envelope and schemas

PLATFORM = "hackerrank". Schema category is fundamentals. CodeTrace’s fetchCard currently tags it dsa.

Try it: playground, docs. Placeholder handle is demo.

No body, no auth. Path username. Heatmap view / year. SVG theme / exclude.

GET /alice/stats HTTP/1.1
Host: hackerrank-stats.tashif.codes

Server-side public REST, Chrome Accept + User-Agent, timeout 20s. Profile 404 means the user is missing. Most other endpoints tolerate 404 so a profile without contests still returns a card.

GET https://www.hackerrank.com/rest/contests/master/hackers/{username}/profile HTTP/1.1
GET https://www.hackerrank.com/rest/hackers/{username}/scores_elo HTTP/1.1
GET https://www.hackerrank.com/rest/hackers/{username}/badges HTTP/1.1
GET https://www.hackerrank.com/rest/hackers/{username}/contest_participation?offset=0&limit=50 HTTP/1.1
GET https://www.hackerrank.com/rest/hackers/{username}/rating_histories_elo HTTP/1.1
GET https://www.hackerrank.com/rest/hackers/{username}/submission_histories HTTP/1.1
GET https://www.hackerrank.com/rest/hackers/{username}/recent_challenges?limit=100&response_version=v2 HTTP/1.1
GET https://www.hackerrank.com/rest/contests/master/challenges/{slug} HTTP/1.1

recent_challenges is the full solved history despite the name. Pagination is cursor, max 25 pages. See Public REST.

{
  "status": "success",
  "message": "retrieved",
  "platform": "hackerrank",
  "username": "alice",
  "cached": false,
  "data": {}
}

GET /{username} still flattens totalSolved, ranking, practiceScore, reputation, submissionCalendar next to data.

Profile: realName, userAvatar, countryName, school, company, aboutMe, websites, github/twitter/linkedin.

Stats: totalSolved prefers badge solved sums, else unique ch_slugs. practiceScore is the sum of track scores, not solved-challenge count. Difficulty and acceptance rate are not in public data. byDifficulty stays zeros. Topics = challenge track.name via process _TRACK_CACHE.

Contests: badge.name → rank, plus topPercentage and globalRanking when present. Empty history is 200 history: [].

Rating: derived from contest history.

Heatmap: submission history keys are epoch seconds or ISO dates. Decoder accepts both. Heatmaps are often empty even when the UI shows activity. Empty days is a 200, not a 404. Levels already 0 to 4 from the decoder.

Badges: active = max stars then level.

SVG: image/svg+xml.

Profile missing: 404. Other sections tolerate 404 so the card still paints.

ranking is the best practice-track rank with score > 0, not a global profile rank. Do not treat it as Codeforces rating rank.

sequenceDiagram
  participant C as Caller
  participant MW as CacheRateLimit
  participant RT as Route
  participant HR as hackerrank.com/rest

  C->>MW: GET /alice/stats
  MW->>RT: miss
  RT->>HR: profile
  RT->>HR: badges
  RT->>HR: recent_challenges pages
  RT-->>C: envelope platform hackerrank

Request path.