holon 0.14.1

A headless, event-driven runtime for long-lived agents
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
use super::*;
use crate::tui::composer::ComposerState;
use unicode_width::UnicodeWidthStr;

pub(super) const MODEL_REASONING_EFFORT_OPTIONS: [&str; 5] =
    ["inherit", "low", "medium", "high", "xhigh"];

#[derive(Debug, Clone, PartialEq, Eq)]
pub(super) enum OverlayState {
    None,
    Agents {
        selected: usize,
    },
    Events {
        selected_event_id: Option<String>,
        detail_scroll: u16,
    },
    Transcript {
        scroll: u16,
    },
    AgentState {
        scroll: u16,
    },
    Tasks {
        selected: usize,
        detail_scroll: u16,
    },
    ModelPicker {
        filter: String,
        selected: usize,
    },
    ModelEffortPicker {
        model: String,
        selected: usize,
        return_filter: String,
        return_selected: usize,
    },
    DebugPromptInput {
        composer: ComposerState,
    },
    DebugPromptView {
        title: String,
        dump: String,
        scroll: u16,
    },
    HelpView {
        scroll: u16,
    },
}

pub(super) fn draw_overlay(frame: &mut Frame<'_>, app: &TuiApp) {
    match &app.overlay {
        OverlayState::None => {}
        OverlayState::Agents { selected } => draw_agents_overlay(frame, app, *selected),
        OverlayState::Events {
            selected_event_id,
            detail_scroll,
        } => draw_events_overlay(frame, app, selected_event_id.as_deref(), *detail_scroll),
        OverlayState::Transcript { scroll } => draw_transcript_overlay(frame, app, *scroll),
        OverlayState::AgentState { scroll } => draw_agent_state_overlay(frame, app, *scroll),
        OverlayState::Tasks {
            selected,
            detail_scroll,
        } => draw_tasks_overlay(frame, app, *selected, *detail_scroll),
        OverlayState::ModelPicker { filter, selected } => {
            draw_model_picker_overlay(frame, app, filter, *selected)
        }
        OverlayState::ModelEffortPicker {
            model, selected, ..
        } => draw_model_effort_picker_overlay(frame, app, model, *selected),
        OverlayState::DebugPromptInput { composer } => draw_input_modal(
            frame,
            "Debug Prompt",
            "Generate the effective prompt for the selected agent.",
            composer,
            76,
            7,
        ),
        OverlayState::DebugPromptView {
            title,
            dump,
            scroll,
        } => draw_large_text_overlay(frame, title, dump, *scroll),
        OverlayState::HelpView { scroll } => draw_help_overlay(frame, *scroll),
    }
}

fn draw_agents_overlay(frame: &mut Frame<'_>, app: &TuiApp, selected: usize) {
    let popup = centered_rect(92, 80, frame.area());
    let layout = Layout::default()
        .direction(Direction::Horizontal)
        .constraints([Constraint::Length(34), Constraint::Min(0)])
        .split(popup);
    frame.render_widget(Clear, popup);

    let items = if app.agents.is_empty() {
        vec![ListItem::new("No public agents")]
    } else {
        app.agents
            .iter()
            .map(|agent| {
                let marker = if agent.identity.is_default_agent {
                    "*"
                } else {
                    " "
                };
                let label = format!(
                    "{} {} [{}]",
                    marker,
                    agent.identity.agent_id,
                    render::trim(&format!("{:?}", agent.agent.status), 12)
                );
                ListItem::new(label)
            })
            .collect::<Vec<_>>()
    };
    let list = List::new(items)
        .block(Block::default().title("Agents").borders(Borders::ALL))
        .highlight_style(Style::default().add_modifier(Modifier::REVERSED))
        .highlight_symbol("> ");
    let mut state = ListState::default();
    let selected = (!app.agents.is_empty()).then(|| selected.min(app.agents.len() - 1));
    state.select(selected);
    frame.render_stateful_widget(list, layout[0], &mut state);

    let text = app
        .agents
        .get(selected.unwrap_or(0))
        .map(render::render_summary)
        .unwrap_or_else(|| "No agent selected.".to_string());
    let detail = Paragraph::new(text)
        .block(Block::default().title("Agent Detail").borders(Borders::ALL))
        .wrap(Wrap { trim: false });
    frame.render_widget(detail, layout[1]);
}

fn draw_events_overlay(
    frame: &mut Frame<'_>,
    app: &TuiApp,
    selected_event_id: Option<&str>,
    detail_scroll: u16,
) {
    let popup = centered_rect(94, 82, frame.area());
    let layout = Layout::default()
        .direction(Direction::Horizontal)
        .constraints([Constraint::Length(44), Constraint::Min(0)])
        .split(popup);
    frame.render_widget(Clear, popup);

    let events = app
        .projection
        .as_ref()
        .map(|projection| projection.event_log())
        .unwrap_or(&[]);

    let items = if events.is_empty() {
        vec![ListItem::new("No raw events observed yet")]
    } else {
        events
            .iter()
            .rev()
            .map(render::render_projection_event_summary)
            .map(ListItem::new)
            .collect::<Vec<_>>()
    };
    let mut state = ListState::default();
    if !events.is_empty() {
        state.select(Some(
            selected_event_id
                .and_then(|event_id| event_reverse_index(events, event_id))
                .unwrap_or(0)
                .min(events.len().saturating_sub(1)),
        ));
    }
    let list = List::new(items)
        .block(Block::default().title("Raw Events").borders(Borders::ALL))
        .highlight_style(Style::default().add_modifier(Modifier::REVERSED))
        .highlight_symbol("> ");
    frame.render_stateful_widget(list, layout[0], &mut state);

    let detail_text = events
        .iter()
        .rev()
        .nth(
            selected_event_id
                .and_then(|event_id| event_reverse_index(events, event_id))
                .unwrap_or(0),
        )
        .map(|event| {
            let payload = serde_json::to_string_pretty(&event.payload).unwrap_or_else(|_| {
                serde_json::to_string(&event.payload).unwrap_or_else(|_| "<invalid json>".into())
            });
            format!(
                "Id: {}\nSeq: {}\nTime: {}\nLane: {:?}\nType: {}\nSummary: {}\n\nPayload:\n{}",
                event.id,
                event.event_seq,
                event.ts.with_timezone(&Local).format("%Y-%m-%d %H:%M:%S"),
                event.lane,
                event.kind,
                event.summary,
                payload
            )
        })
        .unwrap_or_else(|| "No event selected.".to_string());
    let detail = Paragraph::new(detail_text)
        .block(Block::default().title("Event Detail").borders(Borders::ALL))
        .scroll((detail_scroll, 0))
        .wrap(Wrap { trim: false });
    frame.render_widget(detail, layout[1]);
}

fn event_reverse_index(
    events: &[crate::tui::projection::ProjectionEventRecord],
    event_id: &str,
) -> Option<usize> {
    events.iter().rev().position(|event| event.id == event_id)
}

fn draw_transcript_overlay(frame: &mut Frame<'_>, app: &TuiApp, scroll: u16) {
    let popup = centered_rect(92, 82, frame.area());
    frame.render_widget(Clear, popup);
    let lines = conversation_events_overlay_lines(app);
    let body = if lines.is_empty() {
        "No conversation events observed yet.".to_string()
    } else {
        lines.join("\n\n")
    };
    let widget = Paragraph::new(body)
        .block(
            Block::default()
                .title("Conversation Events (Esc closes)")
                .borders(Borders::ALL),
        )
        .scroll((scroll, 0))
        .wrap(Wrap { trim: false });
    frame.render_widget(widget, popup);
}

pub(super) fn conversation_events_overlay_lines(app: &TuiApp) -> Vec<String> {
    let Some(projection) = app.projection.as_ref() else {
        return Vec::new();
    };
    let mut lines = projection
        .durable_conversation_events()
        .map(render::render_projection_event_summary)
        .collect::<Vec<_>>();
    lines.reverse();
    lines
}

fn draw_agent_state_overlay(frame: &mut Frame<'_>, app: &TuiApp, scroll: u16) {
    let popup = centered_rect(92, 82, frame.area());
    frame.render_widget(Clear, popup);
    let widget = Paragraph::new(render::render_agent_state_text(app))
        .block(
            Block::default()
                .title("Agent State (Esc closes)")
                .borders(Borders::ALL),
        )
        .scroll((scroll, 0))
        .wrap(Wrap { trim: false });
    frame.render_widget(widget, popup);
}

fn draw_tasks_overlay(frame: &mut Frame<'_>, app: &TuiApp, selected: usize, detail_scroll: u16) {
    let popup = centered_rect(92, 80, frame.area());
    let layout = Layout::default()
        .direction(Direction::Horizontal)
        .constraints([Constraint::Length(38), Constraint::Min(0)])
        .split(popup);
    frame.render_widget(Clear, popup);

    let items = if app.tasks.is_empty() {
        vec![ListItem::new("No active tasks")]
    } else {
        app.tasks
            .iter()
            .rev()
            .map(render::render_task)
            .map(ListItem::new)
            .collect::<Vec<_>>()
    };
    let mut state = ListState::default();
    if !app.tasks.is_empty() {
        state.select(Some(selected.min(app.tasks.len().saturating_sub(1))));
    }
    let list = List::new(items)
        .block(Block::default().title("Tasks").borders(Borders::ALL))
        .highlight_style(Style::default().add_modifier(Modifier::REVERSED))
        .highlight_symbol("> ");
    frame.render_stateful_widget(list, layout[0], &mut state);

    let detail_text = app
        .tasks
        .iter()
        .rev()
        .nth(selected)
        .map(render::render_task_detail)
        .unwrap_or_else(|| "No active task selected.".to_string());
    let detail = Paragraph::new(detail_text)
        .block(Block::default().title("Task Detail").borders(Borders::ALL))
        .scroll((detail_scroll, 0))
        .wrap(Wrap { trim: false });
    frame.render_widget(detail, layout[1]);
}

fn draw_model_picker_overlay(frame: &mut Frame<'_>, app: &TuiApp, filter: &str, selected: usize) {
    let popup = centered_rect(92, 80, frame.area());
    let layout = Layout::default()
        .direction(Direction::Vertical)
        .constraints([
            Constraint::Length(3),
            Constraint::Min(0),
            Constraint::Length(4),
        ])
        .split(popup);
    frame.render_widget(Clear, popup);

    let filter_text = if filter.is_empty() {
        "Filter: ".to_string()
    } else {
        format!("Filter: {filter}")
    };
    let filter_widget =
        Paragraph::new(filter_text).block(Block::default().title("Model").borders(Borders::ALL));
    frame.render_widget(filter_widget, layout[0]);

    let rows = crate::tui::model_picker::model_picker_rows(
        app.selected_agent_summary(),
        &app.model_availability,
        filter,
    );
    let items = if rows.is_empty() {
        vec![ListItem::new(
            "No runtime-provided model availability matches the filter",
        )]
    } else {
        rows.iter()
            .map(|row| {
                let status = if row.available { " " } else { "!" };
                ListItem::new(format!("{status} {}\n  {}", row.title, row.detail))
            })
            .collect::<Vec<_>>()
    };
    let mut state = ListState::default();
    if !rows.is_empty() {
        state.select(Some(selected.min(rows.len().saturating_sub(1))));
    }
    let list = List::new(items)
        .block(Block::default().title("Models").borders(Borders::ALL))
        .highlight_style(Style::default().add_modifier(Modifier::REVERSED))
        .highlight_symbol("> ");
    frame.render_stateful_widget(list, layout[1], &mut state);

    let current = app
        .selected_agent_summary()
        .map(render::render_model_status)
        .unwrap_or_else(|| "model: <no agent selected>".into());
    let help = Paragraph::new(format!(
        "{current}\nType to filter, Backspace edits, Up/Down moves, Enter selects, Esc cancels"
    ))
    .block(Block::default().borders(Borders::ALL))
    .wrap(Wrap { trim: false });
    frame.render_widget(help, layout[2]);
}

fn draw_model_effort_picker_overlay(
    frame: &mut Frame<'_>,
    app: &TuiApp,
    model: &str,
    selected: usize,
) {
    let popup = centered_rect(70, 42, frame.area());
    let layout = Layout::default()
        .direction(Direction::Vertical)
        .constraints([
            Constraint::Length(3),
            Constraint::Min(0),
            Constraint::Length(3),
        ])
        .split(popup);
    frame.render_widget(Clear, popup);

    let header = Paragraph::new(format!("Model: {model}")).block(
        Block::default()
            .title("Reasoning Effort")
            .borders(Borders::ALL),
    );
    frame.render_widget(header, layout[0]);

    let items = MODEL_REASONING_EFFORT_OPTIONS
        .iter()
        .map(|option| {
            let detail = if *option == "inherit" {
                "use provider/runtime default"
            } else {
                "force reasoning effort"
            };
            ListItem::new(format!("{option}\n  {detail}"))
        })
        .collect::<Vec<_>>();
    let mut state = ListState::default();
    state.select(Some(
        selected.min(MODEL_REASONING_EFFORT_OPTIONS.len().saturating_sub(1)),
    ));
    let list = List::new(items)
        .block(Block::default().title("Effort").borders(Borders::ALL))
        .highlight_style(Style::default().add_modifier(Modifier::REVERSED))
        .highlight_symbol("> ");
    frame.render_stateful_widget(list, layout[1], &mut state);

    let current = app
        .selected_agent_summary()
        .map(render::render_model_status)
        .unwrap_or_else(|| "model: <no agent selected>".into());
    let help = Paragraph::new(format!(
        "{current}\nUp/Down moves, Enter confirms, Esc goes back"
    ))
    .block(Block::default().borders(Borders::ALL))
    .wrap(Wrap { trim: false });
    frame.render_widget(help, layout[2]);
}

fn draw_large_text_overlay(frame: &mut Frame<'_>, title: &str, text: &str, scroll: u16) {
    let popup = centered_rect(90, 80, frame.area());
    frame.render_widget(Clear, popup);
    let widget = Paragraph::new(text.to_string())
        .block(Block::default().title(title).borders(Borders::ALL))
        .scroll((scroll, 0))
        .wrap(Wrap { trim: false });
    frame.render_widget(widget, popup);
}

fn draw_help_overlay(frame: &mut Frame<'_>, scroll: u16) {
    let popup = centered_rect(88, 80, frame.area());
    frame.render_widget(Clear, popup);
    let mut help_lines = [
        "Main View",
        "  Type directly into the composer",
        "  Enter sends the current draft",
        "  Shift+Enter inserts a new line",
        "  Prefix with / to run a local TUI command",
        "  Esc clears the current draft",
        "",
        "Input History (composer must be empty)",
        "  Up browse older input history",
        "  Down browse newer input history",
        "",
        "Editing Shortcuts (work when composer has content)",
        "  Ctrl+A move cursor to start",
        "  Ctrl+E move cursor to end",
        "  Ctrl+B move cursor left",
        "  Ctrl+F move cursor right",
        "  Ctrl+K delete to end of line",
        "  Ctrl+U delete to start of line",
        "  Ctrl+W delete previous word",
        "  Ctrl+H delete previous character (backspace)",
        "  Ctrl+D delete next character",
        "",
        "Overlays",
        "  Esc closes the current overlay",
        "",
        "Quick Help",
        "  ? open this help when the composer is empty",
        "",
        "Scrolling",
        "  PgUp/PgDn scroll the active text view",
        "  Home/End jump to top/bottom",
        "",
        "Exit",
        "  Ctrl+C quit",
    ]
    .into_iter()
    .map(str::to_string)
    .collect::<Vec<_>>();
    help_lines.extend(["".into()]);
    help_lines.extend(crate::tui::input::slash_help_lines());
    help_lines.extend(["".into(), "Default Keymap".into()]);
    help_lines.extend(
        crate::tui::keymap::DEFAULT_BINDING_HINTS
            .iter()
            .map(|hint| {
                format!(
                    "  {}: {} ({})",
                    hint.context.label(),
                    hint.action,
                    hint.keys
                )
            }),
    );
    let help = help_lines.join("\n");
    let widget = Paragraph::new(help)
        .block(Block::default().title("Help").borders(Borders::ALL))
        .scroll((scroll, 0))
        .wrap(Wrap { trim: false });
    frame.render_widget(widget, popup);
}

fn draw_input_modal(
    frame: &mut Frame<'_>,
    title: &str,
    help: &str,
    composer: &ComposerState,
    width_percent: u16,
    height_rows: u16,
) {
    let popup = centered_rect_rows(width_percent, height_rows, frame.area());
    frame.render_widget(Clear, popup);
    let text = format!("{help}\n\n{}", composer.as_str());
    let widget = Paragraph::new(text)
        .block(Block::default().title(title).borders(Borders::ALL))
        .wrap(Wrap { trim: false });
    frame.render_widget(widget, popup);

    let prefix = format!("{help}\n\n{}", &composer.as_str()[..composer.cursor()]);
    let (x, y) = modal_cursor_position(popup, &prefix);
    frame.set_cursor_position(ratatui::layout::Position { x, y });
}

fn modal_cursor_position(area: Rect, rendered_prefix: &str) -> (u16, u16) {
    let input_width = area.width.saturating_sub(2).max(1);
    let lines = rendered_prefix.split('\n').collect::<Vec<_>>();
    let wrapped_rows_before = lines
        .iter()
        .take(lines.len().saturating_sub(1))
        .map(|line| wrapped_rows(line, input_width))
        .sum::<u16>();
    let last_line = lines.last().copied().unwrap_or("");
    let last_line_width = display_width(last_line);
    let soft_wrap_row = if last_line_width == 0 {
        0
    } else {
        last_line_width.saturating_sub(1) / input_width
    };
    let column = if last_line_width == 0 {
        0
    } else {
        last_line_width - soft_wrap_row * input_width
    };
    let max_x = area.x + area.width.saturating_sub(2);
    let max_y = area.y + area.height.saturating_sub(2);
    (
        (area.x + 1 + column).min(max_x),
        (area.y + 1 + wrapped_rows_before + soft_wrap_row).min(max_y),
    )
}

fn wrapped_rows(line: &str, visible_line_width: u16) -> u16 {
    let line_width = display_width(line);
    let rows = (line_width + visible_line_width.saturating_sub(1)) / visible_line_width;
    rows.max(1)
}

fn display_width(text: &str) -> u16 {
    UnicodeWidthStr::width(text).min(u16::MAX as usize) as u16
}

pub(super) fn centered_rect(width_percent: u16, height_percent: u16, area: Rect) -> Rect {
    let width_percent = width_percent.min(100);
    let height_percent = height_percent.min(100);
    let vertical = Layout::default()
        .direction(Direction::Vertical)
        .constraints([
            Constraint::Percentage((100 - height_percent) / 2),
            Constraint::Percentage(height_percent),
            Constraint::Percentage((100 - height_percent) / 2),
        ])
        .split(area);
    let horizontal = Layout::default()
        .direction(Direction::Horizontal)
        .constraints([
            Constraint::Percentage((100 - width_percent) / 2),
            Constraint::Percentage(width_percent),
            Constraint::Percentage((100 - width_percent) / 2),
        ])
        .split(vertical[1]);
    horizontal[1]
}

pub(super) fn centered_rect_rows(width_percent: u16, height_rows: u16, area: Rect) -> Rect {
    let width_percent = width_percent.min(100);
    let height_rows = height_rows.clamp(1, area.height.max(1));
    let top = area.height.saturating_sub(height_rows) / 2;
    let bottom = area.height.saturating_sub(height_rows).saturating_sub(top);
    let vertical = Layout::default()
        .direction(Direction::Vertical)
        .constraints([
            Constraint::Length(top),
            Constraint::Length(height_rows),
            Constraint::Length(bottom),
        ])
        .split(area);
    let horizontal = Layout::default()
        .direction(Direction::Horizontal)
        .constraints([
            Constraint::Percentage((100 - width_percent) / 2),
            Constraint::Percentage(width_percent),
            Constraint::Percentage((100 - width_percent) / 2),
        ])
        .split(vertical[1]);
    horizontal[1]
}