Meteomatics Weather API vs Xweather Weather API

Meteomatics Weather API

A public OpenAPI file, a hosted MCP server whose nine tools are all marked read-only, a published SLA with compensation and ISO 27001 certification suit company use. Access needs a sales contract, with no public price, free tier or self-serve signup found, no status page, and REST calls that authenticate with a username and password.

Xweather Weather API

A public OpenAPI file with 236 operations, a hosted MCP server in the official registry and a free tier of 15,000 accesses a month suit agents. REST credentials travel only in the query string, per-minute limits are unpublished, and the group terms bar commercial use of free plans and passing data to third parties unless a service description allows it.

Meteomatics Weather API

1. Ask the account owner for credentials first. There is no signup, and both the REST API and the MCP server need a Meteomatics account with API access
2. Build REST URLs as validdatetime/parameters/location/format, for example 2026-10-08T00:00:00Z/t_2m:C/52.52,13.40/json. Parameter names carry their unit after a colon
3. Keep each query to 10 locations and 10 parameters unless the contract says otherwise, and use POST when a GET URL passes 2,000 characters
4. Send credentials or the token in the Authorization header. Avoid the documented access_token query parameter, which puts the token in URLs and logs
5. Read /user_stats_json before a large job. It reports queries sent and the contract's limits, and 429 means a limit is spent
6. Treat reserved values such as -888 and -999 as invalid or missing data, and shrink the request when a 408 arrives after the 300-second timeout

Xweather Weather API

1. Check success and error.code on every response. Application errors such as invalid_location return HTTP 200 with success false
2. Send fields, limit and plimit. The docs put a 15-day hourly forecast at about 600 KB, and about 25 KB with three fields
3. Read X-Cost-Tokens after each call. Cost is the endpoint multiplier times the intervals requested, so narrow from and to
4. For MCP, send Authorization: Bearer <client_id>_<client_secret> and avoid the api_key query parameter, which puts the secret in the URL
5. Add include_tags or include_tools to the MCP URL to load only the tool groups the task needs
6. On 429 read Retry-After and the X-RateLimit-Reset-* headers. maxhits_min clears at the next minute, maxhits at the period reset