moto-watch

1import { atom, read, update } from 'claude-code'
2import type { EngineInterface, Register } from 'claude-code'
3
4import type { Pass } from '../types'
5
6// Each pass is one short `moto watch`, which hands over what changed since the last.
7const POLL_MS = 3000
8const TAG = '[moto watch]'
9const SECTION = {
10  id: 'moto-watch:watching',
11  scope: 'session',
12  text: [
13    'The moto-watch mod runs `moto watch` every 3 seconds for this session, so never run it yourself:',
14    'a pass hands its news over once. When a worker needs you, a prompt starting with',
15    `${TAG} arrives after your turn, with one line per worker. Notes from scheduled jobs`,
16    'arrive in the same prompt, each starting with [job].',
17  ].join(' '),
18} as const
19
20const lines = atom({ plugin: 'moto-watch', key: 'lines' } as const, [] as readonly string[])
21const notes = atom({ plugin: 'moto-watch', key: 'notes' } as const, [] as readonly string[])
22
23// Turns under way. News waits for the last to end, then arrives as one prompt.
24const turns = new Set<string>()
25let isPolling = false
26
27async function deliver($: EngineInterface) {
28  if (turns.size > 0) {
29    return
30  }
31  const held = await read($, lines)
32  const left = await read($, notes)
33  if (held.length === 0 && left.length === 0) {
34    return
35  }
36  await update($, lines, () => [])
37  await update($, notes, () => [])
38  const parts = held.length > 0 ? [[TAG, ...held].join('\n'), ...left] : left
39  void $.prompt.submit({ text: parts.join('\n\n') })
40}
41
42async function poll($: EngineInterface) {
43  if (isPolling) {
44    return
45  }
46  isPolling = true
47  try {
48    const { exitCode, stdout, stderr } = await $.process.run(['moto', 'watch'])
49    if (exitCode !== 0) {
50      $.ui.status(stderr.trim().split('\n')[0] || `moto watch exited ${exitCode}`)
51      return
52    }
53    const pass = JSON.parse(stdout) as Pass
54    $.ui.status(`watching ${pass.watching}`)
55    if (pass.lines.length > 0) {
56      await update($, lines, before => [...before, ...pass.lines])
57    }
58    const note = pass.notes
59    if (note !== null) {
60      await update($, notes, before => [...before, note])
61    }
62    await deliver($)
63  } catch (error) {
64    $.ui.status(error instanceof Error ? error.message : String(error))
65  } finally {
66    isPolling = false
67  }
68}
69
70export const register: Register = on => {
71  on('session.start', async ($, e, next) => {
72    const result = await next(e)
73    // A fork of the driver owns no task; moto refuses to watch from one.
74    if ((await $.env.get('MOTO_FORK')) === undefined) {
75      $.clock.every(POLL_MS, () => void poll($))
76    }
77    return result
78  })
79
80  on('prompt.compose', async ($, e, next) => {
81    const { sections } = await next(e)
82    return { sections: [...sections, SECTION] }
83  })
84
85  on('turn.start', ($, e, next) => {
86    turns.add(e.turnId)
87    return next(e)
88  })
89
90  on('turn.complete', async ($, e, next) => {
91    const result = await next(e)
92    turns.delete(e.turnId)
93    await deliver($)
94    return result
95  })
96}
97

1// What one `moto watch` prints.
2export type Pass = {
3  watching: number
4  lines: string[]
5  notes: string | null
6}
7
8declare module 'claude-code' {
9  interface PluginState {
10    // What passes found while a turn ran, held for the turn's end: worker lines and job notes.
11    'moto-watch': { lines: readonly string[]; notes: readonly string[] }
12  }
13}
14