feat(eve): select and copy text in the trace viewer

.changeset/trace-select-copy.md

@@ -0,0 +1,5 @@
+---
+"eve": patch
+---
+
+The `/traces` viewer supports drag-to-select: dragging with the mouse highlights text and releasing copies it to the clipboard (OSC 52 with tmux passthrough, plus the platform clipboard command) with a confirmation toast. Clicks now act on release so drags never toggle cards, and Esc cancels an in-flight selection.

docs/guides/dev-tui.md

@@ -123,7 +123,7 @@ The viewer opens on your current session's trace (or the most recent one). It re
 | `Esc`     | Close the panel (or unfocus it), otherwise close the viewer.             |
 | `q`       | Close the viewer.                                                        |
 
-`←`/`→` or a mouse click expands a card to its full contents (the system prompt, long payloads) and collapses it back; cards that already fit have nothing to expand. The attributes panel opens on the right and stays metadata-only — status, timing, ids, and the span's non-payload OTLP attributes — since the cards already carry the payloads. Model spans capture the system prompt, the prompt messages (rendered as a chat transcript), and the response (text, tool calls, finish reason); tool-call spans capture the call arguments and result, pretty-printed — each capped at 32 KB, with provider transport metadata stripped. When a conversation's messages exceed the cap, the oldest messages are dropped and the transcript notes how many were omitted. Set `EVE_TRACES_CONTENT=off` to stop capturing payload content. With no spans yet, the viewer shows an empty state and keeps watching; if tracing is disabled (`EVE_TRACES=off`) it says so instead.
+`←`/`→` or a mouse click expands a card to its full contents (the system prompt, long payloads) and collapses it back; cards that already fit have nothing to expand. The scroll wheel scrolls the conversation. Dragging with the mouse selects text — the selection highlights as you drag, and releasing copies it to your clipboard (a `✓ Copied to clipboard` toast confirms in the header); `Esc` cancels an in-flight selection. The attributes panel opens on the right and stays metadata-only — status, timing, ids, and the span's non-payload OTLP attributes — since the cards already carry the payloads. Model spans capture the system prompt, the prompt messages (rendered as a chat transcript), and the response (text, tool calls, finish reason); tool-call spans capture the call arguments and result, pretty-printed — each capped at 32 KB, with provider transport metadata stripped. When a conversation's messages exceed the cap, the oldest messages are dropped and the transcript notes how many were omitted. Set `EVE_TRACES_CONTENT=off` to stop capturing payload content. With no spans yet, the viewer shows an empty state and keeps watching; if tracing is disabled (`EVE_TRACES=off`) it says so instead.
 
 ## Display flags
 

packages/eve/src/cli/dev/tui/clipboard.test.ts

@@ -0,0 +1,29 @@
+import { describe, expect, it } from "vitest";
+
+import { clipboardCommand, clipboardSequence } from "#cli/dev/tui/clipboard.js";
+
+describe("clipboardSequence", () => {
+  it("encodes the text as base64 in an OSC 52 write", () => {
+    expect(clipboardSequence("hello", {})).toBe(
+      `\x1b]52;c;${Buffer.from("hello").toString("base64")}\x07`,
+    );
+  });
+
+  it("wraps the sequence for tmux and screen passthrough", () => {
+    const inner = clipboardSequence("hi", {});
+    expect(clipboardSequence("hi", { TMUX: "/tmp/tmux-1000/default" })).toBe(
+      `\x1bPtmux;\x1b${inner}\x1b\\`,
+    );
+    expect(clipboardSequence("hi", { STY: "1234.pts-0" })).toBe(`\x1bPtmux;\x1b${inner}\x1b\\`);
+  });
+});
+
+describe("clipboardCommand", () => {
+  it("picks the platform clipboard tool", () => {
+    expect(clipboardCommand("darwin", {})).toEqual(["pbcopy"]);
+    expect(clipboardCommand("linux", {})).toEqual(["xclip", "-selection", "clipboard"]);
+    expect(clipboardCommand("linux", { WAYLAND_DISPLAY: "wayland-0" })).toEqual(["wl-copy"]);
+    expect(clipboardCommand("win32", {})).toEqual(["clip"]);
+    expect(clipboardCommand("freebsd", {})).toBeUndefined();
+  });
+});

packages/eve/src/cli/dev/tui/clipboard.ts

@@ -0,0 +1,54 @@
+/**
+ * Best-effort clipboard writes for the dev TUI: an OSC 52 escape sequence
+ * (which reaches the user's terminal even over SSH, with tmux/screen
+ * passthrough) plus the platform's native clipboard command as a fallback
+ * for terminals that reject OSC 52. Both paths fail silently — copying is
+ * a convenience, never a hard dependency.
+ */
+
+import { spawn } from "node:child_process";
+
+/** The OSC 52 sequence for `text`, wrapped for tmux/screen when present. */
+export function clipboardSequence(
+  text: string,
+  env: Readonly<Record<string, string | undefined>> = process.env,
+): string {
+  const sequence = `\x1b]52;c;${Buffer.from(text).toString("base64")}\x07`;
+  const multiplexed = env.TMUX !== undefined || env.STY !== undefined;
+  return multiplexed ? `\x1bPtmux;\x1b${sequence}\x1b\\` : sequence;
+}
+
+/** The native clipboard command for a platform, or `undefined` when unknown. */
+export function clipboardCommand(
+  platform: NodeJS.Platform,
+  env: Readonly<Record<string, string | undefined>> = process.env,
+): readonly string[] | undefined {
+  if (platform === "darwin") return ["pbcopy"];
+  if (platform === "linux") {
+    return env.WAYLAND_DISPLAY !== undefined ? ["wl-copy"] : ["xclip", "-selection", "clipboard"];
+  }
+  if (platform === "win32") return ["clip"];
+  return undefined;
+}
+
+/**
+ * Copies `text` to the clipboard: emits OSC 52 through `writeTerminal`
+ * (the same raw write the alt screen paints with) and pipes the text into
+ * the platform clipboard command in the background.
+ */
+export function copyTextToClipboard(text: string, writeTerminal: (chunk: string) => void): void {
+  writeTerminal(clipboardSequence(text));
+  const command = clipboardCommand(process.platform);
+  if (command === undefined) return;
+  try {
+    const child = spawn(command[0]!, command.slice(1), {
+      stdio: ["pipe", "ignore", "ignore"],
+      detached: false,
+    });
+    child.on("error", () => {});
+    child.stdin?.on("error", () => {});
+    child.stdin?.end(text);
+  } catch {
+    // Native clipboard is a fallback; OSC 52 already went out.
+  }
+}

packages/eve/src/cli/dev/tui/terminal-renderer.ts

@@ -113,6 +113,7 @@ import {
 } from "./line-editor.js";
 import { LiveRegion } from "#cli/ui/live-region.js";
 import { AltScreen } from "#cli/ui/alt-screen.js";
+import { copyTextToClipboard } from "./clipboard.js";
 import type { TraceViewerOpenOptions, TraceViewerRenderer } from "./traces/trace-viewer-session.js";
 import { TraceViewerSession } from "./traces/trace-viewer-session.js";
 import { buildStatusLine } from "./status-line.js";
@@ -2669,6 +2670,7 @@ export class TerminalRenderer implements AgentTUIRenderer {
       dimensions: () => ({ width: this.#width(), height: this.#height() }),
       paint: (rows) => this.#altScreen.paint(rows, this.#height()),
       tracingDisabled: process.env.EVE_TRACES === "off",
+      copyText: (text) => copyTextToClipboard(text, (chunk) => this.#altScreen.writeRaw(chunk)),
     });
     this.#traceView = session;
     this.#altScreen.enter();

packages/eve/src/cli/dev/tui/traces/trace-view.test.ts

@@ -4,7 +4,12 @@ import { stripAnsi, visibleLength } from "#cli/ui/terminal-text.js";
 import type { LocalTrace, LocalTraceSpan } from "#harness/local-trace-reader.js";
 
 import { createTheme } from "../theme.js";
-import { renderSpanDetail, renderTraceViewer } from "./trace-view.js";
+import {
+  conversationSelectionText,
+  panelSelectionText,
+  renderSpanDetail,
+  renderTraceViewer,
+} from "./trace-view.js";
 import type { TraceViewerState } from "./trace-viewer-state.js";
 import { applyLoadedTrace, applyTraceList, createTraceViewerState } from "./trace-viewer-state.js";
 
@@ -108,6 +113,87 @@ describe("renderTraceViewer", () => {
     expect(selectedRows.length).toBeGreaterThan(0);
   });
 
+  it("shows the copy toast in the header's top-right corner", () => {
+    const state = viewerState(conversationSpans());
+    const frame = renderTraceViewer(state, {
+      width: 100,
+      height: 30,
+      theme: THEME,
+      toast: "Copied to clipboard",
+    });
+    expect(stripAnsi(frame.rows[0]!)).toContain("✓ Copied to clipboard");
+  });
+
+  it("paints an active drag selection in reverse video", () => {
+    const state = viewerState(conversationSpans(), {
+      textSelection: {
+        anchor: { line: 1, column: 2 },
+        head: { line: 2, column: 10 },
+        dragging: true,
+        region: "conversation" as const,
+      },
+    });
+    const frame = render(state);
+    const highlighted = frame.rows.filter((row) => row.includes("\x1b[7m"));
+    expect(highlighted.length).toBe(2);
+  });
+
+  it("extracts the dragged text from the rendered conversation", () => {
+    const state = viewerState(conversationSpans());
+    // The system card's title row is line 1 ("  ▸ system" once rendered).
+    const selection = {
+      anchor: { line: 1, column: 0 },
+      head: { line: 1, column: 40 },
+      dragging: true,
+      region: "conversation" as const,
+    };
+    const text = conversationSelectionText(state, 100, THEME, selection);
+    expect(text).toContain("system");
+    expect(text).not.toContain("\x1b");
+    // A multi-line drag keeps line structure.
+    const multi = conversationSelectionText(state, 100, THEME, {
+      anchor: { line: 1, column: 0 },
+      head: { line: 5, column: 99 },
+      dragging: true,
+      region: "conversation" as const,
+    });
+    expect(multi.split("\n").length).toBe(5);
+  });
+
+  it("paints a drawer drag selection on the panel, not the cards", () => {
+    const state = viewerState(conversationSpans(), {
+      panelOpen: true,
+      textSelection: {
+        anchor: { line: 1, column: 0 },
+        head: { line: 3, column: 10 },
+        dragging: true,
+        region: "panel" as const,
+      },
+    });
+    const frame = render(state);
+    const highlighted = frame.rows.filter((row) => row.includes("\x1b[7m"));
+    expect(highlighted.length).toBe(3);
+    // The highlight sits in the drawer area (right of the conversation).
+    for (const row of highlighted) {
+      const before = row.slice(0, row.indexOf("\x1b[7m"));
+      expect(visibleLength(before)).toBeGreaterThanOrEqual(frame.contentWidth);
+    }
+  });
+
+  it("extracts the dragged text from the details drawer", () => {
+    const state = viewerState(conversationSpans(), { panelOpen: true });
+    // Detail line 1 is the selected span's name (line 0 is top padding).
+    const text = panelSelectionText(state, 100, THEME, {
+      anchor: { line: 1, column: 0 },
+      head: { line: 2, column: 40 },
+      dragging: true,
+      region: "panel" as const,
+    });
+    expect(text).toContain("ai.streamText.doStream");
+    expect(text).not.toContain("\x1b");
+    expect(text.split("\n").length).toBe(2);
+  });
+
   it("marks error cards and shows the error status in the detail panel", () => {
     const turn = span("a".repeat(16), "agent.turn", 0, 0);
     const step = span("b".repeat(16), "agent.step", 10, 300, turn.spanId, {});