privacy-rules

# privacy-rules Help the user author **privacy custom masking rules** for Snow CLI. Rules live in `privacy.customRules` of `<project>/.snow/settings.json` (scope `project`) or `~/.snow/settings.json` (scope `global`) and are applied to selected tool results in both Local Rules mode and Online API mode. ## Commands (via `session-command-run`) | Goal | command | args | confirm | | -------------------- | ---------------------- | --------------------------------------------------------------------------------------------------------------------------------- | ------- | | List rules | `privacy-rules.list` | `--scope=project` / `--scope=global` (optional) | no | | Dry-run a rule | `privacy-rules.test` | JSON `{"sample":"...","pattern":"...","group":0,"replacement":"","withBuiltinRules":false}` or `{"sample":"...","id":"<ruleId>"}` | no | | Add / update | `privacy-rules.upsert` | `[--scope=global] <rule object or array>` | **yes** | | Replace all | `privacy-rules.set` | `[--scope=global] <rule array>` | **yes** | | Delete | `privacy-rules.remove` | `[--scope=global] <idOrName ...>` or JSON string array | **yes** | | Check privacy switch | `privacy` | `status` | no | `args` is passed through verbatim, so put raw JSON directly in it (no extra quoting). Scope defaults to `project`. Project rules, when defined, fully override global ones. ## Rule format ```json { "id": "optional, generated when omitted", "name": "required, short human label", "pattern": "required JavaScript regex", "group": 0, "replacement": "", "enabled": true } ``` - `pattern`: JavaScript regex syntax. A leading `(?i)` / `(?m)` / `(?s)` flag and `(?P<name>...)` named groups are also accepted (Snow App compatible). Do not use `(?x)` or inline flags in the middle of the pattern. - `group`: capture group to mask; `0` masks the whole match. Use a group to keep the key and mask only the value, e.g. `order[-_ ]?no[:=]\s*(\w+)` with `group: 1`. - `replacement`: literal text such as `[ORDER]`; empty masks every character with `*`. - `upsert` matches an existing rule by `id`, then by `name`, and keeps omitted fields. - Limits: name up to 120 chars, pattern up to 2000 chars, at most 200 rules per scope. - Remember JSON escaping: the regex `\d+` is written as `"\\d+"` inside JSON. ## Workflow 1. **Clarify** what must be hidden. Ask for 1-3 realistic sample lines (fake values are fine) and whether the key/prefix should stay visible. Use `askuser-ask_question` when the target format is ambiguous. 2. **Inspect** current state: `privacy-rules.list` (and `privacy` `status` to see whether privacy filtering is enabled at all). 3. **Draft** the narrowest regex that matches the samples. Prefer anchoring on stable prefixes/keys and word boundaries over broad character classes. 4. **Dry-run** with `privacy-rules.test` on every sample, plus at least one negative sample that must NOT match. Iterate until `matches` is exactly what the user wants. Use `withBuiltinRules: true` to see the combined result with built-in rules. 5. **Confirm** with the user: show the final rule JSON, the scope, and the masked preview. 6. **Save** with `privacy-rules.upsert` and `confirm: true`. Re-run `privacy-rules.list` to verify. 7. **Remind** the user: rules only apply when privacy filtering is enabled and the tool is selected in Privacy Settings -> Tool Results (defaults: `filesystem-read`, `ace-search`, `terminal-execute`). Enabling privacy is `privacy on` (also needs confirm). ## Examples Mask employee ids such as `EMP-1234`: ```json {"name": "Employee id", "pattern": "\\bEMP-\\d{4,6}\\b"} ``` Keep the key, replace only the order number: ```json { "name": "Order number", "pattern": "(?i)order[-_ ]?no[:=]\\s*(\\w+)", "group": 1, "replacement": "[ORDER]" } ``` Mask internal hostnames under `corp.example.com`: ```json { "name": "Internal host", "pattern": "\\b[a-z0-9-]+(?:\\.[a-z0-9-]+)*\\.corp\\.example\\.com\\b" } ``` ## Safety rules - Never write without explicit user approval; writes require `confirm: true`. - Do not paste real secrets into rules or replacements; regexes should describe the format, not embed actual sensitive values. - Avoid catastrophic backtracking (`(a+)+`, `(.*)*`, nested unbounded quantifiers); JavaScript regexes are backtracking and run on every masked tool result. - Prefer `upsert` over `set`; `set` replaces the whole list of that scope. - Changing `--scope=global` affects every project without project-level rules; ask first.