feat(wrangler): Add programmatic type generation API

[NuroDev]

Fixes RM-27721.

This change adds a programmatic Wrangler API for type generation via experimental_generateTypes, using the same core logic as wrangler types so CLI and API outputs stay aligned.

What's changed

• Added a new experimental_generateTypes implementation
• Refactored packages/wrangler/src/type-generation/index.ts to extract shared generation helpers used by both:
  • CLI (wrangler types)
  • Programmatic API (experimental_generateTypes)
• Preserved existing CLI behavior (validation, output structure, logging, runtime guidance, and file writing).
• Added JSDoc for newly introduced internal helper functions.
• Added/merged API-focused tests into packages/wrangler/src/__tests__/type-generation.test.ts, including parity checks.

Usage

import { experimental_generateTypes } from 'wrangler';

const generated = await experimental_generateTypes({
  config: 'path/to/wrangler.jsonc',
  includeRuntime: false,
});

console.log(generated.content);
//                      ^? string

---

• Tests
  • Tests included/updated
  • Automated tests not possible - manual testing has been completed as follows:
  • Additional testing not necessary because:
• Public documentation
  • Cloudflare docs PR(s): Add experimental_generateTypes documentation cloudflare-docs#30418
  • Documentation not necessary because:

A picture of a cute animal (not mandatory, but encouraged)

[changeset-bot]

🦋 Changeset detected

Latest commit: c09a25b

The changes in this PR will be included in the next version bump.

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[ask-bonk]

Review posted on PR #13717 with two findings:

1. Dead-code configPath check (medium) — In the CLI handler at lines 217-223, config.configPath is re-checked for undefined after assertConfigFileDetected already validated it during resolveGenerateTypesOptions. This block is unreachable after the refactoring and should be simplified.

2. Duplicate GenerateTypesOptions interface (low) — The same interface is defined in both src/api/generate-types.ts and src/type-generation/index.ts. These should share a single definition to prevent silent drift.

github run

[pkg-pr-new]

create-cloudflare

npm i https://pkg.pr.new/create-cloudflare@13717

@cloudflare/kv-asset-handler

npm i https://pkg.pr.new/@cloudflare/kv-asset-handler@13717

miniflare

npm i https://pkg.pr.new/miniflare@13717

@cloudflare/pages-shared

npm i https://pkg.pr.new/@cloudflare/pages-shared@13717

@cloudflare/unenv-preset

npm i https://pkg.pr.new/@cloudflare/unenv-preset@13717

@cloudflare/vite-plugin

npm i https://pkg.pr.new/@cloudflare/vite-plugin@13717

@cloudflare/vitest-pool-workers

npm i https://pkg.pr.new/@cloudflare/vitest-pool-workers@13717

@cloudflare/workers-editor-shared

npm i https://pkg.pr.new/@cloudflare/workers-editor-shared@13717

@cloudflare/workers-utils

npm i https://pkg.pr.new/@cloudflare/workers-utils@13717

wrangler

npm i https://pkg.pr.new/wrangler@13717

commit: c09a25b

[github-actions]

✅ All changesets look good

Review of .changeset/many-baths-arrive.md:

• Version Type: minor is appropriate for adding a new programmatic API feature
• Changelog Quality: Clear description explaining the new experimental_generateTypes() API, its relationship to wrangler types, and the options it supports
• Markdown Headers: No h1/h2/h3 headers present
• Experimental Features: Appropriately marked as experimental in both the description and the function name (experimental_generateTypes())

[workers-devprod]

Codeowners approval required for this PR:

• ✅ @cloudflare/wrangler

Show detailed file reviewers

[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no potential bugs to report.

View in Devin Review to see 5 additional findings.

[petebacondarwin]

Do we actually publicly document other unstable_ APIs?

[NuroDev]

Do we actually publicly document other unstable_ APIs?

Actually yes: https://developers.cloudflare.com/workers/wrangler/api/

[dario-piotrowicz]

Looks good to me 🙂

[workers-devprod]

Codeowners reviews satisfied