Add dev blog post about legacy device tracker deprecation

[emontnemery]

Proposed change

Add dev blog post about legacy device tracker deprecation

Type of change

• Document existing features within Home Assistant
• Document new or changing features for which there is an existing pull request elsewhere
• Spelling or grammatical corrections, or rewording for improved clarity
• Changes to the backend of this documentation
• Remove stale or deprecated documentation

Checklist

• I have read and followed the documentation guidelines.
• I have verified that my changes render correctly in the documentation.

Additional information

• Link to relevant existing code or pull request: Deprecate legacy device tracker core#168387
• Architecture proposal: Remove support for legacy (non config entry) device trackers architecture#1375

Summary by CodeRabbit

• Documentation
  • Announced deprecation of legacy device tracker platform API with removal targeted for Home Assistant 2027.5, providing a 12-month transition window for integrations to migrate to the modern config entry-based approach.

[coderabbitai]

Warning

Rate limit exceeded

@emontnemery has exceeded the limit for the number of commits that can be reviewed per hour. Please wait 51 minutes and 23 seconds before requesting another review.

Your organization is not enrolled in usage-based pricing. Contact your admin to enable usage-based pricing to continue reviews beyond the rate limit, or try again in 51 minutes and 23 seconds.

⌛ How to resolve this issue?

After the wait time has elapsed, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

We recommend that you space out your commits to avoid hitting the rate limit.

🚦 How do rate limits work?

CodeRabbit enforces hourly rate limits for each developer per organization.

Our paid plans have higher rate limits than the trial, open-source and free plans. In all cases, we re-allow further reviews after a brief timeout.

Please see our FAQ for further information.

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 7a1a74f3-3783-40b1-9a41-781382df0279

📥 Commits

Reviewing files that changed from the base of the PR and between f8f8860 and 8d6c94a.

📒 Files selected for processing (1)

• blog/2026-04-20-legacy-device-tracker-deprecation.md

📝 Walkthrough

Walkthrough

A new blog post was added announcing the deprecation of the legacy device tracker platform API in Home Assistant, specifying a 12-month deprecation window with removal targeted for the 2027.5 release.

Changes

Cohort / File(s)	Summary
Blog Post blog/2026-04-20-legacy-device-tracker-deprecation.md	New deprecation announcement post describing the legacy device tracker platform API removal timeline, background on config entry device trackers introduced in May 2019, migration status as of April 2026, and a table of core integrations with installation counts and API type (modern vs. legacy).

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and directly describes the main change: adding a developer blog post about legacy device tracker deprecation.
Description check	✅ Passed	The description follows the template structure, includes a clear proposed change, selects the appropriate type of change, and provides relevant links to related core PR and architecture proposal.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch blog_legacy_device_tracker_deprecation

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

Actionable comments posted: 4

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@blog/2026-04-20-legacy-device-tracker-deprecation.md`:
- Line 10: Replace the phrase "12 month deprecation period" with the hyphenated
compound modifier "12-month deprecation period" in the blog post text (search
for the exact string "12 month deprecation period") to conform to Microsoft
Style Guide compound-modifier rules and improve readability.
- Around line 7-22: Heading levels skip in the post: change "### Summary" to "##
Summary" and demote the subsequent "#### Background" and "#### List of core
integrations, sorted by reported use" to "### Background" and "### List of core
integrations, sorted by reported use" respectively so headings progress
consistently (use the exact heading text values "### Summary", "####
Background", and "#### List of core integrations, sorted by reported use" to
find and update them).
- Around line 18-20: Fix the typo "legacye" -> "legacy" and tighten the awkward
phrasing in the sentence about xiaomi_miio by replacing "has a wide mix of
functionality including other things than device tracker" with a concise phrase
such as "provides functionality beyond device tracking" (refer to the text
mentioning xiaomi_miio and the phrase "legacy device tracker API"); apply
Microsoft Style Guide conciseness rules to the surrounding sentences to ensure
clarity and brevity while keeping the reference to architecture proposal 1375
intact.
- Line 26: The markdown contains an untyped fenced code block (triple backticks)
in the legacy device tracker deprecation post; update the opening fence to
specify the language by changing the opening "```" to "```text" so linting and
formatting are explicit for that code block.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 14a099ac-7191-4714-87e1-f4b3509fceb1

📥 Commits

Reviewing files that changed from the base of the PR and between 0ca211d and f8f8860.

📒 Files selected for processing (1)

• blog/2026-04-20-legacy-device-tracker-deprecation.md

[MartinHjelmare]

Suggested change

	By the end of the 12-month deprecation period, all legacy device tracker platforms will be removed from the core repo, and custom integrations implementing the legacy API will stop working.
	By the end of the 12-month deprecation period, all remaining legacy device tracker platforms will be removed from the core repository, and custom integrations implementing the legacy API will stop working.

[home-assistant]

Please take a look at the requested changes, and use the Ready for review button when you are done, thanks 👍

Learn more about our pull request process.