{
    "api": "YAML JSON TOON Database",
    "version": "1.0.0",
    "format": "json",
    "dataset": {
        "id": 54,
        "slug": "http-content-negotiation",
        "title": "HTTP Content Negotiation",
        "description": "HTTP content negotiation: Accept, Accept-Language, Accept-Encoding, Accept-Charset headers, content type selection, and server-driven vs agent-driven negotiation.",
        "summary": "How clients and servers agree on a representation: Accept, Accept-Language, Accept-Encoding and Content-Type headers, the Vary header that records dependence, and common media types from JSON and XML to multipart and form encodings.",
        "use_when": [
            "You are serving more than one format, language or compression from one URL.",
            "You need the correct media type for a payload."
        ],
        "caveats": [
            "Content negotiation interacts with caching: responses that vary must include a Vary header or caches may serve the wrong variant.",
            "Servers may ignore Accept; the response Content-Type states what was actually sent."
        ],
        "related": [
            "http-request-headers",
            "http-response-headers",
            "http-caching-guide",
            "http-methods-reference"
        ],
        "category": "HTTP Status Codes",
        "category_slug": "http-status-codes",
        "tags": "http,content-negotiation,accept,accept-language,accept-encoding,media-types",
        "view_count": 0,
        "created_at": 1778695229,
        "updated_at": 1778695229,
        "entry_count": 15,
        "fields": [
            {
                "section": "headers",
                "field": "header",
                "type": "string",
                "example": "Accept"
            },
            {
                "section": "headers",
                "field": "direction",
                "type": "string",
                "example": "Request"
            },
            {
                "section": "headers",
                "field": "description",
                "type": "string",
                "example": "Client specifies preferred media types with qua…"
            },
            {
                "section": "headers",
                "field": "example",
                "type": "string",
                "example": "Accept: application/json, text/html;q=0.9, */*;…"
            },
            {
                "section": "headers",
                "field": "notes",
                "type": "string",
                "example": "Server responds with Content-Type or 406 Not Ac…"
            },
            {
                "section": "media_types",
                "field": "type",
                "type": "string",
                "example": "application/json"
            },
            {
                "section": "media_types",
                "field": "use",
                "type": "string",
                "example": "REST APIs, configuration"
            },
            {
                "section": "media_types",
                "field": "notes",
                "type": "string",
                "example": "Standard for API responses; use application/pro…"
            }
        ]
    },
    "data": {
        "headers": [
            {
                "header": "Accept",
                "direction": "Request",
                "description": "Client specifies preferred media types with quality values (q-factor)",
                "example": "Accept: application/json, text/html;q=0.9, */*;q=0.8",
                "notes": "Server responds with Content-Type or 406 Not Acceptable if no match"
            },
            {
                "header": "Accept-Language",
                "direction": "Request",
                "description": "Client specifies preferred natural languages",
                "example": "Accept-Language: en-US,en;q=0.9,es;q=0.8",
                "notes": "Server may return localized content or 406; often ignored in APIs"
            },
            {
                "header": "Accept-Encoding",
                "direction": "Request",
                "description": "Client specifies supported content codings (compression algorithms)",
                "example": "Accept-Encoding: gzip, deflate, br",
                "notes": "Server responds with Content-Encoding; brotli (br) offers best compression for text"
            },
            {
                "header": "Accept-Charset",
                "direction": "Request",
                "description": "Client specifies acceptable character sets",
                "example": "Accept-Charset: utf-8, iso-8859-1;q=0.5",
                "notes": "Rarely used today; UTF-8 is de facto standard everywhere"
            },
            {
                "header": "Content-Type",
                "direction": "Request/Response",
                "description": "Media type of the request/response body",
                "example": "Content-Type: application/json; charset=utf-8",
                "notes": "Required for POST/PUT requests with body; server must respect or return 415"
            },
            {
                "header": "Content-Encoding",
                "direction": "Response",
                "description": "Compression applied to the response body",
                "example": "Content-Encoding: gzip",
                "notes": "Must match what client Accept-Encoding advertised; browser auto-decompresses"
            },
            {
                "header": "Vary",
                "direction": "Response",
                "description": "Indicates which request headers affect cache key for content negotiation",
                "example": "Vary: Accept, Accept-Language",
                "notes": "Critical for CDNs to cache multiple variants; missing Vary causes wrong content served"
            }
        ],
        "media_types": [
            {
                "type": "application/json",
                "use": "REST APIs, configuration",
                "notes": "Standard for API responses; use application/problem+json for errors (RFC 7807)"
            },
            {
                "type": "application/xml",
                "use": "SOAP, legacy APIs, RSS/Atom feeds",
                "notes": "Still common in enterprise; use application/atom+xml for feeds"
            },
            {
                "type": "text/html",
                "use": "Web pages",
                "notes": "Always include charset=utf-8"
            },
            {
                "type": "text/plain",
                "use": "Plain text responses",
                "notes": "Use for non-structured text; browser won't render as HTML"
            },
            {
                "type": "application/octet-stream",
                "use": "Binary data, file downloads",
                "notes": "Default when type is unknown; browser triggers download"
            },
            {
                "type": "multipart/form-data",
                "use": "File uploads in HTML forms",
                "notes": "Requires boundary parameter; use for file uploads not JSON payloads"
            },
            {
                "type": "application/x-www-form-urlencoded",
                "use": "HTML form submissions (default)",
                "notes": "Key=value&key2=value2 format; use for simple form data, not file uploads"
            },
            {
                "type": "application/graphql+json",
                "use": "GraphQL API responses",
                "notes": "Emerging standard; use instead of application/json for GraphQL endpoints"
            }
        ]
    }
}