Sourced from rack's changelog.

Changelog

All notable changes to this project will be documented in this file. For info on how to format all future additions to this file please reference Keep A Changelog.

Unreleased

SPEC Changes

• Define rack.response_finished callback arguments more strictly. (#2365, @​skipkayhil)

Added

• Add Rack::Files#assign_headers to allow overriding how the configured file headers are set. (#2377, @​codergeek121)
• Add support for rack.response_finished to Rack::TempfileReaper. (#2363, @​skipkayhil)
• Add support for streaming bodies when using Rack::Events. (#2375, @​unflxw)

Changed

• Raise before exceeding a part limit, not after. (#2362, @​matthew-puku)
• Rack::Deflater now uses a fixed GZip mtime value. (#2372, @​bensheldon)

Fixed

• Fix an issue where a NoMethodError would be raised when using Rack::Events with streaming bodies. (#2375, @​unflxw)

[3.2.0] - 2025-07-31

This release continues Rack's evolution toward a cleaner, more efficient foundation while maintaining backward compatibility for most applications. The breaking changes primarily affect deprecated functionality, so most users should experience a smooth upgrade with improved performance and standards compliance.

SPEC Changes

• Request environment keys must now be strings. (#2310, [@​jeremyevans])
• Add nil as a valid return from a Response body.to_path (#2318, [@​MSP-Greg])
• Rack::Lint#check_header_value is relaxed, only disallowing CR/LF/NUL characters. (#2354, [@​ioquatix])

Added

• Introduce Rack::VERSION constant. (#2199, [@​ioquatix])
• ISO-2022-JP encoded parts within MIME Multipart sections of an HTTP request body will now be converted to UTF-8. (#2245, @​nappa)
• Add Rack::Request#query_parser= to allow setting the query parser to use. (#2349, [@​jeremyevans])
• Add Rack::Request#form_pairs to access form data as raw key-value pairs, preserving duplicate keys. (#2351, [@​matthewd])

Changed

• Invalid cookie keys will now raise an error. (#2193, [@​ioquatix])
• Rack::MediaType#params now handles empty strings. (#2229, [@​jeremyevans])
• Avoid unnecessary calls to the ip_filter lambda to evaluate Request#ip (#2287, [@​willbryant])
• Only calculate Request#ip once per request (#2292, [@​willbryant])
• Rack::Builder #use, #map, and #run methods now return nil. (#2355, [@​ioquatix])
• Directly close the body in Rack::ConditionalGet when the response is 304 Not Modified. (#2353, [@​ioquatix])

... (truncated)

• 0f76d43 Bump patch version.
• 493a411 Fix thin integration.
• 54e4ffd Unbounded parameter parsing in Rack::QueryParser.
• 9163ac3 Bump patch version.
• 8e52d2a Backport #2263 to v2.2, fix: malformed charset param (#2338)
• 2a32eca Bump patch version.
• 034a13c Change CGI::Cookie.new to Cookie.new (#2335)
• d2b6af2 Bump patch version.
• f34f2eb Feature detect CGI::Cookie. (#2333)
• 2f928b9 Replace usage of CGI::Cookie (#2329)
• Additional commits viewable in compare view

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot close will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
• @dependabot show <dependency name> ignore conditions will show all of the ignore conditions of the specified dependency
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
  You can disable automated security fix PRs for this repo from the Security Alerts page.