Slack
TAS Score: S0/3 — D1/5 — A0 / T0 S0 not S3: cannot pause without losing workspace access (Q1); exit loses message history, integrations, and channel structure (Q2); no self-recovery — depends on Salesforce/Slack infrastructure (Q3). D1 not D5: builds usage profiles and analytics on team behaviour (Q4); notification design creates urgency (Q5); free tier limits message history to 90 days — you pay with data loss (Q6); closed platform, no audit possible (Q7). D1 for trajectory only: acquired by Salesforce, enterprise features growing (Q8).
Brief Description
Cloud-based team messaging platform. Channels, threads, integrations, file sharing. Free tier with 90-day message history limit. Owned by Salesforce since 2021.
Architectural Role
Communication layer: team messaging, integrations hub, notification system. Central to many organisations’ daily workflows.
Technical Autonomy
- Works without internet
- Stores data locally
- Does not require external accounts — requires Slack account
- Allows data export — workspace export available for admins (JSON format); free tier limited; DMs require Corporate Export (paid)
- Provides offline updates
Philosophical Assessment (whose.world criteria)
| Criterion | Status | Comments |
|---|---|---|
| Pause | ❌ | Pausing means losing access to all channels and history. No clean pause. |
| Exit | ❌ | Export is JSON — not importable to alternatives. Integrations, bots, and workflows do not transfer. Channel structure and context lost. |
| Recoverability | ❌ | No local backup. If Slack suspends workspace or changes terms, no self-recovery. |
| Visibility | ❌ | Closed source. No visibility into data processing or retention beyond stated policies. |
| External Dependencies | ❌ | Fully dependent on Slack/Salesforce infrastructure. |
Rating key: ✅ fully meets · ⚠️ partially meets or requires configuration · ❌ does not meet
Why it’s in the catalog
Slack is the de facto standard for team communication — and a textbook example of convenience lock-in. The more integrations you build, the harder it becomes to leave. The 90-day message history limit on free tier means your team’s knowledge disappears unless you pay. Export format (JSON) is not importable anywhere else.
Autonomous Alternatives
- Matrix/Element (A3/T2) — federated, E2EE, selfhosted, open protocol
- Mattermost (A3/T2) — Slack-like UI, selfhosted, open source
Alternatives
| Alternative | Autonomy | Notes |
|---|---|---|
| Matrix/Element | A3 / T2 | Federated protocol, E2EE, selfhosted server, different UX |
| Mattermost | A3 / T2 | Closest Slack alternative in UX, selfhosted, MIT (community) |
| Telegram | A1 / T0 | Easier UX, partially open client, server is proprietary |
Trajectory
Direction: closing
Acquired by Salesforce in 2021. Enterprise features expanding. Free tier increasingly limited (90-day history introduced 2022). Pricing increases. Deeper Salesforce integration. The trend is toward enterprise monetization, not user independence.
Signal assessment:
| Signal | Status | Evidence |
|---|---|---|
| License | ⚠️ | Proprietary. No change. |
| Feature gating | ⚠️ | 90-day history limit on free. DM export requires Corporate plan. Enterprise features growing. |
| Self-hosting | ⚠️ | No self-hosting option. Never offered. |
| Governance | ⚠️ | Salesforce subsidiary. Decisions driven by enterprise revenue. |
Signal key: ✅ opening · ➖ neutral · ⚠️ closing
Sources
- Website: https://slack.com
- Documentation: https://api.slack.com
- Repository: -
- Docker image: -
- Community: -