Slack Workflow Steps¶

The Slack plugin exposes public reusable workflow steps through SlackPlugin.get_steps(). The current surface covers connection validation, target selection, messaging, and conversation summaries.

For full contract details for every public step, including documented inputs, outputs, and return behavior, see the detailed step reference.

Summary¶

Step	Group	Used by built-in workflows
`validate_connection`	Validation and Discovery	`discover-slack-workspace`
`list_public_channels`	Validation and Discovery	`discover-slack-workspace`
`list_users`	Validation and Discovery	`discover-slack-workspace`
`select_user_target`	Selection and Target Resolution	`send-slack-direct-message`
`select_channel_target`	Selection and Target Resolution	`send-slack-channel-message`
`select_default_or_search_channel_target`	Selection and Target Resolution	-
`prepare_message_destination`	Messaging	`send-slack-direct-message`, `send-slack-channel-message`
`open_direct_message`	Messaging	-
`prompt_message_body`	Messaging	`send-slack-direct-message`, `send-slack-channel-message`
`post_message`	Messaging	`send-slack-direct-message`, `send-slack-channel-message`
`upload_file`	Messaging	`post-file`
`select_target`	Conversation Summaries	`summarize-slack-target`
`ensure_target_conversation`	Conversation Summaries	`summarize-slack-target`
`read_recent_messages`	Conversation Summaries	`summarize-slack-target`
`ai_summarize_messages`	Conversation Summaries	`summarize-slack-target`

Validation and Discovery¶

Use these steps to validate the current Slack connection and inspect the accessible workspace surface.

validate_connection: validate the configured Slack token and expose identity metadata
list_public_channels: list public channels visible to the current token
list_users: list users visible to the current token

Selection and Target Resolution¶

Use these steps to resolve a reusable Slack target object for later workflows.

select_user_target: filter visible Slack users by query and select one canonical user target
select_channel_target: filter visible Slack channels by query and select one canonical channel target
select_default_or_search_channel_target: choose one configured default channel or fall back to a unified person/channel search

Messaging¶

Use these steps to resolve a message destination and post a plain-text Slack message or upload a file.

prepare_message_destination: resolve the selected user or channel target into the destination conversation used for posting
open_direct_message: open or reuse a direct message conversation for the selected user target
prompt_message_body: capture a multiline Slack message body for later posting
post_message: post the prepared message to the selected conversation
upload_file: upload a local file to the selected conversation, with the prepared message as its comment

Conversation Summaries¶

Use these steps to resolve a target conversation, read its recent messages, and summarize them with AI.

select_target: search both users and channels and select one unified Slack target
ensure_target_conversation: resolve a Slack conversation from the selected target
read_recent_messages: read the latest messages from the resolved conversation
ai_summarize_messages: summarize the retrieved messages with AI

Notes¶

Built-in workflows may use only a subset of these steps.
select_default_or_search_channel_target is the step that uses repo-configured default_channels; when none are configured, or the user chooses to search instead, it falls back to the unified select_target search (person or channel). It is available for custom workflows but is not used by any built-in workflow.
The built-in summary workflow uses the unified select_target step directly, so it can resolve either a person or a channel from one search.

Detailed Step Contracts¶

The summaries above show what each slack step is for. The sections below show the documented contract for each public step: what it expects from ctx.data, what it saves back, and what result types it may return.

Expand a step to see its workflow usage, required context, inputs, outputs, and result behavior.

How to read these contracts:

Inputs (from ctx.data) = values the step expects before it runs.
Outputs (saved to ctx.data) = metadata keys saved for later steps when the step returns Success or Skip.
Returns = the workflow result type (Success, Skip, Error, Exit), not a separate payload.

Validation and Discovery¶

validate_connection

Validate the configured Slack connection and expose identity metadata.

Workflow usage

- plugin: slack
  step: validate_connection

Used by built-in workflows: post-file, post-message, summarize-slack-target

Available to later steps: slack_auth, slack_team_id, slack_team_name, slack_user_id, slack_user_name

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient.

Inputs (from ctx.data)

Name	Type	Description
None documented.	-	-

Outputs (saved to ctx.data)

Name	Type	Description
`slack_auth`	UISlackAuth	Slack auth identity details from `auth_test()`.
`slack_team_id`	str \| None	Team identifier reported by Slack.
`slack_team_name`	str \| None	Team name reported by Slack.
`slack_user_id`	str \| None	User identifier reported by Slack.
`slack_user_name`	str \| None	User name reported by Slack.

Returns

Result	Saved for later steps	Description
`Success`	`slack_auth`, `slack_team_id`, `slack_team_name`, `slack_user_id`, `slack_user_name`	If the Slack connection validates successfully.
`Error`	-	If the Slack client is not available or the auth request fails.

list_public_channels

List public Slack channels visible to the current token.

Workflow usage

- plugin: slack
  step: list_public_channels

Available to later steps: slack_channels, slack_channels_next_cursor

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient.

Inputs (from ctx.data)

Name	Type	Description
`slack_limit`	int, optional	Maximum number of channels to request. Defaults to 100.
`slack_cursor`	str, optional	Pagination cursor for the next page.
`slack_exclude_archived`	bool, optional	Whether to exclude archived channels. Defaults to True.

Outputs (saved to ctx.data)

Name	Type	Description
`slack_channels`	list[UISlackChannel]	Public channels returned by Slack.
`slack_channels_next_cursor`	str \| None	Pagination cursor for a later request.

Returns

Result	Saved for later steps	Description
`Success`	`slack_channels`, `slack_channels_next_cursor`	If the channel list is retrieved successfully.
`Error`	-	If the Slack client is not available or the Slack request fails.

list_users

List Slack users visible to the current token.

Workflow usage

- plugin: slack
  step: list_users

Available to later steps: slack_users, slack_users_next_cursor

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient.

Inputs (from ctx.data)

Name	Type	Description
`slack_limit`	int, optional	Maximum number of users to request. Defaults to 100.
`slack_cursor`	str, optional	Pagination cursor for the next page.

Outputs (saved to ctx.data)

Name	Type	Description
`slack_users`	list[UISlackUser]	Users returned by Slack.
`slack_users_next_cursor`	str \| None	Pagination cursor for a later request.

Returns

Result	Saved for later steps	Description
`Success`	`slack_users`, `slack_users_next_cursor`	If the user list is retrieved successfully.
`Error`	-	If the Slack client is not available or the Slack request fails.

Selection and Target Resolution¶

select_user_target

Select a Slack user target through query filtering and final confirmation.

Workflow usage

- plugin: slack
  step: select_user_target

Available to later steps: slack_target, slack_target_type, slack_target_id, slack_target_name, slack_target_query

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient.

Inputs (from ctx.data)

Name	Type	Description
`slack_target_query`	str, optional	Pre-filled query used to filter Slack users.
`slack_search_limit`	int, optional	Maximum number of matches to return. Defaults to 20.
`slack_search_page_size`	int, optional	Page size used while scanning Slack users. Defaults to 1000.
`slack_search_max_pages`	int, optional	Maximum pages to scan while searching. Defaults to 50.

Outputs (saved to ctx.data)

Name	Type	Description
`slack_target`	UISlackTarget	Canonical selected Slack target.
`slack_target_type`	str	Selected target type (`user`).
`slack_target_id`	str	Slack user ID.
`slack_target_name`	str	User-facing target name.
`slack_target_query`	str	Query used to resolve the selection.

Returns

Result	Saved for later steps	Description
`Success`	`slack_target`, `slack_target_type`, `slack_target_id`, `slack_target_name`, `slack_target_query`	If the user target is selected successfully.
`Error`	-	If Slack is unavailable, the query is invalid, the search fails, or no match is selected.

select_channel_target

Select a Slack channel target through query filtering and final confirmation.

Workflow usage

- plugin: slack
  step: select_channel_target

Available to later steps: slack_target, slack_target_type, slack_target_id, slack_target_name, slack_target_query

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient.

Inputs (from ctx.data)

Name	Type	Description
`slack_target_query`	str, optional	Pre-filled query used to filter Slack channels.
`slack_search_limit`	int, optional	Maximum number of matches to return. Defaults to 20.
`slack_search_page_size`	int, optional	Page size used while scanning Slack channels. Defaults to 1000.
`slack_search_max_pages`	int, optional	Maximum pages to scan while searching. Defaults to 50.
`slack_exclude_archived`	bool, optional	Whether to exclude archived channels while searching. Defaults to True.

Outputs (saved to ctx.data)

Name	Type	Description
`slack_target`	UISlackTarget	Canonical selected Slack target.
`slack_target_type`	str	Selected target type (`channel`).
`slack_target_id`	str	Slack channel ID.
`slack_target_name`	str	User-facing target name.
`slack_target_query`	str	Query used to resolve the selection.

Returns

Result	Saved for later steps	Description
`Success`	`slack_target`, `slack_target_type`, `slack_target_id`, `slack_target_name`, `slack_target_query`	If the channel target is selected successfully.
`Error`	-	If Slack is unavailable, the query is invalid, the search fails, or no match is selected.

select_default_or_search_channel_target

Select Slack targets from a preferred value, configured defaults, or search.

Workflow usage

- plugin: slack
  step: select_default_or_search_channel_target

Used by built-in workflows: post-file, post-message

Available to later steps: slack_target, target was resolved viaslack_preferred_targetor manual search., slack_targets, that resolved successfully, when one or more configured default channels were, selected via the checklist., slack_conversation_ids, that resolved successfully, set together withslack_targets., slack_unresolved_channels, be resolved, set together withslack_targets. Empty when every checked channel, resolved.

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient.

Inputs (from ctx.data)

Name	Type	Description
`slack_preferred_target`	str, optional	Person or channel name (without `#`) to select
automatically without prompting, when it resolves to exactly one match. Takes priority	-	-
over configured default channels and manual search.	-	-
`slack_target_query`	str, optional	Pre-filled query used if the user falls back to search.
`slack_search_limit`	int, optional	Maximum number of matches to return during manual search. Defaults to 20.
`slack_search_page_size`	int, optional	Page size used while scanning Slack. Defaults to 1000.
`slack_search_max_pages`	int, optional	Maximum pages to scan while searching. Defaults to 50.
`slack_exclude_archived`	bool, optional	Whether to exclude archived channels while searching. Defaults to True.

Outputs (saved to ctx.data)

Name	Type	Description
`slack_target`	UISlackTarget, optional	Canonical selected Slack target, when exactly one
target was resolved via `slack_preferred_target` or manual search.	-	-
`slack_targets`	list[UISlackTarget], optional	Resolved targets for every checked channel
that resolved successfully, when one or more configured default channels were	-	-
selected via the checklist.	-	-
`slack_conversation_ids`	list[str], optional	Conversation IDs for every checked channel
that resolved successfully, set together with `slack_targets`.	-	-
`slack_unresolved_channels`	list[str], optional	Names of checked channels that could not
be resolved, set together with `slack_targets`. Empty when every checked channel	-	-
resolved.	-	-

Returns

Result	Saved for later steps	Description
`Success`	`slack_target`, `target was resolved via`slack_preferred_target`or manual search.`, `slack_targets`, `that resolved successfully, when one or more configured default channels were`, `selected via the checklist.`, `slack_conversation_ids`, `that resolved successfully, set together with`slack_targets`.`, `slack_unresolved_channels`, `be resolved, set together with`slack_targets`. Empty when every checked channel`, `resolved.`	If at least one selected target was resolved (channels that failed to resolve
`are skipped with a warning, the rest still get posted to).`	-	-
`Error`	-	If Slack is unavailable, or none of the selected channels could be resolved.

Messaging¶

prepare_message_destination

Prepare a Slack message destination from the selected target(s).

Workflow usage

- plugin: slack
  step: prepare_message_destination

Used by built-in workflows: post-file, post-message

Available to later steps: slack_conversation, conversation, when a singleslack_targetwas used., slack_conversation_id, operations, when a singleslack_targetwas used., slack_conversation_name, together withslack_conversation_id., slack_conversation_ids, slack_targets`, when multiple targets were used.`, `slack_conversation_names`,slack_conversation_ids, set together withslack_conversation_ids.

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient.

Inputs (from ctx.data)

Name	Type	Description
`slack_targets`	list[UISlackTarget], optional	Selected Slack channel targets, when
multiple channels were checked via a checklist (e.g.	-	-
`select_default_or_search_channel_target`). Takes priority over `slack_target`.	-	-
`slack_target`	UISlackTarget, optional	Selected Slack target. Must be a `user` or
`channel` target. Used when `slack_targets` is not set.	-	-

Outputs (saved to ctx.data)

Name	Type	Description
`slack_conversation`	UISlackConversation, optional	Resolved Slack destination
conversation, when a single `slack_target` was used.	-	-
`slack_conversation_id`	str, optional	Conversation or channel ID used for later message
operations, when a single `slack_target` was used.	-	-
`slack_conversation_name`	str, optional	User-facing name of the destination, set
together with `slack_conversation_id`.	-	-
`slack_conversation_ids`	list[str], optional	Conversation IDs for every channel in
`slack_targets`, when multiple targets were used.	-	-
`slack_conversation_names`	list[str], optional	User-facing names for every channel in
`slack_conversation_ids`, set together with `slack_conversation_ids`.	-	-

Returns

Result	Saved for later steps	Description
`Success`	`slack_conversation`, `conversation, when a single`slack_target`was used.`, `slack_conversation_id`, `operations, when a single`slack_target`was used.`, `slack_conversation_name`, `together with`slack_conversation_id`.`, `slack_conversation_ids`, slack_targets`, when multiple targets were used.`, `slack_conversation_names`,slack_conversation_ids`, set together with`slack_conversation_ids`.`	If the Slack message destination(s) are ready.
`Error`	-	If Slack is unavailable, no target is provided, or the Slack request fails.

open_direct_message

Open or reuse a direct message conversation for the selected Slack user target.

Workflow usage

- plugin: slack
  step: open_direct_message

Available to later steps: slack_conversation, slack_conversation_id

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient.

Inputs (from ctx.data)

Name	Type	Description
`slack_target`	UISlackTarget	Selected Slack target. Must be a `user` target.

Outputs (saved to ctx.data)

Name	Type	Description
`slack_conversation`	UISlackConversation	Opened or reused Slack conversation.
`slack_conversation_id`	str	Conversation ID used for later message operations.

Returns

Result	Saved for later steps	Description
`Success`	`slack_conversation`, `slack_conversation_id`	If the direct message conversation is ready.
`Error`	-	If Slack is unavailable, the target is missing or invalid, or the Slack request fails.

prompt_message_body

Capture a multiline Slack message for later formatting and posting.

Workflow usage

- plugin: slack
  step: prompt_message_body

Used by built-in workflows: post-message

Available to later steps: slack_message_markdown

Inputs (from ctx.data)

Name	Type	Description
`slack_message_text`	str, optional	Already Slack-ready message text. If present, the prompt is skipped.
`slack_message_markdown`	str, optional	Standard Markdown message already provided by a caller. If
present (and slack_message_text isn't), the prompt is skipped.	-	-

Outputs (saved to ctx.data)

Name	Type	Description
`slack_message_markdown`	str	Captured message text, to be converted to Slack mrkdwn by a later step.

Returns

Result	Saved for later steps	Description
`Success`	`slack_message_markdown`	If the message body is captured successfully.
`Skip`	`slack_message_markdown`	If a message was already provided by the caller.
`Error`	-	If the user cancels or the message body is empty.

format_markdown_message

Convert a standard Markdown message into Slack mrkdwn, if provided.

Workflow usage

- plugin: slack
  step: format_markdown_message

Used by built-in workflows: post-file, post-message

Available to later steps: slack_message_text

Inputs (from ctx.data)

Name	Type	Description
`slack_message_text`	str, optional	Already Slack-ready text. If present, this step does
nothing and leaves it untouched.	-	-
`slack_message_markdown`	str, optional	Standard Markdown text to convert to Slack mrkdwn.
Ignored when `slack_message_text` is already present.	-	-

Outputs (saved to ctx.data)

Name	Type	Description
`slack_message_text`	str	Slack mrkdwn-ready message text, when `slack_message_markdown` was converted.

Returns

Result	Saved for later steps	Description
`Skip`	`slack_message_text`	If `slack_message_text` is already set, or neither input is provided (a later step
`can still prompt the user to compose one interactively).`	-	-
`Success`	`slack_message_text`	If `slack_message_markdown` was converted successfully.
`Error`	-	If the Textual UI context is not available.

post_message

Post a plain-text Slack message to the prepared conversation(s).

Workflow usage

- plugin: slack
  step: post_message

Used by built-in workflows: post-message

Available to later steps: slack_message, single conversation was used., slack_message_ts, conversation was used., slack_message_channel, conversation was used., slack_messages, conversation that succeeded, when multiple conversations were used., slack_message_channels, posted to, when multiple conversations were used.

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient.

Inputs (from ctx.data)

Name	Type	Description
`slack_conversation_ids`	list[str], optional	Slack conversation IDs to post into. Takes
priority over `slack_conversation_id` when set.	-	-
`slack_conversation_id`	str, optional	Single Slack conversation ID to post into. Used
when `slack_conversation_ids` is not set.	-	-
`slack_message_text`	str	Message body to post.
`slack_thread_ts`	str, optional	Thread timestamp for replies. Only applied when posting
to a single conversation.	-	-

Outputs (saved to ctx.data)

Name	Type	Description
`slack_message`	UISlackPostedMessage, optional	Posted Slack message metadata, when a
single conversation was used.	-	-
`slack_message_ts`	str, optional	Timestamp of the posted message, when a single
conversation was used.	-	-
`slack_message_channel`	str, optional	Channel the message was posted to, when a single
conversation was used.	-	-
`slack_messages`	list[UISlackPostedMessage], optional	Posted message metadata for every
conversation that succeeded, when multiple conversations were used.	-	-
`slack_message_channels`	list[str], optional	Channels the message was successfully
posted to, when multiple conversations were used.	-	-

Returns

Result	Saved for later steps	Description
`Success`	`slack_message`, `single conversation was used.`, `slack_message_ts`, `conversation was used.`, `slack_message_channel`, `conversation was used.`, `slack_messages`, `conversation that succeeded, when multiple conversations were used.`, `slack_message_channels`, `posted to, when multiple conversations were used.`	If the Slack message is posted to at least one conversation.
`Error`	-	If Slack is unavailable, required context is missing, or every post fails.

upload_file

Upload a local file to the prepared Slack conversation(s), with an optional message above it.

Workflow usage

- plugin: slack
  step: upload_file

Used by built-in workflows: post-file

Available to later steps: slack_uploaded_file, slack_uploaded_files

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient with the `files:write` scope.

Inputs (from ctx.data)

Name	Type	Description
`slack_file_path`	str	Local path of the file to upload.
`slack_file_title`	str, optional	Title shown on the Slack file. Defaults to the file name.
`slack_message_text`	str, optional	Slack-ready text posted as the message above the file.
`slack_conversation_ids`	list[str], optional	Conversation IDs to upload into; wins over `slack_conversation_id`.
`slack_conversation_id`	str, optional	Single conversation ID, used when `slack_conversation_ids` is not set.
`slack_thread_ts`	str, optional	Thread timestamp to share the file into; single conversation only.

Outputs (saved to ctx.data)

Name	Type	Description
`slack_uploaded_file`	UISlackUploadedFile, optional	Uploaded file metadata, single conversation case.
`slack_uploaded_files`	list[UISlackUploadedFile], optional	Uploaded file metadata per successful conversation.

Returns

Result	Saved for later steps	Description
`Success`	`slack_uploaded_file`, `slack_uploaded_files`	If the file is uploaded to at least one conversation.
`Error`	-	If Slack is unavailable, the file is missing, or every upload fails.

Conversation Summaries¶

select_target

Search both Slack users and channels for a single unified target selection.

Workflow usage

- plugin: slack
  step: select_target

Used by built-in workflows: summarize-slack-target

Available to later steps: slack_target, slack_target_type, slack_target_id, slack_target_name, slack_target_query

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient.

Inputs (from ctx.data)

Name	Type	Description
`slack_target_query`	str, optional	Query used to search both users and channels.
`slack_search_limit`	int, optional	Maximum number of matches to keep from each search. Defaults to 10.
`slack_search_page_size`	int, optional	Page size used while scanning Slack. Defaults to 1000.
`slack_search_max_pages`	int, optional	Maximum pages to scan while searching. Defaults to 50.
`slack_exclude_archived`	bool, optional	Whether to exclude archived channels. Defaults to True.

Outputs (saved to ctx.data)

Name	Type	Description
`slack_target`	UISlackTarget	Canonical selected Slack target.
`slack_target_type`	str	Selected target type (`user` or `channel`).
`slack_target_id`	str	Slack target identifier.
`slack_target_name`	str	User-facing target name.
`slack_target_query`	str	Query used to resolve the selection.

Returns

Result	Saved for later steps	Description
`Success`	`slack_target`, `slack_target_type`, `slack_target_id`, `slack_target_name`, `slack_target_query`	If the unified target is selected successfully.
`Error`	-	If Slack is unavailable, the query is invalid, the search fails, or no match is selected.

ensure_target_conversation

Resolve a Slack conversation from the selected target.

Workflow usage

- plugin: slack
  step: ensure_target_conversation

Used by built-in workflows: summarize-slack-target

Available to later steps: slack_conversation, slack_conversation_id

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient.

Inputs (from ctx.data)

Name	Type	Description
`slack_target`	UISlackTarget	Selected Slack target.

Outputs (saved to ctx.data)

Name	Type	Description
`slack_conversation`	UISlackConversation	Resolved Slack conversation.
`slack_conversation_id`	str	Conversation ID used for later operations.

Returns

Result	Saved for later steps	Description
`Success`	`slack_conversation`, `slack_conversation_id`	If the target conversation is resolved successfully.
`Error`	-	If Slack is unavailable, the target is missing, or the Slack request fails.

read_recent_messages

Read the most recent messages from the resolved Slack conversation.

Workflow usage

- plugin: slack
  step: read_recent_messages

Used by built-in workflows: summarize-slack-target

Available to later steps: slack_messages, slack_user_display_names, slack_channel_display_names, slack_messages_next_cursor, slack_messages_has_more

Requires

Name	Type	Description
`ctx.slack`	-	An initialized SlackClient.

Inputs (from ctx.data)

Name	Type	Description
`slack_conversation_id`	str	Slack conversation ID to read.
`slack_history_limit`	int, optional	Number of recent messages to fetch. Defaults to 30.

Outputs (saved to ctx.data)

Name	Type	Description
`slack_messages`	list[UISlackMessage]	Retrieved Slack messages.
`slack_user_display_names`	dict[str, str]	Resolved Slack user display names keyed by user ID.
`slack_channel_display_names`	dict[str, str]	Resolved Slack channel names keyed by channel ID.
`slack_messages_next_cursor`	str \| None	Pagination cursor for later reads.
`slack_messages_has_more`	bool	Whether more messages are available.

Returns

Result	Saved for later steps	Description
`Success`	`slack_messages`, `slack_user_display_names`, `slack_channel_display_names`, `slack_messages_next_cursor`, `slack_messages_has_more`	If recent messages are retrieved successfully.
`Error`	-	If Slack is unavailable, required context is missing, or the Slack request fails.

ai_summarize_messages

Summarize recent Slack messages with AI.

Workflow usage

- plugin: slack
  step: ai_summarize_messages

Used by built-in workflows: summarize-slack-target

Available to later steps: slack_summary, slack_summary_source_count, slack_summary_transcript_chars

Requires

Name	Type	Description
`ctx.textual`	-	Textual UI context.

Inputs (from ctx.data)

Name	Type	Description
`slack_messages`	list[UISlackMessage]	Messages to summarize.
`slack_target_name`	str, optional	Human-facing target label for the summary.
`slack_summary_max_chars`	int, optional	Maximum transcript size passed to AI. Defaults to 12000.

Outputs (saved to ctx.data)

Name	Type	Description
`slack_summary`	str	AI-generated Slack summary.
`slack_summary_source_count`	int	Number of source messages summarized.
`slack_summary_transcript_chars`	int	Transcript size sent to AI after truncation.

Returns

Result	Saved for later steps	Description
`Success`	`slack_summary`, `slack_summary_source_count`, `slack_summary_transcript_chars`	If the summary is generated successfully.
`Skip`	`slack_summary`, `slack_summary_source_count`, `slack_summary_transcript_chars`	If AI is not configured or not available.
`Error`	-	If messages are missing or the AI request fails.