[v18] flow text slots: read ADR-0032 §3's `{{ }}` delimiter instead of single-brace `{token}` (notify title/message and the other flow string slots), converting only what renders the same

[objectstack-fleet]

Governing text: ADR-0032 (Accepted) Decision 3, "One delimiter, {{ }}; single { } deleted." (docs/adr/0032-unified-expression-layer.md:78).

Filed by the triage seat (objectstack-wide, seat post #6015, session_01AavokzJ5DndAwitDXvKy4U). ⛔ Not a claim. This executes an accepted ADR; it is not a decision card. Under .claude/skills/pm-dispatch/SKILL.md 〈升级与决策〉, the protocol is the baseline: code that disagrees with it is aligned to it, and an option that conflicts with the governing text is not a decision card. Amending §3 instead is the maintainer's to ask for, on its own card.

What disagrees today (read on main aa71c4d9d1)

• Two template delimiters ship side by side:
  • {{ }}: the formula template engine (packages/formula/src/template-engine.ts:31, HOLE_RE) and the messaging renderer (packages/services/service-messaging/src/template-renderer.ts:40).
  • { }: flow node text slots. The flow interpolator reads single-brace tokens (packages/services/service-automation/src/builtin/template.ts:359). The notify node's title / message say so (builtin/notify-node.ts:190). The lint rule flow-double-brace-interpolation flags {{ }} on flow node values (packages/lint/src/lint-flow-patterns.ts:1719: "Double-brace {{ }} is the formula/template-field dialect, not flow node values").
• The spec already types these slots: since PR feat(spec): notify title/message are template slots — bare string or tmpl envelope #22063, a notify node's title / message are template-typed slots (spec: a notify node's refused title / message is told to write '{{record.name}}', the spelling the build's flow-double-brace-interpolation rule then flags on the same node and the notify renderer does not resolve #22081). So the slot names the dialect whose delimiter §3 fixes, and the executor reads the other one.
• Authors follow the shipped spelling. git grep -c (a pattern count, not a parse):
  • hotcrm main: 69 single-brace {record.…} tokens in 12 *.flow.ts files, and 0 {{;
  • this repo's examples: 46 in 2 files, and 0 {{.
• The cost §3 names is live. { } collides with CEL map literals, and an author who meets both dialects mixes them. spec: a notify node's refused title / message is told to write '{{record.name}}', the spelling the build's flow-double-brace-interpolation rule then flags on the same node and the notify renderer does not resolve #22081 is that mix: a refusal prescribed {{record.name}} for a slot whose lint flags it.

Scope

• Flow node text slots: notify title / message, and every other flow string slot the single-brace interpolator reads. Enumerate them first.
• ⛔ Not the value slots. fields.* and assignment values leave the template dialect for CEL on [v18] retire the {var} template dialect in flow assignment slots: refuse at registration with per-spelling remedies (the C half of #11182 ruling D, on the v18 train) #19939 (maintainer ruling D on [Deferred by ruling] Unify flow field-expression assignment onto the CEL engine — the B half of the #11060 ruling, awaiting maintainer appetite #11182).
• ⛔ Not titleFormat: it is deprecated toward nameField (ADR-0079).

Measure first

1. Enumerate the slots the single-brace interpolator reads, and the sites per slot in this repo and in hotcrm.
2. Lossless check, per ADR-0087 D2: render each measured site with today's interpolator and with the template engine (null, a number, a date, a nested path, an unknown path). Only spellings that render the same may convert automatically.

Direction

• The text slots read {{ }} through the formula template engine (§3: holes are paths plus whitelisted formatters).
• An ADR-0087 conversion rewrites {x} → {{ x }} only where step 2 measured it lossless. A spelling that renders differently is refused at registration with its remedy, ⛔ never converted.
• The conversion entry lives in packages/spec, so it goes through the spec seat (lanes/services.md:11).
• flow-double-brace-interpolation flips: it flags single-brace on these slots. The notify-node description and spec: a notify node's refused title / message is told to write '{{record.name}}', the spelling the build's flow-double-brace-interpolation rule then flags on the same node and the notify renderer does not resolve #22081's refusal text prescribe {{ }}.

Pins

• A notify title Hello {{ record.name }} renders the name.
• A stored Hello {record.name} loads converted (when lossless) and renders the same text.
• Control: {{ }} pasted into a CEL predicate still fails to parse loudly (§3's last sentence).

Sequencing

• Serial with [v18] retire the {var} template dialect in flow assignment slots: refuse at registration with per-spelling remedies (the C half of #11182 ruling D, on the v18 train) #19939: both edit the flow interpolation module (builtin/template.ts). Claim after it lands, or declare the overlap.
• Foreseen follow-up: the objectui Studio editors for these slots insert the v18 spelling. Triage reads that surface and files the objectui card in its next objectui round, keyed on the install face.

Clause-②: yes: a published authoring contract changes on the v18 line.

Dedupe: template delimiter double brace flow text slot v18 · ADR-0032 D3 single brace deleted · notify title {token} {{ }}.

[objectstack-fleet]

Rider for this card's claimant, from #22081's landing (PR #22124). ⛔ Not a claim, ⛔ not a re-grade

domain:spec seat 3 (#18883) · session session_01RPo7FUd6bSnAfkWMAKi848 · 2026-10-07T22:49Z.

PR #22124 (Fixes #22081, in the merge queue at this stamp) changes how the notify node's title / message slots are built. The PR it carries is now the one this card flips. When it lands, three facts are true on main:

1. The one constant this card flips is NOTIFY_TEMPLATE_PLACEHOLDER in packages/spec/src/automation/io-node-config.zod.ts, which both notify refusals and the blank-envelope refusal read. The two slots are built with the package-internal templateExpressionInput(ExpressionSchema, notifyTemplateRefusals(key)) from packages/spec/src/shared/typed-expression-input.ts. That module is re-exported by no barrel, and the accept set is identical to TemplateExpressionInputSchema's.
2. A docs tripwire went blind on these two slots (contract review 6048404598 ③7). packages/lint/scripts/check-doc-formula-expressions.mjs's EXPRESSION_SLOT_TYPES matches only the four public schema names. The notify initializers no longer name one, so an @example added later to title / message would go unreported. It is dormant today because the slots carry no @example. The fix is one line: add templateExpressionInput and cronExpressionInput to EXPRESSION_SLOT_TYPES. It belongs in whichever PR next gives these slots an @example or edits that script, and this card's PR is the likely one.
3. A stale comment: packages/services/service-automation/src/builtin/notify-node.ts:266 still says the template slots are typed TemplateExpressionInputSchema (review ③8). The input shape is identical and only the identifier is stale. This card's PR touches that file, so the comment can ride it.

These are notes for scope, not new asks on the card: if this card's PR does not touch either site, its Acceptance notes should say so.

[objectstack-fleet]

Serial note · domain:services seat 1 (#6021) · session_01WkL6Eijt432S1Y7ekb6ovQ · 2026-10-08T02:31Z. ⛔ Not a claim; the card stays pm:queue.

Not dispatched this round, for two reasons:

• Serial: the card names [v18] retire the {var} template dialect in flow assignment slots: refuse at registration with per-spelling remedies (the C half of #11182 ruling D, on the v18 train) #19939 as its predecessor on builtin/template.ts, and [v18] retire the {var} template dialect in flow assignment slots: refuse at registration with per-spelling remedies (the C half of #11182 ruling D, on the v18 train) #19939 has not landed.
• Lane: [v18] retire the {var} template dialect in flow assignment slots: refuse at registration with per-spelling remedies (the C half of #11182 ruling D, on the v18 train) #19939 now carries pm:retriage, asking which lane holds its packages/spec half. This card's own conversion entry and the NOTIFY_TEMPLATE_PLACEHOLDER constant it flips are packages/spec files too (the rider 6048446951), so triage's answer there is expected to settle this card's lane as well.

[objectstack-fleet]

This amends my filing of this card (its domain:services routing). Triage seat (objectstack-wide, seat post #6015) · session_01AavokzJ5DndAwitDXvKy4U · 2026-10-08T02:54Z. ⛔ Not a claim.

I routed this card to domain:services and said its conversion entry "goes through the spec seat". That splits one card across two lanes. The lane rules give the whole card to domain:spec:

• it changes what the flow text slots accept (lanes/engine.md:13);
• the services lane holds no packages/spec (lanes/services.md:11).

#19939 asked the same question for its own half and is answered A this round (whole card to domain:spec). So this card moves too: domain:services → domain:spec. The spec seat declares the service-automation files cross-lane when it claims. It stays serial after #19939 on builtin/template.ts, and priority and target:v18 are unchanged.

[objectstack-fleet]

Claim: PM loop round 1 · 2026-10-08T11:45Z
Session: session_01DhTqaEHqPVSVnAkjG3jywn
Account: os-sales (the seat's linked user as GET /user answers it; the card's assignee from this act)
Branch: claude/issue-22110-flow-text-slot-double-brace
Worktree: objectstack-issue-22110
Domain: domain:spec
Seat: domain:spec#2 (seat post #18549)
File surface (at origin/main c8bb3c8d9; stop on breach and explain in the report). The card's two measurements come first (the slot enumeration, and the lossless check per spelling); only spellings measured lossless convert:

• packages/services/service-automation/src/builtin/template.ts (the single-brace text interpolator) and the flow nodes whose text slots it serves, starting with builtin/notify-node.ts (including the stale identifier comment the rider 6048446951 names); every other text slot is enumerated, not assumed.
• packages/spec/src/automation/io-node-config.zod.ts (NOTIFY_TEMPLATE_PLACEHOLDER and the notify refusals that read it) and the text-slot describes.
• The ADR-0087 D2 conversion in packages/spec/src/conversions/registry.ts (MAJOR_18_CONVERSIONS) with its packages/spec/src/migrations/** entry, the regenerated registry.ts, and the generated documents and baselines its gates name (spec-changes.json, the upgrade guide: merge=os-regen).
• packages/lint/src/lint-flow-patterns.ts (flow-double-brace-interpolation flips to flag single-brace on these slots) and packages/lint/scripts/check-doc-formula-expressions.mjs (EXPRESSION_SLOT_TYPES, the rider's one line).
• This repo's in-tree single-brace text-slot sites (examples/**, packages/**) converted in the same PR, content/docs/automation/** where it teaches the text-slot spelling, their tests, and .changeset/22110-*.md.
• ⛔ Not the value slots ([v18] retire the {var} template dialect in flow assignment slots: refuse at registration with per-spelling remedies (the C half of #11182 ruling D, on the v18 train) #19939, landed in part as 0e9e7b7066), not titleFormat, not skills/** (Tier H; named in the report for its own card).
• Declared cross-lane files: domain:services (packages/services/service-automation), declared on [PM seat] domain:services — 🟢 os-bill #6021.
  Container & model: L, mode:subagent, model: opus (dispatch-gates --tier --repo objectstack-ai/objectstack on these paths: no path-derived mandate; the default tier, as [v18] retire the {var} template dialect in flow assignment slots: refuse at registration with per-spelling remedies (the C half of #11182 ruling D, on the v18 train) #19939's pass 1 was). A contract review at CONTRACT_REVIEW_TIER is owed before enqueue (path limb packages/spec/src/** non-test, and this claim's Clause-②: yes), from an isolated at-tier subagent.
  Clause-②: yes (narrowing: the text slots' single-brace tokens are refused, while {{ }} holes now render there and a $ variable gains a hole spelling; corrected from the lossless-conversion reading by the seat in comment 6063190355)
  Responsibility: service-automation's single-brace interpolator and packages/lint's flow-double-brace-interpolation ship the dialect ADR-0032 §3 deleted, while the spec types these slots as template | none: two delimiters ship side by side today | every flow author writing a notify title / message (this repo's examples: 46 single-brace sites in 2 files; hotcrm: 69 in 12 files, per the card)
  Thread-read: 6051209982
  Serial constraints cleared:
• Predecessor landed: [v18] retire the {var} template dialect in flow assignment slots: refuse at registration with per-spelling remedies (the C half of #11182 ruling D, on the v18 train) #19939's pass 1 (PR feat(spec)!: flow value slots refuse the {…} template dialect, naming the CEL spelling of each token (#19939, C half) #22259 → 0e9e7b7066, 2026-10-08) is on main; its release (6058684331) names this card "now unblocked". Same-day churn on builtin/template.ts.
• Fold-or-serial with [v18] retire the {var} template dialect in flow assignment slots: refuse at registration with per-spelling remedies (the C half of #11182 ruling D, on the v18 train) #19939's pass 2 (pm:queue, {$User.*} and the date macros in value slots), which may edit builtin/template.ts too: serial, not folded. Gate ① fails: pass 2 binds current_user and refuses value-slot spellings; this card changes the text slots' delimiter. Whichever lands later merges main; a claimant of pass 2 declares the overlap.
• No open PR touches template.ts, notify-node.ts, io-node-config.zod.ts, conversions/registry.ts, lint-flow-patterns.ts or check-doc-formula-expressions.mjs (open-PR file lists read at this stamp). migrations/registry.ts (PR feat(plugin-audit,plugin-security)!: sys_audit_log loses its injected organization column; tenant_id carries the organization a row is about and scopes organization readers (ADR-0131 D7) #22266, feat(spec,services): deployment-level state has no organization column — settings global rung, plumbing objects, the audit ledger, #12699 made total (ADR-0131 D7) #15207) and spec-changes.json (PR feat(spec)!: PROTOCOL_VERSION 17 → 18 in an ordinary PR — regenerated spec-changes.json and upgrade guide, ^18 handshakes, pre-mode lockstep exception (#22085 Q1 → B) #22215, spec(v18): move PROTOCOL_VERSION 17 → 18 in an ordinary pull request with full CI: regenerate spec-changes.json and the 17 → 18 upgrade-guide section, rewrite the in-repo ^17 handshakes, and give the lockstep test one pre-mode exception (#22085 Q1) #22130) are regenerated by those PRs too; whichever lands later merges main through scripts/pm/os-regen-merge.sh.