feat(teams): the slash-command seam, and the first command through it

Phase 7 of TEAMS.md. `api.registerSlashCommands` stops throwing: a module
registers a command's DEFINITION and its HANDLER together, the bot pulls the
definitions over the internal listener and runs none of our code, and the
handler executes here — forced by the bot container having no `modules` volume,
and the right boundary anyway.

Registration validates what Discord would reject as a batch (names, description
lengths, the four option types, required-before-optional), because the bot
registers the whole set in one PUT and a single bad entry costs every command
including the bot's own. Commands are not namespaced under their owner — there
is no dot in Discord's name grammar — so collisions are first-come with the
holder named.

The dispatcher is the access boundary: `linked` has no Discord equivalent, so
the platform-side permission default can only ever be advertising. It resolves
the actor by `auth_providers.kind` rather than the id slug, treats a banned
account as unlinked, bounds a handler under the bot's own timeout, and keeps
`ok` outside the envelope so a handler cannot forge it.

Liveness is asked at both the pull and the dispatch. The registries have no
removal path, so a module an operator disables at runtime would otherwise keep
a live handler behind a command Discord still advertises.

Co-Authored-By: Claude <noreply@anthropic.com>
This commit is contained in:
2026-08-18 18:53:34 -05:00
parent b1d3b87cd6
commit cecd72915f
21 changed files with 1459 additions and 27 deletions

View File

@@ -0,0 +1,210 @@
// Slash commands whose DEFINITION and HANDLER live in the website process
// (TEAMS.md §7.1). The bot pulls the definitions, registers them alongside its
// own, and executes one by deferring, asking the app, and editing the reply in.
//
// Everything Discord-specific is here and nothing else is: the app's dispatcher
// resolves the actor, enforces access and produces a platform-neutral envelope,
// and this file turns that envelope into an interaction reply. A module never
// touches an interaction, which is what makes the registration API something a
// second platform could implement.
const { PermissionFlagsBits } = require('discord.js')
const appInternal = require('../site/appInternalClient')
const staticCommands = require('./commands')
const createLogger = require('../utils/logger')
const log = createLogger('dynamic-commands')
// §7.1.1's four types, and the only four. The app rejects anything else at
// registration; this map is the second half of that agreement.
const OPTION_TYPE = { string: 3, integer: 4, boolean: 5, user: 6 }
// The pulled set, and the app's module-state counter it came from. `null`
// version means "never successfully pulled", which is distinct from 0 ("pulled
// while the app had no modules loaded") — the first should retry, the second is
// a true answer.
let pulled = []
let version = null
/**
* Ask the app for the current definitions.
*
* **A failed pull KEEPS the previous set.** The app being briefly unreachable is
* not the same as it having no commands, and treating it as such would
* deregister every module command from Discord on a restart blip — then
* re-register them a minute later, with members watching commands appear and
* disappear. Nothing changes until the app actually answers.
*
* @returns {Promise<{ok: boolean, changed: boolean, count: number}>}
*/
async function pull() {
const res = await appInternal.fetchCommands()
if (!res.ok) {
log.warn('command pull failed — keeping the set already registered', {
error: res.error,
holding: pulled.length,
})
return { ok: false, changed: false, count: pulled.length }
}
const { version: pulledVersion, commands } = res.data || {}
const next = Array.isArray(commands) ? commands.filter(usable) : []
const changed = version === null || pulledVersion !== version || next.length !== pulled.length
pulled = next
version = typeof pulledVersion === 'number' ? pulledVersion : 0
return { ok: true, changed, count: pulled.length }
}
/**
* Drop a pulled definition the bot cannot honour.
*
* **The name collision the app cannot see.** The app validates a command against
* everything IT has registered; it does not know the bot's own static array
* exists. A module registering `ping` would produce two `ping` entries in one
* `REST.put`, which Discord rejects as a batch — taking down every command
* including the bot's own. The bot's built-ins win, because they are the ones a
* module cannot be asked to change.
*/
function usable(definition) {
if (!definition || typeof definition.name !== 'string') return false
if (staticCommands.get(definition.name)) {
log.warn('module slash command collides with a built-in and is ignored', {
command: definition.name,
owner: definition.owner,
})
return false
}
return true
}
/**
* The pulled definitions as Discord command data, for the whole-set PUT.
*
* `access: 'staff'` becomes a Discord-side permission default; `linked` cannot
* be expressed in Discord's permission model at all — there is no "has a website
* account" predicate — so it is simply not advertised and the app's dispatcher
* refuses it. That asymmetry is the reason §7.1 says access is enforced twice
* and that only the server half is the gate.
*/
function definitions() {
return pulled.map((c) => {
const data = {
name: c.name,
description: c.description,
options: (c.options || []).map((o) => ({
name: o.name,
description: o.description,
type: OPTION_TYPE[o.type],
required: Boolean(o.required),
...(o.choices ? { choices: o.choices } : {}),
})),
}
if (c.access === 'staff') data.default_member_permissions = PermissionFlagsBits.ModerateMembers.toString()
return data
})
}
/** Is this a command the app owns? Asked before the static registry is consulted. */
const has = (name) => pulled.some((c) => c.name === name)
// Read the options the member actually supplied, by the names the definition
// declared. A `user` option is passed on as the Discord user id and nothing else
// — a handler receives platform ids, never a platform object.
function collectOptions(interaction, definition) {
const out = {}
for (const option of definition.options || []) {
const supplied = interaction.options.get(option.name)
if (supplied === null || supplied === undefined) continue
out[option.name] = option.type === 'user' ? String(supplied.value) : supplied.value
}
return out
}
// What the caller sees when the app declined. The COPY lives here rather than in
// the app on purpose: the app answers with a machine reason, and how a refusal is
// phrased to a member is the platform's own voice.
function refusal({ reason, access }) {
if (reason === 'forbidden' && access === 'linked') {
return 'Link your Discord account on the site to use this command.'
}
if (reason === 'forbidden') return 'You do not have access to that command.'
if (reason === 'unknown') return 'That command is no longer available.'
return 'Something went wrong running that command.'
}
// Envelope → interaction payload. A response with fields or a title is an embed;
// a bare `text` is plain content, which reads better for a one-line answer.
function render(envelope) {
const { text, title, fields, url } = envelope
if (!title && !fields) return { content: text || '' }
const embed = {}
if (title) embed.title = title
if (text) embed.description = text
if (url) embed.url = url
if (fields) embed.fields = fields
return { embeds: [embed] }
}
/**
* Defer, dispatch, edit.
*
* **The deferral comes first, always.** Discord gives three seconds to acknowledge
* an interaction; the app is given four to answer. Deferring before the dispatch
* is what keeps the website out of that critical path entirely — a wedged handler
* costs its own reply and never an "application did not respond".
*
* A failure at any point after the defer is an edit, not a reply: the interaction
* has already been acknowledged, and `reply()` on a deferred interaction throws.
*/
async function execute(interaction) {
const definition = pulled.find((c) => c.name === interaction.commandName)
if (!definition) return false
// Ephemerality has to be decided BEFORE the answer exists, because it is a
// property of the deferral. A command declared for linked users only is
// answered privately by default — its answer is about the caller's own
// account — and everything else defers publicly; a handler that wants the
// opposite says so, and the follow-up carries it.
const ephemeral = definition.access === 'linked'
await interaction.deferReply({ ephemeral })
const res = await appInternal.dispatchCommand({
command: definition.name,
options: collectOptions(interaction, definition),
platformUserId: interaction.user.id,
guildId: interaction.guildId,
})
// A transport failure and a handler failure are the same sentence to the
// member and different lines in the log: one is the app being unreachable,
// the other is a module's code.
if (!res.ok) {
log.warn('command dispatch failed', { command: definition.name, error: res.error })
await interaction.editReply({ content: refusal({ reason: 'error' }) })
return true
}
if (!res.data || !res.data.ok) {
await interaction.editReply({ content: refusal(res.data || {}) })
return true
}
const envelope = res.data.response || {}
await interaction.editReply(render(envelope))
// The private aside beside a public answer (§9 answer 5). Skipped when the
// reply was already private — the member would just be told the same thing
// twice, in the same place.
if (envelope.notice && !ephemeral && !envelope.ephemeral) {
await interaction.followUp({ content: envelope.notice, ephemeral: true })
}
return true
}
// Test-only: the pulled set is process-global, so a test that pulls has to be
// able to hand the process back.
function _reset() {
pulled = []
version = null
}
module.exports = { pull, definitions, has, execute, _reset }