adf-codec/docs/decisions.md

Decisions

Each call names its flavour

2026-10-09, the maintainer; names by a developer panel, 2026-10-09. Goals 4, 5 and 6.1. Valid while each flavour has a standard or a spec of its own.

A function's name says which markdown it reads or writes, and a reader reads that flavour alone:

Call	Flavour
adfToLosslessMarkdown, losslessMarkdownToAdf	the lossless flavour, spec/flavour.md
commonMarkToAdf	CommonMark as its spec says: a directive, a pipe table, ~~, == and an adf: fence read as CommonMark reads them
adfToPortableMarkdown, portableMarkdownToAdf	CommonMark, GFM's pipe tables, ~~, alerts and task markers, and Obsidian's callouts and ==; no directive and no adf: fence

The calls between markdown and HTML that todo.md item 139 ships take their flavour's name too. No adfToCommonMark: the portable writer serves every persona a CommonMark writer would. The panel picked portable 4 of 7 over plain 3, gfm and rendered none: the export readers read it as "renders anywhere, lossy", and three readers read plain as holding no tables or alerts.

Portable markdown is a flavour of the grammar

2026-09-27, the maintainer. Goal 2. Valid while the portable flavour's spellings are ones the markdown grammar can read and write.

The lossy pair is the portable flavour: the markdown grammar's reader and writer with the flavour set, its spellings — alerts, callouts, task markers, == — read and written there, so a marker line and a backslash reach them intact; what the flavour cannot spell reduces ADF→ADF ahead of the writer.

The round-trip is the product

2026-08-23, real payloads 2026-09-15, the maintainer. Goal 1. Valid while a consumer saves back through the lossless pair.

losslessMarkdownToAdf(adfToLosslessMarkdown(doc)) and htmlToAdf(adfToHtml(doc)) must deep-equal doc — anything less silently destroys content an editor could not represent, in a document it did not author. When losslessness and readability conflict, losslessness wins. Round-trip equality is a property tested over a checked-in corpus (corpus/README.md), not a claim made in prose. Its real payloads are invented content written in Atlassian's editor on the maintainer's test site, so none is sanitized and a mention keeps the test user's real account id.

Markdown in is a canonical fixpoint

2026-08-23, the maintainer; every parsed document has converted back since 2026-10-04. Goals 1 and 5. Valid while markdown input may be written by hand.

The other direction is a canonical fixpoint, not byte-identity: human markdown normalizes, the way back yields the library's canonical spelling, and that spelling round-trips byte-identically.

Equality is deep

2026-08-24, deep 2026-10-03, the maintainer. Goal 1. Valid while a pipeline or a bot can build a shape the editor would not.

"Equals" is deep equality over the document's JSON values: assert.deepStrictEqual on plain objects as JSON.parse builds them, since ADF is JSON. Every key and value in doc counts, including two adjacent text nodes, an empty attrs, content or marks, and -0. Neither side is normalized. CommonMark's spelling stays wherever a document holds none of those shapes. The portable reader builds what is written, as losslessMarkdownToAdf does. Only the portable writer is lossy: its reduction reads and writes editor-normal ADF — adjacent text nodes of identical marks and no attributes merged, -0 as 0, and an empty attrs, content or marks the absent key, except the doc's content, which ADF's schema requires — so two documents the editor holds equal write the same portable markdown.

!adf:textBreak{} parts text CommonMark would join

2026-10-03, the maintainer. Goal 1. Valid while CommonMark reads adjacent text as one run.

Two adjacent text nodes CommonMark would read back as one are parted by the reserved inline leaf !adf:textBreak{}: a leaf building no node keeps both nodes and asks nothing of the text around it. A code span holds no directive, so the spans close and reopen around the leaf. The grammar: spec/flavour.md §Inline nodes, Adjacent text nodes.

A list right after one of its kind takes the other marker

2026-10-04, ordered lists in portable markdown 2026-10-09, the maintainer. Goals 4 and 5. Valid while CommonMark starts a new list where the bullet character or the ordered delimiter changes.

Every reader parts lists where the marker changes, as CommonMark does, so both writers alternate the marker between adjacent lists of a kind and no directive parts them. * is the maintainer's pick. For ordered lists in portable markdown, this overrides a reader panel's 2026-09-25 verdict, 5 of 7, for one bullet list with escaped numbers (- 1\. a). The panel chose that while no other portable spelling parted the lists, so the maintainer overrode it without a new panel. The grammar: spec/flavour.md §Canonical form.

An empty key spells empty

2026-10-03, a writer panel and the maintainer. Goals 1 and 6. Valid while no attribute value spells an empty object or array.

An attrs, content or marks key holding an empty object or array is the reserved key with the bare value empty, so a container opener and closer with nothing between them stays the node holding no content key. A writer panel chose the spelling, 5 of 7. The grammar: spec/flavour.md §Directives, Attributes, and §Marks.

-0 is spelled -0

2026-10-03, the maintainer. Goal 1. Valid while JSON's own serialization writes -0 as 0.

-0 is spelled -0 wherever the flavour writes a number or a JSON value, since JSON's grammar reads it back as -0. The grammar: spec/flavour.md §Block nodes and §The CommonMark blocks.

A block's marks are named, and colwidth is a comma list

2026-10-03 for colwidth, 5 of 7, and 2026-10-14 for marks, 3 of 3: writer panels of product managers, engineers and support agents. Goal 6. Valid while ADF types these attributes as src/adf/ does.

colwidth is its widths joined by commas, colwidth="340,420", where it was a JSON array. A block's marks names each mark with its {attrs}, in order, marks="indentation{level=2} fragment{localId=f1 name=\"Price list\"}", chosen over the escaped JSON array and the JSON array unquoted. All three writers first sketched a key per mark, {align=center}, which loses the marks' order and can clash with the node's own attributes. Where src/adf/ does not type a mark or one of its attributes, or a value holds another type, the whole array stays JSON, the general form (§Readable spellings take the try prefix). The grammar: spec/flavour.md §Block nodes.

Empty markdown is a document of no blocks

2026-10-03, a writer panel and the maintainer. Goals 1 and 6. Valid while ADF's schema requires content on doc.

Markdown holding no block reads as { content: [], type: 'doc', version: 1 }, the document spec/adf-schema/full.json requires. A document holding no content key is !adf:doc {content=none} as its only block, and a named error anywhere else. The writer panel split 4 for none and 3 for absent, and the maintainer chose none; all seven rejected a bare !adf:doc.

Unknown nodes ride the carry

2026-08-23, extended to misplaced known nodes 2026-08-26 and to code block children 2026-10-03, the maintainer. Goal 1. Valid while ADF holds nodes, or node positions, this library does not spell.

An unknown ADF node is carried opaquely — raw JSON rides a dedicated syntax in both formats and restores to a deep-equal node. The round-trip holds for documents newer than the library. So does a known node no section spells where it stands: a markdown serializer spells a node by type without checking its position, and refusing loses a document ADF itself keeps in an unsupportedBlock. A codeBlock holding a child no fence holds — anything but a text node carrying no marks, attrs or content — rides the carry whole.

The carry fence names the node type

2026-10-03, the maintainer. Goals 1 and 6. Valid while a code fence's info string reads back verbatim.

The block carry is a code fence whose info string adf:<type> names the node's type, its body the node's JSON without type: ```adf:blockCard. A type no info string carries back — by the rule a code language follows — leaves the info string adf: and keeps type in the body. Every info string opening adf: is reserved, so a codeBlock whose language opens so takes the language attribute, and carry is an ordinary language. A body holding type under a named type, or a fence whose info string is adf: alone while its body's type could be spelled in the info string, is unsupported-node-shape. The reservation is the lossless flavour's alone.

A code block is a fence per text node

2026-10-03, the maintainer. Goal 1. Valid while ADF holds a code block's text in more than one node.

A codeBlock holding several text nodes is the !adf:codeBlock container holding one fence per node, so each node keeps its own text. The fences carry one info string, since ADF holds one language, and none is empty beside another, since a text node holds text. The grammar: spec/flavour.md §The CommonMark blocks, the codeBlock bullet.

Foreign HTML sorts three ways

2026-08-23, the sort 2026-09-20, the maintainer. Goals 1 and 5. Valid while ADF holds no node for a bare container, a comment or a script. Lands with todo.md item 137.

Every foreign element htmlToAdf and the markdown readers read sorts one of three ways, never a silent drop of content:

• A container around document content that ADF has no node for unwraps to its children, its own attributes dropped: <div align="center">text</div> keeps text, losing the alignment.
• Content ADF cannot hold is an error result naming it. A comment is one: a person wrote those words, and neither of Atlassian's schemas holds them — annotation's inlineComment carries an id, placeholder is the editor's own hint, extension names a vendor app.
• What is not document content drops whole: <script> and <style>, their text with them.

<details><summary>Title</summary>…</details> is an expand titled by its summary, a nestedExpand inside another; an empty one is refused, since expand requires content. A style attribute is not read at 0.4.0: the textColor and backgroundColor it could reach cost more than they buy. The three markdown readers share one parser, so they take the same set.

Names stay text

2026-08-23, the maintainer. Goal 8. Valid while resolving a name to an id needs I/O.

A bare @name or :smile: in typed text stays a text node. Only directives produce mention/emoji/media nodes; resolving names to ids is the consumer's job.

Directives under !adf:

2026-08-23, prefixed !adf: 2026-09-16, the maintainer. Goals 5 and 6. Valid while prose does not write !adf:.

Directives are one grammar for everything markdown lacks, namespaced under !adf:: !adf:panel info … !adf:/panel blocks, !adf:mention[@Mikael]{id=5b10a2} inline, \!adf: the one escape. Not CommonMark's generic-directives proposal: its ::: claims a form prose writes, and its fence-length discipline ties a container's opener to its own body, where closing from the opener nests by itself and leaf versus container falls out of the node's content model.

CommonMark is a subset

2026-08-23, the maintainer. Goal 5. Valid while prose rarely writes the shapes the carve-outs claim.

CommonMark is a subset of the lossless flavour, with carve-outs (spec/flavour.md): literal text shaped like a directive, a pipe table or a ~~ pair is claimed, and so is a code fence whose info string opens adf: (§The carry fence names the node type). commonMarkToAdf claims none of the carve-outs (§Each call names its flavour).

Tables

2026-08-23, the maintainer. Goal 6. Valid while a pipe table holds only one header row and inline cells.

One header row plus plain inline cells → pipe table; anything richer → directive form.

Links

2026-09-13, nesting 2026-09-17, the maintainer. Goals 1 and 6. Valid while CommonMark's link syntax is what readers edit.

[text](url "title"), or <url> for a bare autolink-shaped text, wherever CommonMark spells the mark; !adf:link[text]{attrs} where it does not — an attribute CommonMark cannot hold, an href or title no canonical escape spells, a paragraph opening whose CommonMark spelling would read as a link reference definition — and a directive link CommonMark could spell is refused. No link wraps a link — the bracket form goes literal, the directive form refused — which is CommonMark's prose where its reference implementation nests one <a> in another.

An image reads as an image only alone in its paragraph, else as its alt text linked; a link text of hard breaks alone reads as its destination, then the breaks

2026-10-04, the maintainer and a writer panel, 3 of 3; []() 2026-10-09, by Goals 4 and 7, as the maintainer's plan item asked; a link text of hard breaks alone 2026-10-09, the maintainer; an image inside a link 2026-10-22, a reader panel, 3 of 3 and 5 of 7. Goals 4, 5, 6 and 7. Valid while mediaInline carries no URL, ADF holds no empty text node, a hard break takes no marks and no consumer has reported a link of hard breaks alone.

Every reader reads every CommonMark image and empty link, as spec/flavour.md §The CommonMark image and §Marks spell out. An image alone in its paragraph reads as the image, its title as the caption. Anywhere else it reads as its alt text linked to its URL, titled by its title. An empty alt text reads as the URL, and an empty link text as its destination. A link text holding only hard breaks reads as its destination, then those breaks: four of seven readers expected that over dropping them. []() reads as nothing: it renders nothing, so Goal 7 loses no content. A link alone in its paragraph whose whole text is one image reads as that image, with the link marking its media.

Inside any other link, the alt text is plain text the link marks. After the link comes (image), where image links to the image's URL and carries its title, so Goal 7 keeps both. Three readers, the bot, the LLM pipeline and a support agent, picked this 3 of 3 for a link whose text is the image alone. For a link with words beside the image, the three split on where (image) goes. Four fresh readers joined: a second bot, a second LLM pipeline, a product manager and an engineer. Five of the seven put (image) after the whole link rather than right after the alt text. Every reader rejected linking the alt text to the image, since the words would lose the link they were written in.

A link to the image's own URL takes no (image), since the link already reaches the image. The exception is an image whose title the link lacks: there (image) keeps the title.

In portableMarkdownToAdf, a [!WORD] marker with no + or - stands apart from the lines after it, and so does a + or - callout's title line, so an image alone on the marker line or after the title reads as the image: a reader panel of the bot, the LLM pipeline and a support agent, 3 of 3 on 2026-10-09, expected the picture in every case, a ticked task included. A task item holds no image in Atlassian's schema, so the paragraph a task marker opens reads its image as linked alt text, the fallback two of the three named.

The same panel confirmed the other readings on 2026-10-09: a title as the caption, an image amid text as linked alt text, and an empty link text as its URL, each 3 of 3; []() as nothing, 5 of 7. Their CommonMark suite exceptions are node-model (§The CommonMark suite checks three ways).

The title's caption, and the reader panel of 2026-10-18 that tested it, are in §An image's title is its caption when the image stands alone in its paragraph.

An image's title is its caption when the image stands alone in its paragraph, since a title counts as content

2026-10-18, the maintainer. The 2026-10-09 panel read a title as the caption, 3 of 3, and the 2026-10-11 writer panel read it as hover text, so a reader panel tested the reading again. Seven readers split: two picked the caption, two the picture alone, and three neither. Those three described hover text. No output reached the five of seven that settles a panel, so Goal 7 decided: a title counts as content, so it keeps its words. ADF holds no hover text for an image, so the caption is the one ADF node that keeps them. Valid while a link's or an image's title counts as content (README.md ## Goals, Goal 7).

A mark skips a node that cannot hold it, and a directive mark wrapping only such nodes is refused, as is a [text](url) link unless its text is hard breaks alone

2026-10-14, two reader panels of the viewer/editor app, the LLM pipeline and a support agent, 3 of 3 each. Goals 1, 4 and 6. Valid while Atlassian's schema withholds marks from inline nodes. Extended to code text under this rule, without a panel, 2026-10-14; retitled by the maintainer the same day, keeping the directive-mark refusal the old title held. Extended to border on text, which the schema withholds from text, 2026-10-31, without a panel.

A mark spelling skips a node that takes none of its type. Code text takes only code, link and annotation, and no text takes border. So **Ping !adf:mention[@A]{id=x} now** reads as bold text around a plain mention, and **`npm ci`** as plain code. A directive mark wrapping only nodes that take none of its type is unsupported-node-shape in losslessMarkdownToAdf. So is a link whose text holds something besides hard breaks but no node that takes a link: the panel refused to have [!adf:status[Done]{color=green}](/u) read as /u linked beside the status. A link text of hard breaks alone still reads as its destination, then the breaks (§An image reads as an image only alone in its paragraph). adfToLosslessMarkdown writes a node holding a mark its type does not take as !adf:carry, so the round-trip holds, except an inline card a link marks, which is refused (§Schema refusals are made in the first step alone).

A linked image is written [![alt](url)](href), a captioned image as its directive

2026-10-11, a writer panel of a product manager, an engineer and a support agent, 3 of 3 on each. Goal 6. Valid while the audience reads a title as hover text.

adfToLosslessMarkdown writes a media whose only mark is a link as [![alt](url)](href), which each reader expected before seeing the options. A captioned image keeps the !adf:caption directive: each reader read ![alt](url "title") as hover text, not a caption. The library's readers build a title as the image's caption when the image stands alone in its paragraph, since a title counts as content (§An image's title is its caption when the image stands alone in its paragraph).

A linked image standing inline in portable markdown, its link to another target, is written [alt](href) ([image](url))

2026-10-14, a reader panel of the export tool, the LLM pipeline and a support agent, and a writer panel of a product manager, an engineer and that support agent, 3 of 3 each. Goals 6 and 7. Valid while ADF holds no inline external image, so the portable reader reads an image inside a link as linked text.

Where adfToPortableMarkdown writes an external image inline, as in a table cell, and a link to another target marks it, the link keeps its target and the image follows as a link reading image. With no alt text, the link text is the link's target, which is how the reader reads [](href), so the rewrite holds. Every seat first wrote [![alt](url)](href), but the reader reads that as [alt](href) ([image](url)), so writing it breaks the byte-for-byte rewrite. Each then picked this over [alt](url) and [alt](href), which drop a target.

Ids stay site-local

2026-08-23, the maintainer. Goal 1. Valid while ADF ids are minted per site.

Identity-bearing nodes carry their ids in attributes; a document is only portable within its site — accepted.

Portable task ids come from position

2026-09-26, spelling 2026-09-29, the maintainer. Goals 7 and 8. Valid while a site rejects a task node with no localId.

portableMarkdownToAdf gives each taskList, taskItem and blockTaskItem a localId in the editor's UUID v4 shape, hashed from the whole markdown and the node's order among those it mints: the same markdown reads to the same ids every run, different markdown to different ids. The same markdown pasted twice into one document repeats its ids: determinism wins over that case.

A block a task item cannot hold stands after its task list

2026-10-09, a reader panel, 6 of 7. Goals 4, 6 and 7. Valid while Atlassian's schema holds a blockTaskItem to paragraphs and extensions.

In portableMarkdownToAdf and adfToPortableMarkdown, a task item keeps its paragraphs, then its nested task lists. The rest of the item stands after the task list. The list resumes at the next task. The panel of two bots, two LLM pipelines, a support agent, a product manager and an engineer, shown an image, a code block and a nested bullet list in a task item, picked this over turning those blocks into text inside the item (1 of 7) and over a plain bullet list keeping the markers as text (none): every reader wanted the checkboxes, and six wanted the blocks in their own form.

A callout title keeps its link targets

2026-09-29, the maintainer. Goals 6 and 7. Valid while an expand's title is a string.

portableMarkdownToAdf writes a link in a folded callout's title as its text and its target in parentheses: > [!faq]- See [x](http://y) reads to the title See x (http://y). A link whose text is its target, with or without mailto:, keeps its text alone: <http://y> titles http://y, <a@b.c> a@b.c — three persona readers agreeing, 2026-09-30.

The portable flavour's spellings

2026-09-14, panels 2026-09-25 and 2026-09-29, the maintainer. Goals 6 and 7. Valid while GitHub's renderer is the one the audience's markdown is read in.

README §Portable markdown's rows come from a survey of GitHub, GitLab, Gitea, Obsidian, Pandoc, MkDocs, Docusaurus, Typora, Joplin, Logseq, Bear, Notion, Azure DevOps and Discord, GitHub's renderer confirming each shape. Reader panels settled error as an error panel, the == bounds (3 of 3) and a Han, Hangul, kana, Thai, Lao, Khmer or Myanmar character on either side bounding a delimiter, so は==日本語==で (3 of 3), ==한국어==에서만 and iPhone==専用== (6 of 7) highlight, the external image's two forms (6 of 7), a rule opening a list item dropping and the omission notes (3 of 3), and a list's numbering overflowing into bullets (3 of 3). An omission note reads as the converter's, never as the author's. Reading takes other tools' spellings, since it reads their output and writes none of them. Rejected: ~sub~ and ^sup^ (~2~ is a strike on GitHub, so subsup drops), underline and colour spellings, raw HTML (<details>, <mark>), MkDocs !!! and the ::: admonition family, footnotes, definition lists, wikilinks, embeds, tags, comments, TOC tokens, spoilers, task states past [x]/[ ], and lifting bare URLs, @name, :shortcode: or ISO dates into nodes.

The portable reader refuses what GFM's reading would drop

2026-10-14, the maintainer; the ruling of Goal 7 over Goal 4, 2026-10-17, the maintainer. Goals 4 and 7. Valid while a refusal is a result and the caller can fix the markdown it sent.

Where GFM's reading of a shape drops content, portableMarkdownToAdf refuses the shape. A pipe table body row holding more cells than its header is malformed-pipe-table, where GFM cuts the extra cells. Cutting the cells breaks Goal 7. Building a table GFM does not, such as a wider one, breaks Goal 4. A refusal builds no table, but it still breaks Goal 4: a bot gets an error for a row GitHub renders. Goal 7 is a Maintain goal, holding whatever it costs, so it wins over Goal 4, an Achieve goal.

The HTML dialect

2026-08-23, the maintainer; Atlassian's HTML+ 2026-10-28, the maintainer. Goals 6 and 8. Valid while HTML output is read by consumers styling it themselves, and while Atlassian publishes no spec for HTML+, its Rovo MCP server's HTML for agents; a published spec reopens the goals.

The HTML dialect mirrors the markdown flavour: semantic elements, stable adf-* classes, data-* for what HTML cannot express, text always escaped. No stylesheet ships.

The spellings, spec/html.md, are six writer panels' (2026-10-23, -24, 2026-11-04 and -05), each of a product manager, an engineer and a support agent. The first picked each of these 3 of 3:

• an image standing alone as <p><img …></p>, over <figure> and a bare <img>;
• a list item's first paragraph bare, <li>Bolt</li>, over <li><p>Bolt</p></li>;
• class="language-js", over lang-js;
• <br>, over <br />.

Seven readers picked data-adf for the carry element, 6 of 7, over data-adf-node. Four wanted the class adf-carry and three no class; this entry's stable adf-* classes settle it.

Atlassian's editor puts a localId on every block, so carrying each block holding one would leave no element at all. The second panel picked each of these 3 of 3:

• an attribute the element cannot express as data-local-id, over data-adf-local-id and id;
• a link inside a carry element as <a>, over text (url) and its text alone;
• a carried node's blocks as <p>, over <br> and a line feed;
• media a carry element cannot show as <em>(image)</em>, over <em>(image not shown)</em> and nothing.

A third panel, seven readers in the same three roles, was asked how to write a list item whose first paragraph holds an attribute, the shape of every item Atlassian's editor writes. It picked <li data-local-id="i1"><p data-local-id="p1">Bolt</p></li>, 6 of 7, over the same elements with the <p> on a line of its own, 1 of 7, and over <li data-local-id="i1" data-paragraph-local-id="p1">Bolt</li>, 0 of 7.

A fourth panel of the same three roles picked, 3 of 3, a code block inside a carry element as <pre><code>…</code></pre> over <pre>…</pre> and over a <p> whose lines part at <br>, which loses the indentation. All three wrote <code class="language-python">, which no option held, so the shown code keeps the class its code block's own element takes.

Inside a carry element, an image marked by a link to another target shows as portable markdown writes it inline (§A linked image standing inline in portable markdown, its link to another target, is written [alt](href) ([image](url))), so both targets stay; Goal 7 counts them as content. A link marking a node that shows a note goes around the note. Recorded 2026-10-24 without a panel of its own: it joins the second panel's <a> to that portable spelling.

HTML nests no <a> in an <a>, so no element can hold both a card's URL and the target of a link marking it. Every writer refuses such a card, and a carry element holding one, as the maintainer chose on 2026-11-04 over a new spelling (§Schema refusals are made in the first step alone).

A fifth panel (2026-11-04, three readers in the same roles, then four more for what the first three split on) was asked how to write a mention, emoji, status, date and inline card, which until then rode the carry. The first three picked each of these 3 of 3:

• an emoji as <span class="adf-emoji" data-id="1f389" data-short-name=":tada:">🎉</span>, its text the content, over an <img>;
• a status as <span class="adf-status" data-color="yellow">In review</span>;
• a card holding a URL as <a class="adf-inline-card" href="https://example.com/spec">https://example.com/spec</a>, over a data-url beside the href.

Seven readers picked a date as <time class="adf-date" datetime="2025-08-25" data-timestamp="1756080000000">2025-08-25</time>, 5 of 7: the day for people, the exact timestamp for scripts. Two questions stayed split. A mention's data-id, data-access-level and data-user-type drew 4 of 7, over data-mention-id 2 and data-user-id 1; a card holding data and no URL drew <a … href data-data> 3, <a … data-card> 2 and <span … data-data> 2. The maintainer took the leading spelling of each, 2026-11-04:

• a mention is <span class="adf-mention" data-access-level="CONTAINER" data-id="5b10a2" data-user-type="DEFAULT">@Mikael</span>, its text the content;
• a card holding data and no URL is <a class="adf-inline-card" href="https://example.com/plan" data-data="{…}">Release plan</a>, href the URL its data holds and the text its name, else that URL. A card holding both data and a url rides the carry: its href, read back, could not say which of the two URLs it spells.

A sixth panel (2026-11-05, three readers in the same roles) picked each of these 3 of 3 for a table:

• a first row of header cells alone in <thead> and the rest in <tbody>, a row to a line, over a bare <table> of <tr> rows and over a line per cell;
• a cell's first paragraph bare, <td>Bolt M8</td>, as a list item's;
• a cell's attributes as <td colspan="2" rowspan="2" style="background-color:#fffae6" data-colwidth="120,80">, over data-* for all four.

htmlToAdf also reads the dialect as a browser serializes it

2026-10-28, the maintainer. Goal 6. Valid while a viewer/editor app may show adfToHtml's HTML in a browser and post the page back.

A browser does not write the dialect back as adfToHtml wrote it. htmlToAdf reads both spellings: a page's innerHTML, as WHATWG HTML §Serializing HTML fragments spells it, and a form post, which ends each line in \r\n. In text, a raw " reads as " does; in an attribute value, a raw < or > reads as < or > (a browser from before the algorithm escaped them writes them raw); in both,   reads as a no-break space; and \r\n reads as a line feed. All of it holds in what a carry element shows too. These are every difference the algorithm leaves between a browser's HTML and adfToHtml's, checked against Firefox's own innerHTML in the browser leg, and they hold for every element the dialect writes, later ones included. Other HTML stays refused, a lone \r among it. A refusal's position counts the HTML as handed in.

No runtime dependencies

2026-08-23, the maintainer. Goal 8. Valid while ~20 lines of own code, or a vendored table, do each job a dependency would.

dependencies is empty. A runtime dependency enters only through an entry here stating why ~20 lines of own code cannot do the job, who maintains it, and what auditing it costs. So the CommonMark and HTML parsers are written in this repo.

Standards ship as data

2026-08-30, the CommonMark suite 2026-09-05 and ADF's schemas 2026-09-13, the maintainer. Goals 1, 5 and 8. Valid while each table is fixed data a dependency would only wrap.

A table a standard fixes is data rather than a dependency: HTML5's 2125 semicolon-terminated character references ship packed in their own module, so entity decoding is complete without one. The CommonMark spec suite is the same shape of data and ships vendored at corpus/commonmark-spec/ rather than as the commonmark-spec dev dependency — that package is CommonJS-only, and Renovate auto-bumping a spec version would silently point the vendored exception list's example numbers at a renumbered suite. A spec bump is a deliberate re-pin, exceptions re-derived by hand beside it. Atlassian's ADF JSON Schemas ship vendored the same way, at spec/adf-schema/, rather than as the @atlaskit/adf-schema dev dependency — CommonJS-only, some fifty packages with React among them, and a release most days for Renovate to automerge — re-pinned by hand when a payload or a report shows the need.

fast-check

2026-09-14, the maintainer. Goal 1. Valid while a failing generated document needs shrinking by hand otherwise.

fast-check earns its place as a devDependency shrinking a failing generated document to the nodes that break it.

Stryker in its own package

2026-10-28, the architecture review. Code health: the code is easy to change safely. Valid while the gate runs no mutation tests.

Mutation testing with Stryker lives in mutation-tests/'s own package, so the gate's npm ci never installs it.

Any ES2022 engine

2026-09-01, the maintainer. Goal 8. Valid while ES2022 is the floor browsers and servers share.

The library runs on any ES2022 engine, not only Node — a browser as readily as a server. The shipped source is ECMAScript and nothing else: no host import, no host global, no DOM. tsconfig.build.json is that gate, typechecking and emitting the shipped files alone, so node:fs, process and an ES2024 method are compile errors here rather than a consumer's crash there. The standard is the line, never an engine list: one implementing it in part — Hermes is the live doubt, on the Unicode property escapes emphasis matching leans on and on lookbehind — is out of scope rather than a bug. Node's test runner, the corpus reads and the build are the repo's own, never the library's, and engines.node states the floor the shipped JavaScript needs — >=18 — never the higher one those repo-only tools want.

ESM only

2026-08-23, the maintainer. Goal 8. Valid while the audience's toolchains all import ES modules.

No CommonJS build, no dual-package hazard.

One built entrypoint

2026-08-23, the maintainer. Goal 8. Valid while Node refuses to type-strip under node_modules.

Built JavaScript, .d.ts beside it. Do not add a TypeScript-source entrypoint — Node refuses to type-strip under node_modules (ERR_UNSUPPORTED_NODE_MODULES_TYPE_STRIPPING), so it cannot serve an npm consumer.

Public on npm

2026-08-23, the name 2026-09-01, the maintainer. Goals 2 and 8. Valid while the package's source stays public beside it.

Published to public npm as @larvit/adf-codec. Public source: the GitHub repository, LICENSE in place. A codec, since it converts both directions, and named for the hub rather than the formats around it.

GitHub is canonical

2026-10-04, the maintainer. Goal 3. Valid while developers search GitHub for a library.

github.com/larvit/adf-codec owns the history, its issues and its CI, and publishes to npm with the organization's NPM_TOKEN secret. gitea.larvit.se/larvit/adf-codec becomes a read-only pull mirror of it. A move back to Gitea stays possible, and Gitea never holds a commit, issue or pull request of its own. Until todo.md item 72 re-creates it as that mirror, the Gitea copy is stale: it holds the commits from before the 2026-10-04 history rewrite, its description points at GitHub, and its issues and Actions are off. Push to GitHub only.

The formats are API

2026-08-23, strict input 2026-09-01, content models 2026-09-16, the maintainer; what a carry element shows 2026-10-28, the systems-architect. Goal 1. Valid while consumers store what the library emits.

The emitted markdown and HTML are contracts. After 1.0: previously-emitted output parsing differently, or not at all, is MAJOR; new syntax while old output still round-trips is MINOR. Pre-1.0, normal 0.x rules. A spelled node's content model is part of that contract — leaf or container is the model, not the syntax — so giving a spelled node's model content it had not, or taking it away, is MAJOR whatever ADF's own schema does. Input reads the canonical directive spelling alone — spacing, key order, each value's spelling — since loosening it later is MINOR.

What an HTML carry element shows is part of that contract too. htmlToAdf refuses a carry element showing anything but what adfToHtml shows for its node, so an edit there is refused rather than lost (Goal 7). A change to what a carry element shows, in src/html/carry-content.ts or in the src/adf/shown-text.ts it shares with portable markdown, makes HTML an earlier release wrote unreadable: MAJOR after 1.0, and a MIGRATION.md entry before.

The error surface is a contract too; README.md §The errors states it to the consumer, and the types in src/result.ts hold its shape.

The code list

2026-08-25, the maintainer; dated below where a rule came later. Goal 1. Valid while a consumer switches on code with no default.

• Adding, removing or renaming a code is breaking, so a new cause takes an existing code whose name reads true of it in both directions; where none does and a plain name exists, a new code — in any 0.x minor, and after 1.0 only in a MAJOR (2026-09-18).
• A refusal whose cause is this library's own invariant rather than the input takes the existing code nearest what the consumer sees — a document that does not convert is unsupported-node-shape — since a code no input reaches is one no consumer can switch on (2026-09-20).
• A refusal no spelling recovers from is a gap in the flavour rather than a code: give the flavour the spelling and the code goes (unspellable-link, 2026-09-13; unspellable-character and unspellable-line-start, 2026-10-04). A cause the carry answers gets no code: a mark no spelling writes rides the carry with its node.

Which code a cause takes

2026-08-28, the maintainer; dated below where a rule came later. Goal 1. Valid while a consumer handles one cause alike whichever node, attribute or direction raised it.

• A code names the cause; where one cause recurs across node types, across one mark's attributes or across directions, one code covers them all and path and message say which — unsupported-nesting-depth is the 500-level guard whichever direction hits it.
• A claim code names the spelling claimed, never the node that spelling would have built: a malformed !adf:table is a malformed-directive. An alignment colon in losslessMarkdownToAdf is a malformed-pipe-table: the flavour's own delimiter row is - runs, so the grammar refuses the colon rather than ADF's missing column model doing it. portableMarkdownToAdf reads GFM's colon and drops the alignment (2026-10-14). What the grammar itself refuses stays a claim code, key order among it, and a leaf given a body is refused at its opener, as a container missing its closer is (2026-09-16).
• A directive whose name reads back to no node is unknown-directive-name rather than a claim code — the spelling is well formed, and telling that apart from a typo is what a consumer switches on when a later MINOR gives the name meaning. A reserved name is a known name, so never that code, and the names the flavour reserves part on form: a form the grammar does not have is a claim code — !adf:carry, whose carry is the fence — and a well-formed form in the wrong place is unsupported-node-shape, !adf:textBreak{} parting anything but two adjacent text nodes CommonMark would read back as one, !adf:doc standing beside another block (2026-09-01, the text break and doc 2026-10-03).
• A well-formed directive the node tables refuse — an attribute a node does not hold or spells elsewhere, a value outside its kind or its canonical spelling, an argument, or a body of a shape its content model does not take — is unsupported-node-shape, the emitter's code for the same mismatch read the other way: one code across both directions for good, since the call site knows which direction it called and parting them after 0.1.0 is MAJOR (2026-09-23). A line ending or a null character in an emoji, mention or status content slot is such a value; the emitter carries such a node (2026-10-14).
• A non-finite number takes two codes: unsupported-node-shape parsing, not-an-adf-document emitting — no document holds one, so no round-trip crosses them (2026-09-23).
• A document whose output would be longer than V8's longest string is unsupported-node-shape at the document's path, in every writer, and so is a directive losslessMarkdownToAdf reads whose CommonMark spelling would be: the document does not convert, and no spelling in the input causes the bound (§The code list). A carried node passes it on about 1 MB of deeply nested JSON, since the block carry indents two spaces a level; todo.md item 107 respells the carry in a length linear in its JSON (2026-10-11).
• A conversion the engine stops with a throw of its own, past its longest array, Map or Set or short of memory, is engine-limit, at the empty path. A retry may pass the memory case, so unsupported-node-shape, which no retry passes, cannot hold the class. JavaScriptCore throws the same Out of memory past its longest string as when its heap runs short. Nothing tells the two apart, so both are engine-limit (2026-10-13, the maintainer).
• The markdown readers and htmlToAdf refuse a value that is not a string as not-a-string, at position { line: 1, offset: 0 } with an empty path: no existing code reads true of it, and not-an-adf-document names the emitters' input (2026-10-05).

message and path

2026-09-03, the path 2026-09-23, the maintainer. Goals 1 and 5. Valid while a person fixing the input reads message.

• A message names the violation, not the rule alone — a rule by itself states a truth the reader must invert before it reads as a failure — and where the flavour's claim refuses ordinary prose it names the escape that unclaims the form claimed: \!adf: for a directive, block line and inline alike, \| for every pipe row.
• not-an-adf-document carries the document's own path throughout: seven of the guard's nine branches read the document's own shape, and threading a path to the other two, which look anywhere in the tree — a malformed node, or an object holding itself — wants the manual stack §Nothing recurses unbounded forces. The message names the violation instead.

Publish on a version bump

2026-08-23, converging 2026-09-03, the maintainer. Goal 8. Valid while CI on main holds the npm token.

package.json version on main is the source of truth. CI on main: tests green and the version not yet on npm → publish and tag vX.Y.Z. No bump, no deploy. publish.sh is that job.

The publish and the tag each check their own end state — the version on npm, the tag on the remote — so a run that dies between them converges on the next push to main rather than leaving npm ahead of the tags. An unanswered registry reads the same as an unpublished version, which npm's own duplicate rejection is what catches. The job rebuilds rather than taking the gate's dist: the lockfile is committed, the image is patch-pinned and tsc is deterministic, so the two builds agree, and promoting an artifact would make the release path depend on a store that the gate would then have to keep.

Docs describe the release being built

2026-09-16, the maintainer. Goal 8. Valid while a bump on main publishes.

Docs on main describe the release being built rather than the version npm holds, so they match it the moment the bump publishes; add no interim note marking the gap.

Plan items rank by rank_todo.py's goal weights, code health first

2026-10-20, the maintainer, asking that this repo follow rank_todo.py's ranking after it changed. It serves code health and the order ## Goals gives its Achieve goals. Valid while rank_todo.py sets the weights.

rank_todo.py is the maintainer's ranking script, kept outside this repo. The repo doesn't keep any weights of its own. The script puts code health first, since every project pursues code health above each achieve goal its README states. The README's Achieve goals follow in the order ## Goals gives them, and by position each weighs 0.97 times the one before. While the comprehension panel's overall score is under 7.0, or docs/comprehension-history.md holds no scoring run, code health weighs 4 times its position weight.

todo.md's ## Scoring keeps the formula and the bar, the lowest Score a non-exempt item may have. Both are the project's to tune: the maintainer confirmed the bar at 0.1 on 2026-10-21.

Posts announcing a release wait for its publish, and their drafts wait for the finished release

2026-10-21, the maintainer, asking for the choice that best reaches the goals. Serves Goal 3. A post that goes out before its publish sends readers to a version without what the post describes. They then open issues saying a call did something else, which Goal 3 counts as a counter-signal. Drafts describe the finished release, so they wait for every item in it. Valid while a version bump on main publishes (§Publish on a version bump).

A chunk ruled worse merges where a plan item of its release already restores that code's reading, and that item takes the ruling's places

2026-10-30, the maintainer, merging PR #107 only because a plan item of its release would fix exactly the places its paired ruling voted worse. Serves code health. Valid while the comprehension check runs once per chunk.

The comprehension check runs once per chunk, after review. A restructure made after it goes unmeasured, and past a pass's round cap it goes unreviewed. Where an item of the same release reworks that code again, restructuring it inside the chunk does the work twice. Before the chunk merges, that item's detail names every place the ruling voted worse.

A chunk ruled worse that restructures the places takes a paired ruling after each restructure, against the same base, and merges once one is not worse

2026-10-31, widened to each restructure 2026-11-03, the maintainer, on PR #112: its ruling voted Locality worse, no plan item of its release reworked that code, and a restructure after the ruling addressed most of its places. Serves code health. Valid while the comprehension check runs once per chunk.

Where a plan item of the release already restores that code, the entry above holds instead, and the chunk restructures nothing. Each later ruling reads the restructured head against the first ruling's base, with the same seats, and every ruling stays in the history. Each restructure runs one rung higher; past the top rung, the maintainer decides. After the fifth ruling they gave the restructure to a subagent on model fable, told to look past the current design for a better reading rather than answer the ruling's places one by one (2026-11-04). A ruling judges the code, never the behaviour: item 91's spanning stays, since the paragraphs it spells, such as bold around a code span, occur in documents all the time (2026-11-03). The maintainer's call on how: refactor first, ruled alone (item 166), then make spanning part of grouping, with the span rule in one home. inlineRuns in emit/inline-runs.ts groups a line spanned or parted, runCrosses says which node a run passes, and a run ends at its last holder. The writer tries the spanned line once and, where it needs any fallback, runs its fallback loop on the parted line, so takeFallback takes what it is handed; whether a node is carried is decided once per pass, on its RunNode (the restructure of 2026-11-04). The reducer judges the same two lines, each trimmed by its own runs, which runsSharedWithNext counts beside inlineRuns. withoutOpeningLinkCode stays on insideRun alone, since it answers the parted line. A refactor that merges as its own chunk took its own ruling, so the chunk's later rulings read against that merge, the commit larv-review ruling-base prints. A restructure past a pass's round cap still goes unreviewed, so the PR summary names it.

Schema refusals are made in the first step alone

2026-11-04, replacing §No schema validation of 2026-08-23 (its mark refusal 2026-08-25) and the entry of this date that kept the card refusal alone, the maintainer. Goal 1 and code health. Valid while Atlassian's schema forbids shapes a converter would otherwise meet.

A shape Atlassian's schema forbids, and the library refuses, is refused in the first step, where the document is checked once: writableContent opens every writer, and carriedNode opens every carry reader's node. No converter refuses one. A document one call refuses on a schema rule every writer refuses alike, with one code, message and path, wherever the shape stands, in a carried node too, and a carry reader refuses it with the same code and the writers' message after its holder's name. The first step refuses an inlineCard with a link mark as unsupported-node-shape: the schema gives a card the annotation mark alone (§The node tables answer to Atlassian's schema), and HTML nests no <a> in an <a>. The first step also refuses a known block holding text, a known non-text inline node holding text or non-empty content, and a known block that takes no content holding non-empty content.

Nothing else joins the first step. Nothing refuses a node type, mark or attribute the schema does not name (§Unknown nodes ride the carry), a known node where no section spells it, or a mark a node cannot hold (§A mark skips a node that cannot hold it), so they ride the carry. A refusal that is no schema rule stays where it is met: a node holding one mark type twice, which the schema allows and no spelling holds; nesting depth; output length; what a portable line can spell; and a reader's refusal of markdown or HTML it cannot read. A schema refusal a converter gains later is made in the first step too.

The aim is the same behaviour in and out, with the checks run at the first step and alike in every format. Each shape the first step refuses is one some writer refuses today. The change this makes is that every writer, and every carry reader, now refuses it: the maintainer accepts that breaking change, since the library is not on 1.x.

The earlier entries premised that the site a document is saved to validates the rest. A hand-built document has not reached the site yet, and the viewer/editor persona relies on a refusal arriving before the save.

The gate runs on Deno and Bun

2026-09-01, Deno's reason 2026-09-28, the maintainer. Goals 4 and 8. Valid while the library claims any ES2022 engine.

The gate runs the suite under Deno and Bun as well as Node. Bun runs JavaScriptCore, the one engine of the three that is not V8, where the Unicode property escapes emphasis matching leans on can disagree. Deno shares Node's V8 and stays to prove the library runs there too, catching what the two runtimes leave undocumented. Both refuse a run matching no test, so Node's is the only vacuous-green guard, and AGENTS.md §3's node: shims rule is the price of proving those engines over the corpus rather than over a smoke import.

The gate installs the tarball

2026-09-03, the maintainer. Goal 8. Valid while consumers install the packed package.

The gate packs the build and installs the tarball under package-tests/, so files, exports and types are proved on the artifact that ships rather than on the source tree a self-reference would resolve against. consumer.ts typechecks the emitted .d.ts from outside tsconfig.build.json — declaration emit leaves the .ts specifiers rewriteRelativeImportExtensions rewrites in the JavaScript, and this is what says a consumer's resolver maps them, under NodeNext alone; a .d.ts reader that is not tsc stays unproven. node-floor.js round-trips the installed package under a Node pinned to engines.node's floor.

Firefox reads the build

2026-09-04, the maintainer. Goal 8. Valid while the library claims a browser and no other leg runs SpiderMonkey.

A headless Firefox loads dist/index.js over HTTP and converts the round-trip, normalization and error fixtures and the real payloads — the commonmark-spec sort is the Node suite's to check — which is the browser half of §Any ES2022 engine and the only SpiderMonkey there is — the gate's other engines are two V8s and a JavaScriptCore that is not Safari's. It also sets adfToHtml's HTML into the page and reads the page's own innerHTML back through htmlToAdf (§htmlToAdf also reads the dialect as a browser serializes it). A WebDriver session is what carries a verdict back out, the driver and the page's server sharing one network namespace so each is the other's 127.0.0.1; --headless --screenshot has no such channel, and loading dist/index.js in a globals-stripped realm buys one by not running a browser. The leg re-checks the conversions and nothing else — each fixture's emitted markdown, its parsed document, its error code — leaving the corpus's pairing, uniqueness, source positions and byte-level equality to the Node suite that owns them. selenium/standalone-firefox runs it over the smaller instrumentisto/geckodriver: the leg is worth a current SpiderMonkey, and that image fell four Firefox majors behind.

The coverage floors

2026-08-24, the maintainer. Goal 1. Valid while noUncheckedIndexedAccess and ADF's optional keys force guards with a half no valid document reaches.

The floors live in the test script, so npm test and the gate are one path: 100% of lines and functions, and a branch floor that only ever moves upward. It sits below 100 because the guards noUncheckedIndexedAccess and ADF's optional keys force — ?? [], ?? {}, ?., an index compared against undefined — have a half no valid document reaches.

The size ratchet

2026-09-20, the maintainer; the import boundaries, 2026-10-22, the maintainer. KISS, a technical principle. Valid while no measure picks out what readers find hard better than a function's length.

.oxlintrc.json holds one size rule. It also holds the import boundaries §The source parts by ADF and format draws. The size rule, over the files tsconfig.build.json builds, is a per-function line ceiling, set at that set's worst and moving only downward. It covers the built files alone, since one ceiling over the tests too would have to be their worst, loosening the guard over the shipped code. It guards against drift and never drives a refactor, so no cyclomatic rule and no second size rule join it: neither measure picked out what nine readers found hard (the comprehension panel, 2026-09-20). oxlint measures it since TypeScript 7 is a native compiler publishing no in-process parser, only the unstable/ AST surface an out-of-process handshake reaches. Three switches guard a silent green: IIFEs: true, since oxlint exempts an IIFE otherwise; an explicit -c, so a config gone missing fails the leg instead of falling back to oxlint's own defaults; and --deny-warnings, since a rule from a category this config never names arrives as a warning it exits 0 on.

Properties on a fixed seed

2026-09-14, the maintainer. Goal 1. Valid while a red gate must reproduce.

Beside the corpus, properties run over documents generated from the node tables and over generated markdown, on a fixed seed in the gate; a counterexample found becomes a round-trip fixture.

The CommonMark suite checks three ways

2026-08-27, against commonMarkToAdf 2026-10-09, the maintainer. Goals 1 and 4. Valid while the suite's answers are HTML ADF cannot be compared against.

Each example is a named error or markdown commonMarkToAdf reads to a document that adfToLosslessMarkdown writes and losslessMarkdownToAdf reads back deep-equal, since CommonMark has no writer of its own. The example's reference HTML's text, tags stripped and entities decoded, equals the parsed document's; and its elements count the marks and nodes they map to. The fixpoint alone passes a parser returning the empty document, the text alone one dropping every emphasis. An exception is the maintainer's to add, and valid CommonMark parsing to a document adfToLosslessMarkdown refuses is a bug to fix, never an exception. Kind node-model (2026-10-09, the maintainer) is a permanent divergence where ADF holds no node for what CommonMark renders.

The flavour spec is read as a source

2026-09-01, the maintainer. Goal 1. Valid while spec/flavour.md restates the node tables in prose.

spec/flavour.md is read as a source, so the node tables cannot drift from the prose they copy: its node and mark bullets must equal the tables in adf/. It guards the attributes alone: nodes that differ in content model share a bullet, and the argument attribute is spelled outside the bullet's attribute list, so both answer to the round-trip corpus and to nothing else where a node has no fixture.

The node tables answer to Atlassian's schema

2026-09-13, the maintainer. Goal 1. Valid while a site's editor writes what Atlassian's schema holds.

For every node and mark the tables spell, the attribute names and kinds equal what full.json and stage-0.json (§Standards ship as data) hold between them, and so do the mark types each inline node takes. Value sets stay documentation, since any value round-trips. What the schema holds and the tables do not spell is pinned by name — an attribute as a gap, a type as carried — so a re-pin adding either goes red until someone spells it or pins it.

Output past V8's longest string is refused on every engine

2026-10-11, HTML 2026-10-23, the maintainer. Goals 1 and 6. Valid while V8's longest string, 2^29 − 24 characters, is the shortest of the engines the library claims.

Every writer, and losslessMarkdownToAdf's commonMarkSpelling ask, refuses markdown or HTML longer than 2^29 − 24 characters (longestOutput), so the same document converts alike everywhere. A writer first refuses a document whose text alone passes the bound: the lossless writer spells every character of it, and the portable reduction refuses on the caller's text, edge whitespace and all, since merging that text first could build past the bound. Each block, the writer's result and the CommonMark ask's spelling are held to the bound as they are built. V8 throws building the same string past the bound, SpiderMonkey past its own longest string, and withinEngineLimits refuses both throws as the same tooLong, so every engine stops at the same block with the same answer. The carry's two-space JSON, which indents every value its depth over, stops at the bound unbuilt (joinedWithin).

JavaScriptCore builds a joined block up to its own longest string, 2^31 − 1, before the check. Past that, JavaScriptCore throws Out of memory, which is engine-limit (§Which code a cause takes).

HTML writes a URL as the ADF holds it, whatever its scheme

2026-10-23, the maintainer; kept over a scheme filter 2026-10-26. Goal 1. Valid until the maintainer adds scheme filtering.

adfToHtml writes every URL exactly as the ADF holds it, escaped as every attribute value is, javascript:, vbscript:, file: and data: included. That covers a link's href, an image's src, a card's href, and the href of each link the carry element shows: a carried node's link mark, a card's url or data.url, and an external image's url. The markdown writers don't filter schemes either.

cmark leaves such a URL out of its HTML by default. Keeping it out of the visible HTML here, in data-adf alone, was weighed and not taken: it would make the carry show a link without its target, make htmlToAdf restore the URL from data-adf, and need a scheme list the library keeps current. Sanitizing HTML from an author a consumer does not trust stays the consumer's, as the README says.

Nothing recurses unbounded

2026-08-25, the directive form's count 2026-09-18, the maintainer. Goal 1. Valid while an engine's stack overflows near 2000 frames.

The guards walk iteratively, and blocks, marks and JSON values — an attribute's and a carried node's alike — are all held to 500 levels (largestNesting), so a deep document is a Result rather than the stack overflow that waits near 2000. An attribute is counted from its value; a spelling that nests it deeper — the block directive's marks, the carry — refuses in its own format, as its parser does. A list giving way to the directive form refuses at zero headroom rather than walking again; counting every list twice halved the list limit, counting the directive form once doubled the parser's frames per level.

JSON text is read by parseJsonText

2026-10-08, a remedy the maintainer planned. Goal 1. Valid while a V8 engine with https://issues.chromium.org/issues/521080746 unfixed can run the library.

The library reads JSON text with parseJsonText, never JSON.parse: from V8 13.6, JSON.parse can read an escaped key as another key it read before, and the round-trip then refuses its own output. A test fails on JSON.parse( in a shipped file. The tests' own oracles keep JSON.parse, since a misread there fails the gate and never hides a bug.

No value JSON.parse or structuredClone builds loops a call

2026-10-04, the maintainer. Goals 1 and 9. Valid until todo.md item 77 lands.

The guards walk a value by Object.values and refuse a cycle in it. An inherited or non-enumerable key, a getter, a Proxy or a custom iterator is the caller's to rule out: no persona builds one. Goal 9's size counts ADF as JSON, so a shared object costs once per place it is held.

Nothing spreads an unbounded array

2026-09-18, the maintainer. Goal 1. Valid while engines cap a call's arguments.

Nothing spreads an unbounded array into a call — a node's siblings, a code block's held lines, a mark run's segments: the argument list caps near 125k and throws a RangeError where a Result is owed. A walk pushes one at a time. A literal spread ([...value]) is not the same thing and is fine.

A retry loop checks its own termination

2026-09-20, the maintainer. Goal 1. Valid while a fallback can fail to spell what it is handed.

A loop retrying an input until a fallback spells it refuses the pass taking no fallback, so its termination is the loop's own check.

After 32 passes, a line carries or drops every em, strike and strong mark

2026-10-30, the maintainer. Goals 9 and 1. Valid while a writer finds a misread run only by reading the line back.

Each pass, the lossless and portable writers spell the line, read it back, and fall back on the first misread emphasis run and on every run unspellableRuns proves falls with it: the lossless writer carries the run's nodes, and the portable writer drops its mark. When em and strong share a delimiter run, as in ***, and the strong closes first, the next strong opener can pair with em's leftover *. unspellableRuns can't foresee that pairing, so each pass falls back on one strong, and a line repeating such a pattern 1000 times took 33 seconds lossless and 39 portable. After 32 passes, both writers fall back on every em, strike and strong run at once. Such a line keeps fewer marks than one strong per pass would leave, and takes time linear in its length. 32 clears the most passes any line in the suite needs, 22 portable and 5 lossless, with room to spare. The properties' reference, which falls back on only the first misread emphasis run each pass, takes no cap.

With the first misread emphasis run, unspellableRuns returns only runs that, taken back early, leave the line as the one-run-per-pass reference writes it

2026-10-29, the maintainer. Goals 9 and 6. Valid while a writer finds a misread run only by reading the line back.

A writer takes a run back by carrying its nodes, lossless, or by dropping its mark, portable. The one-run-per-pass reference takes back only the first misread emphasis run each read-back pass, so it spends a pass per run. To spend fewer, unspellableRuns returns, with the first misread run, every run it proves can go back early and still leave the line as the reference writes it. A run the proof misses costs one more pass. The properties beside inline-line.ts and inline-reduction.ts define the reference, and check that every line the 32-pass cap (§After 32 passes) doesn't reach comes out as the reference writes it.

unspellableRuns reads each emphasis run as a pair, its opener and its closer, and orders the pairs by where they close. Its sweep judges the pairs closing after the first misread pair, nearest first, then those closing before it, nearest first, and each verdict reads the verdicts made before it. A judged pair is settled to fall, and goes back with the first, where both hold:

• It falls cleanly. Under a drop, no drop may merge runs at either of its ends, so no delimiter there moves. Under a carry, it holds no pair closing before it over fewer nodes, which the reference may carry first, splitting it.
• It cannot read, whichever character it is written with. Either its opener cannot open, or both of these hold: its closer cannot close, and it holds no pair, other than those settled to fall, that may be written with the same character. An opener that may open can pair with such an inner pair's closer. The reference may then take the inner pair back first, while taking the judged pair back early may let the inner pair read as written.

Em has no fixed character: resolveEmphasis writes _, and * beside a word character. CommonMark judges a delimiter by the characters either side of its whole delimiter run. So whether a pair can read depends on the pairs whose delimiters touch its own, and a verdict tries every character they leave possible. A verdict reads each such pair as that pair stands when the reference reaches the judged pair. pairStanding returns the first of these cases that fits:

• stands: the judged pair itself.
• moves: a pair at whose ends a drop may merge runs. The merge may move its delimiters, so the verdict can't rely on it.
• stands: a pair closing after the judged one, where the judged one closes after the first. The reference takes back the first misread pair in closing order. Each pair settled to fall that closes before the judged one is misread once those settled before it are gone, and the judged pair is misread once all of them are gone. So the reference reaches the judged pair before any pair closing after it.
• Under a carry, stands for a pair over exactly the judged pair's nodes, else moves. One carry takes both back at once, and any other may be carried or split first.
• Under a drop, fallen for a pair settled to fall, else unsettled. The reference takes back every pair settled to fall, so the judged pair need only fail to read once they are gone. An unsettled pair may stand or have fallen, so the verdict must hold both ways.

Readers scan by index

2026-08-30, the kept scan 2026-09-18, the maintainer. Goal 9. Valid while the pipeline persona feeds documents nobody typed.

A reader takes the text and an index — a sticky regex whose lastIndex the caller sets on the line before it reads, indexOf — never a fresh slice per character, and a per-character walk hoists the scan that does not vary with the character: a megabyte through a quadratic walk is a minute rather than a millisecond. A scan may keep what it read for a later walk of the same text, and the fallback where it kept nothing must be the same reader over the same text at the same index, so the two cannot disagree — which is what makes the kept value a memo rather than a second spelling.

The spelling memo

2026-09-19, the maintainer. Goal 9. Valid while the commonMarkSpelling ask spells a node once per level above it otherwise.

When the parse or the portable reduction asks commonMarkSpelling about a node, the node's readable spelling goes into a memo, so the ask stops spelling a node once per level above it. Reading an entry drops it, and no entry is kept for the nodes below the asked one: the walk above spells those nodes into its own text, so keeping them would make every level of a deep subtree hold the subtree's whole text (2026-10-11). text, alternateText and spelling carry no depth and headroom is affine in it, so a read at or above the depth that filled the entry rebases; a read below re-spells, because a hit skips the depth guards the walk it replaces runs and an ordered list past the marker cap gives way, spending two emitter levels where the parser spent one. A refusal is never kept, so no path minted at another position is ever read.

Cost fixes are measured, never timed

2026-09-18, the maintainer and the stability-reviewer. Goal 9. Valid while Goal 9 promises growth rather than a figure.

A cost fix that changes no behaviour lands on the suite staying green with no fixture output changed, and a before-and-after figure in its PR; the gate times nothing. Measured and kept: adfDocumentFault's shape and depth walks stay two — the parting gives depth its own code — at 52 ms for a 9 MB document the emit takes 314 ms over. The 500-level guard runs after the block walk, so it doesn't bound the walk's cost.

Only the hard break holds a raw newline

2026-08-26, the maintainer. Goal 1. Valid while the whitespace carry finds a line edge by its raw newline.

Only the hard break's inline segment holds a raw newline — every other spelling escapes one or refuses it — which is how the whitespace carry finds a line edge.

Emphasis follows CommonMark's matching

2026-08-27, the maintainer. Goals 1 and 4. Valid while CommonMark's emphasis rules are the reader's.

Emphasis is spelled against CommonMark's matching, never flanking alone: a delimiter run in text escapes wherever CommonMark could open or close with it, leaving the emitter's own delimiters the only ones in play, and a pair that matching hands to another delimiter rides the carry instead.

Where a text backtick or [ opens a code span, a link or an image, every text backtick or [ in its line escapes

2026-10-28, a writer panel, 3 of 3. Goals 1, 6 and 9. Valid while the writers find a construct by reading the escaped line back.

The panel rejected escaping only the text [s before the last link a text [ opens, which writes [a](b) [c] as \[a](b) [c], as arbitrary. Escaping each opener in turn costs a read per opener, against goal 9. The rule: spec/flavour.md §Canonical form.

Readable spellings take the try prefix

2026-09-21, the maintainer. Goals 1 and 6. Valid while a readable spelling's refusal would cost a document the general form spells.

A readable spelling tried ahead of a general one takes the try prefix and fails only where the general form fails on the same node: refusing there refuses a document the general form spells, so a refusal the general form does not share belongs in the general form or nowhere. A readable spelling that must spell its subtree before it can give way — the list, whose thematic-break first line and blank lines exist only spelled — hands that one walk to the general form instead: giving way after the walk walks again at every level, doubling per level.

The attribute vocabulary is ADF's

2026-08-27, the maintainer. Goal 2. Valid while every format spells the same ADF attributes.

adf/ walks the attribute vocabulary and narrows each value to its kind, and a format spells the narrowed value. A spelling that re-checks the type is the check's second copy. Reading a spelling back is the format's own: the reader sits beside the spelling it inverts, so decode-respell-compare cannot drift, and each format writes its own — canonical JSON for a number is the markdown flavour's choice, not ADF's.

The source parts by ADF and format

2026-08-27, placement 2026-09-18, adf/'s bar 2026-09-21, plain/ 2026-10-03, the import boundaries' lint 2026-10-22, the maintainer; parse/ and emit/ free of portable/, 2026-10-22. Goal 2. Valid while each format has a reader and a writer through ADF.

src/adf/ holds ADF's own knowledge, imports no format, and is where a construct both formats read lives: the question is answered in ADF's vocabulary — a node type, an attribute kind, a content model — and no delimiter, element name or escape reaches it. A helper that cannot answer that way is two constructs, the ADF question there and the spelling in each format, the seam markAttributes and markSpellings already draw; one that cannot be split is a gap to ask. markdown/ and html/ are peers: neither imports the other, and no third directory sits between them. A primitive knowing neither ADF nor a format stays at src/ root. A construct rises to adf/ on its second consumer, not in anticipation of one. A directory follows a split spec/flavour.md draws, and a placement nothing here settles goes beside its only reader, or in what both read where there are two.

A flavour's own code, both directions included, sits in its own directory: markdown/portable/. The portable reader and writer hand parse/ and emit/ their own block readers and writers (FlavourBlockReaders, FlavourBlockWriters), so neither imports portable/. Syntax that parse/ and emit/ read under a flavourClaims claim, such as ==, sits outside portable/. The directive grammar, both directions included, sits in markdown/directive/, which imports neither emit/ nor parse/. Otherwise each format directory parts into emit/ (ADF→format) and parse/ (format→ADF), the rest of it holding what both directions read. A construct's reader lives there beside the regex the emitter escapes against, so the two cannot drift; a reader with no emit counterpart goes in parse/, unless it is part of a construct that side already holds — a grammar stays in one file rather than splitting across the seam. A rule both directions must answer alike — whether a list marker interrupts a paragraph — is one function there too, never a copy per direction, however conservative the copy would be. Where the rule is the emitter's own choice, input consults it rather than restating it, so no fixture the emitter writes can be refused, and a spelling the emitter refuses gives its own error rather than a second name for it. That consulting is the only import parse/ takes from emit/, through emit/spelling-questions.ts.

.oxlintrc.json enforces that limit for markdown/parse/, keeps html/parse/ from importing html/emit/, keeps markdown's parse/ and emit/ from importing portable/, keeps markdown/directive/ from importing emit/ or parse/, keeps markdown/ and html/ from importing each other, and keeps adf/ from importing either, as no-restricted-imports overrides. A later override replaces an earlier one's rule, so each subdirectory's override repeats its format's ban on the other format, and ci.sh probes every override. They are lint rules because the technical principles refuse a test that scans the source, and a lint rule reads every import spelling: from, a bare import, double quotes and a dynamic import().

The comparison table lists every converter that starts and converts

2026-10-28, the maintainer, answering the bar for the README's "Other ADF converters" table. It serves goal 3: a developer choosing a converter sees every one, and what it gets wrong.

A converter that starts and converts anything stays in its table, however poorly. Its row says where it fails ordinary input, such as a list or a quote. A converter that doesn't start, or needs a page rather than Node, goes in the second table. A wrapper or fork of a listed package is left out.

The real-world corpus holds anonymized documents from sites whose licence it records

2026-11-04, on the maintainer's answers of 2026-11-03, and their answer of 2026-11-05 accepting the inferred licence and credit by link. It serves goal 6: real documents show what ordinary input must convert without surprise. Valid while no public source with a clearer licence serves ADF.

Each document keeps every node, mark and attribute key. Its words, names, ids and URLs are replaced with values drawn from fejkdata, a fake-data tool run from its image. Replaced text keeps its punctuation and case, and a number keeps its digit count. A document stays out if its structure changed or its output still holds an original token. The fetched originals are never committed: corpus-gathering/run.sh refuses a raw folder inside the repo.

Each document's credit is its url in corpus/real-world-sources.json, a page a person reads, since naming a creator would undo the anonymizing.

A site joins only with a published licence, its own or its host's. Where the host's terms don't name the site, applying them is an inference, which corpus/README.md tells the reader. All six sites in corpus-gathering/sites.json are hosted by the Linux Foundation:

• The foundation's terms of use put wikis and other non-code submissions under CC-BY-3.0. Those terms don't name issue trackers or *.atlassian.net, so every site but the ONAP wiki rests on that inference. When a site states its own licence, that licence replaces them in sites.json.
• The ONAP wiki states its own, but its pages disagree: a 2017 page says CC-BY-SA-4.0 and a 2019 page says CC-BY-4.0. Its documents record CC-BY-SA-4.0, which satisfies both.

None of the 22,773 fetched documents holds a type in typesNoFetchedDocumentHolds (src/conformance/corpus.test.ts), and neither did up to 40 pages per site with "decision" in the title. A regenerated corpus holding one of those types fails that test until the type leaves the list.

The feature table is a section per corpus example, led by a summary table

2026-11-05, a developer panel, 3 of 3. Goal 3. Valid while the page lists about fifteen examples.

Readers from the viewer/editor, export/indexing and LLM/agent pipeline personas picked labelled code blocks stacked under a heading per example, with a table of the round-trip results on top, over one wide pipe table and over one wide HTML table with a <pre> per cell. Examples come from corpus/round-trip/ and are the ones feature-table/examples.json lists, never corpus/real-world/, whose licence is not the package's.

A reader panel (2026-11-05, goal 6) judged each of the page's fifteen rows. The same three personas first wrote what they expected of the three writers for every example, each in its own shuffled order, then saw the page's outputs and ruled each row reasonable or not. Eleven rows drew 3 of 3 reasonable. Three drew 3 of 3 not reasonable, each because adfToHtml writes a node or mark it knows as an opaque adf-carry element. An editor shows that element's visible copy, and an edit to the copy is refused as unmappable-html rather than saved. They expected:

• A panel as <div class="adf-panel" data-panel-type="warning"><p>…</p></div>, with its localId, colour and icon in data-local-id, data-panel-color, data-panel-icon, data-panel-icon-id and data-panel-icon-text.
• A task list as <ul class="adf-task-list" data-local-id="…"> of <li data-state="DONE" data-local-id="…"><input type="checkbox" checked disabled> Write the spec</li>. A blockTaskItem is an <li> of two <p>, a nested list an inner <ul>, and an empty item an <li data-state="TODO">.
• The strike mark in Emphasis and strikethrough as <s>relay</s> or <del>relay</del>.

todo.md items 134 and 141 will write these; their writer panels pick the spelling with these expectations as input. The Date row drew 1 of 3 not reasonable, so four more readers (bot, reader of the markdown, export/indexing, viewer/editor) read it, and 5 of 7 found it reasonable. adfToLosslessMarkdown keeps writing !adf:date{timestamp=1756080000000}. The two who rejected it wanted the day shown, as !adf:date[2025-08-25]{timestamp=…}.