Fastify · Schema

Fastify Route Schema Definition

JSON Schema for Fastify route schema definitions used for request validation and response serialization.

FrameworksHigh PerformanceJavaScriptJSON SchemaNode.jsTypeScript

Properties

Name	Type	Description
method	object	HTTP method(s) for the route.
url	string	Route URL path (e.g., /api/users/:id).
schema	object	Schema definitions for request validation and response serialization.
attachValidation	boolean	Attach validation errors to the request instead of sending 400.
exposeHeadRoute	boolean	Automatically create a HEAD route for GET routes.
prefixTrailingSlash	string	How to handle trailing slashes when a prefix is set.
bodyLimit	integer	Maximum allowed body size for this route in bytes.
logLevel	string	Route-specific log level.
config	object	Custom route-level configuration.
constraints	object	Custom route constraints (e.g., version, host).

View JSON Schema on GitHub

JSON Schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://github.com/api-evangelist/fastify/json-schema/fastify-route-schema.json",
  "title": "Fastify Route Schema Definition",
  "description": "JSON Schema for Fastify route schema definitions used for request validation and response serialization.",
  "type": "object",
  "properties": {
    "method": {
      "description": "HTTP method(s) for the route.",
      "oneOf": [
        {
          "type": "string",
          "enum": ["GET", "POST", "PUT", "DELETE", "PATCH", "HEAD", "OPTIONS"]
        },
        {
          "type": "array",
          "items": {
            "type": "string",
            "enum": ["GET", "POST", "PUT", "DELETE", "PATCH", "HEAD", "OPTIONS"]
          }
        }
      ]
    },
    "url": {
      "type": "string",
      "description": "Route URL path (e.g., /api/users/:id)."
    },
    "schema": {
      "type": "object",
      "description": "Schema definitions for request validation and response serialization.",
      "properties": {
        "body": {
          "type": "object",
          "description": "JSON Schema for request body validation.",
          "additionalProperties": true
        },
        "querystring": {
          "type": "object",
          "description": "JSON Schema for query string parameter validation.",
          "additionalProperties": true
        },
        "params": {
          "type": "object",
          "description": "JSON Schema for URL parameter validation.",
          "additionalProperties": true
        },
        "headers": {
          "type": "object",
          "description": "JSON Schema for request header validation.",
          "additionalProperties": true
        },
        "response": {
          "type": "object",
          "description": "Response schemas keyed by HTTP status code for serialization.",
          "patternProperties": {
            "^[1-5][0-9]{2}$": {
              "type": "object",
              "description": "JSON Schema for response body at this status code.",
              "additionalProperties": true
            },
            "^2xx$": {
              "type": "object",
              "description": "JSON Schema for all 2xx responses.",
              "additionalProperties": true
            }
          },
          "additionalProperties": true
        },
        "tags": {
          "type": "array",
          "description": "OpenAPI tags for documentation.",
          "items": {
            "type": "string"
          }
        },
        "summary": {
          "type": "string",
          "description": "OpenAPI summary for the route."
        },
        "description": {
          "type": "string",
          "description": "OpenAPI description for the route."
        },
        "consumes": {
          "type": "array",
          "description": "Accepted content types.",
          "items": {
            "type": "string"
          }
        },
        "produces": {
          "type": "array",
          "description": "Produced content types.",
          "items": {
            "type": "string"
          }
        },
        "security": {
          "type": "array",
          "description": "OpenAPI security requirements.",
          "items": {
            "type": "object",
            "additionalProperties": {
              "type": "array",
              "items": { "type": "string" }
            }
          }
        }
      },
      "additionalProperties": true
    },
    "attachValidation": {
      "type": "boolean",
      "description": "Attach validation errors to the request instead of sending 400.",
      "default": false
    },
    "exposeHeadRoute": {
      "type": "boolean",
      "description": "Automatically create a HEAD route for GET routes.",
      "default": true
    },
    "prefixTrailingSlash": {
      "type": "string",
      "description": "How to handle trailing slashes when a prefix is set.",
      "enum": ["slash", "no-slash", "both"],
      "default": "both"
    },
    "bodyLimit": {
      "type": "integer",
      "description": "Maximum allowed body size for this route in bytes."
    },
    "logLevel": {
      "type": "string",
      "description": "Route-specific log level.",
      "enum": ["trace", "debug", "info", "warn", "error", "fatal", "silent"]
    },
    "config": {
      "type": "object",
      "description": "Custom route-level configuration.",
      "additionalProperties": true
    },
    "constraints": {
      "type": "object",
      "description": "Custom route constraints (e.g., version, host).",
      "properties": {
        "version": {
          "type": "string",
          "description": "Version constraint for content-type versioning."
        },
        "host": {
          "type": "string",
          "description": "Host constraint for virtual hosting."
        }
      },
      "additionalProperties": true
    }
  },
  "required": ["method", "url"],
  "additionalProperties": true
}