release: 3.19.3

[stainless-app]

Automated Release PR

3.19.3 (2026-04-03)

Full Changelog: v3.19.2...v3.19.3

Features

• Replace default model used in server-v3 api spec examples (fb347d2)

---

This pull request is managed by Stainless's GitHub App.

The semver version number is based on included commit messages. Alternatively, you can manually set the version number in the title of this pull request.

For a better experience, it is recommended to use either rebase-merge or squash-merge when merging this pull request.

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📚 Read the docs
🙋 Reach out for help or questions

[stainless-app]

🧪 Testing

To try out this version of the SDK:

pip install 'https://pkg.stainless.com/s/stagehand-python/fb347d256fea9453c9eb23d935558bd43405f934/stagehand-3.19.2-py3-none-any.whl'

Expires at: Sun, 03 May 2026 19:21:14 GMT
Updated at: Fri, 03 Apr 2026 19:21:14 GMT

[cubic-dev-ai]

No issues found across 7 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

Architecture diagram

sequenceDiagram
    participant User as User Application
    participant SDK as Stagehand Python SDK
    participant API as Stagehand API (v3)
    participant LLM as LLM Provider (OpenAI)

    Note over User,LLM: Session Initialization Flow

    User->>SDK: sessions.start(model_name="openai/gpt-5.4-mini")
    SDK->>API: CHANGED: POST /v1/sessions/start
    Note right of SDK: Request body includes updated<br/>default model: gpt-5.4-mini
    API-->>SDK: Session Configuration
    SDK-->>User: Session Object

    Note over User,LLM: Task Execution Flow (Act / Extract / Observe)

    User->>SDK: sessions.act(instruction, options)
    SDK->>API: POST /v1/sessions/{id}/act
    
    API->>LLM: CHANGED: Forward instruction to model
    Note right of API: Uses openai/gpt-5.4-mini<br/>as the execution engine
    
    alt Success
        LLM-->>API: Inference results (actions/data)
        API-->>SDK: ActionResponse
        SDK-->>User: Success result
    else Model Error / Timeout
        LLM-->>API: Error
        API-->>SDK: APIStatusError (500)
        SDK->>SDK: CHANGED: Execute retry logic
        SDK-->>User: Throw Exception
    end

    Note over SDK,API: Version Header: X-Stainless-Package-Version: 3.20.0

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[stainless-app]

Release version edited manually

The Pull Request version has been manually set to 3.19.3 and will be used for the release.

If you instead want to use the version number 3.20.0 generated from conventional commits, just remove the label autorelease: custom version from this Pull Request.

[stainless-app]

🤖 Release is at https://github.com/browserbase/stagehand-python/releases/tag/v3.19.3 🌻