[FEATURE]: Plugin dataflow panel — reserved UI space for per-session metrics and data logs

Summary

• I have searched for existing issues before filing this

Reserve a dedicated plugin dataflow / metrics panel in the session screen where plugins can surface live data logs, structured metrics, and contextual dashboards — without polluting the chat stream.

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Problem

OpenCode's current GUI is clean and minimal, which is great for focus. But plugins that produce structured data — logs, metrics, performance stats, cost tracking, time-vs-expected comparisons — have no standard place to display it.

Today:

• Plugin output goes into the main chat stream — polluting conversation context
• Or it goes nowhere visible — silent background execution
• Or it requires a separate standalone app/dashboard — fragmented UX

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What Users Want

A plugin metrics panel — a frame, side div, or collapsible section — where plugins render:

Metric	Example
Execution time	"Ran in 2.3s (expected 5s — 54% faster)"
Cost tracking	"This session: $0.023 (12k tokens)"
Rate limits	"429 hit 3×, backed off 2s each"
File changes	"+127 / -34 lines across 8 files"
Custom dashboards	Plugin-defined charts, tables, status

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This Extends #5971

#5971 ("Plugin API for custom sidebar panels") asked for sidebar panels. This is more specific:

1. Per-session, not global — each session gets its own plugin data stream
2. Structured metrics, not arbitrary HTML — a typed plugin.metrics.push({...}) API
3. Time-comparison framing — "actual vs expected" makes OpenCode feel smarter
4. Low footprint by default — collapsed unless a plugin has data to show

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Proposed Implementation

interface MetricsPanel {
  push(data: MetricEntry): void;
  setTitle(title: string): void;
  collapse(): void;
  expand(): void;
}

interface MetricEntry {
  label: string;
  value: string;
  comparison?: { expected: string; unit: string; delta: number };
  icon?: string;
  color?: "green" | "yellow" | "red";
}

// Example
agent.metrics.push({
  label: "Build",
  value: "2.3s",
  comparison: { expected: "5s", unit: "%", delta: -54 },
  icon: "⏱",
  color: "green"
});

Panel UI:

• Collapsible right-side drawer or bottom panel
• Per-session (not global)
• Auto-collapses when empty
• Plugin-defined color coding and icons

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Plugin Potential

This unlocks a whole class of observability plugins: cost-tracking, performance benchmarking, security audit plugins — that today have nowhere attractive to render their output.

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OS

Cross-platform (Desktop + TUI + Web).

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Related Issues

• #5971 (open) — "Plugin API for custom sidebar panels" — the original sidebar panel request this extends

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🦙 Creative Monkey at FrenzyPenguin Media — open-source security hardening & privacy tools