# Stepfun Step1x Edit Image Editing

> Image Generation

Submit a synchronous OpenAI-compatible image request for
`stepfun-ai/step1x-edit`. The request includes a text prompt and a
source image supplied as Base64 data or an image URL.

## Endpoint

`POST https://api.modelverse.cn/v1/images/generations`

## Request Body

## Responses

- **200** — Image response.
- **400** — Invalid request parameters or image generation error.
- **default** — Error response.

## OpenAPI Definition

```json
{
  "openapi": "3.1.0",
  "x-language": "en-US",
  "info": {
    "title": "ModelVerse stepfun-ai/step1x-edit Image API",
    "version": "1.0.0",
    "description": "Self-contained OpenAPI 3.1 schema for the ModelVerse OpenAI-compatible\n`stepfun-ai/step1x-edit` image request documented in\n\nThe source document describes an edit-oriented model that accepts an input\nimage, but the documented compatible endpoint is\n`POST /v1/images/generations` with an `application/json` request body.\n"
  },
  "servers": [
    {
      "url": "https://api.modelverse.cn",
      "description": "ModelVerse API endpoint documented for this model."
    }
  ],
  "tags": [
    {
      "name": "stepfun-ai/step1x-edit",
      "description": "Image editing requests with the stepfun-ai/step1x-edit model."
    }
  ],
  "security": [
    {
      "bearerAuth": []
    }
  ],
  "paths": {
    "/v1/images/generations": {
      "post": {
        "tags": [
          "stepfun-ai/step1x-edit"
        ],
        "operationId": "createStepfunAiStep1xEditImageGeneration",
        "summary": "Stepfun Step1x Edit Image Editing",
        "description": "Submit a synchronous OpenAI-compatible image request for\n`stepfun-ai/step1x-edit`. The request includes a text prompt and a\nsource image supplied as Base64 data or an image URL.\n",
        "requestBody": {
          "required": true,
          "content": {
            "application/json": {
              "schema": {
                "$ref": "#/components/schemas/StepfunAiStep1xEditRequest"
              },
              "examples": {
                "base64Image": {
                  "summary": "Source document Base64 image request",
                  "value": {
                    "model": "stepfun-ai/step1x-edit",
                    "prompt": "Convert to quick pencil sketch",
                    "image": "data:image/png;base64,{image_base64_string}",
                    "negative_prompt": "blurry, low quality"
                  }
                },
                "imageUrlWithControls": {
                  "summary": "Edit an image URL with generation controls",
                  "value": {
                    "model": "stepfun-ai/step1x-edit",
                    "prompt": "Turn the product photo into a clean pencil sketch",
                    "image": "https://example.com/source.png",
                    "n": 2,
                    "strength": 0.8,
                    "seed": 42,
                    "steps": 20,
                    "guidance_scale": 2.5,
                    "response_format": "url"
                  }
                },
                "base64ResponseFormat": {
                  "summary": "Request Base64 output",
                  "value": {
                    "model": "stepfun-ai/step1x-edit",
                    "prompt": "Convert to quick pencil sketch",
                    "image": "data:image/png;base64,{image_base64_string}",
                    "response_format": "b64_json"
                  }
                }
              }
            }
          }
        },
        "responses": {
          "200": {
            "description": "Image response.",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/StepfunAiStep1xEditResponse"
                },
                "examples": {
                  "documentedResponse": {
                    "summary": "Source document response example",
                    "value": {
                      "created": 1750667997,
                      "data": [
                        {
                          "url": "https://xxxxx/xxxx.png",
                          "b64_json": "data:image/png;base64,{image_base64_string}"
                        }
                      ],
                      "usage": {
                        "input_tokens_details": {}
                      }
                    }
                  },
                  "urlResponse": {
                    "summary": "Response containing an image URL",
                    "value": {
                      "created": 1750667997,
                      "data": [
                        {
                          "url": "https://xxxxx/xxxx.png"
                        }
                      ],
                      "usage": {
                        "input_tokens_details": {}
                      }
                    }
                  },
                  "base64Response": {
                    "summary": "Response containing Base64 image data",
                    "value": {
                      "created": 1750667997,
                      "data": [
                        {
                          "b64_json": "data:image/png;base64,{image_base64_string}"
                        }
                      ],
                      "usage": {
                        "input_tokens_details": {}
                      }
                    }
                  }
                }
              }
            }
          },
          "400": {
            "description": "Invalid request parameters or image generation error.",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/StepfunAiStep1xEditErrorResponse"
                },
                "examples": {
                  "documentedError": {
                    "$ref": "#/components/examples/StepfunAiStep1xEditError"
                  }
                }
              }
            }
          },
          "default": {
            "description": "Error response.",
            "content": {
              "application/json": {
                "schema": {
                  "$ref": "#/components/schemas/StepfunAiStep1xEditErrorResponse"
                },
                "examples": {
                  "documentedError": {
                    "$ref": "#/components/examples/StepfunAiStep1xEditError"
                  }
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "securitySchemes": {
      "bearerAuth": {
        "type": "http",
        "scheme": "bearer",
        "bearerFormat": "API key",
        "description": "ModelVerse API key sent in the `Authorization: Bearer <API_KEY>`\nheader.\n"
      }
    },
    "schemas": {
      "StepfunAiStep1xEditModel": {
        "type": "string",
        "const": "stepfun-ai/step1x-edit",
        "description": "The only model ID documented by the source file."
      },
      "StepfunAiStep1xEditPrompt": {
        "type": "string",
        "minLength": 1,
        "description": "Text prompt describing the requested image edit.",
        "examples": [
          "Convert to quick pencil sketch"
        ]
      },
      "StepfunAiStep1xEditImage": {
        "type": "string",
        "minLength": 1,
        "description": "Input image as Base64 data or an image URL. The source document shows a\ndata URL such as `data:image/png;base64,{image_base64_string}` and\ndescribes image links with the form `http://xxx`.\n",
        "examples": [
          "data:image/png;base64,{image_base64_string}",
          "https://example.com/source.png"
        ]
      },
      "StepfunAiStep1xEditImageCount": {
        "type": "integer",
        "minimum": 1,
        "maximum": 4,
        "default": 1,
        "description": "Number of generated images to return."
      },
      "StepfunAiStep1xEditStrength": {
        "type": "number",
        "format": "float",
        "minimum": 0,
        "maximum": 1,
        "default": 0.8,
        "description": "Degree to which the reference image is transformed."
      },
      "StepfunAiStep1xEditSeed": {
        "type": "integer",
        "default": -1,
        "description": "Random seed used to control generation randomness. Reusing the same\nseed can help keep generated content consistent.\n",
        "examples": [
          -1,
          42
        ]
      },
      "StepfunAiStep1xEditSteps": {
        "type": "integer",
        "minimum": 1,
        "maximum": 50,
        "default": 20,
        "description": "Number of inference steps."
      },
      "StepfunAiStep1xEditGuidanceScale": {
        "type": "number",
        "format": "float",
        "minimum": 1,
        "maximum": 10,
        "default": 2.5,
        "description": "How closely the model output follows the prompt. Higher values reduce\ngeneration freedom and increase prompt relevance.\n"
      },
      "StepfunAiStep1xEditNegativePrompt": {
        "type": "string",
        "description": "Text describing content that should not appear in the image.",
        "examples": [
          "blurry, low quality"
        ]
      },
      "StepfunAiStep1xEditResponseFormat": {
        "type": "string",
        "enum": [
          "url",
          "b64_json"
        ],
        "default": "url",
        "description": "Format for returned generated images. The source document lists `url`\nas the default and describes `b64_json` as the Base64 response option.\n"
      },
      "StepfunAiStep1xEditRequest": {
        "type": "object",
        "additionalProperties": false,
        "required": [
          "model",
          "prompt",
          "image"
        ],
        "properties": {
          "model": {
            "$ref": "#/components/schemas/StepfunAiStep1xEditModel"
          },
          "prompt": {
            "$ref": "#/components/schemas/StepfunAiStep1xEditPrompt"
          },
          "image": {
            "$ref": "#/components/schemas/StepfunAiStep1xEditImage"
          },
          "n": {
            "$ref": "#/components/schemas/StepfunAiStep1xEditImageCount"
          },
          "strength": {
            "$ref": "#/components/schemas/StepfunAiStep1xEditStrength"
          },
          "seed": {
            "$ref": "#/components/schemas/StepfunAiStep1xEditSeed"
          },
          "steps": {
            "$ref": "#/components/schemas/StepfunAiStep1xEditSteps"
          },
          "guidance_scale": {
            "$ref": "#/components/schemas/StepfunAiStep1xEditGuidanceScale"
          },
          "negative_prompt": {
            "$ref": "#/components/schemas/StepfunAiStep1xEditNegativePrompt"
          },
          "response_format": {
            "$ref": "#/components/schemas/StepfunAiStep1xEditResponseFormat"
          }
        }
      },
      "StepfunAiStep1xEditResponse": {
        "type": "object",
        "additionalProperties": false,
        "required": [
          "created",
          "data"
        ],
        "properties": {
          "created": {
            "type": "integer",
            "format": "int64",
            "description": "Unix timestamp in seconds for when the request was created."
          },
          "data": {
            "type": "array",
            "minItems": 1,
            "description": "Output image information. When the image is returned as a URL, the\nitem contains `url`; when returned as Base64 data, it contains\n`b64_json`. The source notes that generated links expire within\n7 days.\n",
            "items": {
              "$ref": "#/components/schemas/StepfunAiStep1xEditDataItem"
            }
          },
          "usage": {
            "$ref": "#/components/schemas/StepfunAiStep1xEditUsage"
          }
        }
      },
      "StepfunAiStep1xEditDataItem": {
        "type": "object",
        "additionalProperties": false,
        "anyOf": [
          {
            "required": [
              "url"
            ]
          },
          {
            "required": [
              "b64_json"
            ]
          }
        ],
        "properties": {
          "url": {
            "type": "string",
            "format": "uri",
            "description": "URL for downloading the generated image."
          },
          "b64_json": {
            "type": "string",
            "description": "Base64 image data, optionally prefixed as a data URL."
          }
        }
      },
      "StepfunAiStep1xEditUsage": {
        "type": "object",
        "additionalProperties": true,
        "description": "Optional usage object shown by the source response example.",
        "properties": {
          "input_tokens_details": {
            "type": "object",
            "additionalProperties": true
          }
        }
      },
      "StepfunAiStep1xEditErrorResponse": {
        "type": "object",
        "additionalProperties": true,
        "required": [
          "error"
        ],
        "properties": {
          "error": {
            "$ref": "#/components/schemas/StepfunAiStep1xEditError"
          }
        }
      },
      "StepfunAiStep1xEditError": {
        "type": "object",
        "additionalProperties": true,
        "properties": {
          "message": {
            "type": "string",
            "description": "Error message."
          },
          "type": {
            "type": "string",
            "description": "Error type."
          },
          "param": {
            "type": "string",
            "description": "Request ID or related parameter."
          },
          "code": {
            "type": "string",
            "description": "Error code."
          }
        }
      }
    },
    "examples": {
      "StepfunAiStep1xEditError": {
        "summary": "Source document error response example",
        "value": {
          "error": {
            "message": "error_message",
            "type": "error_type",
            "param": "request_id",
            "code": "error_code"
          }
        }
      }
    }
  }
}
```