If you’ve ever scrolled through a fast-moving Slack thread thinking “there were at least three action items in here… somewhere,” you’re not alone. Chat is great for velocity, terrible for accountability. The fix isn’t “tell people to be more disciplined,” it’s making the jump from conversation to task frictionless. That’s exactly what Slack and Trello integration delivers: turn any Slack message into a Trello card in seconds, without leaving the conversation, so you stop losing work to the scroll and start shipping reliably.
This guide shows you exactly how to do that, with a pragmatic setup, a few habits that stick, and optional automation for teams that love going from good to great.
What You’ll Need
Before you dive into settings, make sure you’ve got the basics lined up so setup takes minutes, not hours:
- A Slack workspace where you can install apps (or an admin who can).
- A Trello account and at least one board per team or project.
- The official Trello app for Slack (from Slack’s App Directory).
- Optional but helpful: admin access for workspace-wide defaults and governance.
Keep your Trello board(s) ready and decide which Slack channels will feed which Trello lists. That little decision upfront saves a lot of back-and-forth later.
Quick Start: Install & Connect Trello to Slack
- Install the Trello app in Slack: open Slack → Apps → “Trello” → Add.
- Connect your Trello account: you’ll be prompted to authorize Slack to access Trello.
- Pick defaults (you can change later): default board, default list, and notification preferences.
- Verify: type /trello in any channel or DM to see the help panel. If it responds, you’re good.
A pro tip: create a dedicated #trello-updates channel to aggregate bot notices so your working channels stay focused on discussion.
Core Workflow: Turn a Message into a Trello Card
Before you start creating cards, think of this as a two-step reflex: spot an action item → capture it instantly. The goal is zero context-switching—use the fastest method available where you’re already working, then enrich the card only if needed. Here are three ways to do it, from ultra-quick to more structured.
- Message Actions (the fastest way)
- Hover any message → click More actions (⋯) → Create a Trello card.
- Pick the Board and List, set Title, Description (Slack quotes the original message), Assignee(s), Due date, and Labels.
- Hit Create. Slack drops a confirmation with a link to the card; the card includes a permalink back to the message for context.
This is the 5-second habit that changes everything capture while the context is hot.
- Slash Commands (for power users)
Create a card quickly:
/trello add “Draft v2 pricing one-pager” on “Marketing Ops” > “Triage” due 10/30 @alex
Add more detail with a description and a Slack link:
/trello add “Customer story: March draft” desc “From #content thread: <https://…>” on “Editorial” > “Backlog” @sam
Slash commands are great in standups or DMs no hunting for the original message.
- App Shortcuts (channel-level)
Open Shortcuts (lightning bolt in the composer) → Create a Trello card. Use this when summarizing outcomes (e.g., end of a huddle or after a decision in #product).
Best Practices for Clean, Actionable Cards
Titles that work. Use verb + object + context:
- “Ship v1 landing page (US campaign)”
- “Fix 404 on pricing → redirect to /plans”
- “Interview 3 customers about onboarding friction”
Descriptions that clarify. Paste the Slack permalink at the top, then bullet out acceptance criteria, e.g.:
- Link: https://slack.com/archives/…/p169…
- Done when:
- CTA copies match brief v3
- Mobile hero renders <2.0s LCP
- Page tracked in GA4 (event: lp_us_launch_view)
Labels & assignees. Decide team-wide conventions (e.g., “Campaign,” “Bug,” “Design”). Avoid unassigned cards no owner, no progress.
Due dates that reflect reality. Timebox to avoid backlog creep. If the work depends on another card, note the dependency in the description or Trello’s “Dependencies” Power-Up.
Recommended Channel & Board Architecture
Map your chat to your boards so people always know where tasks will land.
| Slack Channel | Trello Board | Notes |
| #marketing | Marketing Ops | Default list: Triage for Slack-captured items |
| #support | Customer Issues | Auto-labels: “Bug,” “Customer Impact” |
| #product | Product Roadmap | Use “Next Up” for cards ready post-discussion |
| #engineering | Sprint Board | “Ready for Dev” gets cards with clear acceptance criteria |
Pin a short guide in each channel: “When to create a card vs. continue the thread,” plus the default board/list.
Automations that Save Time
You don’t need to automate everything just the parts that add reliable speed. A few high-leverage rules:
- Auto-route triage. When a card is added to “Triage” with label “SEO,” move it to “Backlog” and assign @alex.
- Assign by keyword. When a card contains “Stripe,” add label “Payments” and assign @fin-eng.
- Daily digest to Slack. Each morning at 9 a.m., post in #project-daily:
- Cards due today
- Overdue cards by list
- New cards added to “Triage” in last 24h
- Emoji to complete. When someone reacts with ✅ to a Slack confirmation message, mark the linked card as Done (via Butler + webhook or a lightweight custom app).
These small automations remove babysitting and let the board “nudge” the team at the right moments.
Role-Based Examples (Mini Playbooks)
Marketing. When feedback pours into #campaign-launch, capture decisions as cards: “Update CTA on hero,” label “Campaign: Q4,” due Friday. Use a Butler rule to auto-assign design vs. copy based on label.
Product/Design. During a Slack huddle, a note-taker uses the shortcut to create one card per decision with a checklist: “Review states,” “QA on responsive,” “A11y pass.”
Support/Ops. A hot incident hits #support-alerts. Use message action → “Create Trello card,” auto-label “P1,” assign on-call, and add an SLA due time. The Slack confirmation embeds back in the incident thread.
Governance, Privacy, and Access
Strong hygiene prevents chaos at scale.
- Who can create cards? Encourage everyone to capture; empower a few owners to groom “Triage.”
- Private channels ↔ private boards. If the conversation is sensitive (HR, finance), route to a private board with restricted membership.
- Token hygiene. Connect Trello with a service account, not a single employee’s personal account. Rotate API keys on a schedule and maintain an owner’s playbook with scopes and audit links.
- Board conventions. Standardize list names (“Triage,” “In Progress,” “Review,” “Done”), label palettes, and card templates. Pin these in the board description.
Troubleshooting & Noise Control
Most snags fall into two buckets: permissions and notification overload.
Common fixes
- “Create card” not visible. Ensure the Trello app is installed in that workspace and the user has access to the target board. Private boards require explicit membership.
- Wrong board/list. Set or reset the default board/list with /trello in the channel where people work.
- Cards missing Slack links. Train folks to use message actions (which auto-quote) or paste the permalink in the description.
Taming the noise
- Route high-volume updates (list moves, comment storms) to #trello-updates.
- Keep only signal in work channels: due date changes, assignments, and new card creation.
- Encourage “digest over drip.” One daily summary beats 20 event pings.
Measuring Impact
You can’t improve what you don’t measure. Run a two-week baseline, then a two-week post-adoption comparison.
Helpful KPIs
- Message-to-task conversion rate. (# cards created from Slack / # messages tagged “action/decision”)
- Time-to-capture. Average minutes from message posted → card created.
- % unassigned cards. Lower is better; aim <10%.
- Cycle time. “Triage” → “Done” median days.
Share the results in a short Slack post. Nothing sells a habit like proof that it saves time and missed work.
Advanced: Custom App
For teams that want an extra edge or have unique workflows, building a small custom app is worth it. This is often where a specialist partner Fivewalls comes in: they design and implement tailored Slack apps that talk to Trello (and your other systems), so your “create-a-card” flow matches your exact process not the other way around.
What a custom app can do
- Enriched card creation. A custom message action parses @mentions into Trello members, dates into due dates, URLs into attachments, and compiles a “thread summary” (first message + most reacted reply) into the card description.
- Approvals in Slack. Add a “Submit for Review” button under the Slack confirmation; clicking moves the Trello card to “Review,” @mentions the reviewer, and logs the action.
- Emoji automations. Map common emoji to card actions: 🧪 adds a “QA” checklist; 📌 pins the card to a “Priority” list; 🏁 moves to “Ready for Release.”
- Multi-system handoffs. Kick off a Trello card and create a matching ticket in another system (e.g., Jira or your CRM) while keeping a single Slack thread as the source of truth.
Why bring in Fivewalls
- Domain expertise. They focus on Slack-first workflows and know where native integrations fall short and how to fill the gaps without adding noise.
- Security & scale. Proper scopes, token vaulting, and audit trails matter. Fivewalls builds with least privilege, clean logging, and clear ownership so IT is comfortable from day one.
- Future-proofing. They design for change: feature flags, config via Slack commands, and modular connectors if you later swap tools.
You can prototype with Slack’s Bolt framework and Trello’s REST API over a weekend; productionize with Fivewalls when you’re ready for hardened security, governance, and features that go beyond what off-the-shelf integrations can do.
Rollout Plan & Enablement
Don’t flip the switch everywhere; pilot it where the pain is highest.
- Pick one channel (e.g., #product), one board, and appoint a “triage owner.”
- Publish conventions: when to create a card, naming pattern, default list, label palette.
- Run a 30-minute training: demo message action, one useful slash command, and how to grab a Slack permalink. Share a one-page cheat sheet.
- Hold a “cleanup Friday.” Groom the “Triage” list weekly; archive duplicates, clarify vague titles, and assign owners.
- Expand to #marketing or #support once the first team is humming.
Small, visible wins build momentum and reduce resistance to change.
Conclusion
Turning Slack messages into Trello cards isn’t about adding another tool it’s about closing the gap between conversation and commitment. When capture takes seconds, titles are clear, and your board nudges you at the right times, teams follow through more, meet deadlines more often, and spend fewer cycles re-asking “who’s doing what by when?”
Start with the basics: install the Trello app, use message actions religiously, and create a “Triage” list. Layer in a couple of Butler rules and a daily digest when you’re ready. If your workflow includes approvals, structured summaries, or specific parsing needs, a small custom app can make the experience feel tailor-made.
Less context switching. Clearer ownership. Faster outcomes. That’s the promise and with a few disciplined habits, it’s also your new normal.