This PR was opened by the [Changesets
release](https://github.com/changesets/action) GitHub action. When
you're ready to do a release, you can merge this and the packages will
be published to npm automatically. If you're not ready to do a release
yet, that's fine, whenever you add more changesets to main, this PR will
be updated.


# Releases
## vercel@50.27.0

### Minor Changes

- Add `vercel agent init` command that generates an AGENTS.md file with
Vercel deployment best practices
([#15356](#15356))

### Patch Changes

- print vercel CLI version on VERCEL=1
([#15359](#15359))

- Updated dependencies
\[[`62700e88d527e3a3be2b317b805f778f3bf97f86`](62700e8)]:
    -   @vercel/next@4.15.40

## @vercel/next@4.15.40

### Patch Changes

- vary fallback `allowQuery` by params for partial fallback shells
([#15338](#15338))


<!-- VADE_RISK_START -->
> [!NOTE]
> Low Risk Change
>
> This PR is an automated Changesets release that only bumps version
numbers in package.json files and updates CHANGELOG.md files with
release notes.
> 
> - Version bumps: vercel 50.26.1 → 50.27.0, @vercel/next 4.15.39 →
4.15.40
> - Changelog updates documenting new features and patches
> - Deleted changeset markdown files consumed by release process
>
> <sup>Risk assessment for [commit
61c7c67](https://github.com/vercel/vercel/commit/61c7c67b4789c68204b0a7bb6ab66c75e3c57997).</sup>
<!-- VADE_RISK_END -->

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

Summary

- Adds vercel agent init command that generates an AGENTS.md file with
Vercel
  deployment best practices
- When an AGENTS.md already exists, appends the best practices section
to the bottom
  - Skips if the best practices section is already present (idempotent)
- Supports interactive TTY mode with confirmation prompt and
non-interactive CI mode
  via --yes flag
  - Includes spinner animation and styled success output
  - Adds telemetry tracking for init argument and --yes flag
  - Adds 10 unit tests covering all code paths


  Context

AI coding agents (Claude Code, Cursor, Gemini, Codex, etc.) read
AGENTS.md files to
understand project conventions. This command gives users a one-liner to
inject
Vercel-specific best practices - covering functions, caching, edge
runtime,
environment variables, security, observability, and more - so agents
follow Vercel
  conventions out of the box.

  Test plan

  - Unit test: --help returns exit code 2
  - Unit test: --help tracks telemetry
  - Unit test: creates AGENTS.md in TTY mode with user confirmation
  - Unit test: creates AGENTS.md in non-TTY mode with --yes
  - Unit test: errors in non-TTY mode without --yes
  - Unit test: appends to existing AGENTS.md without best practices
  - Unit test: skips when best practices already present (idempotent)
  - Unit test: user declining prompt returns 0 with "Canceled"
  - Unit test: implicit init subcommand (vercel agent --yes)
  - Unit test: unknown subcommand returns exit code 1
  - All 10 agent init tests pass

<!-- VADE_RISK_START -->
> [!NOTE]
> Low Risk Change
>
> This PR adds a new CLI command `vercel agent init` that
generates/updates an AGENTS.md file with best practices documentation,
containing only new feature code, telemetry tracking, and comprehensive
unit tests with no security-sensitive changes.
> 
> - New CLI command `agent init` for generating AGENTS.md documentation
file
> - Telemetry tracking for command usage and flags
> - 10 unit tests covering all code paths
>
> <sup>Risk assessment for [commit
2bc4480](https://github.com/vercel/vercel/commit/2bc44807871bfc4846614ec9ec714a7fdca894c7).</sup>
<!-- VADE_RISK_END -->