Craft Packet Rendering Overhaul

Plan for redesigning how the Craft transcript renders agent activity — text, thinking, tool calls, todos, subagents, and skills. The current rendering is generic across tools, ships two parallel "tool pill" implementations, and violates the design system in a few high-visibility places. This doc captures what we're changing, why, and how — borrowing inspiration from Claude Code, Codex, and the opencode TUI.

Issues to Address

1. Two parallel tool-rendering implementations. ToolCallPill (used for task and other non-working tools) and WorkingLine (rows inside the WorkingPill group) are 80% the same code with diverging padding, status styling, and expand behavior. Touching one rarely updates the other.

2. Every tool renders the same way. bash, read, edit, glob/grep, webfetch, websearch all collapse into the same generic header + raw output blob. Bash output isn't terminal-styled, search results aren't a clickable list, web results don't show titles/URLs, fetches don't show status codes.

3. ThinkingCard defaults to open (ThinkingCard.tsx:26). The thinking block is the loudest, least-scannable item in the transcript and yet it starts expanded.

4. Design-system violations in tool surfaces. DiffView uses hardcoded #fafafa / #151617 / green-100 / red-100 and raw dark: modifiers (DiffView.tsx:172-263). RawOutputBlock does the same. Both break the color-token rules in web/CLAUDE.md. The diff also forces a unified view — side-by-side is missing for hunks where it would read much better.

5. Subagents (task tool) are awkward. Today the parent's ToolCallPill shows the subagent's prompt, and the subagent's text gets emitted as a stray StreamItem into the parent transcript (useBuildStreaming.ts:287-296). There's no way to view the subagent's own activity — its tool calls, thinking, and message stream are invisible. A subagent event-stream endpoint would let us render this as a panel; that endpoint is not yet built.

6. Skills are not first-class. Skill invocations currently look like any other tool call. There's no badge, no namespace hint, no visual cue that "this came from a skill."

7. Raw output silently truncates. RawOutputBlock caps at maxHeight and becomes a scroll container with no indication that there's more, no click-to-expand affordance, and no copy button.

8. Past Working groups auto-collapse, but the latest stays expanded. This is fine while one tool is running but feels noisy once a turn has 5+ completed tools — you have to manually scan and collapse.

Important Notes

Existing code surface

• web/src/app/craft/components/ is where all transcript-side components live. Current files relevant to this overhaul:
  • BuildMessageList.tsx — switch-statement renderer for StreamItems. Routes working_group → WorkingPill, non-working tool_call → ToolCallPill, text → TextChunk, etc.
  • ToolCallPill.tsx, WorkingLine.tsx, WorkingPill.tsx — current tool rendering.
  • ThinkingCard.tsx — thinking block, defaults open.
  • DiffView.tsx, RawOutputBlock.tsx — shared body renderers.
  • TodoListCard.tsx — todo rendering (leave largely alone; already its own specialized renderer).
• web/src/app/craft/types/displayTypes.ts defines ToolCallState. It already carries kind, title, description, command, rawOutput, subagentType, isNewFile, oldContent, newContent. We do not need to broaden this shape much — most per-tool data is already present.
• web/src/app/craft/utils/parsePacket.ts is the single funnel that turns ACP packets into ToolCallStates. Any new fields (skill name, exit code, bytes fetched, etc.) get extracted here.

Design-system rules to follow

web/CLAUDE.md is binding. Highlights relevant to this PR series:

• Opal first, refresh-components as fallback. Existing craft code is already on @opal/utils / @opal/icons. Where new components want buttons or text or layouts, prefer Opal: Button from @opal/components/buttons/button/components, Text from @opal/components, Content / ContentAction from @opal/layouts.
• No raw dark: modifiers. The color system handles dark mode via CSS vars — using dark:bg-... directly breaks it. DiffView and RawOutputBlock currently violate this; fixing is part of the overhaul.
• No raw Tailwind colors. Use tokens (background-neutral-01, status-success-05, text-03, etc.).
• Icons only from @opal/icons or web/src/icons/. No lucide-react or react-icons.
• No raw <button> / <input> / <textarea>. Use Opal Button. The existing craft code uses raw <button> via Radix Collapsible's asChild pattern, which is fine since the button comes from Radix — keep that pattern but the surrounding chrome should use Opal where it fits.

Backend hooks we'll lean on

• A subagent event-stream endpoint (e.g. GET /sessions/{id}/subagents/{child_opencode_id}/events) is not yet built — it's a prerequisite for the SubagentPanel work and is flagged in the Deferred section below. The current TaskBody renders the subagent prompt + final output inline without the live stream.
• Skill invocations come through the same tool_call_start / tool_call_progress packets but with a skills.<name> tool name (or a similar namespacing convention — to confirm during Phase 1 by spot- checking what comes through parsePacket.ts).

Implementation Strategy

A. The CraftToolCard foundation

Replace ToolCallPill + WorkingLine with a single entry point that composes the main-chat timeline primitives:

• CraftToolCard — composes TimelineRow + TimelineSurface from web/src/app/app/message/messageComponents/timeline/primitives/, renders a status-aware rail icon, an inline header (title + description + optional SkillBadge + chevron), and a per-tool body via a collapsible content slot. railVariant chooses between "rail" (top-level, default), "spacer" (nested under a parent rail), and "none" (no left column — used inside WorkingPill).
• SkillBadge — small chip rendered in the header when toolCall originated from a skill namespace.

Callers (BuildMessageList, WorkingPill) wrap their card lists in TimelineRoot so the shared timeline CSS variables resolve. The body of the card is a slot; per-tool body components render into it.

B. Per-tool body components

Lives under web/src/app/craft/components/tool-cards/:

Tool kind	Body component	Inspiration & behavior
bash (execute)	BashBody	Terminal-styled output block (dark, monospace, ANSI-aware later). Header pins the command even when collapsed. Footer shows exit code badge + duration.
read	ReadBody	File-card preview: file icon + path + first ~10 lines with line numbers. "Open full file" expands to a side preview (or full scrollable block).
edit / write	DiffBody	Rebuilt diff using design tokens (replaces DiffView). Unified by default. Toggle to side-by-side for hunks >20 lines or via user pref. Stats in footer.
glob / grep	SearchBody	Result list as clickable file:line rows with snippet preview. Result count badge. No syntax highlighting on the list itself.
websearch	WebSearchBody	Result cards: title (link) + domain + URL + 2-line snippet. Cribbed from Perplexity / Claude Code's search rendering.
webfetch	WebFetchBody	URL header + status code + content-type. Body collapsed by default behind "Show response."
task (subagent)	TaskBody	Subagent label + "View transcript →" that opens SubagentPanel. Drops the current behavior of dumping subagent text into the parent transcript.
todowrite	(use existing TodoListCard, light polish)	Already specialized. Leave alone except for visual-token cleanup.
other / unknown	GenericBody	Falls back to today's behavior (raw output block, no specialization). Safety net so we never render nothing.

SubagentPanel (in tool-cards/subagent/) would host its own BuildMessageList — recursive, since a subagent can itself spawn subagents. It would subscribe to a subagent event-stream endpoint via a new hook (e.g. useSubagentStream). SubagentFooter would give prev/next navigation across sibling subagents within the same parent turn, mirroring the opencode TUI. This is deferred until the backend endpoint exists.

C. Cross-cutting polish

1. Default-collapse completed tool cards. Header alone gives enough information for the common case. WorkingPill itself can stay open while in progress, then collapse on completion.
2. Thinking starts collapsed. Flip the default in ThinkingCard.tsx. Add a one-line summary like "Thinking · 312 tokens" so users can see the size without expanding.
3. DiffView / RawOutputBlock rewrite. Both move into tool-cards/ and use Opal tokens. RawOutputBlock gains a "truncated · expand" affordance and a copy button.
4. Text coalescing across tools. When the agent emits text → tool → text inside the same assistant turn, collapse those into one text bubble in BuildMessageList.tsx so the prose reads as one continuous voice.
5. Turn-grouping visual rail. Optional Phase 4 — wrap each agent turn in a card with a subtle left-rail so users can scan turn boundaries.

D. Migration plan (single branch, split into stacked PRs later)

This branch (craft-ui-overhaul) gets all four phases. After it's working end-to-end we use ez to split into a stack:

• Phase 1 — ToolCard foundation, BashBody, DiffBody, retire WorkingLine, keep ToolCallPill as fallback for any tool kind that doesn't have a body yet.
• Phase 2 — ReadBody, SearchBody.
• Phase 3 — WebSearchBody, WebFetchBody, TaskBody.
• Phase 4 — Cross-cutting polish: thinking default flip, default-collapse completed Working pills, retire ToolCallPill, WorkingLine, old DiffView.

Phase boundaries are clean: each phase compiles and ships independently because unimplemented tools always fall back to GenericBody.

E. What landed and what's deferred

Landed in this branch:

• web/src/app/craft/components/tool-cards/ — SkillBadge plus body components: BashBody, DiffBody, ReadBody, SearchBody, WebSearchBody, WebFetchBody, TaskBody, GenericBody.
• CraftToolCard.tsx as the single entry point. Routes on toolName first (to distinguish websearch / webfetch inside the broader search / other kinds), then on kind.
• Tool-card chrome now composes the main-chat timeline primitives (TimelineRow + TimelineSurface from web/src/app/app/message/messageComponents/timeline/primitives/) so Craft and /app share rail / connector visual identity. BuildMessageList and WorkingPill wrap their children in TimelineRoot so the timeline CSS variables resolve; top-level cards default to railVariant="rail", while children nested inside the WorkingPill use railVariant="none" because the pill provides its own visual container. The legacy ToolCard.tsx and ToolCardHeader.tsx were retired in this migration.
• parsePacket.ts skill detection (detectSkillName) — matches skills.X, skills:X, superpowers.X, superpowers:X.
• ToolCallState gained toolName, taskOutput, and skillName.
• useBuildStreaming.ts no longer emits a stray text StreamItem for task output — it's stored on the tool call and rendered by TaskBody.
• ThinkingCard defaults to collapsed with a token-count summary, auto-opens during streaming.
• WorkingPill auto-collapses once all contained tools terminate.
• Retired files: ToolCallPill.tsx, WorkingLine.tsx, DiffView.tsx, tool-cards/ToolCard.tsx, tool-cards/ToolCardHeader.tsx.

Deferred:

• SubagentPanel + SubagentFooter: requires an SSE endpoint at GET /sessions/{id}/subagents/{cid}/events that does not yet exist. The current TaskBody renders the subagent's prompt and final output as a clean inline card — enough to remove the stray parent-transcript text dumps — but does not yet expose the subagent's own tool calls / thinking stream. Add the SSE endpoint on the backend, then build the panel in a follow-up.
• Text coalescing across tools: collapsing consecutive text bubbles within a single assistant turn requires a refactor of useBuildStreaming.ts text accumulation. Not blocking the rest of the overhaul; revisit if the visual rhythm still feels choppy in real use.
• RawOutputBlock truncation affordance + copy button: RawOutputBlock is still in place under GenericBody; the "expand to full" affordance and copy button are nice-to-haves rather than load-bearing for the overhaul.
• Turn-grouping visual rail: optional polish from the original plan, left for a future iteration.
• WorkingPill as a StepContainer: the pill itself could be modeled as a parent rail row with nested children at railVariant="spacer". Today the pill stays a bordered container and its children render with railVariant="none". Worth doing if/when we unify the working-pill chrome with the rest of the timeline.

Rationale: bypassing TimelineStepContent

CraftToolCard composes TimelineRow + TimelineSurface directly rather than going through StepContainer / TimelineStepContent. The primitive's header layout exposes collapse as a dedicated Button onClick={onToggle} chevron on the right, with only the button itself as the click target. Craft's interaction model is whole-row-click via Radix Collapsible asChild — wrapping the entire header in a CollapsibleTrigger'd <button>. Threading that through TimelineStepContent would require either changing the primitive's API or fighting against it; composing one level deeper keeps both interaction models intact without churn in shared code.

Tests

This is a frontend rendering overhaul, so the cheapest high-value coverage is Playwright e2e — they exercise the real packet stream end to end.

• Playwright (primary). One e2e test that drives a chat session through each tool kind and asserts the new body component renders. Lives at web/tests/e2e/craft/tool-cards.spec.ts. Covers: bash (exit code badge), edit (diff stats), read (file preview), grep (clickable rows), websearch (result cards), webfetch (status code), task (panel opens and shows subagent's own tool calls). Skill badge asserted on at least one skill-namespaced invocation.
• Unit tests for parsePacket.ts additions only. If we add new field extraction (skill name, exit code, bytes fetched), cover those in web/src/app/craft/utils/__tests__/parsePacket.test.ts. Don't unit-test the React components — they're shallow enough that Playwright is the right tool.

No backend tests required. No integration tests required.