Problem

The embeddable @smooai/chat-widget only grew a prose bubble from stream_token — the agent's tool activity streaming over the smooth-operator protocol as stream_chunk events was invisible (send()'s loop default: break'd on it). The smooth daemon SPA already renders interleaved tool chips via its blocks model; this ports that to the widget.

What changed — and how the gate works

Because this is a customer-facing widget, exposing raw tool calls (grep / bash / read_file) to a support-site end-user is usually undesirable. So the feature is gated behind showToolActivity (default false):

• false (default): behavior is byte-for-byte unchanged — the assistant streams a single prose bubble, no blocks are built, stream_chunk is ignored exactly as before.
• true: a turn that invokes a tool renders as an ordered strip of prose bubbles + inline tool chips (running… / done ✓ / error), in the order the model produced them. Enable via the show-tool-activity HTML attribute or showToolActivity: true in the config object.

Wiring:

• config.ts — new showToolActivity option, defaulted false in resolveConfig.
• conversation.ts — new MessageBlock/ToolCall types + blocks? on ChatMessage; send() folds stream_token into a trailing text block and stream_chunk tool activity into the block list (only when gated). Prose-only turns drop blocks on finalize so they render via the normal markdown path.
• element.ts / styles.ts — renderAssistantBlocks + ToolChip, reusing the existing rAF reveal for the live trailing text block; chip styles keyed to the theme tokens.

Correctness / security

• Tool activity is read from state.rawResponse.toolCall / state.rawResponse.toolResult — the correct nested path. Reading state.toolResult (one level too high) leaves chips stuck "running…"; a test asserts the wrong-path payload does not resolve a chip.
• Tool name + args preview are rendered with textContent (never innerHTML), so a tool payload can't inject markup.

Protocol notes

• The single for await turn loop interleaves stream_token (prose) and stream_chunk (tools) in arrival order; concurrent tools sharing a name resolve most-recent-open-first (matches the daemon).
• The rAF typewriter now binds to the live trailing text block for a tool turn (composite reveal key), and to the whole message for a plain-prose turn — unchanged for the default path.

Tests / build

pnpm typecheck clean; pnpm test 68 pass (10 new across gate default, interleave, error, wrong-path guard, and chip rendering); pnpm build green. New public MessageBlock/ToolCall exports; README config table updated.

🤖 Generated with Claude Code