Implementing Feature

Implementing feature

Implement a feature from a specification document, from reading the spec through to a merge-ready PR.

Usage examples

Use by pointing to a spec folder:

/implementing-feature specs/2025-12-12-menu-button

Or with a URL to a raw document:

/implementing-feature https://raw.githubusercontent.com/streamlit/streamlit/refs/heads/develop/specs/2025-12-12-menu-button/product-spec.md

Or with a GitHub issue (feature request as spec):

/implementing-feature https://github.com/streamlit/streamlit/issues/12345

When to use

• You have a spec folder, URL, or GitHub issue to implement
• You want end-to-end implementation: spec → code → tests → PR
• You want a guided workflow that ensures all implementation steps are followed

Workflow

Copy this checklist and track your progress:

Progress:
- [ ] Phase 1: Read and understand the spec
- [ ] Phase 2: Research and plan
- [ ] Phase 3: Implement and test
- [ ] Phase 4: Verify against spec
- [ ] Phase 5: Finalize for merge

Phase 1: Read and understand the spec

• If given a folder path (e.g., specs/YYYY-MM-DD-feature-name):
  • Read all files in the folder (specs, images, code samples)
• If given a URL to a raw document:
  • Fetch the spec content directly from the URL
• If given a GitHub issue URL:
  • Use the gh client to read the issue and all comments
  • Treat the issue description and discussion as the feature specification

Phase 2: Research and plan

• Search for similar existing features to follow patterns
• Use the /understanding-streamlit-architecture skill to understand relevant internals
• If there is technical complexity, write a tech-spec / implementation plan in work-tmp/

Phase 3: Implement and test

• Implement the feature based on the provided spec. Read wiki/new-feature-guide.md for tips.
• Run make protobuf after any protobuf changes
• Add unit tests (Python in lib/tests/, frontend co-located) and E2E tests in e2e_playwright/
• Use the /debugging-streamlit skill to test and debug backend, frontend, and UI

Phase 4: Verify against spec

• Re-read the spec to verify all requirements are met; document any necessary divergences in work-tmp/

Phase 5: Finalize for merge

• Run /finalizing-pr skill to execute quality checks, create the PR, and make it merge-ready
• Follow all steps until the PR is merge-ready

Important notes

• Be fully autonomous - Do NOT stop or pause to ask for confirmation. You are tasked to go from spec to merge-ready PR without human intervention. Note any open questions or ambiguities in the PR description rather than blocking on them.
• Follow Streamlit patterns - Check existing similar features for conventions
• Reference the spec in PR - Include spec link in PR description
• Test thoroughly - Use /debugging-streamlit before finalizing
• Commit incrementally - Make logical commits as you implement each phase

Converted and distributed by TomeVault — claim your Tome and manage your conversions.