There is very little to configure, which is deliberate. Everything below has a default that works.

Ignore rules

The one setting worth attention — it is behind most surprises about speed and file counts.

Prism combines these sources:

A builtin list of directories nobody wants indexed
Your .gitignore
.prismignore at the repository root, if present
Optional excludeGlobs in .prism/config.json

.prismignore uses gitignore syntax and applies on top of the others. Use it for things that belong in the repository but not in the analysis — generated clients, vendored code, large fixtures:

src/generated/**
fixtures/large/**

Defaults already cover node_modules, dist, build, .next, out, coverage, .git, .turbo, .cache, minified JavaScript and source maps, plus ecosystem-specific additions once Prism detects the ecosystem.

`.prism/config.json`

Shared indexing knobs for CLI and IDE (Core reads this at workspace open):

{
  "excludeGlobs": ["vendor/**", "fixtures/large/**"],
  "maxFileBytes": 5242880
}

Field	Effect
`excludeGlobs`	Extra gitignore-style patterns
`maxFileBytes`	Skip hashing files larger than this; `null` = no limit

Precedence when indexing: CLI / API flags → .prism/config.json → defaults (5 MiB max file size).

Environment variables

Variable	Effect
`PRISM_WORKSPACE`	The repository to analyse, when not passed explicitly
`NO_COLOR`	Disables ANSI colour in CLI output
`COLUMNS`	Terminal width used for wrapping, when it cannot be detected

CLI

Most behaviour is flags; indexing also honours .prism/config.json. See using the CLI for global options and the command reference for per-command options.

Workspace resolution, most explicit first: --workspace, then PRISM_WORKSPACE, then (MCP only) the host WORKSPACE_FOLDER_PATHS, then the nearest ancestor with a .git, then the current directory. prism doctor prints which rule won.

MCP server

Configured by your MCP client, not by Prism. Happy path — no path flags, no workspace variable:

{
  "mcpServers": {
    "prism": {
      "command": "npx",
      "args": ["-y", "--prefer-online", "@repo-prism/mcp-server@latest"],
      "env": {
        "NODE_USE_SYSTEM_CA": "1"
      }
    }
  }
}

Canonical copy: packages/mcp-server/mcp-install.json — keep @latest so the server can hop to the newest publish.

Resolution: --workspace → PRISM_WORKSPACE → host WORKSPACE_FOLDER_PATHS → CURSOR_WORKSPACE → nearest git root → cwd. When that lands on a directory with no git root (an editor sandbox), the server asks the client for its open folders via MCP roots — retried until answered — and follows roots/list_changed. Only set --workspace / PRISM_WORKSPACE when the client cannot report roots. See MCP install.

Extension settings

See IDE settings. One VS Code setting lives in the editor:

Setting	Default	Effect
`prism.codeLens.enabled`	`true`	Blast Radius, Ownership and Map lenses above the first line of TS/JS files

Consent and privacy toggles are documented under consent and privacy.

What is stored, and where

Settings that belong to a repository — consent, bookmarks — live in .prism/ alongside the index. Presentation settings belong to the client.

Troubleshooting · CLI usage · Consent and privacy

Configuration