How Enterprises Test Third-Party App Compatibility in Slack

Deploying untested third-party apps in Slack can lead to security risks, workflow disruptions, and data vulnerabilities - especially for large enterprises. This guide outlines practical steps to test app compatibility, ensuring secure and reliable integrations within Slack environments. Here's a quick overview of what you'll need to focus on:

• Risk Assessment: Categorize app permissions (OAuth scopes) into low, medium, and high-risk levels to prioritize testing.

• Sandbox Testing: Use Slack's developer sandboxes to safely test apps in a controlled environment that mimics your production setup.

• Key Testing Areas: Verify functionality, security, scalability, and compliance to ensure apps meet enterprise standards.

• Security Best Practices: Limit permissions, validate request authenticity, and safeguard data against risks like prompt injection.

• User Testing: Simulate real-world usage with admin and non-admin roles to catch potential issues early.

Planning Your Compatibility Testing Strategy

Slack App Permission Scope Risk Levels and Approval Requirements

A strong testing strategy is essential for seamless app integration, especially when dealing with third-party apps. Before installing any app, create a plan that balances functionality, security, and compliance. This plan should focus on identifying potential risks and ensuring the app operates safely within your Slack environment.

The first step is to categorize apps by their risk level. According to Slack's security guidance, OAuth scopes can be grouped into three tiers: "Always Allowed" for low-risk permissions like commands or chat:write, "Requires Approval" for medium-risk scopes such as users:read or channels:history, and "Restricted" for high-risk permissions like admin.* scopes [5]. This classification helps prioritize testing efforts, ensuring apps with sensitive permissions undergo thorough evaluation.

"Every app should only have the minimum permissions (scopes) necessary to perform its function." - Slack Security Guide [5]

Once the risk levels are defined, establish clear objectives to address potential vulnerabilities.

Setting Clear Testing Objectives

Your testing objectives should target four key areas: functionality, security, scalability, and compliance. Start by ensuring the app performs its intended tasks without disrupting workflows. On the security side, confirm that the app uses Transport Layer Security (TLS) for all traffic and employs request signing to verify that payloads originate from Slack [5].

For enterprises using Enterprise Grid, testing should confirm that the app supports "Organization-ready deployment", allowing it to function seamlessly across multiple workspaces and Slack Connect channels [1]. If the app incorporates generative AI, include checks to ensure Slack data isn’t used to train Large Language Models and that safeguards are in place against prompt injection and data exfiltration [1]. Additionally, confirm that OAuth token exchanges are completed securely within the 10-minute expiration window [8].

Reviewing Third-Party App Requirements

Once objectives are defined, review the app’s specific requirements to ensure compliance and security, particularly for knowledge management integrations for Slack. Examine the app’s manifest and its Security & Compliance tab to verify permissions, data handling, and retention practices [1][5].

When evaluating AI Slack tools for knowledge retrieval, check whether the vendor discloses details about the Large Language Model (LLM) used, where data is stored, and whether link unfurling is enabled by default - a feature that could expose your organization to data exfiltration risks [5]. Your team should also evaluate the app’s infrastructure, including any web servers or databases that interact with Slack.

To maintain control over your Slack environment, enable the "Require App Approval" setting. This ensures that no app bypasses your testing process, giving IT and security teams the authority to review and approve all integrations before they are deployed in production [5].

Building Test Environments

Once you've outlined your objectives and reviewed the requirements, the next step is setting up a secure environment to test third-party apps without interfering with your production Slack workspace. This is particularly important when you plan to build custom Slack workflows that automate complex enterprise tasks. Many enterprises rely on dedicated sandbox environments that replicate their live setup. These environments allow IT teams to assess functionality, security, and compliance before deploying apps to thousands of users.

Creating Separate Workspaces for Testing

Slack's Developer Program offers Enterprise Grid sandboxes that mimic production environments. These sandboxes let you create up to three workspaces and include up to eight users per sandbox. This controlled setup ensures you can safely test apps without risking disruptions to live operations [2][9]. Each organization can maintain up to two active sandboxes, with a default duration of six months, extendable for active program participants [2][9].

However, it’s important to note that developer sandboxes only retain messages and files for three days. This limitation makes them unsuitable for storing real data [2][9]. To ensure your testing environment closely resembles your production workspace, use the "Manage Workspaces" tool within the sandbox admin panel. This tool allows you to create subdomains that mirror your production structure, giving you a realistic view of how apps will function across teams or departments [2].

For organizations that rely on single sign-on (SSO), authentication testing is a key focus. Slack provides a mock Identity Provider called "Simple IdP", which supports SAML SSO testing and user account management within the sandbox. To use it effectively, install Simple IdP at the organization level rather than the workspace level. This allows you to validate user provisioning and SSO-related app behaviors in the sandbox before moving to production [2][9].

With your test workspaces in place, the next step is configuring admin settings to mirror your production environment.

Configuring Admin Settings

Once the test workspaces are set up, it's essential to adjust admin settings to emulate your production environment. Proper configuration ensures the sandbox accurately predicts how apps will behave post-deployment.

Start by enabling "Require App Approval" in the test workspace’s App Management Settings [11]. This replicates the governance process your organization uses in production, allowing you to test the submission, review, and approval workflow before apps reach end users.

Next, organize app scopes into categories such as "Always allowed", "Requires approval", and "Restricted." This step ensures that the permission policies in your production environment will function as intended [11]. Use the Slack CLI to audit collaborators and permission scopes for all installed apps, identifying any potential security risks before moving to production [11]. If your production setup limits OAuth token usage to specific IP ranges, configure the same "Allowed IP Address Ranges" in your test environment. Slack allows up to 10 IP address range entries, ensuring compatibility during testing [11].

For Enterprise Grid organizations, it’s important to determine whether apps should be installed at the organization level or within individual workspaces. Organization-level apps use a single token across multiple workspaces but must be explicitly added to each workspace via the admin dashboard or API [10]. To streamline this process, you can automate configurations across environments using the slack deploy command in your CI/CD pipeline. This command ensures consistent updates to app settings and manifests across development, staging, and production environments [4].

Running Compatibility Tests

Ensuring third-party apps perform well in controlled scenarios is a critical step before deploying them across your organization. This process involves testing key functionalities, verifying security measures, and gathering feedback from real users to catch potential issues early.

Functional Testing

Start by evaluating the app's core features, such as shortcuts, slash commands, and the App Home tab. Each element should meet performance benchmarks, like responding within 3,000ms, and function as intended. For instance, slash commands must have unique names to avoid conflicts and should provide clear usage instructions when users type "help." Using ephemeral messages for these responses minimizes unnecessary clutter in Slack channels [1].

The App Home tab is another critical area. It should display relevant content for both authorized and unauthorized users and include accessible settings and support information. Notifications sent by the app should be actionable and context-aware, avoiding default posts to #general or the use of @channel/@everyone unless absolutely necessary [1].

Additionally, confirm that access tokens are generated and stored securely for each workspace and user. URLs for OAuth redirects, interaction payloads, and Events API requests must support SSL. Tools like Qualys SSL Labs can help verify your app’s cryptographic standards [5][12]. Below is a quick checklist for functional testing:

Security and Compliance Checks

Security testing ensures the app adheres to the Principle of Least Privilege, requesting only the permissions necessary to function. Scopes should be categorized by risk: low-risk scopes like commands can be auto-approved, while higher-risk scopes like users:read or admin-level permissions require manual review [5].

Regularly audit installed apps and their permission scopes using the Slack CLI. This helps identify outdated apps or those with unnecessary access. Ensure the app validates incoming requests using Slack's signing secrets and that tokens are securely stored and transmitted via TLS-encrypted POST requests [5][3].

For apps leveraging AI or large language models (LLMs), additional precautions are necessary. Protections against prompt injection and data leaks should be in place, and link unfurling should be disabled by default to avoid accidental data exposure. Review the app’s "Security & Compliance" tab in the Slack Marketplace to understand its policies on data retention, residency, and deletion [3].

Testing should mirror your organization’s governance settings. For instance, if API calls are restricted to specific IP ranges, configure these in the test environment as well. Slack allows up to 10 IP address range entries for such restrictions [5].

When evaluating AI-driven tools, prioritize those that provide verified, reliable information. For example, Question Base integrates directly with trusted sources like Notion, Confluence, Salesforce, and Google Drive, offering expert-approved answers rather than speculative AI interpretations. This makes it ideal for teams managing critical knowledge areas, such as HR or IT support. Question Base also offers features like case tracking, duplicate detection, channel-specific settings, and analytics on resolution rates, along with SOC 2 Type II compliance and optional on-premise deployment for strict data residency requirements.

Once security measures are confirmed, proceed to real-user testing to evaluate the app under typical conditions.

User Acceptance Testing (UAT)

User acceptance testing ensures the app meets real-world expectations in live Slack environments. During this phase, test the app separately for admin and non-admin roles to confirm consistent functionality [6]. The "first-run" experience is particularly important - users should be guided with clear next steps to avoid confusion post-installation [1].

Preloading sample data can improve the testing process by allowing participants to focus on usability rather than setup. Simulate errors during UAT to ensure error messages are clear and actionable. Avoid "one-way doors" in the app interface by ensuring users can always go back or cancel actions without getting stuck [1].

If your organization uses Slack Connect, include tests in shared channels to check how the app handles interactions across different organizations. Note that developer sandboxes retain messages and files for only three days, so inform UAT participants of this limitation upfront [2].

Finally, verify the app’s support channels during UAT. Marketplace apps are expected to respond to support requests within two business days, so ensure your team knows how to escalate issues if needed [1]. For early UAT phases, use slack run for real-time code adjustments, but switch to slack deploy for final acceptance testing to replicate the production environment [8].

Monitoring and Ongoing Improvements

Once compatibility tests are complete, keeping an eye on performance and security is essential to ensure everything runs smoothly post-deployment. Without consistent monitoring, problems like security gaps, performance dips, or compatibility issues might go unnoticed until they disrupt your operations.

Tracking App Performance Metrics

Begin by creating a centralized view of all installed apps. The Slack Enterprise Grid admin dashboard is a great tool for this, allowing you to monitor apps that are requested, approved, and restricted across your organization [7]. This centralized oversight makes it easier to identify which apps are actively used and which ones might need a second look.

For more detailed data, consider using continuous monitoring platforms like Testable. These tools can send custom alerts for specific test milestones and store test results for up to a year, helping you identify patterns or recurring issues [13]. If your app handles sensitive information, tools like Metomic can provide real-time monitoring of Slack channels, flagging potential security incidents, data leaks, or unauthorized sharing of confidential data [14].

To stay ahead of changes, track uninstall events by subscribing to the app_uninstalled event in your app's configuration. This feature instantly notifies you when an app is removed, enabling you to investigate whether it was due to compatibility problems, poor user experience, or shifting business priorities [4]. Additionally, regularly check the Security & Compliance tab in the Slack App Directory. This section is updated by developers to reflect changes in compliance standards like SOC or HIPAA, as well as data retention and residency policies [3].

For apps designed to support internal knowledge sharing, such as Question Base, built-in analytics can provide valuable insights. These metrics track automation rates, resolution times, and knowledge gaps, helping you measure how well the app reduces support workload. Question Base stands out with features tailored for enterprise support teams, including case tracking, duplicate detection, and channel-specific settings. It also maintains SOC 2 Type II compliance and offers optional on-premise deployment, ensuring high-security standards.

While monitoring offers real-time feedback, periodic retesting is key to maintaining long-term compatibility and security.

Regular Testing and Updates

Initial testing is just the beginning. To ensure an app remains reliable as enterprise needs evolve, periodic retesting and updates are crucial. Use Slack Developer Program sandboxes to test updates in a controlled environment before applying them in production [2].

For apps listed in the Slack Marketplace, any changes to configurations - such as new scopes, endpoint updates, or added AI features - require resubmission for review [3]. For custom or internal apps, the Slack CLI with the slack deploy command simplifies the process by automatically checking your manifest.json file for changes. If updates involve permissions, event subscriptions, or key capabilities, existing users will receive a reinstall prompt [4].

Incorporate automated audits into your CI/CD pipeline to revalidate permissions and app configurations with every update [11][15]. Create a scope policy framework to categorize permissions into three levels: "Always allowed" (low-risk, like commands), "Requires approval" (medium-risk, like users:read), and "Restricted" (high-risk or admin-level permissions). This framework streamlines the review process when apps request additional permissions during updates [11]. For apps using AI or large language models, disable link unfurling in chat.postMessage calls to prevent data exfiltration through prompt injection [11].

Lastly, ensure that developer support SLAs are being met. Developers in the Slack Marketplace are required to respond to support requests within two business days. The Marketplace team conducts regular audits to verify that apps meet functional and security standards [1][3]. If an app repeatedly fails to meet these benchmarks, it might be time to reconsider your choice or escalate the issue with the vendor.

Conclusion

Testing third-party Slack apps is not a one-and-done task - it’s an ongoing effort to maintain performance and safeguard your enterprise. A good starting point is using isolated developer sandboxes to test functionality in a controlled environment. These sandboxes support up to three workspaces and eight users, complete with Enterprise Grid features, making them ideal for safe experimentation [2].

To minimize security risks, enforce minimal permissions by categorizing scopes into three groups: "Always allowed", "Requires approval", and "Restricted." This structure simplifies reviews and ensures only necessary access is granted [5]. When selecting apps, prioritize those from the Slack Marketplace, as they undergo compliance and functionality checks. However, remember these reviews are just snapshots in time and not exhaustive code audits [3][4].

Keep app configurations consistent by automating updates through Slack CLI and CI/CD pipelines [4][5]. For apps with AI features, implement safeguards like disabling link unfurling by default to prevent potential data leaks through prompt injection vulnerabilities [5]. These measures strengthen governance and security across your Slack environment. This includes managing data access by role to ensure users only see what they need.

Centralized governance is key. Establish clear approval workflows and use real-time management dashboards to oversee app usage effectively [7]. A great example comes from SoFi, which introduced domain-wide authentication for its 1,500+ employees. This move led to a 790% jump in weekly Google Calendar usage. As one representative from SoFi shared:

"While educating teams on how to use a new feature can take weeks, we were able to onboard thousands of employees to the Google Calendar app in a matter of minutes" [7].

For organizations needing trusted, auditable answers directly within Slack, Question Base provides a robust solution. Unlike generic tools, it connects seamlessly to platforms like Notion, Confluence, and Salesforce, delivering verified answers with built-in analytics, case tracking, and SOC 2 Type II compliance - all without requiring extensive engineering resources. By adopting these best practices, enterprises can create secure, efficient, and well-governed Slack ecosystems.

FAQs

What should we test first for high-risk Slack app permissions?

Before rolling out the app to production, begin by testing its access to sensitive data, such as user details and workspace information. Conduct these tests in a sandbox environment to evaluate security measures and confirm that access permissions are properly configured. This proactive step helps uncover potential vulnerabilities early on, ensuring critical data remains secure.

How can we make a Slack sandbox replicate our production setup?

To set up a replica of your production environment in Slack for testing, you can use Slack's developer or partner sandboxes. These environments provide all the features of an Enterprise organization, allowing you to safely test workflows without impacting your live setup. Each sandbox supports up to three workspaces and eight users, offering a realistic and controlled testing space. They are valid for six months and can be extended if needed, giving you ample time to experiment and refine your processes.

What ongoing checks should we run after approving a Slack app?

After you approve a Slack app, it's crucial to stay proactive. Regularly monitor the app's permissions and access levels, review activity logs for any unusual behavior, and ensure it complies with your organization's security guidelines. Make sure the app remains aligned with company policies, particularly if it's used across the entire enterprise. These ongoing checks help safeguard both security and functionality.

Related Blog Posts

• 10 Slack Security Best Practices for Enterprises

• Checklist for Setting Up Permissions in Slack Integrations

• Validating Slack Data Exchange: Key Steps

• Evaluating Slack Apps for Enterprise Security Compliance