Codex
The public listing in the Codex plugin directory has the Fallow skill and the review skill, with starter prompts for an audit, a branch review and the Impact summary.
View Fallow in CodexThe Fallow plugin for Codex and Claude Code.
A coding agent sees the files that fit in its context window, and in a large repository that is a small part of the code. It writes a new date formatter without knowing about the three the team already has. The plugin lets Codex and Claude Code scan the whole TypeScript or JavaScript codebase before they edit, and check their own branch afterward. The scan runs on your machine.
Fallow Impact
- Issues in the latest full scan
- 7
- Fewer than the scan before it
- 5
- Findings cleared since Impact started
- 4.9k
Four tasks the agent can start by name.
You ask in plain words, for example "review this branch", and the agent runs the matching Fallow commands and reads the results before it answers.
- Audit the codebase
- One local run covers dead code, duplication, complexity, architecture boundaries and the risk in changed code.
- Review the branch
- The agent checks the branch against the module graph and tells a reviewer which changes affect the most other code.
- Clean up
- It lists unused files, exports, dependencies and repeated code. Before it edits anything, it shows a dry run.
- Show the impact
- It reads the local Fallow Impact summary with the current issue count, the trend and the findings cleared so far.
Install the plugin.
Claude Code
Add the public fallow-skills repository as a marketplace, then install the plugin with these two commands.
/plugin marketplace add fallow-rs/fallow-skills
/plugin install fallow@fallow-skillsWith Fallow Cloud, the agent can ask how often production calls a function.
The scan shows the agent every function in the codebase, but not which ones production still calls. When you connect the Fallow MCP server, the agent can use its get_cloud_runtime_context tool. That tool reads the call counts Fallow Cloud collected for your repository over the last 30 days, or up to 90. Before the agent changes or deletes a function, it can check whether production called it last month.
The tool reads the Fallow Cloud API key from FALLOW_API_KEY in the server environment. Apart from telemetry that you turn on yourself, it is the only tool in the server that makes a network call. Without the key it stops before anything runs.
What the Impact numbers mean.
Impact is off until you turn it on, and it keeps its history in a private config directory on your machine. The plugin reads the summary when you ask for it. It never turns tracking on for you and never sends the history anywhere.
- Issues
- The count from the latest full scan of the project.
- Trend
- The difference from the previous full scan that used comparable settings.
- Cleared
- The findings that went away while Impact was on, added up over time.
Other agents can run the same tasks.
The plugin uses the public Agent Skills format. Any other agent that reads that format gets the same four tasks and runs the same scan on your machine.