Guides and examples: email providers, i18n, monorepos, MJML and Beefree, upgrading to 0.3 - #71

Stacked on the MJML and Beefree importers PR (#70), which is stacked on the 0.3.0 library PR (#69): it shows only the guides and examples. Merge it after both, with its base changed to main first. The repo's tests only run on pull requests into main or develop, so CI starts here once the base is main; until then, the validation below was run locally, with #70's head 72c037d (which has #69's head 11ec4e2) merged in.

What

• Email providers: the content-workflows example sends with 14 providers. Mailgun, Azure, MailerSend, Scaleway, Plunk, Lettermint, Brevo, Inbound and EUSend are added, each tested against mocked endpoints. Guide: email providers.
• i18n example: one template in English and Arabic with react-intl, react-i18next and next-intl, including right-to-left output. It runs in CI. Guide: translations and right-to-left, written for 0.3 (inline <FormattedMessage>/<Trans> children, right alignment by default in RTL, Tailwind's logical classes following the direction, a class provider such as <IntlProvider> around the root, and an async component failing a synchronous render).
• Migrating from MJML: leads with npx @unlayer/migrate <dir> --from mjml: what becomes editable blocks, what stays MJML's HTML, includes, MJML 3, what the check compares against (text made too faint to read fails it), and direction: <mjml dir="rtl"> becomes a right-to-left email only where no section or group shows its columns left to right, since Elements lays out every Row in the email's direction and MJML doesn't. The hand mapping stays, for tuning the output.
• Migrating from Beefree (new): the JSON it reads, the HTML export to put beside it so the template is checked (text made too faint to read fails it), ? for unverified, and the declared differences.
• Upgrading: what changes from 0.2 to 0.3 and what to check (17 items: a part that fails fails the render by default, the text block's markup, images sized in their slot, the editor's base stylesheet, the Provider, right-to-left alignment, async components and a <Suspense> around the template, how the plain text differs, React's ids, migrate's range, an app's renderToString providers reaching a template only till Elements learns the context's default, …), what else changed (a class component around the root is unwrapped), the new entries (Tailwind's logical classes follow the text direction; Markdown keeps raw HTML to an allowlist), and the 0.1 to 0.2 guide.
• Monorepos: one Elements copy, React resolution and workspaces (what two copies of React do with 0.3's renderer), previewing with a small render script.
• No unpublished packages: the guides don't mention the local preview package or the CLI commands that need it.
• READMEs: point to the Elements skill in unlayer/unlayer-skills, and list @unlayer/migrate as published, with its MJML and Beefree sources. The changelog only gets a line pointing to the upgrade guide (its 0.1.1 to 0.2.1 history is in @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69).

Validation

• An earlier merge of @unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's head had one conflict, in the changelog: @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69 dates its heading 0.3.0 (2026-10-22) next to the line this PR adds pointing to the upgrade guide; both are kept. The last ones, which bring @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's optional peers of any version (Tailwind CSS 3 and prettier 2 stay installed, with messages that say to upgrade them; the Tailwind and async guides say so) and its Next.js 16 consumer on 16.4.2, had none. The upgrade and i18n guides follow @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's last fixes (the React versions the tests run on; an async template given to a synchronous renderer is a RenderError naming it). The merge before it, which brought @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's fixes for Tailwind and link-target values that could end an attribute, Markdown's size limits, inline JSX's encoded URLs, merge tags in the plain text, and what a context reads around an app's renders, had no conflicts; the upgrade guide adds item 17 for the last of these (0.2.1 passed an app's renderToString providers through; 0.3.0 reads the app's value only before it has learned the context's default, as @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's tests pin). A merge of @unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's head that brought @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's fixes for very long Markdown, Markdown and Tailwind classes from data rendering in time linear in their size, a table in nested quotes charged once, a class whose url() could run code refused, and link targets, Menu text and Social names that aren't strings had no conflicts. A merge of @unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's head that brought the round before: a javascript: URL in the links Elements writes is one that throws with React 18 too; a render reads its first 2,000 different Tailwind classes; only the Tailwind class built alone and seen to fail is refused; a <Tailwind>'s own classes are built at once; a cid: or base64 image url() is kept; a link of null is none had no conflicts. A merge of @unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's head (@unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's head ec22f7e) brought @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's last fixes: a Tailwind plugin that throws for one class fails only the component whose class it is, from the first render, and changes nothing in other renders on the same handle (where Tailwind compiles again, a render that needs a class fails saying to render again, and the async renderers wait); the links the editor's exporters write (a Button's, an Image's, an email's Menu and Social) get a javascript: URL as one that throws, in the HTML and the design; a null Menu item or Social icon is skipped; the Markdown guide gives output and memory per kilobyte. The latest merge of @unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's head (72c037d, @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's head 11ec4e2) brings @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's last fixes: every timing test in the react and shared packages through one helper (a cost at two sizes timed again where it looks slow, each size's fastest of three samples of 20 ms at least; a cost against a limit run twice more where it's over, held to the limit times the machine's measured slowness), after one more CI flake on a 5 ms baseline; and the streamed-context test's page data released once its shell is written, not on a timer that React 18's setImmediate-scheduled shell could lose to. The merge before it (@unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's head aa39347, @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's head 8c7eef3) brought: Tailwind's stylesheet, which each build reads again whole, read in time linear in its size on Node 20 (a compiler's of 2,400 classes, 114 KB, took 118 ms a build, now 5.6 ms); the Tailwind class growth fuzz retimed, with the one variant shape Tailwind's own compiler reads in time squared left out and read at the 512-character cap under 100 ms. The merge before it (@unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's head a60e642, @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's head 37c8880) brought: tests that hold on CI's runners (a turn of the event loop between tests, so vitest's report of them can't time out; the Tailwind swap test's stylesheets read where Elements reads them; the growth tests time a shape that looks slow again, then at ten times the size, and each quote against a quarter of its size; the deep code test within Node 20's stack; 30 s a test), and docs that say what ships (moduleResolution: "node" needs skipLibCheck, an image's source is written as given, a prop leaves out a url() in double quotes). The merge before it (@unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's head 72d24c6, @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's head 1c1a3c2) brought: markup's inline styles hold what an escaped style can (a theme's double-quoted font names, url("…"), a string's ;), and refuse only what could end the attribute or start a tag once read, or a URL a component can't take (url(javascript:…)); a render's shared work is kept across copies of Elements and in all the code it runs; plain text leaves out blocked URLs and keeps its placeholders from text that decodes to them; text placed straight in a Row or Column is said once per render; the main entry's budget is 221 KB. The merge before it (@unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's head 07ef311, @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's head 1894c35) brought: a handle keeps a fresh Tailwind compiler ready, so a synchronous loop of renders gets one at once, and past 8,000 classes on one compiler with none ready a render that needs a new class fails saying to yield or use the async renderers; markup inlines no class value a prop can't take; a render's shared work is kept to its own render (template wrappers, nested renders) and Markdown's table cells count against it; code themes are read by their own names; plain text's skip names are read as written; the main entry's budget is 219.5 KB. The merge before it (@unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's head 94c22fe, @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's head 4613284) brought: Tailwind's shared compiler is given only classes it builds in time (512 characters, 8 variants, 4 & in a class's variants, brackets 8 deep, a render's 64 KB of classes), and a class its build throws for without keeping it is found and left out; a Markdown's headings' and rich text children's classes are compiled with the render's others; an image's size string is read once; Markdown's and code's work is shared across a render, not per block; plain text's tag names are indexed by their parts; the main entry's budget is 218 KB. The merge before it (@unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's head 8c16073, @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's head cdbbce2) brought: a content prop given as null renders nothing, as in 0.2.1; a logo's height class keeps its shape; a Video's id can't add markup; Tailwind classes, rich text's markup, HTML's plain text, code's trailing whitespace, and Markdown's would-be tables, link text, list items, paragraph lines and references are read in time linear in their size; the main entry's budget is 216 KB (the upgrade guide's "Also changed" now says a style prop given as null is one not given and a content prop still renders nothing, and adds a Video's id to the values that can't add markup). The merge before it (@unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's head 4b6a73d, @unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's head 739bc41) brought: a Tailwind plugin's error tied to its class by the value Tailwind gave the function; Tailwind classes in Heading and Button children and on a lone <Link> inlined; a prop given as null one not given; a <script>'s or <style>'s text left out of rich text; a Row's anchor, a Video's link and thumbnail and a Social icon's image kept from adding markup; a Font's javascript: URL loading nothing; highlight.js's time bounded; Markdown's quotes and task lists and designToElements() linear in their size (the upgrade guide's "Also changed" adds a null prop and the anchors and video links). The merge before it (@unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's head 0bc71fe) brought: Markdown's inline syntax from data is read in time linear in its size; a Tailwind plugin's function that gives nothing, or an @apply Tailwind can't compile, no longer breaks the shared handle, and an error that can't be tied to a class fails only its render; an async render that renders again lists and says each part it leaves out once; the docs say a Table's cells are HTML and style props are written as given, and the Markdown guide gives its densest shapes' output, time and memory (the upgrade guide's entry on what's written as given lists them too). The merge before it (@unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's head 06a1825) brought: a block's link is read with its character references decoded (javascript:, javascript:), in every shape, so no javascript: link the editor's exporters write runs; a Tailwind plugin's error is pinned on its class where another utility gives the class CSS too and inside compound variants, in every render; an async render whose own class makes Tailwind compile again renders again once it has; the Markdown guide gives memory for its worst shape, deeply nested quotes. It had no conflicts, and the upgrade guide's "Also changed" lists what of these changes what 0.2 did: every javascript: link runs nothing (the editor's exporters' own links too, and on React 18), and a link or a Menu item or Social icon of null is none. The packages' tests pass on the merged branch (react 1,787, migrate 366, from-react-email 344, convert-core 220, shared 129), and the typechecks are clean.
• content-workflows: typecheck and 13/13 tests pass. i18n: typecheck and 4/4 pass.
• A replay of the repo's CI workflow on a clean checkout, the new i18n step included, passes every step.
• The MJML and Beefree guides' output was checked by running the CLI on the committed fixtures with the merged build (MJML 19 ✓; Beefree 10 ✓ and 7 ?). --strict, includes outside the folder, MJML 3, unknown Beefree versions and the Elements version check were run before the merge, which doesn't change that code; migrate's tests for them pass.
• Each upgrade item was checked by rendering with 0.2.1 and with 0.3.0 (@unlayer/react-elements 0.3.0: Tailwind, Markdown, code, fonts, async, codegen and editor-parity fixes #69's final head for the ones this update adds: the plain text, a class component around the root, error boundaries, a <Suspense> around the template, Tailwind's logical classes in right-to-left), and so were the i18n and monorepo guides' statements about errors, class providers and two copies of React.
• The MJML guide's direction notes follow @unlayer/migrate: MJML and Beefree importers (--from mjml|beefree) #70's converter and the @unlayer/migrate README, and the MJML and Beefree guides' faint-text failure follows its check; migrate's CLI tests for a right-to-left MJML template and for links made too faint to read pass on the merged branch.
• Every relative link in the changed docs resolves.