secret-input

1import { atom, read, update } from 'claude-code'
2import type { EngineInterface, Register } from 'claude-code'
3
4import type { SecretRequest } from '../types'
5
6const PANE = 'secret-input'
7const TOOL = 'request_secret'
8const OWN_TOOL = 'mcp__secret-input__request_secret'
9const NAME = /^[A-Za-z][A-Za-z0-9_]{0,39}$/
10const PLACEHOLDER = /\{\{secret:([A-Za-z][A-Za-z0-9_]{0,39})\}\}/g
11
12const names = atom({ plugin: 'secret-input', key: 'names' } as const, [] as string[], {
13  shape: 'names-1',
14})
15const request = atom(
16  { plugin: 'secret-input', key: 'request' } as const,
17  null as SecretRequest | null,
18  { shape: 'request-1' },
19)
20
21// Values live in module memory only: any plugin can read $.state, and $.store
22// is plain JSON on disk. So a reload or a restart drops them.
23const secrets = new Map<string, string>()
24
25// The model reads this one; it stays in English whatever the language option.
26const TOOL_DESCRIPTION = [
27  'Ask the user for a secret (password, token, API key) through a private input pane,',
28  'so the value never enters the chat. Use this instead of asking the user to paste a secret in chat.',
29  'It returns at once: end your turn and wait; a message arrives when the user has saved it.',
30  "Then write '{{secret:NAME}}' in a Bash or PowerShell command, always inside single quotes;",
31  'the value is put in when the command runs and masked as [secret:NAME] in the output.',
32  'You never see the value: do not try to print, save or read it back.',
33].join(' ')
34
35const TEXT = {
36  en: {
37    commandDescription: 'Enter a secret in a private pane instead of the chat (/secret NAME, /secret, /secret --clear)',
38    argumentHint: '[NAME|--clear]',
39    paneTitle: (name: string) => `Secret: ${name}`,
40    noneSaved: 'No secrets saved. Run /secret NAME to add one.',
41    savedList: (list: string) => `Saved: ${list}`,
42    cleared: 'All saved secrets were cleared.',
43    badName: (name: string) => `A name starts with a letter and uses only letters, digits and _: ${name}`,
44    opened: (name: string) => `Opened the input pane for ${name}. The value stays out of the chat.`,
45    empty: 'An empty value is not saved.',
46    savedToast: (name: string, length: number) => `${name} saved (${length} characters)`,
47    savedNote: (name: string) =>
48      `[secret-input] ${name} has been entered. Write '{{secret:${name}}}' in a command; the value stays hidden.`,
49    cancelNote: (name: string) => `[secret-input] The user cancelled entering ${name}.`,
50    mobile: 'This surface has no input field. Run /secret NAME in the terminal.',
51    idle: 'No secret was requested. Run /secret NAME to open one.',
52    inputLabel: 'Value ',
53    placeholder: 'Paste here, then Enter',
54    submitLabel: 'save',
55    warning: 'Not sent to the chat or the model. Visible in this pane until Enter.',
56    cancel: 'Cancel',
57  },
58  ko: {
59    commandDescription: '비밀값을 채팅 대신 전용 입력창으로 넣기 (/secret 이름, /secret, /secret --clear)',
60    argumentHint: '[이름|--clear]',
61    paneTitle: (name: string) => `비밀값 입력: ${name}`,
62    noneSaved: '저장된 비밀값이 없어요. /secret 이름 으로 넣으세요.',
63    savedList: (list: string) => `저장됨: ${list}`,
64    cleared: '저장된 비밀값을 모두 지웠어요.',
65    badName: (name: string) => `이름은 영문으로 시작하고 영문·숫자·_ 만 써요: ${name}`,
66    opened: (name: string) => `${name} 입력창을 열었어요. 값은 채팅에 남지 않아요.`,
67    empty: '빈 값은 저장하지 않아요.',
68    savedToast: (name: string, length: number) => `${name} 저장됨 (${length}자)`,
69    savedNote: (name: string) =>
70      `[secret-input] ${name} 입력이 끝났습니다. 명령에 '{{secret:${name}}}' 로 쓰세요. 값은 보이지 않습니다.`,
71    cancelNote: (name: string) => `[secret-input] 사용자가 ${name} 입력을 취소했습니다.`,
72    mobile: '이 화면에는 입력창이 없어요. 터미널에서 /secret 이름 으로 넣으세요.',
73    idle: '요청된 비밀값이 없어요. /secret 이름 으로 여세요.',
74    inputLabel: '값 ',
75    placeholder: '여기에 붙여넣고 Enter',
76    submitLabel: '저장',
77    warning: '채팅·모델에는 보내지 않아요. Enter 전까지 이 창에는 보여요.',
78    cancel: '취소',
79  },
80} as const
81
82// The model writes the placeholder inside single quotes: escape the value per shell.
83const quoteFor = (tool: string, value: string) =>
84  tool === 'PowerShell'
85    ? value.replace(/['\u2018\u2019\u201A\u201B]/g, quote => quote + quote)
86    : value.replace(/'/g, `'\\''`)
87
88// Mask the value and its escaped forms (an error message may repeat the command).
89// Longest first, so a value that holds another one wins.
90const masks = () =>
91  [...secrets]
92    .flatMap(([name, value]) =>
93      [...new Set([value, quoteFor('Bash', value), quoteFor('PowerShell', value)])].map(
94        form => [name, form] as const,
95      ),
96    )
97    .sort((a, b) => b[1].length - a[1].length)
98
99const redactText = (text: string) =>
100  masks().reduce((out, [name, form]) => out.split(form).join(`[secret:${name}]`), text)
101
102const hasSecret = (value: unknown): boolean => {
103  if (typeof value === 'string') return masks().some(([, form]) => value.includes(form))
104  if (Array.isArray(value)) return value.some(hasSecret)
105  if (value !== null && typeof value === 'object') return Object.values(value).some(hasSecret)
106  return false
107}
108
109const redactDeep = (value: unknown): unknown => {
110  if (typeof value === 'string') return redactText(value)
111  if (Array.isArray(value)) return value.map(redactDeep)
112  if (value !== null && typeof value === 'object') {
113    return Object.fromEntries(Object.entries(value).map(([key, item]) => [key, redactDeep(item)]))
114  }
115  return value
116}
117
118type Words = (typeof TEXT)[keyof typeof TEXT]
119
120const openPane = ($: EngineInterface, t: Words, name: string) =>
121  $.ui.open({ id: PANE, title: t.paneTitle(name), focus: true, closeOnEscape: true, rows: 7 })
122
123const finish = async ($: EngineInterface, req: SecretRequest, note: string) => {
124  await update($, request, () => null)
125  await $.ui.close({ id: PANE })
126  if (req.isFromModel) await $.prompt.submit({ text: note })
127}
128
129const save = async ($: EngineInterface, t: Words, req: SecretRequest, typed: string) => {
130  const value = typed.replace(/[\r\n]+$/, '')
131  if (value === '') {
132    $.ui.toast(t.empty)
133    return
134  }
135  secrets.set(req.name, value)
136  await update($, names, list => [...new Set([...list, req.name])])
137  $.ui.toast(t.savedToast(req.name, value.length))
138  await finish($, req, t.savedNote(req.name))
139}
140
141const cancel = ($: EngineInterface, t: Words, req: SecretRequest) => finish($, req, t.cancelNote(req.name))
142
143export const register: Register = (on, options) => {
144  const t = options.language === 'ko' ? TEXT.ko : TEXT.en
145
146  on('session.start', async ($, e, next) => {
147    // A reload empties the values, so empty the list of names too.
148    await update($, names, () => [])
149    await $.tool.register({
150      name: TOOL,
151      description: TOOL_DESCRIPTION,
152      isDeferred: false,
153      inputSchema: {
154        type: 'object',
155        properties: {
156          name: { type: 'string', description: 'Letters, digits, _; starts with a letter (DB_PASSWORD)' },
157          reason: { type: 'string', description: 'One line telling the user what it is for' },
158        },
159        required: ['name'],
160      },
161    })
162    await $.command.register({
163      name: 'secret',
164      description: t.commandDescription,
165      argumentHint: t.argumentHint,
166    })
167
168    return next(e)
169  })
170
171  on('command.run', { command: 'secret' }, async ($, e) => {
172    const arg = e.args.trim()
173    if (arg === '') {
174      const list = [...secrets.keys()]
175      return { text: list.length === 0 ? t.noneSaved : t.savedList(list.join(', ')) }
176    }
177    if (arg === '--clear') {
178      secrets.clear()
179      await update($, names, () => [])
180      return { text: t.cleared }
181    }
182    if (!NAME.test(arg)) return { text: t.badName(arg) }
183    // Take over a request the model made for the same name, so it hears back.
184    await update($, request, pending =>
185      pending !== null && pending.name === arg ? pending : { name: arg, reason: '', isFromModel: false },
186    )
187    await openPane($, t, arg)
188
189    return { text: t.opened(arg) }
190  })
191
192  on('tool.call', async ($, e, next) => {
193    if (e.tool === OWN_TOOL) {
194      const name = String(e.name ?? '')
195      const reason = typeof e.reason === 'string' ? e.reason : ''
196      if (!NAME.test(name)) return { deny: `Invalid name "${name}": letters, digits, _; starts with a letter.` }
197      await update($, request, () => ({ name, reason, isFromModel: true }))
198      const opened = await openPane($, t, name)
199      const text = opened.isPlaced
200        ? `The input pane for ${name} is open. End your turn now and wait for the user.`
201        : `The pane could not be shown (${opened.reason}). Ask the user to run /secret ${name}, then wait.`
202      return { result: text }
203    }
204
205    const isShell = e.tool === 'Bash' || e.tool === 'PowerShell'
206    let input = e
207    if (isShell && typeof e.command === 'string') {
208      const used = [...e.command.matchAll(PLACEHOLDER)].map(match => match[1] ?? '')
209      const missing = [...new Set(used.filter(name => !secrets.has(name)))]
210      if (missing.length > 0) {
211        return {
212          deny: `No secret saved for ${missing.join(', ')}. Call ${OWN_TOOL} first, or ask the user to run /secret NAME.`,
213        }
214      }
215      if (used.length > 0) {
216        const command = e.command.replace(PLACEHOLDER, (_, name: string) =>
217          quoteFor(e.tool, secrets.get(name) ?? ''),
218        )
219        input = { ...e, command }
220      }
221    }
222    if (secrets.size === 0) return next(input)
223
224    const ran = await next(input)
225    if (!hasSecret(ran)) return ran
226    if (ran.deny !== undefined) return { deny: redactText(ran.deny) }
227    if (ran.isError) return { deny: redactText(ran.text ?? 'The command failed.') }
228
229    return { result: redactDeep(ran.result) as typeof ran.result }
230  }).catch(($, e, next) =>
231    // When masking fails, withhold the result rather than pass it on.
232    next.called ? { deny: 'secret-input: the result was withheld (masking failed).' } : next(e),
233  )
234
235  // Mask saved values once more in every row the model or the transcript keeps.
236  on('session.append', ($, e, next) => {
237    if (secrets.size === 0 || !hasSecret(e.message.content)) return next(e)
238    return next({ ...e, message: { ...e.message, content: redactDeep(e.message.content) as typeof e.message.content } })
239  }).catch(($, e, next) => next({ ...e, message: { ...e.message, content: [] } }))
240
241  on('ui.close', { id: PANE }, async ($, e, next) => {
242    const req = await read($, request)
243    if (req !== null && e.origin.kind === 'person') {
244      await update($, request, () => null)
245      if (req.isFromModel) await $.prompt.submit({ text: t.cancelNote(req.name) })
246    }
247    return next(e)
248  })
249
250  on('ui.render', { component: 'Pane', requestId: PANE }, async ($, e) => {
251    const req = await read($, request)
252    const saved = await read($, names)
253    if (e.surface === 'mobile') {
254      const { Text } = $.ui.resolve(e)
255      return <Text dimColor>{t.mobile}</Text>
256    }
257    const { Box, Text, Input, Button } = $.ui.resolve(e)
258    if (req === null) {
259      return (
260        <Box flexDirection="column">
261          <Text dimColor>{t.idle}</Text>
262          {saved.length > 0 && <Text dimColor>{t.savedList(saved.join(', '))}</Text>}
263        </Box>
264      )
265    }
266
267    return (
268      <Box flexDirection="column">
269        <Text bold>{req.name}</Text>
270        {req.reason !== '' && <Text dimColor>{req.reason}</Text>}
271        <Input
272          key="value"
273          label={t.inputLabel}
274          placeholder={t.placeholder}
275          submitLabel={t.submitLabel}
276          autoFocus
277          onSubmit={typed => void save($, t, req, typed)}
278        />
279        <Text dimColor>{t.warning}</Text>
280        <Button key="cancel" label={t.cancel} role="dismiss" onPress={() => void cancel($, t, req)} />
281      </Box>
282    )
283  })
284}
285

1export type SecretRequest = {
2  name: string
3  reason: string
4  /** True when the model asked through request_secret: it hears back once saved */
5  isFromModel: boolean
6}
7
8declare module 'claude-code' {
9  interface PluginState {
10    'secret-input': {
11      /** The names of the saved secrets only; a value is never kept here */
12      names: Shaped<string[]>
13      request: Shaped<SecretRequest | null>
14    }
15  }
16}
17