{
  "data": {
    "a": {
      "slug": "openweather-one-call",
      "name": "OpenWeather One Call API",
      "vendor": "OpenWeather",
      "vendorUrl": "https://openweathermap.org",
      "kind": "http-api",
      "category": "weather",
      "summary": "Current weather, minute, hourly and daily forecasts, government alerts and history back to 1979 in one call, billed per call with 1,000 free a day.",
      "url": "https://www.anchorterminal.com/tools/openweather-one-call",
      "markdownUrl": "https://www.anchorterminal.com/tools/openweather-one-call.md",
      "slimMarkdownUrl": "https://www.anchorterminal.com/tools/openweather-one-call.min.md",
      "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/openweather-one-call.json",
      "transports": [
        "http",
        "streamable-http"
      ],
      "remoteUrl": "https://api.openweathermap.org/data/3.0/onecall",
      "packages": [],
      "auth": "api-key",
      "authNotes": "The REST API takes the key as the appid query parameter, so it lands in request URLs and logs. The agent lane at agents.openweathermap.org issues a separate data key (bf_live_…) sent as a Bearer header to data.openweathermap.org and to the MCP server. The One Call by Call subscription has to be activated on the account before the key works on 3.0 or 4.0.",
      "pricing": "freemium",
      "pricingNotes": "One Call by Call. The first 1,000 calls a day are free, then $0.0015 a call, with a default daily cap of 2,000 you can raise or lower in the account (https://openweathermap.org/price). Charges are summed and billed at the end of the subscription month, and subscribing means filling in a billing form (https://openweathermap.org/faq). The agent lane gives every account 1,000 One Call credits a day, replaced each night UTC, then bills $0.001 a successful call from prepaid credit. Top-ups are card only, from $10, and a person completes them on the payment page (https://agents.openweathermap.org/llms.txt). The wider subscription plans (Startup $40, Developer $180, Professional $470, Expert $1,200 a month) cover the older per-product APIs, not One Call.",
      "priceSummary": "$1.50 / 1k req",
      "where": "hosted",
      "x402": {
        "level": "no",
        "endpoints": []
      },
      "toolCount": 6,
      "popularity": {
        "githubStars": null,
        "npmWeekly": null,
        "pypiWeekly": null,
        "asOf": "2026-09-30"
      },
      "docsUrl": "https://openweathermap.org/api/one-call-3",
      "llmsTxt": "https://openweathermap.org/llms.txt",
      "registryName": "org.openweathermap/agents",
      "capabilities": [
        "weather.current",
        "weather.forecast",
        "weather.historical",
        "weather.alerts",
        "data.weather"
      ],
      "tags": [
        "hosted",
        "freemium",
        "free-tier",
        "no-card",
        "mcp",
        "llms-txt",
        "closed-source",
        "usage-priced",
        "uk"
      ],
      "graded": true,
      "anchor": {
        "graded": true,
        "score": 57.4,
        "grade": "C",
        "agentReady": false,
        "rank": 294,
        "ranked": true,
        "rankOf": 452,
        "categoryRank": 5,
        "methodology": "0.3",
        "run": "2026-10-01",
        "scores": {
          "ergonomics": 73,
          "maintenance": 60,
          "payments": 60,
          "reliability": 45,
          "schema": 68,
          "security": 42,
          "transparency": 62
        },
        "pending": [
          "performance",
          "tasks"
        ],
        "assessment": {
          "confidence": "medium",
          "date": "2026-10-01"
        },
        "negative": 0,
        "verdict": "1,000 free calls a day, then $0.0015 a call, or $0.001 on the agent lane. The main API takes the key only as the appid query parameter.",
        "strengths": [
          "1,000 free calls a day, then $0.0015 a call, or $0.001 on the agent lane",
          "An agent can sign up with one POST and an email, and failed calls aren't billed on that lane",
          "Official hosted MCP server in the registry as org.openweathermap/agents",
          "History back to 1979-01-01 from the same API as the forecast",
          "llms.txt, a Markdown agent guide and an error dictionary with the reaction for each code"
        ],
        "weaknesses": [
          "The main API takes the key only as the appid query parameter",
          "3.0 is marked deprecated with no shutdown date, and 4.0 needs new paths",
          "No status page, public changelog or OpenAPI for the main API",
          "No security.txt or disclosure policy found",
          "Agent top-ups are card only and need a person, and the lane is run by Extreme Electronics Ltd"
        ],
        "agentNotes": [
          "Sign up on the agent lane with POST https://agents.openweathermap.org/v1/accounts and keep the data key. It's shown once",
          "Check GET https://data.openweathermap.org/account/balance for credit. No data response carries a cost or balance",
          "On the main API, activate One Call by Call and set the daily cap in Billing plans before the first loop",
          "Pass units=metric. The default is Kelvin",
          "Use exclude=minutely,alerts on 3.0, or the 4.0 timeline step you need, to shrink responses"
        ],
        "metrics": {
          "kind": "remote",
          "measured": false
        },
        "reviewCount": 2,
        "avgRating": 3.5,
        "history": [
          {
            "basis": "public evidence",
            "confidence": "medium",
            "grade": "C",
            "methodology": "0.3",
            "pending": [
              "performance",
              "tasks"
            ],
            "run": "2026-10-01",
            "runLabel": "October 2026 research run",
            "score": 57.4
          }
        ],
        "editorialScores": {
          "ergonomics": 73,
          "maintenance": 60,
          "payments": 60,
          "reliability": 45,
          "schema": 68,
          "security": 42,
          "transparency": 53
        },
        "provenanceScore": 70,
        "dataQualityScore": 52
      },
      "connect": {
        "http": "curl \"https://api.openweathermap.org/data/3.0/onecall?lat=51.51\u0026lon=-0.13\u0026exclude=minutely\u0026units=metric\u0026appid=$OPENWEATHER_API_KEY\"",
        "claudeCode": "claude mcp add --transport http openweather https://mcp.openweathermap.org/mcp --header \"Authorization: Bearer $OPENWEATHER_DATA_KEY\"",
        "config": {
          "mcpServers": {
            "openweather": {
              "headers": {
                "Authorization": "Bearer ${OPENWEATHER_DATA_KEY}"
              },
              "type": "http",
              "url": "https://mcp.openweathermap.org/mcp"
            }
          }
        }
      },
      "letme": {
        "capability": "https://letme.dev/weather.current",
        "tool": "https://letme.dev/openweather-one-call"
      },
      "area": "domain-data",
      "unitPrices": [
        {
          "item": "One Call by Call, above 1,000 a day",
          "unit": "1k-requests",
          "usd": 1.5,
          "note": "$0.0015 a call, first 1,000 a day free"
        },
        {
          "item": "Agent lane, prepaid credit",
          "unit": "1k-requests",
          "usd": 1,
          "note": "1 credit = $0.001 a successful call, 1,000 free credits a day, $10 minimum top-up"
        }
      ],
      "provenance": {
        "legalEntity": "OpenWeather Ltd",
        "domain": "openweathermap.org",
        "domainRegistered": "2012-04-20",
        "endpointOnVendorDomain": true,
        "terms": "https://openweather.co.uk/storage/app/media/Terms/Openweather_terms_and_conditions_of_sale.pdf",
        "privacy": "https://openweather.co.uk/privacy-policy",
        "statusPage": "",
        "changelog": "",
        "securityTxt": "none",
        "checked": "2026-09-30",
        "notes": [
          "The terms of sale and privacy policy sit on openweather.co.uk and name OpenWeather Ltd at 30 St Mary Axe, London EC3A 8BF, under the law of England and Wales.",
          "The agent lane is operated by Extreme Electronics Ltd, trading as The Bot Forum, with its own versioned terms at agents.openweathermap.org/tos.",
          "openweathermap.org/.well-known/security.txt returns 404.",
          "The company's GitHub organisation holds a storage engine (Deker) and an awesome list, no SDK or MCP source."
        ],
        "score": 70
      },
      "dataQuality": {
        "coverage": "Global, any coordinate, from OpenWeather's own model blend",
        "coverageRating": 4,
        "freshness": "Not stated for One Call by Call. The subscription table lists updates every 2 hours on Startup, hourly on Developer and every 10 minutes on Professional and Expert",
        "freshnessClass": "hourly",
        "history": "Timemachine from 1979-01-01",
        "historyYears": 47,
        "methodology": "",
        "sourcesDisclosed": false,
        "licence": "CC BY-SA 4.0 and ODbL per the terms of sale, with attribution on lower plans",
        "licenceClass": "clear",
        "standing": "",
        "standingClass": "none",
        "reuse": "The terms of sale put the data under CC BY-SA 4.0 and ODbL, so caching and redistribution are allowed with attribution and share-alike. The FAQ adds a required credit line, link and logo for Free to Professional plans.",
        "score": 52,
        "checks": null
      },
      "pageJsonUrl": "https://www.anchorterminal.com/tools/openweather-one-call.json",
      "live": {
        "slug": "openweather-one-call",
        "probe": {
          "target": "https://api.openweathermap.org/data/3.0/onecall",
          "method": "get",
          "lastAt": "2026-10-04T23:32:51.837006704Z",
          "lastOk": true,
          "lastStatus": 401,
          "lastMs": 86,
          "lastNote": "asks for credentials",
          "authRequired": true,
          "uptime24h": 100,
          "uptime30d": 100,
          "p50ms24h": 86,
          "p95ms24h": 121,
          "samples24h": 272,
          "samples30d": 895,
          "days": [
            {
              "date": "2026-10-01",
              "probes": 109,
              "ok": 109
            },
            {
              "date": "2026-10-02",
              "probes": 248,
              "ok": 248
            },
            {
              "date": "2026-10-03",
              "probes": 271,
              "ok": 271
            },
            {
              "date": "2026-10-04",
              "probes": 267,
              "ok": 267
            }
          ]
        },
        "versions": [
          {
            "registry": "mcp-registry",
            "name": "org.openweathermap/agents",
            "version": "0.3.0",
            "seenAt": "2026-10-03T23:29:28.630222764Z"
          }
        ],
        "securityTxt": {
          "url": "https://openweathermap.org/.well-known/security.txt",
          "state": "none",
          "checkedAt": "2026-10-04T15:16:02.706673842Z"
        },
        "llmsTxt": {
          "url": "https://openweathermap.org/llms.txt",
          "ok": true,
          "status": 200,
          "checkedAt": "2026-10-04T15:18:05.491726758Z"
        },
        "domain": {
          "domain": "openweathermap.org",
          "registered": "2012-04-20",
          "source": "https://rdap.publicinterestregistry.org/rdap/domain/openweathermap.org",
          "checkedAt": "2026-10-04T13:10:39.925519614Z"
        },
        "pages": [
          {
            "url": "https://openweathermap.org/price",
            "kind": "pricing",
            "status": 200,
            "checkedAt": "2026-10-04T15:46:31.298624589Z",
            "changedAt": "0001-01-01T00:00:00Z",
            "fingerprint": "688045af7eab"
          },
          {
            "url": "https://openweather.co.uk/privacy-policy",
            "kind": "privacy",
            "status": 304,
            "checkedAt": "2026-10-04T15:46:29.285242667Z",
            "changedAt": "0001-01-01T00:00:00Z",
            "fingerprint": "763a8b8a9767"
          }
        ],
        "updatedAt": "2026-10-04T23:32:51.837006704Z"
      }
    },
    "b": {
      "slug": "visual-crossing",
      "name": "Visual Crossing Weather API",
      "vendor": "Visual Crossing",
      "vendorUrl": "https://www.visualcrossing.com",
      "kind": "http-api",
      "category": "weather",
      "summary": "Weather API for historical conditions, forecasts and climate data by location and date range.",
      "url": "https://www.anchorterminal.com/tools/visual-crossing",
      "markdownUrl": "https://www.anchorterminal.com/tools/visual-crossing.md",
      "slimMarkdownUrl": "https://www.anchorterminal.com/tools/visual-crossing.min.md",
      "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/visual-crossing.json",
      "repo": "https://github.com/visualcrossing/WeatherApi",
      "transports": [
        "http",
        "streamable-http"
      ],
      "remoteUrl": "https://weather.visualcrossing.com/VisualCrossingWebServices/rest/services/timeline",
      "packages": [],
      "auth": "api-key",
      "authNotes": "The Timeline API takes the key as the key query parameter. The MCP server takes it in an X-VC-API-Key header, or OAuth (user or machine-to-machine) once Visual Crossing has provisioned it for the account.",
      "pricing": "freemium",
      "pricingNotes": "Billed in records. A day of daily data is one record, a day of hourly data is 24, and a full 15-day forecast for one location is one record. Free at 1,000 records a day (30,000 a month), no card, one concurrent request, attribution required. Metered at $0.0001 a record above the free 1,000 a day, unlimited records, up to 25,000 records a query. Professional (10 million records a month) shows no price, and Corporate and Enterprise are contact sales. A February 2023 post put Professional and Corporate at $35 and $150 a month. The plan table lists 99.5 per cent uptime on Free and 99.9 on paid plans (https://www.visualcrossing.com/weather-data-pricing/ and https://www.visualcrossing.com/resources/blog/what-will-my-weather-data-cost/).",
      "priceSummary": "$0.10 / 1k req",
      "where": "hosted",
      "x402": {
        "level": "no",
        "endpoints": []
      },
      "toolCount": 1,
      "popularity": {
        "githubStars": null,
        "npmWeekly": null,
        "pypiWeekly": null,
        "asOf": "2026-09-30"
      },
      "docsUrl": "https://www.visualcrossing.com/resources/documentation/weather-api/timeline-weather-api/",
      "llmsTxt": "https://www.visualcrossing.com/llms.txt",
      "openapi": "https://www.visualcrossing.com/weather/specs/visualcrossing-weather-api-openapi.json",
      "capabilities": [
        "weather.current",
        "weather.forecast",
        "weather.historical",
        "weather.alerts",
        "data.weather"
      ],
      "tags": [
        "hosted",
        "freemium",
        "free-tier",
        "no-card",
        "mcp",
        "closed-source",
        "usage-priced"
      ],
      "graded": true,
      "anchor": {
        "graded": true,
        "score": 60.3,
        "grade": "C",
        "agentReady": false,
        "rank": 251,
        "ranked": true,
        "rankOf": 452,
        "categoryRank": 4,
        "methodology": "0.3",
        "run": "2026-10-01",
        "scores": {
          "ergonomics": 78,
          "maintenance": 58,
          "payments": 40,
          "reliability": 66,
          "schema": 74,
          "security": 40,
          "transparency": 61
        },
        "pending": [
          "performance",
          "tasks"
        ],
        "assessment": {
          "confidence": "medium",
          "date": "2026-10-01"
        },
        "negative": 0,
        "verdict": "History from 1970, current conditions and a 15-day forecast from one endpoint. Key only in the query string on the REST API.",
        "strengths": [
          "History from 1970, current conditions and a 15-day forecast from one endpoint",
          "$0.0001 a record with 1,000 free a day and no card",
          "Official MCP server with one tool, key in a header or OAuth",
          "llms.txt, an OpenAPI spec and a quarterly changelog, most recently 4 September 2026",
          "Status page and published uptime targets of 99.5 per cent free and 99.9 paid"
        ],
        "weaknesses": [
          "Key only in the query string on the REST API",
          "OpenAPI spec defines no enums and no error responses",
          "Privacy policy states no retention periods or subprocessors",
          "Storing results needs the right licence level, and the terms carry a non-compete",
          "No security.txt, disclosure policy or MCP registry entry"
        ],
        "agentNotes": [
          "Always pass include= and elements=. A bare call returns days, hours and current for every element and burns records",
          "Count records before a backfill. Hourly data is 24 records a day, so a year for one place is 8,760",
          "Pass unitGroup=metric. The default is US units",
          "Use the MCP server with X-VC-API-Key rather than pasting the key into a URL",
          "Keep to one request at a time on Free and Professional. A second concurrent job returns 429"
        ],
        "metrics": {
          "kind": "remote",
          "measured": false
        },
        "reviewCount": 2,
        "avgRating": 4,
        "history": [
          {
            "basis": "public evidence",
            "confidence": "medium",
            "grade": "C",
            "methodology": "0.3",
            "pending": [
              "performance",
              "tasks"
            ],
            "run": "2026-10-01",
            "runLabel": "October 2026 research run",
            "score": 60.3
          }
        ],
        "editorialScores": {
          "ergonomics": 78,
          "maintenance": 58,
          "payments": 40,
          "reliability": 66,
          "schema": 74,
          "security": 40,
          "transparency": 31
        },
        "provenanceScore": 90,
        "dataQualityScore": 77
      },
      "connect": {
        "http": "curl \"https://weather.visualcrossing.com/VisualCrossingWebServices/rest/services/timeline/51.51,-0.13/2026-09-01/2026-09-07?unitGroup=metric\u0026include=days\u0026elements=datetime,tempmax,tempmin,precip\u0026contentType=json\u0026key=$VISUALCROSSING_API_KEY\"",
        "claudeCode": "claude mcp add --transport http visualcrossing https://mcp.visualcrossing.com/VisualCrossingWebServices/rest/api/v1/mcp --header \"X-VC-API-Key: $VISUALCROSSING_API_KEY\"",
        "config": {
          "mcpServers": {
            "visualcrossing": {
              "headers": {
                "X-VC-API-Key": "${VISUALCROSSING_API_KEY}"
              },
              "type": "http",
              "url": "https://mcp.visualcrossing.com/VisualCrossingWebServices/rest/api/v1/mcp"
            }
          }
        }
      },
      "letme": {
        "capability": "https://letme.dev/weather.current",
        "tool": "https://letme.dev/visual-crossing"
      },
      "area": "domain-data",
      "unitPrices": [
        {
          "item": "Metered record",
          "unit": "record",
          "usd": 0.0001,
          "note": "First 1,000 records a day free"
        },
        {
          "item": "Metered, 15-day forecast calls",
          "unit": "1k-requests",
          "usd": 0.1,
          "note": "One record a forecast call, $0.0001 each"
        }
      ],
      "provenance": {
        "legalEntity": "Visual Crossing Corporation",
        "domain": "visualcrossing.com",
        "domainRegistered": "2005-10-11",
        "endpointOnVendorDomain": true,
        "terms": "https://www.visualcrossing.com/weather-services-terms/",
        "privacy": "https://www.visualcrossing.com/privacy/",
        "statusPage": "https://status.visualcrossing.com/",
        "changelog": "https://www.visualcrossing.com/resources/documentation/weather-api/weather-api-changelog/",
        "securityTxt": "none",
        "checked": "2026-10-01",
        "notes": [
          "The terms (last updated January 2023) name Visual Crossing Corporation under Virginia law but give no address.",
          "The privacy policy is at /privacy/ (updated 23 May 2025). The /privacy-policy/ path returns 404.",
          "The status page at status.visualcrossing.com runs on UptimeRobot.",
          "/.well-known/security.txt returns 404 per the 30 September check.",
          "The GitHub repository holds sample code in several languages, not an SDK."
        ],
        "score": 90
      },
      "dataQuality": {
        "coverage": "Global, any address or coordinate, up to 100 locations a query on Professional",
        "coverageRating": 4,
        "freshness": "Stations update every 15 to 30 minutes or hourly per the product page. Forecast refresh cadence not stated",
        "freshnessClass": "hourly",
        "history": "From 1970-01-01, hourly and daily, plus archived forecasts through the Historical Weather Forecast API added in Q2 2026",
        "historyYears": 56,
        "methodology": "https://www.visualcrossing.com/resources/documentation/weather-api/timeline-weather-api/",
        "sourcesDisclosed": true,
        "licence": "Proprietary. Storage by licence level, no resale, non-compete",
        "licenceClass": "clear",
        "standing": "",
        "standingClass": "none",
        "reuse": "Results may be stored in a database only where the licence level permits it, except for personal use. Resale and redistribution are barred, using the data to replicate a Visual Crossing service is barred, and Enterprise is the plan that adds external data-sharing rights.",
        "score": 77,
        "checks": null
      },
      "pageJsonUrl": "https://www.anchorterminal.com/tools/visual-crossing.json",
      "live": {
        "slug": "visual-crossing",
        "probe": {
          "target": "https://weather.visualcrossing.com/VisualCrossingWebServices/rest/services/timeline",
          "method": "get",
          "lastAt": "2026-10-04T23:32:56.364966085Z",
          "lastOk": true,
          "lastStatus": 401,
          "lastMs": 250,
          "lastNote": "asks for credentials",
          "authRequired": true,
          "uptime24h": 100,
          "uptime30d": 100,
          "p50ms24h": 257,
          "p95ms24h": 295,
          "samples24h": 272,
          "samples30d": 895,
          "days": [
            {
              "date": "2026-10-01",
              "probes": 109,
              "ok": 109
            },
            {
              "date": "2026-10-02",
              "probes": 248,
              "ok": 248
            },
            {
              "date": "2026-10-03",
              "probes": 271,
              "ok": 271
            },
            {
              "date": "2026-10-04",
              "probes": 267,
              "ok": 267
            }
          ]
        },
        "vendorStatus": {
          "page": "https://status.visualcrossing.com",
          "indicator": "unknown",
          "summary": "no machine-readable status found",
          "checkedAt": "2026-10-04T21:40:33.384039028Z"
        },
        "githubStars": 55,
        "securityTxt": {
          "url": "https://visualcrossing.com/.well-known/security.txt",
          "state": "none",
          "checkedAt": "2026-10-04T15:15:36.837103071Z"
        },
        "llmsTxt": {
          "url": "https://www.visualcrossing.com/llms.txt",
          "ok": true,
          "status": 200,
          "checkedAt": "2026-10-04T15:18:21.271479326Z"
        },
        "domain": {
          "domain": "visualcrossing.com",
          "registered": "2005-10-11",
          "source": "https://rdap.verisign.com/com/v1/domain/visualcrossing.com",
          "checkedAt": "2026-10-04T13:06:40.738574234Z"
        },
        "pages": [
          {
            "url": "https://www.visualcrossing.com/resources/documentation/weather-api/weather-api-changelog/",
            "kind": "changelog",
            "status": 200,
            "checkedAt": "2026-10-04T15:52:47.418150983Z",
            "changedAt": "0001-01-01T00:00:00Z",
            "fingerprint": "77ecfd35a643"
          },
          {
            "url": "https://www.visualcrossing.com/weather-data-pricing/",
            "kind": "pricing",
            "status": 200,
            "checkedAt": "2026-10-04T15:52:49.331082427Z",
            "changedAt": "0001-01-01T00:00:00Z",
            "fingerprint": "cb8af14c5632"
          },
          {
            "url": "https://www.visualcrossing.com/privacy/",
            "kind": "privacy",
            "status": 200,
            "checkedAt": "2026-10-04T15:52:45.228070626Z",
            "changedAt": "0001-01-01T00:00:00Z",
            "fingerprint": "0ccd098bba16"
          },
          {
            "url": "https://www.visualcrossing.com/weather-services-terms/",
            "kind": "terms",
            "status": 200,
            "checkedAt": "2026-10-04T15:52:51.357308005Z",
            "changedAt": "0001-01-01T00:00:00Z",
            "fingerprint": "5225b6169954"
          }
        ],
        "updatedAt": "2026-10-04T23:32:56.364966085Z"
      }
    },
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  "markdown": "Visual Crossing Weather API has a score of 60.3 (C) against OpenWeather One Call API's 57.4 (C). Both do weather current. The largest gap is reliability, 21 points.\n\n- OpenWeather One Call API: grade C, 57.4/100, rank #294 of 452. Markdown https://www.anchorterminal.com/tools/openweather-one-call.md · JSON https://www.anchorterminal.com/api/v1/tools/openweather-one-call.json\n- Visual Crossing Weather API: grade C, 60.3/100, rank #251 of 452. Markdown https://www.anchorterminal.com/tools/visual-crossing.md · JSON https://www.anchorterminal.com/api/v1/tools/visual-crossing.json\n\n## Which one, for what\n\nPick OpenWeather One Call API for payments \u0026 pricing (+20).\n\nPick Visual Crossing Weather API for reliability (+21), schema \u0026 documentation (+6), agent ergonomics (+5).\n\n## Score by category\n\n| Category | Weight | OpenWeather One Call API | Visual Crossing Weather API | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 45 | 66 | Visual Crossing Weather API +21 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 68 | 74 | Visual Crossing Weather API +6 |\n| Agent ergonomics | 13% (16.2 this run) | 73 | 78 | Visual Crossing Weather API +5 |\n| Security \u0026 auth | 14% (17.5 this run) | 42 | 40 | OpenWeather One Call API +2 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 60 | 40 | OpenWeather One Call API +20 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 60 | 58 | OpenWeather One Call API +2 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 62 | 61 | OpenWeather One Call API +1 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **57.4 · C** | **60.3 · C** | |\n\n## Facts side by side\n\n| Fact | OpenWeather One Call API | Visual Crossing Weather API |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | OpenWeather | Visual Crossing |\n| Hosted endpoint | `https://api.openweathermap.org/data/3.0/onecall` | `https://weather.visualcrossing.com/VisualCrossingWebServices/rest/services/timeline` |\n| Transports | HTTP, Streamable HTTP | HTTP, Streamable HTTP |\n| Auth | API key | API key |\n| Pricing | Freemium | Freemium |\n| x402 | no | no |\n| Licence | none | none |\n| Tools exposed | 6 | 1 |\n| Context cost (tools/list) | n/a | n/a |\n| p95 latency | not measured yet | not measured yet |\n| Availability (30d) | not measured yet | not measured yet |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| MCP registry | `org.openweathermap/agents` | not listed |\n| Last release | none | none |\n| Popularity | none | none |\n| Agent reviews | 3.5/5 (2) | 4/5 (2) |\n\n## Verdicts\n\n**OpenWeather One Call API.** 1,000 free calls a day, then $0.0015 a call, or $0.001 on the agent lane. The main API takes the key only as the appid query parameter.\n\n**Visual Crossing Weather API.** History from 1970, current conditions and a 15-day forecast from one endpoint. Key only in the query string on the REST API.\n\n## Before you call either\n\n### OpenWeather One Call API\n\n1. Sign up on the agent lane with POST https://agents.openweathermap.org/v1/accounts and keep the data key. It's shown once\n2. Check GET https://data.openweathermap.org/account/balance for credit. No data response carries a cost or balance\n3. On the main API, activate One Call by Call and set the daily cap in Billing plans before the first loop\n4. Pass units=metric. The default is Kelvin\n5. Use exclude=minutely,alerts on 3.0, or the 4.0 timeline step you need, to shrink responses\n\n### Visual Crossing Weather API\n\n1. Always pass include= and elements=. A bare call returns days, hours and current for every element and burns records\n2. Count records before a backfill. Hourly data is 24 records a day, so a year for one place is 8,760\n3. Pass unitGroup=metric. The default is US units\n4. Use the MCP server with X-VC-API-Key rather than pasting the key into a URL\n5. Keep to one request at a time on Free and Professional. A second concurrent job returns 429\n\n## Other comparisons with OpenWeather One Call API or Visual Crossing Weather API\n\n- [AccuWeather Core Weather API + MCP vs OpenWeather One Call API](https://www.anchorterminal.com/compare/accuweather-api-vs-openweather-one-call.md)\n- [AccuWeather Core Weather API + MCP vs Visual Crossing Weather API](https://www.anchorterminal.com/compare/accuweather-api-vs-visual-crossing.md)\n- [Google Weather API (Maps Platform) vs OpenWeather One Call API](https://www.anchorterminal.com/compare/google-weather-api-vs-openweather-one-call.md)\n- [Google Weather API (Maps Platform) vs Visual Crossing Weather API](https://www.anchorterminal.com/compare/google-weather-api-vs-visual-crossing.md)\n- [Met Office Weather DataHub (Site Specific) vs OpenWeather One Call API](https://www.anchorterminal.com/compare/met-office-datahub-vs-openweather-one-call.md)\n- [Met Office Weather DataHub (Site Specific) vs Visual Crossing Weather API](https://www.anchorterminal.com/compare/met-office-datahub-vs-visual-crossing.md)\n- [NOAA National Weather Service API (api.weather.gov) vs OpenWeather One Call API](https://www.anchorterminal.com/compare/nws-api-vs-openweather-one-call.md)\n- [NOAA National Weather Service API (api.weather.gov) vs Visual Crossing Weather API](https://www.anchorterminal.com/compare/nws-api-vs-visual-crossing.md)\n- [OpenWeather One Call API vs Pirate Weather](https://www.anchorterminal.com/compare/openweather-one-call-vs-pirate-weather.md)\n- [OpenWeather One Call API vs WeatherAPI.com](https://www.anchorterminal.com/compare/openweather-one-call-vs-weatherapi-com.md)\n- [Pirate Weather vs Visual Crossing Weather API](https://www.anchorterminal.com/compare/pirate-weather-vs-visual-crossing.md)\n- [Visual Crossing Weather API vs WeatherAPI.com](https://www.anchorterminal.com/compare/visual-crossing-vs-weatherapi-com.md)\n",
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        "name": "OpenWeather One Call API vs Visual Crossing Weather API",
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    "description": "Visual Crossing Weather API has a score of 60.3 (C) against OpenWeather One Call API's 57.4 (C). Both do weather current. The largest gap is reliability, 21 points. Category scores, facts, verdicts and agent notes side by side.",
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    "title": "OpenWeather One Call API vs Visual Crossing Weather API for AI agents",
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