httpuv
httpuv ships almost nothing, which is what you want from the web server under Shiny
Comparison · DevOps
httr2 vs promises
A side-by-side editorial comparison of httr2 and promises — release velocity, themes, recent moves, and the top alternatives to consider.
Shared themes:observability
httr2 vs promises: at a glance
What is httr2?
httr2 is growing production concerns: tracing, throttling and token hygiene.
httr2 is the tidyverse's modern HTTP client and the designated successor to httr. Recent releases have moved past request-building ergonomics into operational concerns — OpenTelemetry traces for every request, throttling that behaves correctly across repeated calls, and a fix for OAuth token caches that were never actually being pruned.
What is promises?
promises drops R6 for plain environments and wires async work into OpenTelemetry
promises supplies the async primitives behind Shiny and plumber. After years of small domain and future() fixes, the last two releases changed both what a promise costs and what it can report: 1.4.0 corrected nested domain ordering and added the first OpenTelemetry integration, and 1.5.0 replaced the R6 promise class with a classed environment while stabilizing the tracing API.
httr2 vs promises: editorial side-by-side
httr2
2.5DEVOPS
httr2 is growing production concerns: tracing, throttling and token hygiene.
◆ Current state
httr2 is the tidyverse's modern HTTP client and the designated successor to httr. Recent releases have moved past request-building ergonomics into operational concerns — OpenTelemetry traces for every request, throttling that behaves correctly across repeated calls, and a fix for OAuth token caches that were never actually being pruned.
◆ Where it's heading
The package is maturing into infrastructure for long-running R services rather than interactive scripts. The 1.2.0 lifecycle purge removed deprecated streaming and mocking APIs in favour of a connection-based model, and debugging affordances like httr2_translate() point at users who need to reproduce a failing request outside R.
◆ Prediction
Expect further observability and credential-handling work, with the rlang-driven cache hash change in 1.3.0 likely to surface follow-up issues as existing caches silently invalidate.
promises
0.0DEVOPS
promises drops R6 for plain environments and wires async work into OpenTelemetry
◆ Current state
promises supplies the async primitives behind Shiny and plumber. After years of small domain and future() fixes, the last two releases changed both what a promise costs and what it can report: 1.4.0 corrected nested domain ordering and added the first OpenTelemetry integration, and 1.5.0 replaced the R6 promise class with a classed environment while stabilizing the tracing API.
◆ Where it's heading
Two things are being fixed at once. Promise domains - the mechanism that carries context across async boundaries - have been the source of nearly every bug in this window, and they are now being used deliberately as the vehicle for tracing rather than just for error handling. Meanwhile the object itself is being made cheap enough to create in volume.
◆ Prediction
Expect the OpenTelemetry surface to lose its experimental label and pick up the same span coverage Shiny would need end to end; the deprecated ospan function names should be removed in a following release.
Alternatives to httr2 and promises
Other DevOps 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 httr2 or promises.
withr
withr rebuilt defer() on base R's own on.exit(), and got much faster for it
htmltools
htmltools spends three releases walking back its own fill-layout opinions
xml2
xml2 relicensed to MIT, then moved its hot accessors from S3 into C
httr
httr's last releases are housekeeping - the package now points users at httr2
magrittr
magrittr rewrote its pipe in C, then base R shipped one and the releases stopped
See all httr2 alternatives → · See all promises alternatives →
Recent activity from httr2 and promises
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 1mo agohttr2httr2 1.3.0 fixes OAuth token caches that never expired
- 1mo agohttr2httr2 1.2.3 translates requests into curl commands
- 8mo agohttr2httr2 1.2.2 emits OpenTelemetry traces for every request ⚡
- 9mo agopromisesOpenTelemetry spans across async work; R6 dropped for environments ⚡
- 9mo agopromisesNested promise domains fixed; then() gains a tee argument
- 1y agohttr2httr2 1.2.1 stops escaping colons in paths
- 1y agohttr2httr2 1.2.0 removes deprecated mocking and streaming APIs
- 1y agopromisesRealigns future object creation with the future package
- 1y agohttr2httr2 1.1.2 fixes AWS request signing and header checks
- 1y agopromisesFixes stack overflow on long promise chains
- 1y agopromisesFixes domains forgotten inside nested handlers
- 3y agopromisesfuture_promise() returns early when workers are exhausted
Frequently asked questions
What is the difference between httr2 and promises?
Both compete on the same themes — observability — within DevOps. httr2 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 httr2 better than promises?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. httr2 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 DevOps products to evaluate alongside.
What are the best alternatives to httr2?
Top httr2 alternatives in DevOps are ranked by recent ship velocity. Browse the "httr2 alternatives" section above for the current picks, or visit /alternatives/httr2 for the full list with editorial commentary on each.
What are the best alternatives to promises?
Top promises alternatives in DevOps are ranked by recent ship velocity. Browse the "promises alternatives" section above for the current picks, or visit /alternatives/promises for the full list with editorial commentary on each.