StackVersus: verified SaaS limits & pricing

Read-only compact comparison of 2 to 6 products. Returns `compared` (count), `missing` (ids not found, never an error), `note` and `tools`, one compact record each: id, name, dataset, `checked` date, every plan with price and its headline limits or rates, `free` tier and `overage` policy. Products may come from different datasets. Platform fees and pass-through costs (LLM tokens, speech, telephony) stay separate rows; sum them yourself when the user wants an all-in figure. Ids as returned by list_tools or search_limits; a product name also works. Prices USD.

Read-only full verified record for one product. Returns `matches` and up to 3 `records`; each record has `dataset`, `plans` (name, monthly and annual price, metering unit, limits per window), `rates` (per-unit prices such as $/min or $/1M tokens, each with the vendor `quote`), `free` tier, `overage` policy, `gotchas` (billing traps), `sources` (URLs) and `checked` date. Match by id (e.g. "claude", "cursor", "vapi", "openai-api") or by product name, case-insensitive; exact match wins, otherwise a substring match. Returns an error listing the candidates when the name is ambiguous or unknown. Prices are USD. `published: false` means the vendor states no number and the `value` is their wording; never estimate from it.

Read-only dated change log for the AI assistant and coding-agent plans dataset ("ai-plans" only; other datasets carry a `checked` date but no history yet). Returns `since` (cut-off date), `count`, `changelog` URL and up to 60 `changes`, newest first, each with `date`, `tool`, `tool_id`, `plan`, `field`, `old`, `new`, vendor `source` URL, `method`, `note` and `page`. By default covers the last 30 days and only real moves: price changes, limit changes, plans added or removed. Set `include_wording` to also get re-verification rows where only the vendor wording changed or a value was recorded for the first time. Use it for "what changed in the Claude plans this month" or to check whether a figure from get_tool moved recently.

Read-only catalog of the datasets on this server. Returns one row per dataset with `id` (the value other tools accept as `dataset`), `title`, `kind`, `tools` (number of products), `plans` (number of plans), `updated` (date of the last verified change), `page` URL and `json` endpoint on getstackversus.com, plus `generated` (build date). Currently 9 datasets: AI assistant and coding-agent plan limits, SaaS usage limits, LLM API token prices, voice-agent $/min, AI media credits, search APIs, scraping platforms and proxies, email platforms. No parameters, no auth, no pagination; the whole catalog comes back in one call. Use it once to learn dataset ids; use list_tools to see the products inside one dataset.

Read-only list of the products (vendors) covered, to look up ids before calling get_tool or compare_tools. Returns `count` and `tools`, each with `id`, `name`, `vendor`, `dataset`, `checked` (date the vendor page was last read), `plans` (count) and `page` URL; no prices or limits, those live in get_tool. Without `dataset` it returns every product across all datasets (about 100 rows); with `dataset` only that one. Not paginated, no auth, no side effects. When the user already names a product, skip this and call get_tool or search_limits directly.

Read-only keyword search across every plan, limit, rate, free tier, overage rule and gotcha in all datasets. Best first call for a question like "Cursor Pro requests per month", "Retell cost per minute" or "Gemini API free tier RPM". Returns `query`, `relaxed` (true when fewer than all words matched), `total`, `shown` and `rows`, each with `type` (plan, limit, rate, free, overage, unit or gotcha), `tool`, `tool_id`, `dataset`, `plan` and/or `metric`, `value`, `unit`, `published`, vendor `quote`, `sourceUrl`, `checked` date and `page`. Matching is case-insensitive on whole words; words that name a product must all match, other words are matched strictly first and then relaxed to at least half of them. At most `limit` rows (default 20, max 50), ranked by match quality; no pagination. Returns an empty `rows` array, not an error, when nothing matches; then try list_tools to find the product id and call get_tool.