feat: default manifest source to manifest.json for Bolt Framework projects

[mwbrooks]

Changelog

Bolt JavaScript and Bolt Python projects now default to using the local manifest.json as the app manifest.

• Previously, it was a remote manifest from App Settings (https://api.slack.com/apps).
• Changes to the app manifest on App Settings will be detected by the Slack CLI and a prompt will be displayed before any manifest update action (e.g. slack run).
• The manifest source is set after creating a new project with slack create or initializing an existing project with slack init and the setting is stored as "manifest.source": "local" in .slack/config.json.

Summary

This pull request defaults Bolt Framework projects to use a manifest.source: "local" when creating and initializing a project.

Reason behind the change: We're making this change after receiving feedback from multiple developers who are confused by the remote setting and would prefer local for Bolt projects. The rationale is that developers using the CLI would prefer to default to managing the manifest with the CLI/Project.

Related #396 that will update app link to not change the manifest source.

Open Question

• Is this considered feat: enhancement or fix: bug fix?

Preview

2026-03-12-bolt-local-manifest.mov

Test Steps

Test Creating a Bolt Framework Project:

# Create a new Bolt Project
$ lack create my-app -t https://github.com/slack-samples/bolt-js-starter-template
$ cd my-app/

# Confirm local manifest
$ cat .slack/config.json
# → Confirm manifest.source: "local"

# Create and run the app
$ lack run
# → Press CTRL+C to stop the server

# Change Something on App Setting to Introduce a Conflict
$ lack app settings
# → Change App Name
# → Set Description and Background Color
# → Save

# Test Manifest Change Warning
$ lack run
# → Confirm warning that manifest is out-of-sync
# → Select Y

# Clean up
$ lack delete -f
$ cd ..
$ rm -rf my-app

Test Initializing a Bolt Framework Project:

# Clone a Bolt Framework Project
$ git clone https://github.com/slack-samples/bolt-js-starter-template.git
$ cd bolt-js-starter-template/

# Initialize it
$ lack init

# Confirm local manifest
$ cat .slack/config.json
# → Confirm manifest.source: "local"

# Clean up
$ cd ..
$ rm -rf bolt-js-starter-template/

Test a Deno Project:

# Create a new Deno Project
$ lack create my-app -t https://github.com/slack-samples/deno-starter-template
$ cd my-app/

# Confirm local manifest
$ cat .slack/config.json
# → Confirm manifest.source: "local"

# Clean up
$ cd ..
$ rm -rf my-app

Requirements

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 67.88%. Comparing base (8e4c0aa) to head (a87561b).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #395      +/-   ##
==========================================
- Coverage   67.88%   67.88%   -0.01%     
==========================================
  Files         218      218              
  Lines       18090    18090              
==========================================
- Hits        12281    12280       -1     
- Misses       4654     4655       +1     
  Partials     1155     1155              

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