GAP-UX-001f: Streaming Output Panels

Description

Real-time streaming panels that display output from delegated harness invocations as they execute. Split-pane or scrolling view showing what each dispatched subagent is doing, with live stdout/stderr capture.

CC Reference

CC has:

• src/components/MessageResponse.tsx -- streams assistant responses token by token
• src/components/VirtualMessageList.tsx -- virtualized scrolling for long output
• src/components/ToolUseLoader.tsx -- loading indicator while tool executes
• src/components/messages/UserBashOutputMessage.tsx -- formatted bash output
• src/components/messages/HookProgressMessage.tsx -- hook execution streaming
• src/components/CompactSummary.tsx -- compact view of large outputs

Current State

invokeHarness() in packages/sdk/src/harness/invoker.ts captures stdout/stderr only after the child process exits. No streaming during execution. No embedded SDK dashboard exists yet to show what a delegated harness is doing in real-time. Task results are visible only after completion.

Target State

An Ink StreamingPanel component that:

• Attaches to child process stdout/stderr pipes from invokeHarness()
• Renders output in a scrollable, bounded panel
• Supports multiple panels for parallel effects (split view)
• Truncates/virtualizes long output to stay within terminal bounds
• Shows elapsed time and byte count
• Color-codes stderr vs stdout

┌─ S000005 generate-gap-files [running 45s] ─────────────────┐
│ Creating gaps/prompt-engineering/GAP-PROMPT-001.md          │
│ Creating gaps/prompt-engineering/GAP-PROMPT-002.md          │
│ Creating gaps/tools-capabilities/GAP-TOOLS-008.md           │
│ ...                                                         │
│ [streaming 2.3KB]                                          │
└─────────────────────────────────────────────────────────────┘

Dependencies

• GAP-UX-001 -- Ink rendering foundation
• GAP-SUBOBS-001 -- streaming capture from harnesses

Key Files

Recommendation

Phase 2-3. Requires changes to invokeHarness() to pipe stdout/stderr in real-time instead of buffering. Pi already has subscribe() for streaming events. The Ink panel needs virtualization for long output. Start with single-panel view, then add split-pane for parallel effects.