Slack Thread to Backlog Issues with Claude Haiku 4.5 (n8n)

Turn Slack thread decisions into Nulab Backlog issues automatically

This n8n workflow watches for Slack app mentions inside a Slack thread, extracts the agreed tasks with Anthropic Claude Haiku 4.5, validates assignees and due dates, then creates matching Nulab Backlog issues—and posts the results back to the same Slack thread.

What this workflow does

• Triggers on Slack app mentions in threads: Listens for app_mention events, ensures the user is on an allowed list, and confirms the mention is posted within a thread.
• Builds a complete thread transcript: Pulls the full thread replies and resolves Slack user profiles to map user IDs to display names.
• Fetches Backlog context for validation: Retrieves the target Nulab Backlog project details (members, issue types, priorities) and recent issues to support deduplication.
• Extracts tasks using Claude Haiku 4.5: Sends the formatted thread transcript to Claude to extract a JSON list of agreed tasks, including exact quoted text, suggested titles, optional assignee wording, and optional due-date wording.
• Validates and normalizes data: Matches extracted quotes back to the original message text, maps assignees to exactly one Backlog member, and converts relative due-date phrases into an absolute due date based on the Slack message date.
• Avoids duplicates and reports back: Skips tasks that already have a Backlog issue created from the same Slack message, creates the remaining issues, and replies once in the original Slack thread with issue links plus any warnings.

Use cases

• Project teams agree on action items in Slack—automatically create the corresponding Nulab Backlog issues.
• Reduce manual work by turning “we’ll do X by next Tuesday” decisions into validated backlog items.
• Ensure ownership and due dates are consistent by mapping assignees to Backlog members.

Technical details

• Integrations: Slack, Nulab Backlog (Backlog API), Anthropic Claude Haiku 4.5.
• n8n nodes/logic: if, set, code, Slack, sticky note, and HTTP Request.
• Key behavior: Thread-only processing, quote matching for task verification, relative-to-absolute due date conversion, and deduplication before issue creation.