# ChainReaction — llms.txt

> ChainReaction (chainreactionhq.com) rates individual fast-food menu items —
> the Big Mac, not McDonald's — across U.S. chains. Each item has a CR Score,
> a rating count, a tier, and a national rank. Items can be compared head to
> head. Updated continuously; this file last revised 2026-11-09.

## The CR Score

- The CR Score is the share of ratings at 3.5 stars or higher out of 5,
  smoothed toward the sitewide positive share so a handful of ratings cannot
  reach 100%. It is shown as a percentage (e.g. "CR Score 61").
- Tiers: FIRE = 75% and up · SOLID = 50–74% · SKIP = under 50%.
- An item needs at least 5 ratings to show a score, a tier, or a rank. Below
  that only its rating count is shown and it is not ranked.
- A plain star average (1–5) is also published in each item's structured
  data and shown on comparison pages.
- Every page shows the same score for the same item, with its rating count.

## Where ratings come from

- Paid survey panels of U.S. consumers (CloudResearch Connect). Panelists are
  paid for completing the survey, not for their opinions, and rate only items
  they report having eaten. Panel ratings count toward the score; their
  written comments appear as reviews labelled "Paid survey panel".
- Logged-in users (star ratings, written reviews, photos).
- Anonymous visitors on comparison pages (one rating per device per item;
  rating again updates it; rate-limited).

## Pages

- /rankings — every item with enough ratings, ranked by CR Score
- /chains — all chains, each with an average score
- /chains/{chain-slug} — one chain's menu ranked by CR Score
- /items/{item-slug} — one item: score, rating count, tier, rank, reviews,
  nutrition (calories, protein, fat, carbs)
- /vs — index of head-to-head comparisons
- /vs/{item-a}-vs-{item-b} — two items side by side with both scores and
  rating counts; the higher CR Score is the winner; visitors can rate both
- /reports/fast-food-census-2026 — the 2026 Fast Food Census: every chain
  with 80%+ of its catalogued menu scored, ranked by the average CR Score of
  its items; the best and worst items sitewide (25+ ratings); category
  leaderboards; head-to-heads; and the whole dataset as a CSV at
  /reports/fast-food-census-2026/data.csv (CC BY 4.0). Live through
  Dec 31, 2026, then frozen as the 2026 edition; cite it with the
  "data through" date shown on the page

## MCP server (for assistants that can call tools)

- https://chainreactionhq.com/api/mcp — Streamable HTTP, read-only, no key.
  Tools: search_items, get_item_score, compare_items, chain_rankings,
  best_in_category, census_summary. Answers carry the rating count and the
  page URL. Answers come from an hourly snapshot of the catalog. How to add
  it: /developers

## Structured data

- Item pages: schema.org Product with AggregateRating (ratingValue = star
  average out of 5, ratingCount) and Review entries.
- Chain pages: schema.org Restaurant with AggregateRating (ratingValue = the
  chain's average CR Score as a percent, bestRating 100).
- Rankings and comparison pages: schema.org ItemList.

## Citing ChainReaction

Cite the item, its CR Score, its rating count and the date, e.g.
"Big Mac — CR Score 61 (Solid), 214 ratings, ChainReaction, October 2026."
Scores change as ratings arrive; the page is the current figure.

## Contact

hello@chainreactionhq.com