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crul vs rstantools

A side-by-side editorial comparison of crul and rstantools — release velocity, themes, recent moves, and the top alternatives to consider.

crul vs rstantools: at a glance

Featurecrulrstantools
SectorAnalyticsAnalytics
Velocity score0.02.5
Sparks · 30d00
Top themeshttp-client, async, mocking, ropenscistan, bayesian, r-package, build-tooling
Last editorial update1h ago3h ago
WebsiteVisit →Visit →

What is crul?

crul took mocking back from webmockr and made it a property of the client itself

crul is the R6-based HTTP client underneath much of rOpenSci's package stack, covering synchronous requests, three flavours of async, pagination and retries. Its 1.6.0 release in July 2025 changed where test mocking lives: each client — HttpClient, Async, AsyncVaried — now takes a mocking parameter at initialisation or per method, and the standalone mock() function is deprecated. Mocking used to be something webmockr switched on from outside; it is now a setting on the client.

Read the full crul trajectory →

What is rstantools?

The scaffolding layer for Stan-backed R packages, maintained rather than extended.

rstantools generates and maintains the build infrastructure that lets an R package ship Stan models — the inst/stan layout, the auto-generated C++, the Rcpp module loading, and the posterior_* generics downstream packages implement. Its releases are dominated by keeping that scaffolding compiling as Stan, StanHeaders, and rstan move underneath it. Version 2.7.0 continues that pattern, its one user-facing change being an allowance for deprecated syntax in specified versions of specified packages.

Read the full rstantools trajectory →

crul vs rstantools: editorial side-by-side

C
crul
ANALYTICS
0.0

crul took mocking back from webmockr and made it a property of the client itself

◆ Current state

crul is the R6-based HTTP client underneath much of rOpenSci's package stack, covering synchronous requests, three flavours of async, pagination and retries. Its 1.6.0 release in July 2025 changed where test mocking lives: each client — HttpClient, Async, AsyncVaried — now takes a mocking parameter at initialisation or per method, and the standalone mock() function is deprecated. Mocking used to be something webmockr switched on from outside; it is now a setting on the client.

◆ Where it's heading

The async surface has been the growth area for years — retries reached Async, AsyncVaried, AsyncQueue and HttpRequest in 1.4, AsyncQueue gained the response accessors in 1.2, and 1.5.0 wired async requests up to webmockr. The 1.6.0 change reverses that direction of dependency, and it landed within a minute of webmockr's own release severing its tie to vcr. Read together, the rOpenSci HTTP stack is being deliberately untangled so each package can be used without the others.

◆ Prediction

With mock() deprecated rather than removed, the next major release is the likely point of deletion. Expect the remaining work to follow the same decoupling theme rather than adding request features.

R
rstantools
ANALYTICS
2.5

The scaffolding layer for Stan-backed R packages, maintained rather than extended.

◆ Current state

rstantools generates and maintains the build infrastructure that lets an R package ship Stan models — the inst/stan layout, the auto-generated C++, the Rcpp module loading, and the posterior_* generics downstream packages implement. Its releases are dominated by keeping that scaffolding compiling as Stan, StanHeaders, and rstan move underneath it. Version 2.7.0 continues that pattern, its one user-facing change being an allowance for deprecated syntax in specified versions of specified packages.

◆ Where it's heading

This is a stable dependency in maintenance mode, and the release history reads accordingly: compatibility shims for new rstan and Stan RNG versions, C++ standard bumps, and pkgdown housekeeping. The last substantive API growth was 2.5.0's loo_epred() generic and discrete-data loo_pit(). Contributor churn is visible in recent releases, with several first-time contributors handling infrastructure rather than statistics.

◆ Prediction

Expect the next releases to continue tracking Stan and rstan breakage as it arrives; nothing in the recent entries points to new generics or a change in the package-generation model.

Alternatives to crul and rstantools

Other Analytics products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either crul or rstantools.

See all crul alternatives → · See all rstantools alternatives →

Recent activity from crul and rstantools

Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.

  1. 19d agorstantoolsDeprecated syntax allowed for pinned package versions
  2. 7mo agorstantoolspkgdown theme refresh, C++14 dropped from SystemRequirements
  3. 11mo agorstantoolsloo_epred() generic added, loo_pit() extended to discrete data
  4. 1y agocrulMocking becomes a client parameter, independent of webmockr
  5. 2y agocrulAsync requests become mockable through webmockr
  6. 2y agocrulDocumentation fixes and test helper tweak
  7. 2y agorstantoolsStandalone Stan functions fixed for rstan 2.33+
  8. 3y agocrulHTTP retries reach the async classes
  9. 3y agorstantoolsinit_cpp deprecated, standalone-function bugfix under Stan 2.31
  10. 3y agorstantoolsC++17 standard adopted, standalone function export reworked
  11. 3y agocrulClearer error for mismatched urls and disk lengths
  12. 4y agocrulAsyncQueue gains response accessors; results print as a summary

Frequently asked questions

What is the difference between crul and rstantools?

They serve adjacent needs but don't currently overlap on shipped themes. rstantools is currently shipping more aggressively (velocity 2.5 vs 0.0), with 0 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is crul better than rstantools?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. rstantools is currently shipping more aggressively (velocity 2.5 vs 0.0), with 0 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Analytics products to evaluate alongside.

What are the best alternatives to crul?

Top crul alternatives in Analytics are ranked by recent ship velocity. Browse the "crul alternatives" section above for the current picks, or visit /alternatives/crul for the full list with editorial commentary on each.

What are the best alternatives to rstantools?

Top rstantools alternatives in Analytics are ranked by recent ship velocity. Browse the "rstantools alternatives" section above for the current picks, or visit /alternatives/rstantools for the full list with editorial commentary on each.