diff --git a/.gitignore b/.gitignore
index 4556905e4..3220ae739 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,6 +13,8 @@
 .claude
 !.claude/skills/
 
+.tool-versions
+
 config/release/bin
 config/release/bundle
 config/release/.bundle
diff --git a/Gemfile b/Gemfile
index 390bdd174..216fa5ed2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,14 +12,14 @@ source "https://rubygems.org"
 group :development do
   gem "aws_lambda_ric", "~> 3.1", ">= 3.1.3"
   # graphql-c_parser is no longer a hard dependency, but we include it here for faster CI tests
-  gem "graphql-c_parser", "~> 1.1", ">= 1.1.3"
+  gem "graphql-c_parser", "~> 1.1", ">= 1.1.3", platforms: :ruby
   gem "benchmark-ips", "~> 2.14"
   gem "coderay", "~> 1.1", ">= 1.1.3"
   gem "factory_bot", "~> 6.5", ">= 6.5.6"
   gem "faker", "~> 3.6"
 
   # Pin to a GitHub SHA until Ruby 4.0 support has been released
-  gem "flatware-rspec", "~> 2.3", ">= 2.3.4", github: "briandunn/flatware", ref: "0403ac1137cc7958fe06db2c0563dfbab0bd24db"
+  gem "flatware-rspec", "~> 2.3", ">= 2.3.4", github: "briandunn/flatware", ref: "0403ac1137cc7958fe06db2c0563dfbab0bd24db", platforms: :ruby
 
   gem "httpx", "~> 1.7", ">= 1.7.2"
   gem "memory_profiler", "~> 1.1"
@@ -40,7 +40,7 @@ group :development do
   gem "simplecov", "~> 0.22"
   gem "simplecov-console", "~> 0.9", ">= 0.9.4"
   gem "standard", "~> 1.53.0"
-  gem "steep", "~> 1.10.0"
+  gem "steep", "~> 1.10.0", platforms: :ruby
   gem "super_diff", "~> 0.18"
   gem "vcr", "~> 6.4"
 end
@@ -50,9 +50,11 @@ group :site do
   # Pin to a GitHub SHA until Ruby 4.0 support has been released: https://github.com/filewatcher/filewatcher/issues/286
   gem "filewatcher", "~> 2.1", github: "filewatcher/filewatcher", ref: "596fad65f3b442fee6cf30a3d8daf2767d63f8c9"
 
-  gem "html-proofer", "~> 5.2"
-  gem "jekyll", "~> 4.4", ">= 4.4.1"
-  gem "redcarpet", "~> 3.6", ">= 3.6.1"
+  platforms :ruby do
+    gem "html-proofer", "~> 5.2"
+    gem "jekyll", "~> 4.4", ">= 4.4.1"
+    gem "redcarpet", "~> 3.6", ">= 3.6.1"
+  end
 
   # Pull in a YAML syntax highlighting fix so that our JSON schemas render correctly at the website:
   # https://github.com/rouge-ruby/rouge/pull/2156
@@ -81,8 +83,9 @@ if repo_root == __dir__
   require_relative "elasticgraph-support/lib/elastic_graph/version"
 
   # Depend on each ElasticGraph gem in the repo.
+  # Use absolute paths for JRuby compatibility (JRuby resolves `path:` relative to cwd, not Gemfile)
   gems_in_this_repo.map do |name|
-    gem name, ::ElasticGraph::VERSION, path: name
+    gem name, ::ElasticGraph::VERSION, path: "#{repo_root}/#{name}"
   end
 else
   # Otherwise, we just load the local `.gemspec` file in the current directory.
diff --git a/Gemfile.lock b/Gemfile.lock
index f6df2bd4b..b38ed5eb6 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -290,6 +290,7 @@ GEM
     benchmark (0.5.0)
     benchmark-ips (2.14.0)
     bigdecimal (4.0.1)
+    bigdecimal (4.0.1-java)
     coderay (1.1.3)
     colorator (1.1.0)
     concurrent-ruby (1.3.6)
@@ -300,6 +301,7 @@ GEM
       json
     csv (3.3.5)
     date (3.5.1)
+    date (3.5.1-java)
     diff-lcs (1.6.2)
     docile (1.4.1)
     drb (2.2.3)
@@ -315,9 +317,11 @@ GEM
       eventmachine (>= 0.12.9)
       http_parser.rb (~> 0)
     erb (6.0.1)
+    erb (6.0.1-java)
     ethon (0.15.0)
       ffi (>= 1.15.0)
     eventmachine (1.2.7)
+    eventmachine (1.2.7-java)
     factory_bot (6.5.6)
       activesupport (>= 6.1.0)
     faker (3.6.0)
@@ -338,6 +342,10 @@ GEM
     ffi (1.17.3-arm-linux-gnu)
     ffi (1.17.3-arm-linux-musl)
     ffi (1.17.3-arm64-darwin)
+    ffi (1.17.3-java)
+    ffi-compiler (1.3.2)
+      ffi (>= 1.15.5)
+      rake
     fiber-annotation (0.2.0)
     fiber-local (1.1.0)
       fiber-storage
@@ -350,6 +358,11 @@ GEM
     google-protobuf (4.33.4-arm64-darwin)
       bigdecimal
       rake (>= 13)
+    google-protobuf (4.33.4-java)
+      bigdecimal
+      ffi (~> 1)
+      ffi-compiler (~> 1)
+      rake (>= 13)
     graphql (2.5.18)
       base64
       fiber-storage
@@ -376,11 +389,13 @@ GEM
     i18n (1.14.8)
       concurrent-ruby (~> 1.0)
     io-console (0.8.2)
+    io-console (0.8.2-java)
     io-event (1.14.2)
     irb (1.16.0)
       pp (>= 0.6.0)
       rdoc (>= 4.0.0)
       reline (>= 0.4.2)
+    jar-dependencies (0.5.5)
     jekyll (4.4.1)
       addressable (~> 2.4)
       base64 (~> 0.2)
@@ -406,6 +421,7 @@ GEM
       listen (~> 3.0)
     jmespath (1.6.2)
     json (2.18.0)
+    json (2.18.0-java)
     json_schemer (2.5.0)
       bigdecimal
       hana (~> 1.3)
@@ -444,6 +460,8 @@ GEM
       racc (~> 1.4)
     nokogiri (1.19.0-arm64-darwin)
       racc (~> 1.4)
+    nokogiri (1.19.0-java)
+      racc (~> 1.4)
     opensearch-ruby (3.4.0)
       faraday (>= 1.0, < 3)
       multi_json (>= 1.0)
@@ -469,8 +487,12 @@ GEM
     psych (5.3.1)
       date
       stringio
+    psych (5.3.1-java)
+      date
+      jar-dependencies (>= 0.1.7)
     public_suffix (7.0.2)
     racc (1.8.1)
+    racc (1.8.1-java)
     rack (3.2.4)
     rack-test (2.2.0)
       rack (>= 1.3)
@@ -602,6 +624,7 @@ GEM
       uri (>= 0.12.0)
     stringio (3.2.0)
     strscan (3.1.7)
+    strscan (3.1.7-java)
     super_diff (0.18.0)
       attr_extras (>= 6.2.4)
       diff-lcs
@@ -643,6 +666,7 @@ PLATFORMS
   riscv64-linux-gnu
   riscv64-linux-musl
   ruby
+  universal-java-24
   x86-cygwin
   x86-linux-android
   x86-mingw-ucrt
@@ -731,6 +755,7 @@ CHECKSUMS
   benchmark (0.5.0) sha256=465df122341aedcb81a2a24b4d3bd19b6c67c1530713fd533f3ff034e419236c
   benchmark-ips (2.14.0) sha256=b72bc8a65d525d5906f8cd94270dccf73452ee3257a32b89fbd6684d3e8a9b1d
   bigdecimal (4.0.1) sha256=8b07d3d065a9f921c80ceaea7c9d4ae596697295b584c296fe599dd0ad01c4a7
+  bigdecimal (4.0.1-java) sha256=95c40a0a92dfb83b293f4b9865cd27caa7c045bedab86f3620e5dc27e6553083
   coderay (1.1.3) sha256=dc530018a4684512f8f38143cd2a096c9f02a1fc2459edcfe534787a7fc77d4b
   colorator (1.1.0) sha256=e2f85daf57af47d740db2a32191d1bdfb0f6503a0dfbc8327d0c9154d5ddfc38
   concurrent-ruby (1.3.6) sha256=6b56837e1e7e5292f9864f34b69c5a2cbc75c0cf5338f1ce9903d10fa762d5ab
@@ -738,6 +763,7 @@ CHECKSUMS
   console (1.34.2) sha256=1c036abf606ccec83f9dc28f0c31710fe5936ffe7ba5d235ae2865590a482d58
   csv (3.3.5) sha256=6e5134ac3383ef728b7f02725d9872934f523cb40b961479f69cf3afa6c8e73f
   date (3.5.1) sha256=750d06384d7b9c15d562c76291407d89e368dda4d4fff957eb94962d325a0dc0
+  date (3.5.1-java) sha256=12e09477dc932afe45bf768cd362bf73026804e0db1e6c314186d6cd0bee3344
   diff-lcs (1.6.2) sha256=9ae0d2cba7d4df3075fe8cd8602a8604993efc0dfa934cff568969efb1909962
   docile (1.4.1) sha256=96159be799bfa73cdb721b840e9802126e4e03dfc26863db73647204c727f21e
   drb (2.2.3) sha256=0b00d6fdb50995fe4a45dea13663493c841112e4068656854646f418fda13373
@@ -770,8 +796,10 @@ CHECKSUMS
   elasticsearch-api (9.2.0) sha256=775136055d56a3d23be13a93ba8d67c5bb0ed2895f15270ca144fbc0ae920190
   em-websocket (0.5.3) sha256=f56a92bde4e6cb879256d58ee31f124181f68f8887bd14d53d5d9a292758c6a8
   erb (6.0.1) sha256=28ecdd99c5472aebd5674d6061e3c6b0a45c049578b071e5a52c2a7f13c197e5
+  erb (6.0.1-java) sha256=5c6b8d885fb0220d4a8ad158f70430d805845939dd44827e5130ef7fdbaed8ba
   ethon (0.15.0) sha256=0809805a035bc10f54162ca99f15ded49e428e0488bcfe1c08c821e18261a74d
   eventmachine (1.2.7) sha256=994016e42aa041477ba9cff45cbe50de2047f25dd418eba003e84f0d16560972
+  eventmachine (1.2.7-java) sha256=11ab7af3505f53ed7565d6a13fe73568fe0d6fac647c8816430e9c3171c8c58f
   factory_bot (6.5.6) sha256=12beb373214dccc086a7a63763d6718c49769d5606f0501e0a4442676917e077
   faker (3.6.0) sha256=4ce80bf91c8d09bbfff4c5596690bf862d60eac420f86737ca8ce12a54dc464a
   faraday (2.14.0) sha256=8699cfe5d97e55268f2596f9a9d5a43736808a943714e3d9a53e6110593941cd
@@ -783,6 +811,8 @@ CHECKSUMS
   ffi (1.17.3-arm-linux-gnu) sha256=5bd4cea83b68b5ec0037f99c57d5ce2dd5aa438f35decc5ef68a7d085c785668
   ffi (1.17.3-arm-linux-musl) sha256=0d7626bb96265f9af78afa33e267d71cfef9d9a8eb8f5525344f8da6c7d76053
   ffi (1.17.3-arm64-darwin) sha256=0c690555d4cee17a7f07c04d59df39b2fba74ec440b19da1f685c6579bb0717f
+  ffi (1.17.3-java) sha256=be1ecc86edbf71b9ab59212a23b33efec431c0446cb3183066d8a960a1946d3a
+  ffi-compiler (1.3.2) sha256=a94f3d81d12caf5c5d4ecf13980a70d0aeaa72268f3b9cc13358bcc6509184a0
   fiber-annotation (0.2.0) sha256=7abfadf1d119f508867d4103bf231c0354d019cc39a5738945dec2edadaf6c03
   fiber-local (1.1.0) sha256=c885f94f210fb9b05737de65d511136ea602e00c5105953748aa0f8793489f06
   fiber-storage (1.0.1) sha256=f48e5b6d8b0be96dac486332b55cee82240057065dc761c1ea692b2e719240e1
@@ -793,6 +823,7 @@ CHECKSUMS
   forwardable-extended (2.6.0) sha256=1bec948c469bbddfadeb3bd90eb8c85f6e627a412a3e852acfd7eaedbac3ec97
   google-protobuf (4.33.4) sha256=86921935b023ed0d872d6e84382e79016c91689be0520d614c74426778f13c16
   google-protobuf (4.33.4-arm64-darwin) sha256=63bb57e3d7108986f961546a536adaa38bd9ab5b1ebc39a1741a16c6eba3e869
+  google-protobuf (4.33.4-java) sha256=f0a4c6c93d857f3b86c0419a30e956d6e10abcc115a2ac278047052ccd11886e
   graphql (2.5.18) sha256=857dc1945e014932077eb7aedf4d4c1b086810faa3c829ffdbd74813ee294120
   graphql-c_parser (1.1.3) sha256=a0a7e3221c091285ca03987de50ba8ad49846f66748b5fdd3780729482bbc358
   hana (1.3.7) sha256=5425db42d651fea08859811c29d20446f16af196308162894db208cac5ce9b0d
@@ -804,13 +835,16 @@ CHECKSUMS
   httpx (1.7.2) sha256=10cdcd5b03794de743bec87e8cdba2ca93e2124084b6cdb1ad01b00c192a51f7
   i18n (1.14.8) sha256=285778639134865c5e0f6269e0b818256017e8cde89993fdfcbfb64d088824a5
   io-console (0.8.2) sha256=d6e3ae7a7cc7574f4b8893b4fca2162e57a825b223a177b7afa236c5ef9814cc
+  io-console (0.8.2-java) sha256=837efefe96084c13ae91114917986ae6c6d1cf063b27b8419cc564a722a38af8
   io-event (1.14.2) sha256=b0a069190eafe86005c22f7464f744971b5bd82f153740d34e6ab49548d4f613
   irb (1.16.0) sha256=2abe56c9ac947cdcb2f150572904ba798c1e93c890c256f8429981a7675b0806
+  jar-dependencies (0.5.5) sha256=2972b9fcba4b014e6446a84b5c09674a3e8648b95b71768e729f0e8e40568059
   jekyll (4.4.1) sha256=4c1144d857a5b2b80d45b8cf5138289579a9f8136aadfa6dd684b31fe2bc18c1
   jekyll-sass-converter (3.1.0) sha256=83925d84f1d134410c11d0c6643b0093e82e3a3cf127e90757a85294a3862443
   jekyll-watch (2.2.1) sha256=bc44ed43f5e0a552836245a54dbff3ea7421ecc2856707e8a1ee203a8387a7e1
   jmespath (1.6.2) sha256=238d774a58723d6c090494c8879b5e9918c19485f7e840f2c1c7532cf84ebcb1
   json (2.18.0) sha256=b10506aee4183f5cf49e0efc48073d7b75843ce3782c68dbeb763351c08fd505
+  json (2.18.0-java) sha256=74706f684baeb1a40351ed26fc8fe6e958afa861320d1c28ff4eb7073b29c7aa
   json_schemer (2.5.0) sha256=2f01fb4cce721a4e08dd068fc2030cffd0702a7f333f1ea2be6e8991f00ae396
   kramdown (2.5.2) sha256=1ba542204c66b6f9111ff00dcc26075b95b220b07f2905d8261740c82f7f02fa
   kramdown-parser-gfm (1.1.0) sha256=fb39745516427d2988543bf01fc4cf0ab1149476382393e0e9c48592f6581729
@@ -833,6 +867,7 @@ CHECKSUMS
   nokogiri (1.19.0-arm-linux-gnu) sha256=572a259026b2c8b7c161fdb6469fa2d0edd2b61cd599db4bbda93289abefbfe5
   nokogiri (1.19.0-arm-linux-musl) sha256=23ed90922f1a38aed555d3de4d058e90850c731c5b756d191b3dc8055948e73c
   nokogiri (1.19.0-arm64-darwin) sha256=0811dfd936d5f6dd3f6d32ef790568bf29b2b7bead9ba68866847b33c9cf5810
+  nokogiri (1.19.0-java) sha256=5f3a70e252be641d8a4099f7fb4cc25c81c632cb594eec9b4b8f2ca8be4374f3
   opensearch-ruby (3.4.0) sha256=0a8621686bed3c59b4c23e08cbaef873685a3fe4568e9d2703155ca92b8ca05d
   optimist (3.2.1) sha256=8cf8a0fd69f3aa24ab48885d3a666717c27bc3d9edd6e976e18b9d771e72e34e
   parallel (1.27.0) sha256=4ac151e1806b755fb4e2dc2332cbf0e54f2e24ba821ff2d3dcf86bf6dc4ae130
@@ -844,8 +879,10 @@ CHECKSUMS
   prettyprint (0.2.0) sha256=2bc9e15581a94742064a3cc8b0fb9d45aae3d03a1baa6ef80922627a0766f193
   prism (1.8.0) sha256=84453a16ef5530ea62c5f03ec16b52a459575ad4e7b9c2b360fd8ce2c39c1254
   psych (5.3.1) sha256=eb7a57cef10c9d70173ff74e739d843ac3b2c019a003de48447b2963d81b1974
+  psych (5.3.1-java) sha256=20a4a81ad01479ef060f604ed75ba42fe673169e67d923b1bae5aa4e13cc5820
   public_suffix (7.0.2) sha256=9114090c8e4e7135c1fd0e7acfea33afaab38101884320c65aaa0ffb8e26a857
   racc (1.8.1) sha256=4a7f6929691dbec8b5209a0b373bc2614882b55fc5d2e447a21aaa691303d62f
+  racc (1.8.1-java) sha256=54f2e6d1e1b91c154013277d986f52a90e5ececbe91465d29172e49342732b98
   rack (3.2.4) sha256=5d74b6f75082a643f43c1e76b419c40f0e5527fcfee1e669ac1e6b73c0ccb6f6
   rack-test (2.2.0) sha256=005a36692c306ac0b4a9350355ee080fd09ddef1148a5f8b2ac636c720f5c463
   rackup (2.3.1) sha256=6c79c26753778e90983761d677a48937ee3192b3ffef6bc963c0950f94688868
@@ -898,6 +935,7 @@ CHECKSUMS
   steep (1.10.0) sha256=1b295b55f9aaff1b8d3ee42453ee55bc2a1078fda0268f288edb2dc014f4d7d1
   stringio (3.2.0) sha256=c37cb2e58b4ffbd33fe5cd948c05934af997b36e0b6ca6fdf43afa234cf222e1
   strscan (3.1.7) sha256=5f76462b94a3ea50b44973225b7d75b2cb96d4e1bee9ef1319b99ca117b72c8c
+  strscan (3.1.7-java) sha256=acde34c12323095e46f9c46d869d41d0170e0a6817fc723ffc296372ed1088ee
   super_diff (0.18.0) sha256=9f5e77464fa75150619f7783174fbbe1bbac50a1eaf157cd39ad5584b0eac142
   terminal-table (3.0.2) sha256=f951b6af5f3e00203fb290a669e0a85c5dd5b051b3b023392ccfd67ba5abae91
   thor (1.5.0) sha256=e3a9e55fe857e44859ce104a84675ab6e8cd59c650a49106a05f55f136425e73
diff --git a/script/flatware_rspec b/script/flatware_rspec
index b9e3d0610..5f9186d06 100755
--- a/script/flatware_rspec
+++ b/script/flatware_rspec
@@ -7,19 +7,25 @@
 # Verbose form of `set -x`.
 set -o xtrace
 
-# Avoid a connection issue if a prior run was interrupted. More info:
-# https://github.com/briandunn/flatware/issues/68
-rm -f flatware-sink
+# Check if flatware is available (not on JRuby due to usage of `fork`)
+if bundle show flatware 2>/dev/null; then
+  # Avoid a connection issue if a prior run was interrupted. More info:
+  # https://github.com/briandunn/flatware/issues/68
+  rm -f flatware-sink
 
-# Limit the number of workers to 8. On some really beefy CI worker hosts, we've seen
-# flatware default to 96 workers (due to the host having 96 vCPUs!), but that's overkill,
-# and using too many workers can perform worse.
-#
-# In addition, using too many parallel processes can overwhelm the locally booted datastore,
-# because we have to create a separate set of indices for each process. The datastore tends
-# to run into limits when we use 16 processes. 8 processes seems to work better
-#
-# Note: `Etc.nprocessors` is what flatware uses internally for the default number of workers.
-worker_count=$(ruby -retc -e "puts [8, Etc.nprocessors].min")
+  # Limit the number of workers to 8. On some really beefy CI worker hosts, we've seen
+  # flatware default to 96 workers (due to the host having 96 vCPUs!), but that's overkill,
+  # and using too many workers can perform worse.
+  #
+  # In addition, using too many parallel processes can overwhelm the locally booted datastore,
+  # because we have to create a separate set of indices for each process. The datastore tends
+  # to run into limits when we use 16 processes. 8 processes seems to work better
+  #
+  # Note: `Etc.nprocessors` is what flatware uses internally for the default number of workers.
+  worker_count=$(ruby -retc -e "puts [8, Etc.nprocessors].min")
 
-bundle exec flatware rspec -w $worker_count "$@"
+  bundle exec flatware rspec -w $worker_count "$@"
+else
+  # Fall back to regular rspec when flatware unavailable (e.g. on JRuby)
+  bundle exec rspec "$@"
+fi