release: 1.29.0

.release-please-manifest.json

@@ -1,3 +1,3 @@
 {
-  ".": "1.28.0"
+  ".": "1.29.0"
 }

.stats.yml

@@ -1,4 +1,4 @@
 configured_endpoints: 34
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/anthropic%2Fanthropic-efe26b096126c693462514b8cbd3ec3e376569232becbfb730cd26fb31c7c7e3.yml
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/anthropic%2Fanthropic-04225437444990f383d0581df2f07022baab6ad510de0f3a8bd6b07c38d83cc9.yml
 openapi_spec_hash: cae9199aabfd7b87f0ff2dcc10760c92
-config_hash: 7aaaa92e479b2962424ce93d7d24e004
+config_hash: fcc34074db6eaf64bc99b578c6c82c61

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## 1.29.0 (2026-04-07)
+
+Full Changelog: [v1.28.0...v1.29.0](https://github.com/anthropics/anthropic-sdk-ruby/compare/v1.28.0...v1.29.0)
+
+### Features
+
+* **api:** Add support for claude-mythos-preview ([3f81797](https://github.com/anthropics/anthropic-sdk-ruby/commit/3f81797e418480fecb7034e7001690cddf97e1e3))
+
 ## 1.28.0 (2026-04-03)
 
 Full Changelog: [v1.27.0...v1.28.0](https://github.com/anthropics/anthropic-sdk-ruby/compare/v1.27.0...v1.28.0)

Gemfile.lock

@@ -11,7 +11,7 @@ GIT
 PATH
   remote: .
   specs:
-    anthropic (1.28.0)
+    anthropic (1.29.0)
       cgi
       connection_pool
 

README.md

@@ -15,7 +15,7 @@ Add to your application's Gemfile:
 <!-- x-release-please-start-version -->
 
 ```ruby
-gem "anthropic", "~> 1.28.0"
+gem "anthropic", "~> 1.29.0"
 ```
 
 <!-- x-release-please-end -->

lib/anthropic/models/beta/message_create_params.rb

@@ -202,6 +202,10 @@ class MessageCreateParams < Anthropic::Internal::Type::BaseModel
         optional :system_, union: -> { Anthropic::Beta::MessageCreateParams::System }, api_name: :system
 
         # @!attribute temperature
+        #   @deprecated Deprecated. Models released after Claude Opus 4.6 do not support setting
+        #   temperature. A value of 1.0 of will be accepted for backwards compatibility, all
+        #   other values will be rejected with a 400 error.
+        #
         #   Amount of randomness injected into the response.
         #
         #   Defaults to `1.0`. Ranges from `0.0` to `1.0`. Use `temperature` closer to `0.0`
@@ -316,6 +320,9 @@ class MessageCreateParams < Anthropic::Internal::Type::BaseModel
         optional :tools, -> { Anthropic::Internal::Type::ArrayOf[union: Anthropic::Beta::BetaToolUnion] }
 
         # @!attribute top_k
+        #   @deprecated Deprecated. Models released after Claude Opus 4.6 do not accept top_k; any value
+        #   will be rejected with a 400 error.
+        #
         #   Only sample from the top K options for each subsequent token.
         #
         #   Used to remove "long tail" low probability responses.
@@ -328,6 +335,10 @@ class MessageCreateParams < Anthropic::Internal::Type::BaseModel
         optional :top_k, Integer
 
         # @!attribute top_p
+        #   @deprecated Deprecated. Models released after Claude Opus 4.6 do not support setting top_p.
+        #   A value >= 0.99 will be accepted for backwards compatibility, all other values
+        #   will be rejected with a 400 error.
+        #
         #   Use nucleus sampling.
         #
         #   In nucleus sampling, we compute the cumulative distribution over all the options

lib/anthropic/models/beta/messages/batch_create_params.rb

@@ -270,6 +270,10 @@ class Params < Anthropic::Internal::Type::BaseModel
                        api_name: :system
 
               # @!attribute temperature
+              #   @deprecated Deprecated. Models released after Claude Opus 4.6 do not support setting
+              #   temperature. A value of 1.0 of will be accepted for backwards compatibility, all
+              #   other values will be rejected with a 400 error.
+              #
               #   Amount of randomness injected into the response.
               #
               #   Defaults to `1.0`. Ranges from `0.0` to `1.0`. Use `temperature` closer to `0.0`
@@ -384,6 +388,9 @@ class Params < Anthropic::Internal::Type::BaseModel
               optional :tools, -> { Anthropic::Internal::Type::ArrayOf[union: Anthropic::Beta::BetaToolUnion] }
 
               # @!attribute top_k
+              #   @deprecated Deprecated. Models released after Claude Opus 4.6 do not accept top_k; any value
+              #   will be rejected with a 400 error.
+              #
               #   Only sample from the top K options for each subsequent token.
               #
               #   Used to remove "long tail" low probability responses.
@@ -396,6 +403,10 @@ class Params < Anthropic::Internal::Type::BaseModel
               optional :top_k, Integer
 
               # @!attribute top_p
+              #   @deprecated Deprecated. Models released after Claude Opus 4.6 do not support setting top_p.
+              #   A value >= 0.99 will be accepted for backwards compatibility, all other values
+              #   will be rejected with a 400 error.
+              #
               #   Use nucleus sampling.
               #
               #   In nucleus sampling, we compute the cumulative distribution over all the options

lib/anthropic/models/message_create_params.rb

@@ -166,6 +166,10 @@ class MessageCreateParams < Anthropic::Internal::Type::BaseModel
       optional :system_, union: -> { Anthropic::MessageCreateParams::System }, api_name: :system
 
       # @!attribute temperature
+      #   @deprecated Deprecated. Models released after Claude Opus 4.6 do not support setting
+      #   temperature. A value of 1.0 of will be accepted for backwards compatibility, all
+      #   other values will be rejected with a 400 error.
+      #
       #   Amount of randomness injected into the response.
       #
       #   Defaults to `1.0`. Ranges from `0.0` to `1.0`. Use `temperature` closer to `0.0`
@@ -280,6 +284,9 @@ class MessageCreateParams < Anthropic::Internal::Type::BaseModel
       optional :tools, -> { Anthropic::Internal::Type::ArrayOf[union: Anthropic::ToolUnion] }
 
       # @!attribute top_k
+      #   @deprecated Deprecated. Models released after Claude Opus 4.6 do not accept top_k; any value
+      #   will be rejected with a 400 error.
+      #
       #   Only sample from the top K options for each subsequent token.
       #
       #   Used to remove "long tail" low probability responses.
@@ -292,6 +299,10 @@ class MessageCreateParams < Anthropic::Internal::Type::BaseModel
       optional :top_k, Integer
 
       # @!attribute top_p
+      #   @deprecated Deprecated. Models released after Claude Opus 4.6 do not support setting top_p.
+      #   A value >= 0.99 will be accepted for backwards compatibility, all other values
+      #   will be rejected with a 400 error.
+      #
       #   Use nucleus sampling.
       #
       #   In nucleus sampling, we compute the cumulative distribution over all the options

lib/anthropic/models/messages/batch_create_params.rb

@@ -220,6 +220,10 @@ class Params < Anthropic::Internal::Type::BaseModel
                      api_name: :system
 
             # @!attribute temperature
+            #   @deprecated Deprecated. Models released after Claude Opus 4.6 do not support setting
+            #   temperature. A value of 1.0 of will be accepted for backwards compatibility, all
+            #   other values will be rejected with a 400 error.
+            #
             #   Amount of randomness injected into the response.
             #
             #   Defaults to `1.0`. Ranges from `0.0` to `1.0`. Use `temperature` closer to `0.0`
@@ -334,6 +338,9 @@ class Params < Anthropic::Internal::Type::BaseModel
             optional :tools, -> { Anthropic::Internal::Type::ArrayOf[union: Anthropic::ToolUnion] }
 
             # @!attribute top_k
+            #   @deprecated Deprecated. Models released after Claude Opus 4.6 do not accept top_k; any value
+            #   will be rejected with a 400 error.
+            #
             #   Only sample from the top K options for each subsequent token.
             #
             #   Used to remove "long tail" low probability responses.
@@ -346,6 +353,10 @@ class Params < Anthropic::Internal::Type::BaseModel
             optional :top_k, Integer
 
             # @!attribute top_p
+            #   @deprecated Deprecated. Models released after Claude Opus 4.6 do not support setting top_p.
+            #   A value >= 0.99 will be accepted for backwards compatibility, all other values
+            #   will be rejected with a 400 error.
+            #
             #   Use nucleus sampling.
             #
             #   In nucleus sampling, we compute the cumulative distribution over all the options

lib/anthropic/models/model.rb

@@ -8,6 +8,8 @@ module Models
     module Model
       extend Anthropic::Internal::Type::Union
 
+      variant const: -> { Anthropic::Models::Model::CLAUDE_MYTHOS_PREVIEW }
+
       variant const: -> { Anthropic::Models::Model::CLAUDE_OPUS_4_6 }
 
       variant const: -> { Anthropic::Models::Model::CLAUDE_SONNET_4_6 }
@@ -49,7 +51,10 @@ module Model
 
       # @!group
 
-      # Most intelligent model for building agents and coding
+      # New class of intelligence, strongest in coding and cybersecurity
+      CLAUDE_MYTHOS_PREVIEW = :"claude-mythos-preview"
+
+      # Frontier intelligence for long-running agents and coding
       CLAUDE_OPUS_4_6 = :"claude-opus-4-6"
 
       # Best combination of speed and intelligence

lib/anthropic/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Anthropic
-  VERSION = "1.28.0"
+  VERSION = "1.29.0"
 end

rbi/anthropic/models/model.rbi

@@ -17,7 +17,11 @@ module Anthropic
       TaggedSymbol = T.type_alias { T.all(Symbol, Anthropic::Model) }
       OrSymbol = T.type_alias { T.any(Symbol, String) }
 
-      # Most intelligent model for building agents and coding
+      # New class of intelligence, strongest in coding and cybersecurity
+      CLAUDE_MYTHOS_PREVIEW =
+        T.let(:"claude-mythos-preview", Anthropic::Model::TaggedSymbol)
+
+      # Frontier intelligence for long-running agents and coding
       CLAUDE_OPUS_4_6 =
         T.let(:"claude-opus-4-6", Anthropic::Model::TaggedSymbol)
 

sig/anthropic/models/model.rbs

@@ -1,7 +1,8 @@
 module Anthropic
   module Models
     type model =
-      :"claude-opus-4-6"
+      :"claude-mythos-preview"
+      | :"claude-opus-4-6"
       | :"claude-sonnet-4-6"
       | :"claude-haiku-4-5"
       | :"claude-haiku-4-5-20251001"
@@ -23,7 +24,10 @@ module Anthropic
 
       def self?.variants: -> ::Array[Anthropic::Models::model]
 
-      # Most intelligent model for building agents and coding
+      # New class of intelligence, strongest in coding and cybersecurity
+      CLAUDE_MYTHOS_PREVIEW: :"claude-mythos-preview"
+
+      # Frontier intelligence for long-running agents and coding
       CLAUDE_OPUS_4_6: :"claude-opus-4-6"
 
       # Best combination of speed and intelligence

test/anthropic/resources/beta/messages_test.rb

@@ -36,7 +36,7 @@ def test_count_tokens_required_params
     response =
       @anthropic.beta.messages.count_tokens(
         messages: [{content: "string", role: :user}],
-        model: :"claude-opus-4-6"
+        model: :"claude-mythos-preview"
       )
 
     assert_pattern do

test/anthropic/resources/completions_test.rb

@@ -7,7 +7,7 @@ def test_create_required_params
     response =
       @anthropic.completions.create(
         max_tokens_to_sample: 256,
-        model: :"claude-opus-4-6",
+        model: :"claude-mythos-preview",
         prompt: "\n\nHuman: Hello, world!\n\nAssistant:"
       )
 

test/anthropic/resources/messages_test.rb

@@ -35,7 +35,7 @@ def test_count_tokens_required_params
     response =
       @anthropic.messages.count_tokens(
         messages: [{content: "string", role: :user}],
-        model: :"claude-opus-4-6"
+        model: :"claude-mythos-preview"
       )
 
     assert_pattern do