Claude Haiku 5.5 Is Now Available in EidoStack!

Anthropic recently released Claude Haiku 5.5, and I've already added it to EidoStack!

Whenever a new AI model comes out, I always want to try it for myself. Not just read the announcement and look at the specs, but send a few prompts, experiment with different instructions, and see how it handles real-world tasks.

That's actually one of the main reasons I'm building EidoStack — to give developers a place where they can freely experiment with AI models without spending time setting up separate tools or writing test scripts.

And now you can try Claude Haiku 5.5 right in the Playground.

What's Interesting About Claude Haiku 5.5?

Haiku is Anthropic's family of lightweight, fast AI models. The new 5.5 version follows the same idea: fast responses, low API costs, and plenty of capabilities for everyday tasks.

Anthropic particularly recommends it for workloads that involve processing lots of requests quickly, such as classifying data, extracting information from text, generating summaries, or handling customer support inquiries.

But there's a lot more you can try with it.

For example, you can ask Haiku to explain an unfamiliar piece of code, turn unstructured text into JSON, help debug a TypeScript issue, or summarize a long document.

There are also a few interesting technical details worth mentioning.

The model supports a context window of up to 1 million tokens, can work with both text and images, and supports Adaptive Thinking — a feature that lets it automatically adjust how much reasoning effort to use.

Another thing I like is the API pricing. For requests of up to 100,000 tokens, Anthropic charges just $0.10 per million input tokens and $0.50 per million output tokens.

That makes Haiku 5.5 an interesting option to explore, especially for tasks that involve processing a large number of requests.

Let's Try It in EidoStack

I've always believed that the best way to get familiar with an AI model is simply to start using it.

Let's say you want to see how well Haiku handles structured data extraction. You can open the Playground and give it a prompt like this:

"Here's a customer support message. Identify the issue category, determine its priority, and briefly summarize the problem. Return the result as JSON."

Got a response? Great! Now try changing the system prompt, adding a few extra requirements, or giving it a more challenging example.

These kinds of small experiments often tell you much more about how a model behaves than simply reading its documentation.

And that's exactly the kind of experience I'm trying to make easier with EidoStack.

Just select Claude Haiku 5.5, connect your Anthropic API key, and start experimenting. You can send prompts, tweak instructions, explore responses, and keep track of token usage and API costs.

Your conversation history is saved too, so you can always come back to previous experiments and pick up where you left off.

No need to build a separate testing app — just you, your prompt, and the model.