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vcr vs webchem

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

Shared themes:ropensci

vcr vs webchem: at a glance

Featurevcrwebchem
SectorAnalyticsAnalytics
Velocity score0.00.0
Sparks · 30d00
Top themestesting, http-mocking, breaking-change, api-cleanupcheminformatics, web-apis, data-access, ropensci
Last editorial update1h ago1h ago
WebsiteVisit →Visit →

What is vcr?

Added the HTTP client everyone moved to, then deleted a decade of its own public surface.

vcr records HTTP interactions to disk so R package tests can replay them without network access. Two releases define its current state. Version 1.6.0 added httr2 support alongside the existing httr and crul backends, following the R ecosystem's migration to httr2. Version 2.0 then removed a large amount of accumulated public surface — the logging functions, vcr_last_error(), the exported R6 classes including RequestHandler, Request, VcrResponse and HTTPInteractionList, and several configuration options that had stopped working or could not be implemented correctly.

Read the full vcr trajectory →

What is webchem?

Adding chemical databases with one hand while public ones close programmatic access with the other.

webchem is the R interface to public chemical data — retrieving identifiers, properties and structures across roughly a dozen web services. Its release history reads as a running account of which of those services still allow automated access. Version 1.3.0 removed two functions outright because their sources withdrew: ChemIDplus was retired by the NLM, and PAN stopped supporting programmatic access. Version 1.3.1 continues the pattern, updating URLs that stopped working and noting that ChemSpider InChIKey validation now requires an API key like the rest of that provider's endpoints.

Read the full webchem trajectory →

vcr vs webchem: editorial side-by-side

V
vcr
ANALYTICS
0.0

Added the HTTP client everyone moved to, then deleted a decade of its own public surface.

◆ Current state

vcr records HTTP interactions to disk so R package tests can replay them without network access. Two releases define its current state. Version 1.6.0 added httr2 support alongside the existing httr and crul backends, following the R ecosystem's migration to httr2. Version 2.0 then removed a large amount of accumulated public surface — the logging functions, vcr_last_error(), the exported R6 classes including RequestHandler, Request, VcrResponse and HTTPInteractionList, and several configuration options that had stopped working or could not be implemented correctly.

◆ Where it's heading

The package is consolidating after years of additive growth. The 2.0 removals are almost all things that were exported without needing to be, or options that promised behaviour the implementation could not guarantee — check_cassette_names() was deprecated precisely because it cannot be made correct. Cassette maintenance is being simplified too, with re_record_interval now the single mechanism for expiring recordings.

◆ Prediction

Expect the post-2.0 releases to be about migration support and fallout from the removed API, since the breaking list is long enough that reverse dependencies will surface problems. Async support for httr2 stays blocked until req_perform_parallel gains a mocking hook, which the entries note is upstream work.

W
webchem
ANALYTICS
0.0

Adding chemical databases with one hand while public ones close programmatic access with the other.

◆ Current state

webchem is the R interface to public chemical data — retrieving identifiers, properties and structures across roughly a dozen web services. Its release history reads as a running account of which of those services still allow automated access. Version 1.3.0 removed two functions outright because their sources withdrew: ChemIDplus was retired by the NLM, and PAN stopped supporting programmatic access. Version 1.3.1 continues the pattern, updating URLs that stopped working and noting that ChemSpider InChIKey validation now requires an API key like the rest of that provider's endpoints.

◆ Where it's heading

Two opposing forces run through these entries. The package keeps widening its coverage — ChEMBL in 1.2.0, LIPID MAPS and SwissLipids identifiers via Wikidata, structure images, Mol export — while the open, unauthenticated end of the chemical web keeps contracting. The other consistent thread is interface harmonisation: successive releases have converged the get_* functions on the same query and from arguments, tibble returns, and CAS reformatting, so the package feels like one interface rather than a dozen wrappers.

◆ Prediction

Expect further defunct functions and URL repairs as more providers move behind keys or shut down, alongside occasional additions of sources that remain open. The entries show no sign of a general credential-management layer, which is what a package facing this trend would eventually need.

Alternatives to vcr and webchem

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 vcr or webchem.

See all vcr alternatives → · See all webchem alternatives →

Recent activity from vcr and webchem

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

  1. 8mo agovcr2.0 removes the logging API and the exported R6 classes
  2. 1y agowebchemRepairs broken URLs; ChemSpider check now needs a key
  3. 1y agovcrMaintainer email address updated
  4. 2y agovcrAdds httr2 support alongside httr and crul
  5. 3y agowebchemChemIDplus and PAN queries removed as sources shut down
  6. 3y agovcrDrops compilation; test setup moves back to helper files
  7. 3y agovcrFixes request matching with escaped characters
  8. 3y agowebchemAdds ChEMBL access for bioactive compound data
  9. 4y agowebchemcir_query() returns a tibble, a breaking change
  10. 4y agowebchemAdds Mol structure export; aw_query renamed to bcpc_query
  11. 5y agovcrvcr_test_path() finds the package root correctly
  12. 5y agowebchemFetches LIPID MAPS and SwissLipids identifiers from Wikidata

Frequently asked questions

What is the difference between vcr and webchem?

Both compete on the same themes — ropensci — within Analytics. vcr and webchem are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.

Is vcr better than webchem?

Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. vcr and webchem are shipping at a similar cadence (velocity 0.0 vs 0.0, both within Sparkpulse's "active" band). For your specific use case, the alternatives sections above list other Analytics products to evaluate alongside.

What are the best alternatives to vcr?

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

What are the best alternatives to webchem?

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