session-journal

1import type { Register } from 'claude-code'
2import { add, fromTool, render, type Entry } from './lib'
3
4export const register: Register = on => {
5  let entries: Entry[] = []
6  let startedAt = 0
7
8  on('session.start', async ($, e, next) => {
9    startedAt = await $.clock.now()
10    await $.command.register({ name: 'journal', description: 'Write a markdown timeline of this session to .claude/journal/' })
11    return next(e)
12  })
13
14  on('prompt.submit', async ($, e, next) => {
15    entries = add(entries, { kind: 'prompt', at: await $.clock.now(), text: String(e.text ?? '') })
16    return next(e)
17  }).catch(($, e, next) => next(e))
18
19  on('tool.call', async ($, e, next) => {
20    const entry = fromTool(e.tool, e as unknown as Record<string, unknown>, await $.clock.now())
21    if (entry) entries = add(entries, entry)
22    return next(e)
23  }).catch(($, e, next) => next(e))
24
25  on('command.run', { command: 'journal' }, async $ => {
26    if (entries.length === 0) return { text: 'Nothing to journal yet.' }
27    const stamp = new Date(startedAt || (await $.clock.now())).toISOString().slice(0, 16).replace(/[:T]/g, '-')
28    const path = `.claude/journal/${stamp}.md`
29    await $.fs.write(path, render(entries, `Session ${stamp.replace(/-(\d\d)-(\d\d)$/, ' $1:$2')}`))
30    return { text: `Journal written to ${path} (${entries.length} entries).` }
31  })
32}
33

1export type Entry =
2  | { kind: 'prompt'; at: number; text: string }
3  | { kind: 'bash'; at: number; text: string }
4  | { kind: 'edit'; at: number; text: string }
5
6const EDIT_TOOLS = new Set(['Edit', 'Write', 'MultiEdit', 'NotebookEdit'])
7const MAX_ENTRIES = 1000
8
9const clip = (s: string, n: number) => {
10  const t = s.replace(/\s+/g, ' ').trim()
11  return t.length > n ? t.slice(0, n - 1) + '…' : t
12}
13
14/** Turns a tool call into a journal entry, or undefined if it is not worth recording. */
15export function fromTool(tool: string, args: Record<string, unknown>, at: number): Entry | undefined {
16  if (tool === 'Bash' && typeof args.command === 'string') return { kind: 'bash', at, text: clip(args.command, 200) }
17  const path = args.file_path ?? args.notebook_path
18  if (EDIT_TOOLS.has(tool) && typeof path === 'string') return { kind: 'edit', at, text: path }
19  return undefined
20}
21
22export function add(list: Entry[], entry: Entry): Entry[] {
23  return [...list, entry].slice(-MAX_ENTRIES)
24}
25
26const hhmm = (ms: number) => new Date(ms).toISOString().slice(11, 16)
27
28export function render(entries: Entry[], title: string): string {
29  const lines = [`# ${title} (UTC)`]
30  const files = new Map<string, number>()
31  for (const e of entries) {
32    if (e.kind === 'prompt') lines.push('', `## ${hhmm(e.at)} · ${clip(e.text, 120)}`, '')
33    else if (e.kind === 'bash') lines.push(`- ran \`${e.text.replace(/`/g, "'")}\``)
34    else { lines.push(`- edited \`${e.text}\``); files.set(e.text, (files.get(e.text) ?? 0) + 1) }
35  }
36  if (files.size) {
37    lines.push('', '## Files changed', '')
38    for (const [f, n] of files) lines.push(`- \`${f}\`${n > 1 ? ` (×${n})` : ''}`)
39  }
40  return lines.join('\n') + '\n'
41}
42