All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

Entries for unreleased work are not written here directly. Each issue drops a fragment in changelog.d/; the fragments are assembled into a version section at release. See that README for the format and for when a change warrants an entry at all.

[0.4.0] 2026-08-30

Added

  • The inspector's Config tab is two labelled sections. Block states the selected block's type label, its id and the slot it sits in, and renders with nothing selected too - three rows in the same place, reading as a dash.
  • StatifierBlocks.Shell.slot_label/2 answers which slot a block sits in, by the slot's label rather than its name, with "root" for the document root.
  • A block type may declare a :string config field keyed label, and the editor draws that value as the card's title with the type's own label as a subtitle underneath - so a host's steps read as the names an author gave them without the type ever being hidden.
  • A card carrying invoke_type in its config draws it in mono on a third line, which is the fact an author checks most on a step that calls out to a handler.
  • StatifierBlocks.ViewModel.title/1 and subtitle/1 answer what a card's two name lines say, and ViewModel.Node carries title and invoke_type for a host rendering its own cards.
  • The compiler refuses a core.subchart whose chart names the document the block sits in, as an :emit-stage :self_reference finding against that block: a document cannot run itself. A cycle through two or more documents needs the host's document graph and stays the host resolver's to refuse.
  • StatifierBlocks.Shell.drawer_tabs/0, drawer_tab/1 and drawer_title/1, in the same shape as the inspector's tab helpers - an unknown tab from a crafted phx-value-tab resolves to the first one.
  • .sb-findings__row, __severity, __subject, __label, __id and __message, the row's parts. The severity colour stays on .sb-finding and its severity modifier, so a host that had restyled one severity keeps that styling with no edit. No new custom property.
  • A slot's header shows the condition it is subject to: the expression source, read-only, in a monospaced chip under the slot's name, clipped to one line with the whole of it in the chip's title. A branch's arms on the canvas now say what picks between them instead of only naming themselves.
  • StatifierBlocks.ViewModel.Slot.condition carries that source. It is derived from the container's own :expression config field keyed by the slot's name, read through the field's declared value_path, so a host block type that guards a slot the way core.branch guards an arm gets the same chip without the editor learning either type's name.
  • The palette and the inspector render as framed panes with a header row. The palette's names the pane and carries a chevron that folds it to a rail, giving its width back to the canvas; the inspector's names the pane and states its subject on the right - the selected block type's label, or no selection.
  • --sb-palette-collapsed-width, the width the folded palette narrows to (tier 2, default 2.25rem).
  • The palette carries a count line under its search box: the size of the palette when nothing is filtering it, and how much of it is left plus what is doing the narrowing when something is - a query, or the acceptance set of the slot the palette was opened from.
  • Each group header carries the number of rows currently under it, so a filtered section says how much of it survived the filter.
  • The editor draws the join marker under a container whose slots sit side by side, reading the words the block type's join_label callback returns - core.parallel completing on its first lane says "continue at first" - and falling back to the editor's own word for a type that declares none.
  • StatifierBlocks.ViewModel.Node carries join_label, the normalized words that callback returned for the block's config, or nil when it declared none.
  • The editor's canvas is a named panel: the toolbar is its header row, with a Canvas label, a nested tree chip, one segmented zoom control, and the depth and block-count metrics as right-aligned chips.
  • The canvas sits on a bordered, dotted ground, and --sb-canvas-grid is the tier-2 token a theme sets to change the dots' colour and spacing together.
  • The editor draws a ONE OF pill above a container whose body slots are alternatives and an ALL OF pill above one whose lanes run concurrently, which is the only place that distinction is stated on the canvas.
  • StatifierBlocks.ViewModel.arrangement/1, body_slots/1 and fan_label/1 derive how a container arranges its body slots, shared by the renderer and the connector geometry so the layout and the lines cannot disagree.
  • StatifierBlocks.Connectors.fan_anchor/1 and join_anchor/1 name the two markers a fan leaves from and rejoins at, so an edge is no longer drawn through the words that say what it means.
  • --sb-card-width sets the width of a block's card, which is what keeps the measured connector geometry from collapsing every edge onto one spine.

Changed

  • Configuration's empty state is a box standing where the form stands, saying what selecting a block would let the author do, rather than the one-line sentence the other tabs use for having nothing to read.
  • A required field is marked with the word Required beside its label instead of an asterisk on the end of it - the asterisk needed a legend the editor does not have and is read aloud as "star".
  • The Findings tab's count is a pill in the error hue rather than a tinted rectangle, and it is still the block's own findings, never the subtree's.
  • The delete control on a card is revealed on hover, on keyboard focus and on the selected card, and is hidden at rest. It is still in the DOM and still focusable, so the keyboard path is unchanged.
  • The card title reads as a title rather than as a native button, and the count badge, the subtitle and the invoke line are placed by a grid on the card's chrome.
  • The per-block-type accent stripe is drawn on cards whose type declared an accent_token and on no others. A type that declared nothing keeps a plain card; its icon tile is unchanged.
  • The document-level findings list is the drawer's Findings tab, beside Truth tables, and no longer a block of text under the canvas (operator ruling R4, 2026-08-29, under ADR-0005 ruling 1A: a list of findings is a grid of rows about the whole document). Each row carries the finding's severity, the block it is about - label and id - and the message, and clicking one selects and reveals that block. The inspector's Findings tab is unaffected and stays the selected block's findings (3A), as do the per-card counts.
  • The collapsed drawer strip reports the active tab. An author who has not picked a tab gets the first one that holds something, so a document with findings and no fixtures reads Findings 4 rather than Truth tables 0; once a tab is picked the pick stands. A host swapping the open document resets the pick along with the drawer's open state.
  • StatifierBlocks.Shell.drawer_view/1 accepts :tab, :findings and :orphan_findings, and its result gains tab, tabs, findings and orphans. title and count now describe the active tab rather than the truth tables specifically; the truth-table status values are unchanged.
  • StatifierBlocks.Editor.Findings.findings/1 takes findings, orphans, root and target instead of view_model, and renders the tab's panel rather than a headed section: the tab is the heading.
  • Slot labels are small, uppercased and letter-spaced - the treatment the fan pill and the join marker already carry for chrome that labels a structure. The transform is presentation only: the string a block type declares for a slot is unchanged, and every other reader still sees it as written.
  • Concurrent lanes carry a rule in the block accent across the top of each lane's header, drawn off data-arrangement="lanes". The pill above says ALL OF once; the rule is what carries that distinction down a document taller than one screen, where a set of lanes and a set of branch arms otherwise look alike.
  • An interrupt rail's dashed edge and its heading take the colour the connector layer already draws an interrupt edge in, so the rail and the edge leaving it read as one thing.
  • StatifierBlocks.Editor.PaletteBrowser takes a collapsed attribute, and the editor answers a palette-collapse event with one boolean and no hook, in the same shape as the shell amendment's other gestures. The fold is not reset when the host swaps the open document: it is a preference about the pane rather than state about the document.
  • The narrow arrangement (ADR-0005 ruling 7A) is unchanged. Below a container width of 780 the strip and its sheet are still the palette's whole chrome and the pane header stands down, so the fold has nothing to do there.
  • A container draws a box around its body only when it is a boundary - a container with a slot in the rail partition (ADR-0005 decision 10c, as amended by 10h). Every other container draws none: its own card stays at the head of its body and its children sit under it with the connectors, where a box around each of them turned a deep document into nested rectangles.
  • A boundary's box is the border, the radius and the inset that enclose its body and its rail, rather than the border colour it was before.
  • A container's card carries its own border, its accent stripe and its selection ring, so the block is still a card on the canvas when the box around its subtree is gone. A leaf card is unchanged.
  • A palette row is now a tile, a name, and the type's description on a second line, at a row height that gives the description room to wrap. The tile is a slot rather than an icon: a block type that declared no icon still renders the box, so every name in the list lines up.
  • A row's accent moved from a stripe down its leading edge onto the tile, which is where the card the pick produces carries it. The stamp itself is unchanged - a type that declares no accent token still gets neither the attribute nor the custom property.
  • A core.wait mints its delayed send under the reserved send role, so a chart containing one now compiles to s_<block id>__send where it compiled to s_<block id>__timer.
  • The package's default JavaScript export now carries both hooks, so hooks: { ...StatifierBlocks } registers StatifierBlocksDrag and StatifierBlocksMeasure together - a host that registered only the drag hook got an editor with no connectors and no error explaining it. Both names are still exported individually, and statifier_blocks/measure still resolves for a host that wants measurement alone.
  • The canvas stage renders inside a .sb-canvas-panel element, which is now the scrolling box; #sb-canvas stays the drag hook's element, the stage anchor, and where the theme assign's declarations land.
  • A container with more than one body slot now lays its slots out side by side and fans into them, as a container declaring layout: :columns already did - a branch's arms no longer stack full-width with each fan edge running down through the arm above its target.
  • Columns are a CSS grid taking their natural heights, cards are a fixed width centred in the box they sit in, and a column's header is card-width and centred over the first card it governs.
  • The "+" between two blocks is now the insertion marker: subtle at rest, highlighted on hover, on keyboard focus and for the whole of a drag, and drawn as a placeholder ring in a slot that is still empty. It is the same button with the same events, so nothing about the keyboard path changed.
  • StatifierBlocks.Editor.Slot stamps data-empty, and StatifierBlocks.Editor.BlockNode stamps data-container and data-arrangement, on the markup a host may style against.
  • The collapsed drawer's strip reads as a label and a quantity: a small-caps title with letter-spacing, and the count as a chip carrying a bare number rather than a parenthesised one inline with the title.

Removed

  • The stub exit tick a rail drew below itself in CSS. The exit edge is measured and drawn now, and a fixed-length mark beside it was a second claim about the same thing that pointed somewhere else.

Fixed

  • Leaving the scope around a core.wait cancels the wait's delayed timer, so a wait abandoned before its duration elapses no longer leaves an armed timer behind in a durable host.
  • A core.subchart outcome-routing condition is no longer attributed to the outcomes config field, so a chart finding landing inside it reports fault: :package with no config_key rather than blaming the author for bytes the compiler composed.

[0.3.0] 2026-08-29

Charts get more shapes to compile into. Campaign 015 adds four emitters to the core.* vocabulary - core.subchart, which runs another chart and routes on the outcome the child reported; core.foreach, a container whose body runs once per item of a datamodel list; scope-correct cancellation for a delayed core.send; and core.parallel's complete: "first", which finishes the block at the first lane's completion and exits the losing lanes. The compiler gains two root-document options, terminate: and declare:, a typed datamodel index that refuses a document reading a path the host declared sensitive, and predicator duration strings wherever a duration is typed. In the editor, connectors graduate out of the spike, a default icon set ships so a host needs no asset pipeline to get one, and the shell is laid out as the arrangement record describes it. This is a minor bump because every block's conventional <final> moves from s_<block>__done to s_<block>__o_done: the compiled bytes of every outcome-bearing chart move with it, so a host that stores compiled charts or provenance maps recompiles them, and a chart-level position saved against the old bytes no longer resolves.

Dependency floor: unchanged - statifier ~> 2.2 and predicator ~> 9.0.

Added

  • A core.subchart block type: a step that runs another chart and waits, routing done.invoke on the outcome the child reported (_event.data.outcome) to one slot per declared outcome, with core.invoke's on_error slot unchanged for a failed invocation.
  • A core.foreach block type: a container whose body runs once for each item of a datamodel list, compiled as a plain SCXML loop - a per-loop cursor and a snapshot of the list taken once on entry, the item_as and index_as bindings re-assigned from that snapshot on each pass, and the body compiled once with an internal loop-back transition. Iteration ends on the out-of-bounds read, snapshot[cursor] === undefined.
  • core.parallel accepts a complete config key choosing when the block is done: "all" (the default, and what a document stored before the key reads as) keeps the shipped rule, and "first" compiles the racing rule - one transition per lane on the <parallel> element itself, taken on that lane's own completion event and targeting the block's done final, so the block finishes at the first lane's completion and the engine exits the losing lanes with their <onexit> content and one CancelInvoke per live invocation.
  • Block types may declare outcomes/1, an optional callback returning ordered {name, label} pairs for the ways a block can finish; a type that does not export it has exactly one outcome, done, and behaves as before.
  • A child summary in the compiler context carries an outcomes field: the child's declared outcomes in declaration order, each with the <final> it compiled to and the completion event a parent wires on. It is never empty.
  • StatifierBlocks.Compiler.compile/3 accepts terminate: true, which emits one top-level <final> per root-block outcome with no <donedata>, so a compiled root document reaches :done when its root block completes; without it a root document never terminates, and passing it together with child_use: true is refused with an :emit finding.
  • StatifierBlocks.Compiler.compile/3 accepts child_use: true, which compiles a document for use as another chart's child: the emission gains one top-level <final> per outcome the root block declares, carrying that outcome name as done data, so a parent session can see which way the child finished.
  • StatifierBlocks.Compiler.compile/3 takes a :declare option - a list of {id, expr} pairs - so a host can declare the <data> roots its root document assigns to and guards on, hoisted ahead of block-declared roots into the chart's single <datamodel>.
  • Compiler.compile/3 takes a :datamodel option and refuses a document that reads a path the host declared sensitive?: true into a position the chart evaluates against the datamodel; with no datamodel supplied nothing is produced.
  • A block type may now contribute declared <data> roots to the chart: StatifierBlocks.Compiler.DeclaredRoots.declare/2 emits a declaration among the block's own children and the compiler lifts every one of them into a single top-level <datamodel>, in document order. A document that declares no roots emits no <datamodel> element, so charts compiled before this change are byte-identical.
  • A new Emit-stage finding, :duplicate_binding: a declared root whose name a block it sits inside already declares is refused against the declaring block and the config field the name was typed into, because early binding makes both roots global and the inner one would silently overwrite the outer.
  • The compiler refuses a block type that declares a malformed or duplicated outcome name with an :invalid_outcome Emit finding, against the block whose type declared it.
  • A chart-stage finding for an expression the author typed carries config_value_span, the byte range of the offending sub-expression within that config value, so an editor can underline the sub-expression rather than the whole field.
  • StatifierBlocks.Predicates.Datamodel indexes a datamodel document - the typed, three-scope declaration sb ADR-0006 defines - into a path/entry index: the type of a path, the entries under a prefix, whether a path is declared, and the record's one total derivation of the declared-path set. The index is advisory; an undeclared path is unknown, never wrong.
  • StatifierBlocks.Datamodel.declared_paths/1 accepts such a document as a fourth shape, alongside nil, a list and a MapSet, and projects it through that derivation. A document declaring no entries normalizes to the empty set - a host claim - rather than to nil, which stays reserved for no datamodel at all.
  • The editor renders the arrangement ADR-0005's shell amendment records: a palette, canvas and inspector across three columns with a full-width drawer row beneath them, at container-query breakpoints of 1280, 1024, 900, 780 and 640.
  • A canvas toolbar with stepped zoom, Fit width, Fit active, and the document's block count and depth.
  • The inspector is tabbed - Config, Findings and Condition - where Findings is the selected block's own and Condition reads the per-arm predicator source.
  • A drawer that is never open-or-gone: collapsed it is a strip carrying a title and the document's table count, and opened on a block with no table it shows an index of the blocks that have one.
  • fixtures, an assign carrying %{block_id => [TruthTable.t()]}, is what the drawer's truth-table tab reads; with none supplied the drawer is still present and reads 0.
  • drawer_height and on_drawer_resize are the host's seam for the drawer's resizable height, which the host remembers per viewer.
  • A :header slot the host fills with the outer header - document identity, the switcher, the theme control, compile and publish - which this package now explicitly does not draw.
  • Below 780 the palette collapses to a strip that opens as a sheet.
  • StatifierBlocks.Shell exposes the shell's arrangement as pure functions - the zoom ladder, the document metrics, the drawer's five states, and which of a block's fields are conditions.
  • Three tier-2 theme tokens: --sb-palette-width, --sb-inspector-width and --sb-drawer-height.
  • The editor draws connectors. Adjacency inside a slot, a container's entry, the fan and rejoin around a container arranged side by side, and a rail's exit are rendered as SVG in the LiveView tree, derived from the document's shape rather than authored.
  • A second JavaScript entry point, statifier_blocks/measure, exporting the StatifierBlocksMeasure LiveView hook. Its whole job is measurement: after a render it reads the boxes the browser laid out for the anchors the server stamped and pushes them, and it issues no commands and mutates no DOM. A host that wants connectors adds one import; a host that does not gets the editor it had before, minus the drawn connectors.
  • StatifierBlocks.Connectors: the connector geometry as pure functions from measured rectangles to SVG path data, outside the Phoenix guard, so a host can route its own connectors and a test can assert them without a browser.
  • Three --sb-* tokens for the connector layer: --sb-edge, --sb-edge-interrupt and --sb-edge-width.
  • StatifierBlocks.Editor.Icons, a default icon set the editor uses when the host passes no icon component. Inline SVG for the eleven names the core block types declare, with no font, no CDN and nothing to register in a host's asset pipeline. Every glyph paints with currentColor and fills its tile, so --sb-block-accent and --sb-block-accent-tint still decide the colour and a per-block-type accent_token still moves a type's tile with its stripe.
  • Palette entries render their icon. The icon assign the editor passes the palette browser was declared and never rendered, so no host could put an icon on a palette row; a type now looks the same in the palette as on the card the pick produces.
  • A slot declaring slot_style: :failure renders in its own vocabulary - a solid error-family edge, its own sb-slot--failure class, and an ordinary flow edge where an interrupt rail draws a dashed escape.
  • StatifierBlocks.ViewModel.exit_edge/1 says which edge vocabulary a slot's exit is drawn in, and the editor stamps it as data-exit-edge.
  • The editor takes an optional datamodel assign - the paths the host declares - and reports a config field whose declared datamodel path is not among them as an :info finding in the findings panel; with no datamodel supplied nothing is produced.
  • Block types may declare a config field with datamodel_path?: true, saying its value is a path into the host's datamodel; core.assign's path field carries it.
  • StatifierBlocks.Core.Parallel.join_label/1, declared on the type's palette entry, so a renderer draws "continue at first" or "continue when all" from the block's config without learning the type's name.
  • StatifierBlocks.DurationInput reads a typed duration for that control, accepting exactly what StatifierBlocks.Core.Duration compiles and naming the limit a refused value hit.

Changed

  • Every block's conventional <final> moves from s_<block>__done to s_<block>__o_done and now raises done.outcome.<state id>.done on entry, so compiled SCXML moves for every document; a host that stores compiled charts or provenance maps recompiles them, and a chart-level position saved against the old bytes no longer resolves.
  • Compiler.compiler_version/0 (and every compilation record's compiler_version) moves to 0.3.0 with the package, per ADR-0004 decision 6, and is the third input to the byte-determinism guarantee: this release is where the outcome-final byte movement is recorded.
  • core.send now emits its <send> with id="<the block's state id>__send", so a delayed send can be named after it is armed.
  • A delayed core.send is now cancelled by its scope: the compiler emits <cancel sendid="..."/> in the <onexit> of the nearest enclosing <state>, so a pending send does not outlive the sequence, group, region or lane that armed it. Charts containing a delayed core.send change bytes; every other chart is unchanged, core.wait timers included.
  • core.wait accepts a predicator duration string (1h30m, 2d, 3d8h) as well as ISO-8601, stores whichever spelling the author typed, and compiles it to the emitted delay attribute; its refusal message names both spellings.
  • core.wait's declared duration default is now the predicator string 1h rather than the ISO-8601 PT1H, so a newly inserted block starts from the spelling an author types. Both spellings stay accepted and each compiles to the same delay attribute, so no chart's emitted SCXML changes and no stored document has to be retyped.
  • A :duration config field renders as one text control taking predicator duration strings, with 30s, 15m, 1h30m, 2d and 3d8h shown beside it; ISO-8601 is still accepted and the author's string is stored verbatim.
  • An empty :duration field omits its config key rather than storing an empty string, so a cleared field and a never-set field are the same value.
  • An icon entry that declares no icon renders no tile, rather than an empty one, and a host's icon component is never called with a nil name.
  • An icon name the shipped set does not have renders a neutral mark with the name in data-icon.
  • A slot_style this editor does not recognize renders as an ordinary body slot instead of reaching the markup unresolved; its children are still rendered, still selectable and still saved.

Removed

  • StatifierBlocks.Editor.Field.units/0, format_duration/2 and parse_duration/1, which served the retired value/unit control. Call StatifierBlocks.Core.Duration.to_iso/1 to canonicalise a stored duration.

Fixed

  • The editor no longer renders a U+25A1 white square in every icon tile when the host passes no icon. Passing one still overrides every tile, on the canvas cards and the palette rows alike.
  • A delayed core.send in the body of a core.group that carries interrupt rules is now cancelled when the group is abandoned. Its <cancel> is emitted in the body region's <onexit> rather than the group's own, and abandoning the group exits the region without exiting the group, so the old placement never fired.

Known limits

  • A core.foreach list holding a nil item iterates to its end rather than stopping at it: === is strict, so only an out-of-bounds read is undefined.
  • Two core.foreach blocks in one document may not bind the same name, even when neither is inside the other; the second is refused with a duplicate-id finding on its item_as field.

0.2.0 2026-08-29

The editor ships. Campaign 014 graduated the authoring spike into the package: StatifierBlocks.Editor renders from assets/ with a documented --sb-* theming surface, a drag marks the slots that accept a block and can say why a slot refused, and a host registers its own block types through Palette.from_modules/2. The core.* vocabulary grows by core.invoke, core.raise, core.assign and core.send; the compiler now evaluates predicator conditions, refuses slot-arity and undeclared-slot violations, and adapts its findings into the shape the editor renders.

Dependency floor: statifier ~> 2.2 (was ~> 2.0); predicator ~> 9.0 is now a direct dependency.

Added

  • core.raise raises an event for an enclosing group's interrupt rules.
  • core.assign writes a literal to a datamodel path.
  • docs/theming.md: the theming guide - the three tiers of the --sb-* surface, the scheme token, per-block-type accents, and a complete host theme that sets custom properties and nothing else.
  • core.send sends an event, now or after a delay.
  • A block type may declare slot_outcome_key in its palette entry, naming the config key the blocks in one of its slots carry their outcome under, so a renderer can route an interrupt rule's escape without branching on a type name; the declaration reaches the view model as Slot.outcome_key and the resolved value as Node.outcome.
  • StatifierBlocks.BlockType.slot_outcome_key/2 and StatifierBlocks.BlockType.outcome_name/2 read that declaration totally: a malformed declaration or value is refused rather than repaired, and reads as no declared outcome.
  • A block type may declare accent_token, the NAME of a --sb-* property, and the editor stamps it on that type's cards and palette rows. Two rules in the stylesheet read it; no rule and no module names a block type (ADR-0005 amendment 14d, consumption side).
  • StatifierBlocks.Finding.severity_class/1, and :info as a third severity for advisory findings (decision 11, amended 2026-08-29). Nothing emits one yet; only :lint may.
  • A form whose config the gate has not accepted names the fields that are outstanding, says why nothing is stored, and offers "Discard edits". A draft was never a command, so it cannot be undone - it can only be thrown away, and that gesture had nowhere to live.
  • :expression and :duration controls carry a placeholder. A bare :string still carries none: there is nothing a type that wide can suggest.
  • A theme audit test over the stylesheet, failing in both directions: a var(--sb-*) with no declaration, and a declared token no rule reads (14e).
  • StatifierBlocks.SlotValidation, a palette-aware whole-document check for a block's declared slots (:undeclared_slot) and each declared slot's arity (:slot_arity_violated).
  • StatifierBlocks.Predicates evaluates a condition expression against a binding context through predicator, returning a boolean or a tagged error.
  • StatifierBlocks.Predicates.TruthTable builds a checked truth table over fixture rows, applying first-match-wins arm ordering.
  • StatifierBlocks.Finding.from_compiler/2 and from_compiler_all/2 adapt a compiler finding into the presentation shape the editor renders, so a host can route compile findings through ViewModel.build/3.
  • StatifierBlocks.Assignability.seam_reason/4, finding_reason/2 and seam_reasons/3 name why a data-flow seam came out the way it did: :not_assignable and {:fixable_by, block_id} for a refusal, and :source_untyped / :target_untyped / :both_untyped for a seam that passed only because a block declared no type. seam_reasons/3 is how a host finds the parts of its palette it has not typed yet.
  • StatifierBlocks.Assignability.target_verdicts/4 returns every position valid_targets/4 enumerates with its full verdict, and StatifierBlocks.Edit.Targets.slot_verdicts/3 projects those to slots - the accepting ones and the reason each refusing one gives.
  • The editor stamps a refused slot's reason as data-drop-reason beside data-drop, so a hover affordance can explain a refusal with no round-trip and no JavaScript.
  • A core.invoke block type: it names an invoke type for the host to run, sends datamodel values along as <param>s, writes the result where its assign_to names, and takes an optional on_error subtree entered on a permanent invoke failure.
  • StatifierBlocks.Compiler.Context.outcome_id/2 and outcome_event/2, for a block type with more than one way to finish: one <final> per outcome, and the done.outcome.<state id>.<outcome> event a parent wires on.
  • StatifierBlocks.Palette.from_modules/2, the registration API a host uses to contribute its own block types: an ordered, explicit list of {type_name, module} registrations, with core: true to sit on top of the core.* vocabulary. Later entries win. It is still a value - no global registry, no application-configuration lookup, and no discovery pass.
  • A palette entry may declare badge, a short chip for the card header, and join_label, a one-argument function of the block's config phrasing the join marker under a side-by-side arrangement (ADR-0002 amendment B). StatifierBlocks.BlockType.badge/1 and join_label/2 read them.
  • Both readers are total and refuse rather than repair: a chip that is blank, carries a newline or tab, or runs past 24 characters is dropped, not clipped, and a join_label that raises degrades to the editor's own word rather than taking the canvas down.
  • accent_token, badge and join_label are admitted keys of StatifierBlocks.BlockType.palette_entry/0.
  • The README carries a worked host example - a myapp.risk_hold block type registered beside the core vocabulary, with a badge and an accent token - and it is executed on every build rather than trusted.

Changed

  • Compiler.compiler_version/0 (and every compilation record's compiler_version) moves to 0.2.0 with the package, per ADR-0004 decision 6: a record compiled by 0.1.0 identifies itself as such.
  • --sb-drop-ok-border moves from #2f9e5f to #2c945a. The outline that says a slot accepts a drop was 2.93:1 on the sunken surface, under the 3:1 a mark carrying information is held to; the tint follows it.
  • predicator is now a direct dependency (~> 9.0), because StatifierBlocks.Core.Duration calls Predicator.Duration.parse/1. It already resolved transitively through statifier, so the resolved version does not move; naming it records the call.
  • The editor's stylesheet carries a scoped reset, and every selector in it matches the container through :where(.sb-editor) so a component rule always wins (ADR-0005 amendment 14b).
  • --sb-color-scheme is declared and read as color-scheme on the editor's own container, so the parts of a control the browser paints - a <select>'s drop-down, the scrollbars, the caret - follow the theme (14a).
  • The --sb-* surface gains the space, type and shape scales, a third text step, a strong border, status tints, the drag seam's drag-time height, and the canvas sizing constants that were literals in rules.
  • A :secondary and a :failure slot are both placed as attached rails, and a container declaring either is drawn as a boundary box - the rail partition, not the :secondary partition (amendments 10c and 10h).
  • --sb-drop-no-opacity is retired. A drag now marks the slots that accept the block and leaves the rest alone rather than dimming them; the disabled-control opacity it doubled as is --sb-disabled-opacity.
  • The compiler now refuses a document whose slots violate their declared arity or name a slot the block type does not declare, instead of silently dropping those children from the emission.
  • Reasons change no verdict: :unknown stays permissive in both positions, Assignability.validate/3 reports exactly the findings it did before, and neither finding tuple gained a field.
  • slot_style admits a third value, :failure, for a slot whose children are an in-band continuation taken on a bad outcome; core.invoke declares it for on_error.
  • The role namespace beginning o_ is reserved for outcome finals; Context.role_id/2 now refuses such a role with a :reserved_role finding.

Fixed

  • The editor's root rule sets font-family rather than the font shorthand, so --sb-font reaches the editor. font: <family-list> is not a valid shorthand, so the whole declaration was dropped and the editor's text did not inherit the host page's font as the token promised.

0.1.0 2026-08-27

First release: the authoring layer above the statifier statechart engine. A block document is the source of truth - a tree of typed blocks, each with a declared shape - and it compiles one way to SCXML plus a provenance map that points a runtime position back at the block that produced it. Block types are host-pluggable: a host registers the types its own domain needs, and the compiler and the editor work off that registry rather than a closed built-in vocabulary. The core.* structural vocabulary, the compiler, the edit algebra, and the LiveView editor shell all ship here.

The Changed entries below describe the shape of callbacks and metadata as they stand at this first release; there is no earlier published version to have changed from.

Added

  • StatifierBlocks.Document.validate/1 checks a block document's structure: schema version, envelope shape, per-block shape, and document-wide id uniqueness.
  • StatifierBlocks.Document.to_json/1 encodes a document to ADR-0001's deterministic canonical JSON: sorted object keys, no insignificant whitespace, empty slots/config/metadata omitted, no floats.
  • StatifierBlocks.Document.content_hash/1 returns a "sha256:" <> hex document identity over to_json/1's canonical bytes.
  • StatifierBlocks.Document.from_json/1 decodes canonical JSON back into a document, structurally and registry-free: unknown block types decode successfully, and every refusal is one of ADR-0001's typed error arms.
  • StatifierBlocks.BlockType behaviour: the nine-callback authoring-time extension seam (ADR-0002), five required (slots/1, config_schema/1, validate_config/1, current_version/0, emit/2) and four optional (io/1, migrate_config/2, fixtures/0, palette_entry/0).
  • StatifierBlocks.Palette: a caller-supplied type_name => module value (ADR-0002 decision 2), with new/1 to build one and a total fetch/2 that returns {:ok, module} or {:error, {:unknown_block_type, type_name}} and never raises (ADR-0002 decision 3).
  • StatifierBlocks.Palette.resolve/2: resolves a block through the palette and migrates its config in memory when the stored type_version is below the type's current_version/0 (ADR-0002 decision 8). Migration is applied to the returned struct only and never written back to a document; a stored version above current_version/0 hard-errors as {:error, {:block_type_too_new, id, version}} rather than reading best-effort, and a failing or missing migrate_config/2 surfaces as {:error, {:migration_failed, id, reason}}.
  • The core.* structural block types (ADR-0002 decision 10), one StatifierBlocks.BlockType module each: StatifierBlocks.Core.Sequence, .Group, .Branch, .Parallel, .Wait, .ResumableGroup and .OnEvent. core.branch derives one slot and one :expression field per declared arm, core.parallel one slot per declared lane, and each type is the authority on its own config through validate_config/1.
  • StatifierBlocks.Palette.core/0 and StatifierBlocks.Palette.core_types/0: the core vocabulary as a palette, and as the plain type_name => module map a host merges its own entries into.
  • Structural placement through ADR-0003 decision 3 kind tags: core.on_event declares kinds: [:interrupt_handler] and the group types accept only that kind in their interrupts slot, so an interrupt handler is admitted there and refused everywhere else, and an ordinary step is refused there - in both directions, from the declarations alone, with no special-cased rule.
  • fixtures/0 on core.branch (an arm condition evaluated against two datasets) and core.on_event (one example event payload). The bundle shape follows an amendment to ADR-0002 decision 9 that is not yet accepted, and is documented as provisional until it is.
  • StatifierBlocks.Assignability: the one decision function for whether a block may land in a slot, checking structural admission by kind tag and data-flow compatibility by type-expression identity plus an optional host-supplied widening relation (ADR-0003). check/5 decides a single candidate position; valid_targets/4 lists every position a candidate may occupy in a document; validate/3 reports every finding already present in a document; inbound_type/4 and assignable?/3 are the two primitives both are built from.
  • StatifierBlocks.Assignability.Relation: the behaviour a host implements to widen data-flow compatibility beyond exact type-expression identity. A host module can only grow the accepted set, never shrink it.
  • StatifierBlocks.Palette gains an assignability field naming the host's Assignability.Relation module, set via Palette.new(types, assignability: MyApp.Blocks.Types). Defaults to nil, meaning no widening relation is declared; existing calls to Palette.new/1 are unaffected.
  • StatifierBlocks.Compiler: the one-way compile (ADR-0004 decisions 1-4, 6-7). compile/3 is a total function of {document, palette} returning {:ok, %StatifierBlocks.Compiled{}} or {:error, [%StatifierBlocks.Compiler.Finding{}]} - no process state, no clock, no IO, and no arm that raises. The pipeline runs Document, Resolve, Config and Emit, stopping at the first stage that produces errors and reporting every error from that stage.
  • StatifierBlocks.Emission: the structural representation of one SCXML subtree a block type returns from emit/2, with element/3 and the child_ref/1 placeholder the compiler splices its children into.
  • StatifierBlocks.Compiler.Serializer: the deterministic serializer. Attributes sorted, one canonical empty-element form, no incidental whitespace at all. It is identity-bearing code - chart identity hashes source bytes (st-ADR-0052) - and serializer_test.exs now enforces the whitespace sensitivity ADR-0004 decision 6 named and left unenforced.
  • StatifierBlocks.Compiler.StateId: state_id/1, state_id/2, unstate_id/1 and done_event/1. State ids derive from block ids ("s_" <> block_id, "__" <> role for an auxiliary state), so they are unique, invertible and total over generated states.
  • StatifierBlocks.Compiler.Context: what a block type is entitled to know while emitting - its own ids, the document id, its children's summaries (block id, state id, done event) and the role-minting function. No palette, and no child's emitted SCXML.
  • StatifierBlocks.Compiled and StatifierBlocks.CompilationRecord: the artifact, and the join between document identity and chart identity. chart_name carries the document id and chart_version stays nil, so a revision bump or a metadata-only edit still matches the identity a running session holds.
  • StatifierBlocks.Core.Emit: the SCXML shapes the core.* vocabulary compiles to, and the builders a host block type follows to compose with them.
  • StatifierBlocks.Provenance: the map from generated SCXML back to the blocks that produced it (ADR-0004 decision 5). Keyed by state id for highlighting a running session's configuration, and by byte span for routing findings that carry no element reference. owner_at/2, owner_of_state/2, owners_of_states/2, and canonical to_json/1 / from_json/1 so a host can store the map beside the chart.
  • StatifierBlocks.Compiled now carries all five of ADR-0004 decision 1's fields: provenance, invoke_types and warnings join scxml and record.
  • invoke_types publishes the sorted set of invoke types the chart emits, unconditionally, so a host can compare it against its Statifier.Session registration at deploy time (ADR-0004 decision 8).
  • Compiler.compile/3 accepts :known_invoke_types, an opt-in lint that warns - never errors - for every emitted invoke type absent from the set the caller believes will be registered.
  • Compiler.compile/3 accepts :entry_type, ADR-0003 decision 4's caller-supplied context, which the new Structure stage passes to StatifierBlocks.Assignability.validate/3.
  • The compiler now runs a Structure stage (assignability) and a Chart stage (statifier's own pipeline over the generated bytes), and maps every upstream finding back to the block that caused it.
  • StatifierBlocks.Emission.attributed_to/2, from_config/2 and attribute_from_config/3: the hints a block type leaves so a finding lands on the block an author would recognise, and on the config field they typed into.
  • StatifierBlocks.Edit: the editor's command algebra - insert, remove, move, and update-config - as a purely structural, invertible rewrite over a document with no palette involved (ADR-0005). apply/2 applies one command and returns both the new document and the command that undoes it; check_config/3 is the separate config-validity gate one layer up.
  • StatifierBlocks.Edit.History: undo and redo over Edit commands. commit/4 is the one funnel a host calls - it runs Edit.check_config/3 before Edit.apply/2, then pushes the inverse and clears the redo stack, so invalid config never reaches the document on any path, undo and redo included.
  • StatifierBlocks.Edit.Targets: droppable_slots/3 and droppable_slots_for/3, which slots would accept a dragged block, at slot granularity rather than gap granularity, built as a reduction of StatifierBlocks.Assignability.valid_targets/4.
  • StatifierBlocks.Finding: the presentation finding ADR-0005 specifies, anchored to a block, a slot, or a config field so the editor knows where to render it. Distinct from the existing StatifierBlocks.Compiler.Finding, which serves the compile pipeline.
  • StatifierBlocks.ViewModel: the structure the editor actually renders, derived from a document, a palette, and a list of findings. Resolves and normalizes every block's slots, form fields, and palette presentation metadata, and routes every finding to the position that renders it.
  • StatifierBlocks.Editor: the LiveView editor shell (ADR-0005). A LiveComponent a host embeds over a %Document{} and a %Palette{}; it is the only stateful module in the package's rendered half, and everything it does is translate a phx- event into one of StatifierBlocks.Edit's four commands. Drag is two round-trips - one at dragstart to enumerate valid slots, one at drop - with zero per hover, because validity reaches the client as data-drop markup rather than as client-side logic.
  • StatifierBlocks.Editor.Canvas, .BlockNode, .Slot, .ConfigForm, .Field, .PaletteBrowser, .Findings: the function components the shell renders, each independently renderable in a test. BlockNode and Slot recurse into each other, and there is no per-block-type component: a block type's layout and slot_style presentation metadata is the only thing that distinguishes a group from a set of lanes.
  • assets/js/statifier_blocks.js: the package's entire client-side surface, one hook named StatifierBlocksDrag, shipped as source. A host adds "statifier_blocks": "file:../deps/statifier_blocks" to its assets/package.json and imports the hook in app.js; this repository bundles nothing and has no Node toolchain.
  • assets/css/statifier_blocks.css: one stylesheet of structural CSS and no visual opinion beyond it. Every class is prefixed sb-, every color, space, radius and drag treatment is a --sb-* custom property with a default, and every top-level component takes a class attr appended to its own.
  • A headless CI job that resolves the dependency tree with phoenix_live_view absent, compiles it with warnings as errors, and runs the non-LiveView suite
    • the acceptance property that makes the optional dependency's guard trustworthy rather than decorative. STATIFIER_BLOCKS_HEADLESS=1 reproduces it locally without disturbing the ordinary build.
  • StatifierBlocks.BlockType: a config field declaration may now carry an optional value_path, a list of keys and list indexes from the config root down to the value it edits (ADR-0002 decision 7, amended 2026-08-27). A declaration without one behaves exactly as before - its key addresses config[key]. The key remains the field's identity in both cases: the DOM id, the form param name, and what a {:config, block_id, key} finding anchors to.
  • StatifierBlocks.BlockType.value_path/1, fetch_value/2 and put_value/3: the reader and writer that resolve a declaration to a path and then read or write through it. value_path/1 answers [key] for a declaration that declares none, so a caller never branches on which case it has. fetch_value/2 is total and answers :error for a path that does not resolve. put_value/3 writes the last segment whether or not a value was already there - an arm with no condition yet is exactly the one an author is about to type into - but never invents an intermediate map or list a block type did not write.
  • StatifierBlocks.ViewModel.Field carries value_path, and ViewModel.Field.value_path/1 reads it with the same [key] default.

Changed

  • StatifierBlocks.BlockType.io/1's return type is StatifierBlocks.Assignability.io/0 instead of term(). Every core block type already returns a value of this shape; a custom block type implementing io/1 should confirm its return value conforms.
  • All seven core.* block types implement emit/2 for real; the {:error, {:not_implemented, block_id}} placeholder and StatifierBlocks.Core.Config.emit_deferred/1 are gone.
  • StatifierBlocks.BlockType.emit/2 is narrowed from (Block.t(), term()) :: {:ok, term()} | {:error, term()} to (Block.t(), StatifierBlocks.Compiler.Context.t()) :: {:ok, StatifierBlocks.Emission.t()} | {:error, StatifierBlocks.BlockType.emit_error()}. A host block type that was returning something else now has a type to conform to.
  • StatifierBlocks.Compiler.Finding gains path, severity, fault and code. fault is :author when a document edit fixes the finding and :package when it is a bug in this package or a host's block type - which is what lets an editor say "this cannot be fixed here" rather than blaming the author for a generated state id.
  • Findings from every stage come back in document order over blocks rather than in the order a stage happened to collect them.
  • A bad :expression config field now surfaces as an :author finding naming the arm's config key, rather than as an unrouted upstream error.
  • StatifierBlocks.BlockType.palette_entry/0's return type is StatifierBlocks.BlockType.palette_entry/0 instead of map(). Every core block type already returns a value of this shape; a custom block type implementing palette_entry/0 should confirm its return value conforms.
  • phoenix_live_view is a declared optional dependency at ~> 1.0, matching statifier_ui's floor. Every module under StatifierBlocks.Editor.* is compiled behind Code.ensure_loaded?(Phoenix.LiveView), and no module outside that namespace references Phoenix - so a host that only compiles documents adds no Phoenix dependency and compiles no editor code.
  • The hex package's files: list includes assets. The hook and the stylesheet ship as source, and source that is not in the tarball is not public API.
  • Every illustrative example in the package - ADR worked examples, doc examples, and the shipped fixture bundles - uses one of the family's two canonical example domains: credit-card authorization and capture, or a signup wizard with A/B testing.
  • StatifierBlocks.Core.Branch.fixtures/0 ships budget-decision datasets ("approved" / "declined") and the expression "budget_remaining > amount". A host rendering the bundle in a palette panel sees those names.
  • The arm-slot and lane-name validation messages on core.branch and core.parallel name "arm_approved" and "capture" as their exemplars.

Fixed

  • A core.branch arm's condition is now readable and editable in the editor. Core.Branch.config_schema/1 keys one :expression field per arm by the arm's slot name, but the condition is stored at config["arms"][i]["cond"]; the form previously read and wrote the slot name as a top-level config key, so every branch condition rendered empty, no edit to one reached the arm, and a junk config["arm_approved"] accumulated beside it. Each per-arm field now declares value_path: ["arms", i, "cond"], and StatifierBlocks.ViewModel and StatifierBlocks.Editor.ConfigForm read and write through it. i is the arm's index in the stored list rather than its index among the well-formed ones, so a good arm below a malformed one still addresses its own condition while an author is mid-edit.
  • StatifierBlocks.Editor's field-list-add and field-list-remove events read and write the rows through the field's value_path as well, rather than through the top-level key. A key naming no field in the selected block's schema now edits nothing, matching the guard ConfigForm.decode/3 already applied.
  • StatifierBlocks.Assignability.check/5 and valid_targets/4 no longer raise a MatchError when the candidate is the document root. Document.fetch_path/2 answers {:ok, []} for the root, and the vacated-seam check now reads that as what it is - the root occupies no slot, so it leaves no seam behind - instead of calling List.last/1 on the empty path. StatifierBlocks.Edit.Targets.droppable_slots/3 answers [] for the root rather than crashing, so a caller no longer has to guard around it.