[4.41/D2] Discord features: ephemeral slash responses, select values, channel allowlist, global mentions opt-in, rename threads

[patrick-chinchill]

Summary

Remaining webhook-side Discord features from chat@4.32–4.41:

• Slash commands can be answered ephemerally through an interaction_flags callback, and the flag sticks to every follow-up.
• Select-menu interactions report the selected value.
• Operators can make the bot respond to every message in allowlisted channels (respond_to_channel_ids).
• @everyone/@here count as mentions only when opted in.
• The adapter can rename thread channels.

Upstream changes

• 022a5027 feat(discord): add ephemeral slash command responses (#514), chat@4.32.0. Adds config interactionFlags(context), where context is {channelId, command, interaction, text, user}. The result goes on the deferred type-5 response as data.flags and is stored as initialResponseFlags on the slash context. The only flag is DiscordInteractionResponseFlag.Ephemeral = 64.
• 5341f909 feat(discord): ignore @everyone/@here pings unless respondToGlobalMentions is set (#701), chat@4.34.0. respondToGlobalMentions (default false) makes data.mention_everyone === true count as a mention.
• 6c2a3918 feat(discord): rename thread channels (#693), chat@4.34.0. setThreadTitle(threadId, title) does nothing when there is no thread segment; otherwise it PATCHes /channels/{thread} {name} on the parent-validated thread.
• 0fdb9029 feat(discord): Components support (#678), chat@4.34.0. For a component action the value is data.values[0] ?? decoded.value ?? actionId. The Components V2 card renderer (contentFormat) is deferred, see [4.41/DEF1] Deferred upstream 4.32–4.41 features (demand-gated backlog) #189.
• 26c05225 feat(discord): add channel response allowlist (#715), chat@4.35.0. respondToChannelIds / DISCORD_RESPOND_TO_CHANNEL_IDS (comma list): non-bot messages whose parent channel is listed count as mentions, so a thread is created for top-level ones.
• b7c9316b fix(chat): tighten conversation boundaries (#875), chat@4.40.0. This is the follow-up part: initialResponseFlags is OR'd into every slash response (flags: initial | (payload.flags ?? 0)), so follow-ups stay ephemeral. The parent-channel part is in [4.41/D1] Discord correctness & security: thread-parent validation, starter-message routing, mentions/URLs, forwarded snapshots, downloads #229.
• 61b98fca chore(discord): update discord-api-types to 0.38 and dedupe types (#927), chat@4.41.0. Relevant part: stops reading the forwarder-supplied is_mention field (see Porting notes); the rest is in [4.41/D1] Discord correctness & security: thread-parent validation, starter-message routing, mentions/URLs, forwarded snapshots, downloads #229 or N/A (Discord adapter: port native Gateway WebSocket support (HTTP-only today) #57).

Current Python behavior

• src/chat_sdk/adapters/discord/adapter.py:297-303 (handle_webhook) returns {"type": DEFERRED_CHANNEL_MESSAGE_WITH_SOURCE} with no data.flags. The forwarded-gateway path (_handle_forwarded_interaction, :625-633, and _defer_gateway_interaction, :649-668) posts {"type": response_type} only. grep -rn 'interaction_flags\|initial_response_flags' src/chat_sdk/adapters/discord finds nothing.
• types.py:78-83 DiscordSlashCommandContext has no flags field. post_message (adapter.py:923-938) sends the slash follow-up without flags.
• adapter.py:399-403 (_handle_component_interaction) sets value=decoded.value if decoded.value is not None else decoded.action_id and never reads data["values"].
• adapter.py:704-711 (_handle_forwarded_message): is_mentioned is the forwarder's data.get("is_mention", False) OR a user ping OR a role ping. mention_everyone is not read. grep -rn 'respond_to_channel_ids\|RESPOND_TO\|respond_to_global' src/chat_sdk/adapters/discord finds nothing.
• grep -rn 'set_thread_title' src/chat_sdk finds nothing.
• types.py:20-47 DiscordAdapterConfig has no interaction_flags, respond_to_channel_ids or respond_to_global_mentions.

Scope

• Add a DiscordInteractionFlagsContext dataclass (channel_id, command, interaction, text, user) and DiscordInteractionResponseFlag.EPHEMERAL = 64 to types.py.
• Add these fields to DiscordAdapterConfig:
  • interaction_flags: Callable[[DiscordInteractionFlagsContext], int | None] | None
  • respond_to_channel_ids: list[str] | None
  • respond_to_global_mentions: bool | None
• Add initial_response_flags: int | None = None to DiscordSlashCommandContext.
• Split _handle_application_command_interaction in two:
  • _build_application_command_context(interaction) -> DiscordInteractionFlagsContext | None, which parses channel_id, command and text once.
  • A handler that takes (context, initial_response_flags, options).
• HTTP path: compute the flags and return {"type": 5, "data": {"flags": f}} when f is not None. Forwarded path: pass the flags to _defer_gateway_interaction.
• post_message slash follow-up: when initial_response_flags is not None, send flags = initial | payload.get("flags", 0) on the @original edit and later follow-ups.
• Component actions: value = values[0] when data.get("values") is a non-empty list, else decoded.value if it is not None, else decoded.action_id.
• _handle_forwarded_message: compute is_mentioned as user ping OR role ping OR (respond_to_global_mentions and data.get("mention_everyone") is True) OR (the author is not a bot and parent_channel_id in respond_to_channel_ids). Stop reading the forwarder's data["is_mention"] (decision below).
• async set_thread_title(thread_id, title): return if there is no thread; otherwise call _resolve_thread_channel_id (from [4.41/D1] Discord correctness & security: thread-parent validation, starter-message routing, mentions/URLs, forwarded snapshots, downloads #229) and then PATCH /channels/{id} {"name": title}.
• Resolve respond_to_channel_ids as config.respond_to_channel_ids when it is not None, else DISCORD_RESPOND_TO_CHANNEL_IDS split on , and stripped (upstream keeps empty entries; dropping them is harmless), else []. Do not copy the or in the existing mention_role_ids parse (adapter.py:137-139): an explicit [] must win over the env var (upstream ??). respond_to_global_mentions likewise uses is not None, default False.

Out of scope

• Components V2 (content_format), the 40-component and 4000-character validation, and V2 select rendering: [4.41/DEF1] Deferred upstream 4.32–4.41 features (demand-gated backlog) #189. Record them as non-parity.
• The legacy discord.js gateway listener and forwarder enrichment: N/A (Discord adapter: port native Gateway WebSocket support (HTTP-only today) #57).
• Thread-parent validation: [4.41/D1] Discord correctness & security: thread-parent validation, starter-message routing, mentions/URLs, forwarded snapshots, downloads #229. is_mention returning True|None: [4.41/C2a] Core mentions & message model: tri-state is_mention, mention regex, Author.email/is_system, Message.reply_to #192.

Porting notes

• interactionFlags may return undefined. Test with is not None: a return of 0 is a real flag value and must still be sent.
• Bitfields: initial | (flags if flags is not None else 0).
• An empty-string select value is legal. Pick values[0] whenever the list is non-empty, even if values[0] == "".
• mention_everyone is True: strict identity, matching === true.
• The allowlist checks the parent channel id, so messages inside threads of an allowlisted channel qualify. A top-level message in an allowlisted channel creates a thread, as a mention does today (adapter.py:714).
• The callback is synchronous (as upstream). Python-only hardening: if it raises, log and fall back to no flags rather than failing the ACK (upstream lets it throw); record this in docs/UPSTREAM_SYNC.md.
• Design decision: upstream no longer honours a forwarder-supplied is_mention field. Recommended default: drop it (parity, and it closes an @everyone leak for forwarders that computed it with discord.js mentions.has). Record it in docs/UPSTREAM_SYNC.md and the CHANGELOG as a behaviour change for custom forwarders.

Tests

packages/adapter-discord/src/index.test.ts is not fidelity-mapped (see #78). Port into tests/test_discord_adapter.py / tests/test_discord_extended.py:

• "sets initial deferred slash command interaction flags from config"
• "keeps slash command follow-up responses ephemeral"
• "sets gateway deferred slash command interaction flags from config". Upstream drives discord.js deferReply; adapt the assertion to the Python forwarded GATEWAY_INTERACTION_CREATE path, where _defer_gateway_interaction must carry data.flags.
• "uses selected values from select interactions"
• "should resolve respondToChannelIds from DISCORD_RESPOND_TO_CHANNEL_IDS env var"
• "keeps allowlisted forwarded messages in their Discord thread"
• describe("respondToGlobalMentions handling"):
  • "ignores @everyone in forwarded gateway messages by default"
  • "treats @everyone in forwarded gateway messages as a mention when respondToGlobalMentions is true"
  • "still detects direct user mentions when @everyone is ignored"
• describe("setThreadTitle"): "renames Discord thread channels"

N/A (drive the discord.js listener): "creates a thread for messages in an allowlisted channel", "reuses the existing thread for messages in a thread of an allowlisted channel", "does not treat a parentless thread message as allowlisted", "ignores @everyone in legacy gateway mode by default", "treats @everyone in legacy gateway mode as a mention when respondToGlobalMentions is true". Carry their assertions to the forwarded path only where not covered above.

Python-specific: a raising flags callback still ACKs; an empty-string select value is kept; an explicit respond_to_channel_ids=[] beats the env var. AsyncMock for _discord_fetch.

Acceptance criteria

• With interaction_flags returning 64, the deferred response and every follow-up carry the ephemeral flag.
• @everyone does not trigger mention handlers unless opted in, and allowlisted channels trigger them without a mention.
• The full validation command from CLAUDE.md passes.
• docs/UPSTREAM_SYNC.md records the Components V2 deferral, the forwarder is_mention decision and the flags-callback error handling.
• A CHANGELOG entry under "Unreleased (4.41 wave)" calls out the new options and that forwarder-supplied is_mention is ignored.

Dependencies

Blocked by #229.

Metadata

• Effort: M (~400–650 LOC including tests)
• Consumer impact: low. It is Discord only; the one behaviour change is for custom forwarders. None for Slack/Teams.
• Suggested branch: sync/4.41-d2

Part of #184.