{
    "documentation_version": 1,
    "base_url": "https://c7dev.com",
    "instructions_url": "https://c7dev.com/api_instructions",
    "selection": {
        "method": "GET",
        "parameter": "api",
        "required": false,
        "description": "Omit api for the full suite, or use an endpoint name for its instructions only.",
        "example_url": "https://c7dev.com/api_instructions?api=media_api"
    },
    "instructions": [
        "Choose an endpoint by its description, then use its documented HTTP method and parameter location.",
        "URL-encode GET query values. Preserve identifiers such as VAT numbers and registration codes as strings.",
        "For JSON APIs, require HTTP success and result=true before using returned data. Read error_message on failure.",
        "Do not fabricate missing data or treat null as zero or false. Warnings may indicate incomplete or older data.",
        "Do not blindly retry invalid input or access errors. Temporary service failures may be retried with bounded backoff.",
        "Responses prohibit browser caching. Inspect cached, timestamps and X-API-Version when those fields are available."
    ],
    "authentication": {
        "documentation": "Public; no token is required to read these instructions.",
        "restricted_endpoints": "Supply credentials provided by the API operator when access control requires them.",
        "token_locations": [
            "Authorization: Bearer YOUR_ACCESS_TOKEN",
            "X-Access-Token: YOUR_ACCESS_TOKEN",
            "access_token query or form parameter"
        ],
        "domain": "Send domain as a query or form parameter when the client token is restricted to registered domains. Access may also be restricted by IP.",
        "ai_generate": "Requires both access_token and domain in the form body."
    },
    "json_response_envelope": {
        "result": "boolean; request succeeded",
        "error": "boolean; request failed",
        "error_message": "string; empty on success",
        "server_time": "integer; Unix timestamp in seconds"
    },
    "errors": {
        "400": "Missing or invalid input.",
        "403": "Access denied; check token, registered domain and IP permissions.",
        "404": "Unknown API selected for instructions.",
        "405": "Unsupported method for the instructions endpoint.",
        "500": "Processing failed.",
        "503": "Service temporarily unavailable."
    },
    "apis": [
        {
            "name": "currency_api",
            "method": "GET",
            "path": "/currency_api",
            "description": "Exchange rates normalized to a requested fiat base, with fiat, fixed/legacy fiat, cryptocurrency and metal categories.",
            "instructions_url": "https://c7dev.com/api_instructions?api=currency_api",
            "request": {
                "parameter_location": "query",
                "parameters": {
                    "base": {
                        "type": "string",
                        "required": false,
                        "description": "Supported three-letter fiat currency code.",
                        "default": "EUR"
                    },
                    "required_currencies": {
                        "type": "string_or_array",
                        "required": false,
                        "description": "Codes separated by commas or spaces, or sent as required_currencies[] form-style query values."
                    },
                    "return_only_required": {
                        "type": "boolean",
                        "required": false,
                        "description": "Return only requested codes.",
                        "default": false
                    },
                    "refresh_mode": {
                        "type": "string",
                        "required": false,
                        "description": "Refresh preference.",
                        "default": "slow",
                        "enum": [
                            "slow",
                            "fast"
                        ]
                    }
                }
            },
            "response": {
                "format": "application/json",
                "response_fields": [
                    "base",
                    "fiat",
                    "fiat_fixed",
                    "crypto",
                    "metals"
                ],
                "headers": {
                    "X-API-Version": "currency_api_v1"
                }
            },
            "details": {
                "Base currency": "Any supported 3-letter fiat code; default EUR",
                "Currency types": "Fiat, fixed/legacy fiat, cryptocurrency, precious/industrial metals",
                "Crypto codes": "BTC, ETH, SOL, XRP, BNB, ADA, DOGE, TRX, AVAX, LINK, DOT, LTC, BCH, XLM, XMR, ATOM, ETC, UNI, AAVE, FIL, NEAR, ICP, TON, SHIB, USDT, USDC, DAI",
                "Metal codes": "XAU, XAG, XPT, XPD, XRH, ALU, XCO, XCU, XGA, XIN, IRON, XPB, XLI, XMO, NI, XND, XSN, XTE, XU, ZNC",
                "Optional parameters": "base, required_currencies (comma/space separated or repeated), return_only_required, refresh_mode=slow|fast",
                "Returns": "base plus separate fiat, fiat_fixed, crypto and metals rate maps; metal rates are expressed per troy ounce"
            },
            "notes": [
                "Keep fiat, fiat_fixed, crypto and metals maps separate.",
                "Metal rates are expressed per troy ounce.",
                "Encode boolean query values as 1 or 0."
            ],
            "examples": [
                {
                    "method": "GET",
                    "url": "https://c7dev.com/currency_api?base=EUR&required_currencies=USD%2CGBP%2CBTC%2CXAU&return_only_required=1"
                }
            ]
        }
    ],
    "result": true,
    "error": false,
    "error_message": "",
    "server_time": 1791673087
}