# @gotgenes/pi-permission-system
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Permission enforcement extension for the [Pi](https://pi.mariozechner.at/) coding agent that provides centralized, deterministic permission gates over tool, bash, MCP, skill, and special operations.
> **Fork notice:** This package is a full fork of [MasuRii/pi-permission-system](https://github.com/MasuRii/pi-permission-system), published to npm as `@gotgenes/pi-permission-system`.
> It has diverged substantially from upstream in config format, internal architecture, and permission model.
>
> **my-pi maintenance note:** This directory was imported from upstream tag `pi-permission-system-v26.2.1` at commit `ec4fdb11343dc94f7185b113e559a4cf9f8dc035`. It is loaded from source and maintained directly by my-pi; npm `dist` output is not used. The local delegation envelope accepts an authorizer `allow` for built-in read-only path tools (`read`, `find`, `grep`, `ls`) accessing `external_directory`, while write, edit, bash, unknown tools, and all `path` asks still defer to human confirmation.
## What It Does
- **Hides disallowed tools** before the agent starts — no wasted turns probing for blocked tools
- **Enforces allow / ask / deny** at tool-call time with UI confirmation dialogs
- **Controls bash commands** with wildcard pattern matching (`git *: ask`, `rm -rf *: deny`)
- **Gates MCP and skill access** at server, tool, and skill-name granularity
- **Protects sensitive file patterns** — cross-cutting `path` rules deny `.env`, `~/.ssh/*`, etc. across all tools and bash at once, matching both the path as referenced and its symlink-resolved form so a deny cannot be evaded through a symlink alias
- **Guards external paths** — prompts before file tools or bash commands reach outside `cwd`
- **Fails closed** — an internal gate error blocks the tool (with a `gate_error` review-log entry), and an unparseable bash command — or an indirection wrapper that hides the gated command (`bash -c`/`eval`, `sudo`, `env`, `xargs`, `find -exec`, …) — prompts (`ask`) rather than passing silently
- **Forwards prompts from subagents** — `ask` policies work even in non-UI execution contexts
- **Broadcasts UI prompt events** — `permissions:ui_prompt` fires only when the permission system is about to invoke the active user-facing permission UI
- **Native [`@gotgenes/pi-subagents`](https://github.com/gotgenes/pi-subagents) integration** — in-process child sessions register with the permission system automatically, enabling per-agent policy enforcement and `ask`-state forwarding to the parent UI without configuration
## Install
```bash
pi install npm:@gotgenes/pi-permission-system
```
## Quick Start
1. Create the global config file at `~/.pi/agent/extensions/pi-permission-system/config.json`:
```jsonc
{
"permission": {
"*": "allow",
"path": {
"*": "allow",
"*.env": "deny",
"*.env.*": "deny",
"*.env.example": "allow"
},
"bash": {
"*": "ask",
"rm -rf *": "deny",
"sudo *": "ask"
},
"external_directory": "ask"
}
}
```
2. Start Pi — the extension automatically loads and enforces your policy.
All permissions use one of three states:
| State | Behavior |
| ------- | ---------------------------------------- |
| `allow` | Permits the action silently |
| `deny` | Blocks the action with an error message |
| `ask` | Prompts the user for confirmation via UI |
When the dialog prompts, you can approve once or approve a pattern for the rest of the session.
In an interactive TUI session the prompt is an inline keybind dialog — `y` approve, `s` approve for this session, `n` deny, `r` deny with a reason — where each hotkey arms and a second press confirms (configurable via `doublePressToConfirm`).
The prompt shows one fact per line — who is asking, the tool, the matched rule, the value being decided — within a row budget, so a large tool input cannot take over the transcript; `Ctrl+O` (`app.tools.expand`) expands it to the complete request.
See [docs/configuration.md](docs/configuration.md#inline-permission-dialog-tui) for the hotkeys and [docs/session-approvals.md](docs/session-approvals.md) for session-scoped rules and pattern suggestions.
The `path` surface is a cross-cutting gate that applies to **all** file access — Pi tools, bash commands, MCP calls, and extension tools alike.
Extension and MCP tools that operate on paths (via `input.path`, MCP's `input.arguments.path`, or a registered access extractor) are gated by default, so a `path` deny cannot be overridden by a per-tool allow — making it the right place to protect sensitive files like `.env` or `~/.ssh/*` from every tool at once.
A `path` pattern matches both the path as the agent references it and its canonical (symlink-resolved) form, so a deny still fires when a symlink aliases a sensitive target.
For per-tool path patterns (`read`, `write`, `edit`, `find`, `grep`, `ls`), patterns are matched against the file path from `input.path`.
This lets you express rules like "allow reads but deny `.env` files" at the individual tool level.
Like the cross-cutting `path` surface, per-tool patterns match both the referenced path and its canonical (symlink-resolved) form, so a per-tool deny resists symlink-alias evasion.
When Pi's current working directory is known, relative path inputs also match their cwd-normalized absolute form, so `src/App.jsx` can match both `src/*` and `/workspace/project/*`.
The `external_directory` surface is the CWD-boundary gate: it decides whether reaching **outside** the working tree is allowed, and accepts a pattern map so you can allow specific outside-CWD directories without opening up all external access.
This is the right surface for silencing repeated prompts on a local cache like `~/.cargo/registry` — allow it here, not on `path`:
```jsonc
{
"permission": {
"external_directory": {
"*": "ask",
"~/.cargo/registry/*": "allow"
}
}
}
```
The trailing `*` is greedy and crosses subdirectory boundaries, so it allows every file beneath the directory; a bare `~/.cargo/registry` matches only the directory entry itself.
Four layers compose with most-restrictive-wins: `path` (cross-cutting) → `external_directory` (CWD boundary) → per-tool patterns → `bash` command patterns.
Because `ask` is more restrictive than `allow`, a `path` allow cannot loosen an `external_directory: ask` boundary — allow outside-CWD directories on `external_directory`.
See [docs/configuration.md](docs/configuration.md) for the full recipe.
## Configuration
Config lives in one JSON file per scope:
| Scope | Path |
| ------- | --------------------------------------------------------- |
| Global | `~/.pi/agent/extensions/pi-permission-system/config.json` |
| Project | `/.pi/extensions/pi-permission-system/config.json` |
Project overrides global; per-agent YAML frontmatter overrides both.
Project config (policy and runtime knobs) is loaded only once the project is trusted — in an untrusted directory only global config applies, so an untrusted repository cannot loosen your global policy (see [Upgrading](#2200--project-config-requires-project-trust)).
Within a surface map like `bash` or `mcp`, **last matching rule wins** — put broad catch-alls first and specific overrides after.
The optional `shellTools` field records which non-`bash` tools carry shell semantics (e.g. an `exec_command` tool that replaces native `bash`), so they are gated at full parity with native `bash` — see [docs/configuration.md](docs/configuration.md#shelltools--gating-aliased-shell-tools).
Registered custom input previews for those aliases are preserved as authorization evidence and review-log context, allowing an extension to disclose execution context such as an SSH target without weakening bash enforcement.
A shell alias may also set `decisionFloor: "ask"`: Bash `allow` results are raised into the configured authorizer chain, while existing `ask` and hard `deny` decisions remain unchanged.
The optional `authorizerChain` field names registered case-by-case decision links (e.g. a light model judge) to consult when a request lands on `ask`, ahead of the interactive prompt.
A downstream extension registers a link via `getPermissionsService().registerAuthorizer(name, authorize)`; it decides nothing until you name it here (opt-in), config order fixes the chain order, and the chain owner caps any link's `allow` on `external_directory`/`path` to keep it within your policy — see [docs/configuration.md](docs/configuration.md#authorizer-chain--case-by-case-decision-links).
A subagent's ask is reviewed by the chain of the session serving it, one hop up, rather than inside the subagent — see the same section.
[`@gotgenes/pi-permission-model-judge`](https://github.com/gotgenes/pi-packages/tree/main/packages/pi-permission-model-judge) is a first-party reference implementation of such a link — a deny-first reviewer that auto-denies mistyped out-of-directory paths.
For the full reference — all surfaces, runtime knobs, per-agent overrides, merge semantics, and common recipes — see [docs/configuration.md](docs/configuration.md).
## Upgrading
### 22.0.0 — project config requires project trust
Project-scoped configuration (the project `config.json` and project-agent frontmatter — both permission policy and runtime knobs such as `yoloMode`) is now loaded only when Pi reports the project as trusted.
In an untrusted directory, only global config applies; a skip is surfaced with a warning and a `project_trust.skipped` review-log entry.
Grant project trust (or set `defaultProjectTrust`) to load a project's config.
See [docs/migration/0644-project-trust-gating.md](docs/migration/0644-project-trust-gating.md).
### 16.0.0 — the bash gate now fails closed
The permission gate fails closed: an internal gate error blocks the tool (with a `gate_error` review-log entry) instead of running it ungated, and a non-empty bash command that cannot be parsed resolves to `ask` (sentinel ``) rather than falling through to a permissive top-level `*`.
Commands that previously slipped through silently on the error or empty-parse path now block or prompt.
If you relied on the old permissive behavior for bash, set an explicit permissive bash policy — `"bash": { "*": "allow" }` — which also suppresses the new startup warning emitted when a top-level `"*": "allow"` leaves bash ungated.
## Documentation
| Document | Contents |
| ------------------------------------------------------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------- |
| [docs/configuration.md](docs/configuration.md) | Full policy reference, runtime knobs, per-agent overrides, recipes |
| [docs/session-approvals.md](docs/session-approvals.md) | Session-scoped rules, pattern suggestions, bash arity table |
| [docs/cross-extension-api.md](docs/cross-extension-api.md) | Cross-extension service accessor, event bus integration, prompt and decision broadcasts |
| [docs/subagent-integration.md](docs/subagent-integration.md) | Permission forwarding, coexistence with subagent extensions |
| [docs/guides/permission-frontmatter-for-subagent-extensions.md](docs/guides/permission-frontmatter-for-subagent-extensions.md) | Convention guide for subagent extension authors |
| [docs/opencode-compatibility.md](docs/opencode-compatibility.md) | OpenCode compatibility — shared concepts, divergences, porting guide |
| [docs/troubleshooting.md](docs/troubleshooting.md) | Common issues, diagnostic logging, threat model |
| [docs/migration/legacy-to-flat.md](docs/migration/legacy-to-flat.md) | Migration from pre-v2 config layout |
| [docs/migration/strict-config-validation.md](docs/migration/strict-config-validation.md) | Strict config validation (breaking) — rejected configs, and the cross-scope fail-closed clamp |
| [docs/migration/0644-project-trust-gating.md](docs/migration/0644-project-trust-gating.md) | Project-trust gating (breaking) — project config loads only after project trust |
| [docs/migration/0745-prompt-payload-contracts.md](docs/migration/0745-prompt-payload-contracts.md) | Prompt payload contracts (breaking) — the forwarded wire, the `ui_prompt` broadcast, and the deprecated preview caps |
| [docs/migration/0746-review-log-fields.md](docs/migration/0746-review-log-fields.md) | Review-log fields (breaking) — `message` replaced by request facts, and the `reviewLogFieldMaxWidth` bound |
## Development
```bash
pnpm run check # Type-check TypeScript (no emit)
pnpm run lint # Biome + ESLint + lint:md
pnpm run lint:md # rumdl on README and docs
pnpm run test # Run tests from ./test
pnpm run test:watch # Run tests in watch mode
```
### Pre-commit hooks
This project uses [prek](https://prek.j178.dev/) to run Biome, ESLint, and rumdl on staged files before each commit.
Run `pnpm install` to set up hooks automatically.
## Acknowledgments
This project began as a fork of [MasuRii/pi-permission-system](https://github.com/MasuRii/pi-permission-system).
Thank you to [MasuRii](https://github.com/MasuRii) for the original work that made this possible.
Thank you to the [OpenCode](https://opencode.ai) team for the permission model design that inspired the flat config format and evaluation semantics used in this extension.
## License
[MIT](LICENSE)