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Sweep 22 Oct 2026 · 04:32Z Build v2.1.308 527 read Stable v2.1.308 Latest v2.1.308 Next v2.1.308 Feeds RSS JSON llms.txt llms-full.txt Unofficial
HomeDocsClaude Developer Platform 16 Oct 2026
One change · api

whats-new-fable-5-1 changedmodels/fable-5-1/whats-new-fable-5-1

Nearest release: v2.1.302, published an hour after this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.

Recorded here
Lines+11added
Lines−9removed
From line 172 where the diff opens
First seen 1 Sep 2026 this site's first read of the page
Recorded edits18to this page, all time

The whole hunk

from line 172, old and new numbered
/
lines
from line 172
172172 ```csharp C#
173173 using Anthropic.Models.Beta;
174174 using Anthropic.Models.Beta.Messages;
175 using Model = Anthropic.Models.Messages.Model;
175176 
176177 AnthropicClient client = new();
177178 
178179 var response = await client.Beta.Messages.Create(new MessageCreateParams
179180 {
180 Model = "claude-fable-5-1",
181 Model = Model.ClaudeFable5_1,
181182 MaxTokens = 4096,
182183 OutputConfig = new() { Effort = Effort.High },
183184 Messages =
from line 210
209210 client := anthropic.NewClient()
210211 
211212 response, err := client.Beta.Messages.New(context.Background(), anthropic.BetaMessageNewParams{
212 Model: "claude-fable-5-1",
213 Model: anthropic.ModelClaudeFable5_1,
213214 MaxTokens: 4096,
214215 OutputConfig: anthropic.BetaOutputConfigParam{
215216 Effort: anthropic.BetaOutputConfigEffortHigh,
from line 247
246247 import com.anthropic.models.beta.messages.BetaOutputConfig;
247248 import com.anthropic.models.beta.messages.BetaSystemMessageOutputConfig;
248249 import com.anthropic.models.beta.messages.MessageCreateParams;
250 import com.anthropic.models.messages.Model;
249251 
250252 void main() {
251253 AnthropicClient client = AnthropicOkHttpClient.fromEnv();
252254 
253255 MessageCreateParams params = MessageCreateParams.builder()
254 .model("claude-fable-5-1")
256 .model(Model.CLAUDE_FABLE_5_1)
255257 .maxTokens(4096L)
256258 .addBeta(AnthropicBeta.MID_CONVERSATION_OUTPUT_CONFIG_2026_07_01)
257259 .outputConfig(BetaOutputConfig.builder()
from line 448
446448 ```
447449 
448450 ```csharp C#
449 var model = "claude-fable-5"; // Before
450 model = "claude-fable-5-1"; // After
451 var model = Model.ClaudeFable5; // Before
452 model = Model.ClaudeFable5_1; // After
451453 ```
452454 
453455 ```go Go
454 model := "claude-fable-5" // Before
455 model = "claude-fable-5-1" // After
456 model := anthropic.ModelClaudeFable5 // Before
457 model = anthropic.ModelClaudeFable5_1 // After
456458 ```
457459 
458460 ```java Java
459 String model = "claude-fable-5"; // Before
460 model = "claude-fable-5-1"; // After
461 Model model = Model.CLAUDE_FABLE_5; // Before
462 model = Model.CLAUDE_FABLE_5_1; // After
461463 ```
462464 
463465 ```php PHP
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