Intents

Gateway intents have two halves. discord.py implements the client half (cache policy, flag validation) — and because SimCord runs your real bot, that half always worked. SimCord also implements the server half, the part real Discord does:

• Events outside your declared intents are never delivered to the bot.
• Without the message_content privileged intent, message content is censored.
• GUILD_CREATE carries only the bot's own member; the rest arrives via member chunking (members intent) exactly as on the real gateway.

That means the single most common intent bug — a prefix-command bot constructed with Intents.default() that passes local testing and then silently ignores every command in production — now fails your tests too:

bot = commands.Bot(command_prefix="!", intents=discord.Intents.default())

@bot.command()
async def ping(ctx):
    await ctx.send("Pong!")

async with simcord.run(bot) as env:
    guild = env.create_guild()
    channel = guild.create_text_channel("general")
    alice = guild.add_member(env.create_user("alice"))
    await alice.send(channel, "!ping")
    assert channel.last_message.content == "Pong!"   # FAILS — and should!

Without intents.message_content = True, the bot receives the MESSAGE_CREATE event with content="" — Discord's documented behaviour — so the command never fires. The transcript explains why:

GATEWAY  MESSAGE_CREATE               author=alice content='!ping'
CENSORED MESSAGE_CREATE               'content hidden: requires the message_content intent'

Event delivery

Every gateway event is gated on the matching intent from Discord's intent list, with guild/DM context decided by the payload, just like the real gateway:

Events	Intent
GUILD_*, CHANNEL_*, THREAD_*, role events	guilds
GUILD_MEMBER_ADD/UPDATE/REMOVE	members (privileged)
MESSAGE_CREATE/UPDATE/DELETE	guild_messages / dm_messages
MESSAGE_REACTION_*	guild_reactions / dm_reactions
TYPING_START	guild_typing / dm_typing
PRESENCE_UPDATE	presences (privileged)

Dropped events are recorded in the transcript so a mysteriously-quiet test can explain itself:

DROPPED  GUILD_MEMBER_ADD             'requires the members intent'

READY, INTERACTION_CREATE and GUILD_MEMBERS_CHUNK are always delivered — interactions are not intent-gated on real Discord either.

Message content censoring

Without message_content, the content, embeds, attachments, components and poll fields of guild messages are blanked, with Discord's documented exemptions: messages in DMs, messages authored by the bot, and messages that mention the bot keep their content (the censoring also applies to referenced_message, recursively).

Member chunking

GUILD_CREATE inlines only the bot's own member — the real gateway never ships the full member list there (except for small guilds when the presences intent is enabled, which SimCord also honours). With the members intent, discord.py's real chunking machinery kicks in and SimCord answers REQUEST_GUILD_MEMBERS authentically: 1000 members per GUILD_MEMBERS_CHUNK, nonce echoing, case-insensitive username/nick prefix queries, user_ids lookups with not_found, and presences when requested. So all of these work — and keep discord.py's own client-side intent guards:

await guild.chunk()                          # needs intents.members
await guild.query_members(query="ali")       # prefix-matches usernames and nicks
await guild.query_members(user_ids=[user_id])

Without the members intent, members never enter the bot's cache via the gateway — guild.get_member(...) returns None for everyone but the bot, just like production. Fetch them over REST instead, or enable the intent.

Privileged intents and the developer portal

Real Discord refuses the connection (close code 4014 → discord.PrivilegedIntentsRequired) when the bot declares a privileged intent (members, presences, message_content) that is not enabled in the developer portal. By default SimCord behaves as if every toggle is enabled. To simulate an unapproved portal, pass approved_intents:

bot = commands.Bot(command_prefix="!", intents=intents_with_members)

with pytest.raises(discord.PrivilegedIntentsRequired):
    async with simcord.run(bot, approved_intents=discord.Intents.default()):
        ...