Crates / scc
Rust crate · real downloads · data Oct 24, 2026
scc downloads, and should you depend on it?
A collection of high-performance asynchronous/concurrent containers with both asynchronous and synchronous interfaces crates.io · docs · repository
Owned on crates.io by wvwwvwwv · alternatives · is it still maintained?
Feature flags + Cargo.toml picker · Security history
Established and steady.
scc: 133 crates depend on it; downloads don't spike on releases.
How this verdict is decided (4 rules)
- Usage: crates.io reverse dependencies (crates that list it as a dependency): 10,000+ = foundational, 1,000+ = widely used, 100+ = established, under 100 = few direct dependents.
- Direction: the median quiet day in the last 30 days of the window against the first 30, read against the median tracked crate (the whole field moved +39% from late summer to October, so a raw trend says nothing). 10%+ ahead of the field = gaining; 10%+ behind = losing ground; otherwise steady. Steady with no release in 2+ years = quiet for years.
- Release spikes: the median release-window day against the quiet-day baseline: under 1.15x = no spike, 1.15x to 1.3x = small bumps, 1.3x or more = jumps on release days.
- Release recency: days since the newest version that was not yanked, from crates.io publish times.
release window (release day + next day)quiet dayquiet-day median · download the 89 days as CSV
The numbers in one paragraphscc got 20,018,677 crates.io downloads from Jul 27, 2026 to Oct 23, 2026. 6% of them landed within 2 days of one of its 3 releases. On the other 83 quiet days it got a median of 240,754 a day, about 1,685,278 a week. Capping release days at that baseline leaves 19,941,172 release-adjusted downloads for the window.
What this means if you're choosing a dependency
- Used, not everywhere. 133 crates depend on it. Look at how fast its issues get answered before you lean on it.
- Actively released. 3.8.8 shipped 53 days ago (Sep 1, 2026).
- Fit check: license Apache-2.0, edition 2024, needs Rust 1.85.0 or newer (from the latest version's manifest).
- Compare it by the baseline, not the raw count. 6% of its 20,018,677 downloads in the window landed within 2 days of a release; the steady number is 240,754 a day.
Alternatives that do a similar job
Crates that share its crates.io category or keywords, most similar first. Each line is the crate's own description, then how it compares on the same data.
Its place in the dependency graph
scc builds on
Tracked crates its latest version (3.8.8) depends on (optional ones marked).
What the chart says
- Weekend quiet days ran at 44% of weekday quiet days (113,866 vs 259,613). A dip that deep is the signature of work-week CI pipelines and developers building on weekdays.
- Biggest day: 419,045 on Oct 22, 2026, a quiet day with no release nearby.
Every number
| All-time downloads | 97,097,014 (rank #931 on crates.io by all-time downloads) |
| Downloads in the window | 20,018,677 (Jul 27, 2026 to Oct 23, 2026, 89 days) |
| Within 2 days of a release | 1,227,476 (6.1%) |
| Quiet-day median (baseline) | 240,754 a day; weekdays 259,613, weekends 113,866 |
| Release-adjusted downloads | 19,941,172 (release-window days capped at the baseline) |
| Baseline rank | #934 of the 1000 crates we track |
| Quiet-day trend | +27% raw, -8% against the median tracked crate (+39%) |
| Releases in the window | 3 |
| Versions published, ever | 254 |
| Latest version | 3.8.8, published Sep 1, 2026 (license Apache-2.0, edition 2024, MSRV 1.85.0) |
| First published | Nov 20, 2020 |
| Reverse dependencies | 133 |
Releases in the window
Each one opens a 2-day release window on the chart.
| Version | Published | Downloads that version got (lifetime) |
|---|---|---|
| 3.8.8 | Sep 1, 2026 | 195,064 |
| 3.8.7 | Aug 29, 2026 | 10,649 |
| 3.8.6 | Jul 27, 2026 | 285,805 |
How we compute this
crates.io counts every download, including CI runners, mirrors and bots that fetch each new version, so raw counts run high (why, in The Manual). We split the last 89 days into release windows (the day a version of scc was published, plus the next day) and quiet days, and use the median quiet day as the baseline: an upper bound on steady use, never a head count. The method and data come from our study of 90 days of crates.io data from 69 crates, featured in This Week in Rust #674; check any crate live with the real-downloads checker.
Badge for your README
Maintainers can show the baseline in a README. It is optional, updates when we refresh the data, and links back here. Preview, then copy:
README, light
README, dark
Publishing a crate of your own? How to publish a Rust crate to crates.io, step by step.
Categories
Sources
- Daily downloads: crates.io API, /crates/scc/downloads (last 90 days, all versions), fetched Oct 24, 2026.
- Versions and publish times: crates.io API, /crates/scc/versions, same fetch.
- Reverse dependencies: crates.io reverse dependencies, same fetch. Dependency edges between tracked crates: each crate's default version, crates.io API.
- Fetched politely (one request every 2 seconds, identified User-Agent) per the crates.io data access policy. Data is crates.io's; the release-window split, baseline and verdict rules are ours, CC BY 4.0.
Up next
Next in caching: Back to the top in Caching by real downloads: 2,599,767 a day, 104 dependents. Established and steady.yokeRust crate. Abstraction allowing borrowed data to be carried along with the backing data it borrows from. Real use: 2.6M downloads a day on quiet days; 104 crates depend...Read it next →Also worth your time