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
}