Dutis

Use Dutis for macOS Launch Services associations. Preserve its inspect -> plan -> policy check -> approval -> apply -> verify boundary.

Workflow

1. Start read-only. Check readiness with dutis doctor --json and the effective policy with dutis policy show --json, then inspect the requested association targets and installed handlers. Use dutis get <extension> --json for the current default or dutis query <extension> --json for supporting apps. A restricted macOS shell can hide Launch Services associations and make dutis get report no default even when one exists. If that happens, try the read-only dutis_get or dutis_handler_defaults MCP tool when available; otherwise report the uncertainty instead of concluding that no default is set. Use dutis handler get or dutis_handler_get for UTIs, MIME types, URL schemes, and role-specific defaults. Use dutis handler query or dutis_handler_query to discover apps that explicitly register the requested kind and compatible role. Treat imported or exported UTI definitions as type evidence, not handler capability. When roles may differ, use dutis handler defaults or dutis_handler_defaults to inspect the native Launch Services role matrix before planning a change. If an event command reports a delivery failure, inspect events health (dutis_event_health over MCP), then inspect events pending only when event-level details are necessary. Use events replay only after confirming the configured sink is healthy. Preview events archive and events purge before using --yes; purge is permanent and applies only to events already moved into dead-letter storage.
2. If the user asks for a general setup or is unsure which application to use, inspect dutis_profiles / dutis_profile, then use dutis_recommend (or the equivalent CLI commands). Present candidate evidence and treat the recommendation strictly as a proposal, never as approval. Treat profiles returned by Dutis as the effective catalog: local profiles.toml overlays may extend built-ins or add custom typed profiles. Never accept caller-supplied overlay contents through MCP. Treat candidate policy_eligible, policy_reasons, and source fields as required evidence; do not substitute caller-provided preferences for the effective local policy. For UTI, MIME, and URL-scheme recommendations, require declares_target = true; typed fleet preferences apply to every profile recommendation but never authorize a mutation.
3. Express multi-target changes as version 2 TOML. Build a fresh plan and run the policy check. Treat unresolved selectors or policy violations as a stop condition.
4. Show the user the exact changed kinds, identifiers, roles, target bundle IDs, plan digest, and any policy constraints. Run dry-run before requesting approval.
5. Ask for explicit approval immediately before a write. Never infer approval from an earlier inspection request.
6. Apply only the reviewed digest, include a meaningful requester identity, and report the resulting safety snapshot and audit IDs.
7. Verify with dutis get, then use dutis audit when the user needs the full local record.

When the user requests integration with another local tool, prefer the global --event-log or --event-command sink. Treat an event command as executable code: require a user-chosen trusted absolute path, and never generate or enable one implicitly. Events may contain application paths, bundle IDs, requester identity, and complete plans, but never approval tokens.

For HTTPS delivery, prefer the packaged dutis-event-http external command. Keep DUTIS_HTTP_ENDPOINT and DUTIS_HTTP_BEARER_TOKEN out of Dutis TOML, plans, prompts, and audit records. Run dutis-event-http --check --json before enabling it, and use a Keychain-backed wrapper for a LaunchAgent rather than persisting transport credentials in its plist.

For monitoring requests, use dutis_drift or dutis watch <config> --once first. Explain whether the report is in_sync, drift_detected, or unresolved. Do not enable --remediate or install a remediating LaunchAgent without explicit user authorization for continuous system changes. A notification-only LaunchAgent is the safe default.

For CLI workflows, prefer dutis plan, dutis policy check, and dutis apply --dry-run before the confirmed dutis apply command with --yes, --plan-digest, and --requester. For rollback, preview with dutis rollback <id> --dry-run before the confirmed command.

For MCP workflows, use dutis_diff and dutis_policy_check before dutis_apply, or dutis_rollback_plan before dutis_rollback. Mutation tools must be advertised by the server and require a fresh digest, an approval token, and requester. Never invent, persist, echo, or request disclosure of a secret token; use only a token supplied through the authorized workflow.

Do not pass recommendation output directly to a write tool. Rebuild the plan from the reviewed proposed TOML so current state and policy are checked again.

Do not bypass Dutis with raw duti mutation commands. Do not weaken or rewrite the local policy unless the user explicitly asks to change that policy.