Validations API #

The Validations API provides access to validation data from Project Sidewalk, where community members review and validate labels placed by other users. Each validation record includes the validator's judgment (Agree, Disagree, or Unsure), any changes made to tags or severity levels, and associated metadata.

This API is useful for researchers studying data quality, community validation patterns, and the reliability of crowdsourced accessibility data. The validation process helps ensure the accuracy and consistency of Project Sidewalk's accessibility information.

Validations API Preview #

Below is a live preview showing validation result distributions by label type, retrieved directly from the API:

Endpoint #

Retrieve validation data with optional filtering by various criteria.

GET /v3/api/validations

Quick Download #

Download validation data directly in your preferred format:

Query Parameters#

This endpoint accepts the following optional query parameters to filter validation data.

Responses#

Success Response (200 OK)#

On success, the API returns an HTTP 200 OK status code and the requested data in the specified format.

JSON Format (Default) #

Returns a JSON array containing validation objects:

[
    {
        "label_validation_id": 12345,
        "label_id": 67890,
        "label_type_id": 2,
        "label_type": "NoCurbRamp",
        "validation_result": 1,
        "validation_result_string": "Agree",
        "old_severity": 3,
        "new_severity": 4,
        "old_tags": ["narrow"],
        "new_tags": ["narrow", "steep"],
        "user_id": "user_abc123",
        "validator_type": "Human",
        "mission_id": 1234,
        "canvas_x": 186,
        "canvas_y": 148,
        "heading": 239.29465,
        "pitch": -15.819197,
        "zoom": 2,
        "canvas_height": 288,
        "canvas_width": 384,
        "start_timestamp": "2025-08-04T21:52:05.158Z",
        "end_timestamp": "2025-08-04T21:52:05.158Z",
        "source": "ExpertValidate"
    },
    {
        "validation_id": 12346,
        "label_id": 67891,
        "label_type_id": 1,
        "label_type": "CurbRamp",
        "validation_result": 2,
        "validation_result_string": "Disagree",
        "old_severity": 2,
        "new_severity": 2,
        "old_tags": ["wide"],
        "new_tags": ["wide"],
        "user_id": "user_def456",
        "validator_type": "AI",
        "mission_id": 1235,
        "canvas_x": 186,
        "canvas_y": 148,
        "heading": 239.29465,
        "pitch": -15.819197,
        "zoom": 2,
        "canvas_height": 288,
        "canvas_width": 384,
        "start_timestamp": "2025-08-04T21:52:05.158Z",
        "end_timestamp": "2025-08-04T21:52:05.158Z",
        "source": "SidewalkAI"
    }
]

JSON Field Descriptions #

CSV Format #

If filetype=csv is specified, the response will be CSV data with the same field structure:

label_validation_id,label_id,label_type_id,label_type,...
12345,67890,2,NoCurbRamp,...
12346,67891,1,CurbRamp,...

Error Responses#

If an error occurs, the API will return an appropriate HTTP status code and a JSON response body containing details about the error.

• 400 Bad Request: Invalid parameter values (e.g., invalid validationResult, unsupported filetype).
• 404 Not Found: The requested resource does not exist.
• 500 Internal Server Error: An unexpected error occurred on the server.
• 503 Service Unavailable: The server is temporarily unable to handle the request.

Error Response Body #

Error responses include a JSON body with the following structure:

{
    "status": 400,
    "code": "INVALID_PARAMETER",
    "message": "Invalid validationResult value. Must be 1 (Agree), 2 (Disagree), or 3 (Unsure).",
    "parameter": "validationResult"
}

Validation Result Types #

Project Sidewalk uses three validation result types to categorize validator responses:

You can also retrieve this information programmatically from the/v3/api/validationResultTypes endpoint, which includes current count statistics for each validation result type. We include these counts for both Human and AI validations separately. You'll notice that there is no "Unsure" result type for AI; we only include AI validations if the AI is confident in its classification, but we haven't counted how often the AI is unsure.

Data Analysis Tips #

The Validations API provides rich data for understanding community consensus and data quality. Here are some suggestions for effectively using this data:

• Analyze agreement patterns by label type to identify which accessibility features are easier or harder for the community to classify consistently
• Track tag and severity changes to understand how validation improves label accuracy and completeness
• Use temporal filtering to study validation patterns over time
• Cross-reference with user data to analyze validation behavior across different user types and experience levels
• Map validation results geographically to identify neighborhoods or street types where labels are more controversial
• Calculate inter-rater reliability by analyzing multiple validations of the same labels

Contribute#

Project Sidewalk is an open-source project created by the Makeability Lab and hosted on GitHub. We welcome your contributions! If you found a bug or have a feature request, please open an issue on GitHub.

You can also email us at sidewalk@cs.uw.edu

Project Sidewalk in Your City!#

If you are interested in bringing Project Sidewalk to your city, please read our Wiki page.