stepfun.ai/step_plan/v1	International
   stepfun-plan-api-key-cn	https://api.stepfun.com/step_plan/v1	China

2. Run onboarding

   velaclaw onboard --auth-choice stepfun-plan-api-key-intl
   

   Or for the China endpoint:

   velaclaw onboard --auth-choice stepfun-plan-api-key-cn
   
3. Non-interactive alternative

   velaclaw onboard --auth-choice stepfun-plan-api-key-intl \
     --stepfun-api-key "$STEPFUN_API_KEY"
   
4. Verify models are available

   velaclaw models list --provider stepfun-plan
   

Model refs

• Default model: stepfun-plan/step-3.5-flash
• Alternate model: stepfun-plan/step-3.5-flash-2603

Advanced

Full config: Standard provider

{
  env: { STEPFUN_API_KEY: "your-key" },
  agents: { defaults: { model: { primary: "stepfun/step-3.5-flash" } } },
  models: {
    mode: "merge",
    providers: {
      stepfun: {
        baseUrl: "https://api.stepfun.ai/v1",
        api: "openai-completions",
        apiKey: "${STEPFUN_API_KEY}",
        models: [
          {
            id: "step-3.5-flash",
            name: "Step 3.5 Flash",
            reasoning: true,
            input: ["text"],
            cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
            contextWindow: 262144,
            maxTokens: 65536,
          },
        ],
      },
    },
  },
}

Full config: Step Plan provider

{
  env: { STEPFUN_API_KEY: "your-key" },
  agents: { defaults: { model: { primary: "stepfun-plan/step-3.5-flash" } } },
  models: {
    mode: "merge",
    providers: {
      "stepfun-plan": {
        baseUrl: "https://api.stepfun.ai/step_plan/v1",
        api: "openai-completions",
        apiKey: "${STEPFUN_API_KEY}",
        models: [
          {
            id: "step-3.5-flash",
            name: "Step 3.5 Flash",
            reasoning: true,
            input: ["text"],
            cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
            contextWindow: 262144,
            maxTokens: 65536,
          },
          {
            id: "step-3.5-flash-2603",
            name: "Step 3.5 Flash 2603",
            reasoning: true,
            input: ["text"],
            cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
            contextWindow: 262144,
            maxTokens: 65536,
          },
        ],
      },
    },
  },
}

Notes

• The provider is bundled with Velaclaw, so there is no separate plugin install step.
• step-3.5-flash-2603 is currently exposed only on stepfun-plan.
• A single auth flow writes region-matched profiles for both stepfun and stepfun-plan, so both surfaces can be discovered together.
• Use velaclaw models list and velaclaw models set <provider/model> to inspect or switch models.

For the broader provider overview, see Model providers.

Related

Model providers

Overview of all providers, model refs, and failover behavior.

Configuration reference

Full config schema for providers, models, and plugins.

Model selection

How to choose and configure models.

StepFun Platform

StepFun API key management and documentation.