Block generated edits. Check renames and deletes.

Where the agent supports hooks, Prism joins the session: it stops edits to generated or vendor files and warns about widely used code. On every agent, it checks renames and deletes before they happen.

Your agent

YouAdd an email field to the API schema

Prism✗ Denied: src/api/generated/schema.ts is generated. Do not edit generated or vendored files.

AgentThat file is generated. I’ll change its source and regenerate it.

~/northwind

$ prism strength liteStrength set to lite in /Users/sam/.prism/config.json.$ prism strengthStrength: lite (~/.prism/config.json)

The hook answers in the chat. You set its strength in the terminal.

Stops generated edits

Edits to generated or vendor paths are denied, with the reason.

Safe renames

rename_impact lists every edit site before a rename. Nothing is written.

Safe deletes

safe_delete says whether anything still imports a file or symbol.

Flags widely used code

Files many others depend on get a sign-off warning before the edit.

You choose the strength

prism strength full, lite (rules and the receipt only; the edit hooks go quiet) or off.

Per agent

Hooks where the agent supports them. Everywhere else, the MCP server and a rule.

Rename without missing a spot

“Rename getUser to fetchUser safely.” Your agent gets every edit site before it starts.

Your agent

YouRename getUser to fetchUser safely

Prismrename_impactgetUser → fetchUser
3 edit sites in 3 files:
src/users/api.ts, src/users/profile.ts, src/pages/checkout.ts

AgentRenamed in all 3 files. Nothing else refers to getUser.

~/northwind

$ prism rename getUser fetchUser --symbolRename impact: getUser → fetchUserEdit sites 3Affected files 3Breaking-change hints 0This is a report. Nothing is written.EDIT REFSsrc/users/api.ts 1src/users/profile.ts 1src/pages/checkout.ts 1

Delete only what nothing uses

“Can I delete cart.js?” Prism answers from the map, and names what still imports it.

Your agent

YouCan I delete src/legacy/cart.js?

Prismsafe_delete
Not safe: 1 file still depends on it.
src/pages/checkout.ts imports src/legacy/cart.js

AgentNot yet. I’ll move checkout.ts off cart.js first.

~/northwind

$ prism safe-delete src/legacy/cart.jsSafe delete: src/legacy/cart.jsNot safe — 1 file still depends on it.BLOCKED BY WHYsrc/pages/checkout.ts imports src/legacy/cart.js

Agent	How Prism joins
With hooks	Session start, before and after an edit, and stop, where the agent supports them
With a rule	The MCP server plus a rule that asks the agent to call Prism

Try it in your repo.

Install Prism, then connect every agent on this machine. Open the agent again.

$npm install -g @prismapp/cli && prism install all

Install guide Star on GitHub10