Permission Preflight

Permission Preflight is a Forge quality-of-life utility that previews whether block, container, entity, and item interactions are likely allowed before players attempt them.

It is designed for multiplayer servers, protected areas, spawn regions, adventure-mode zones, and modded setups where it is not always obvious whether something is broken, restricted, claimed, or simply unavailable.

Before wasting time trying to open a chest, break a block, place something, or interact with an entity, Permission Preflight can give a quick read on what is likely allowed.

What does it do?

Permission Preflight helps answer questions like:

Can I break this block?
Can I place here?
Can I open this chest?
Can I interact with this block?
Can I interact with this entity?
Is this a permission issue, claim issue, protection issue, or setup issue?

The mod shows a compact HUD overlay when it has useful information. Denied and Partial results are shown by default, while Allowed and Unknown results can be enabled through config or detailed mode.

Result types

Permission Preflight uses four simple result types:

Allowed
Available checks found no restriction.
Denied
The action is likely blocked.
Partial
Some part of the action may be possible, but the result is incomplete or mixed.
Unknown
No provider could verify the action. This is normal and does not mean something is broken.

The mod is conservative with its wording. If it cannot verify something, it reports Unknown instead of guessing.

Supported actions

Permission Preflight can check common player actions, including:

Breaking blocks
Placing blocks
Using or interacting with blocks
Opening containers
Interacting with entities
Attacking entities
Using items on blocks

HUD overlay

The overlay is designed to be compact and unobtrusive.

By default:

Denied results are shown
Partial results are shown
Allowed results are hidden unless enabled in config
Unknown results are hidden in normal mode unless enabled or detailed mode is active

Detailed mode can show extra information such as:

Action being checked
Provider name
Confidence level
Cache freshness
Provider trace details

The overlay can be configured to appear above the hotbar or near the crosshair.

Chat warnings

Permission Preflight can show a short chat warning when a player attempts an action that was already predicted as denied.

Warnings are rate-limited so they do not spam chat.

Example:

Preflight: likely denied, cannot open containers here.

Important behavior

Permission Preflight is informational by default.

It does not:

Grant permissions
Bypass protections
Disable claims
Override server rules
Force actions to succeed
Block player actions by itself

The mod only reports what its available checks can determine.

Server-side checks are authoritative, and the client overlay only displays results received from the server.

Providers

Permission Preflight 1.0.0 includes two main providers.

Vanilla provider

The vanilla provider checks common vanilla restrictions, including:

Spectator mode
Adventure/build restrictions
World border
Spawn protection
Missing or unloaded target blocks
Missing or dead target entities

Recent observation provider

The recent observation provider watches cancelled Forge interaction events and briefly remembers denied actions.

This can help surface restrictions from other protection systems after the first failed attempt, even when there is no direct integration for that protection mod.

It can observe denied attempts for actions such as:

Breaking blocks
Placing blocks
Using blocks
Interacting with entities
Attacking entities

Claim mod support

Permission Preflight does not currently include direct API adapters for FTB Chunks, Open Parties and Claims, Flan, or other claim mods.

There are no hard dependencies on claim mods, and missing claim mods will not crash the game.

Claim-related denials may still appear after an attempted interaction if another mod cancels the Forge event and the recent observation provider can detect it.

Direct claim-mod integrations may be added in future versions.

Commands

Permission Preflight includes the following commands:

/preflight here
Checks the block or entity you are currently targeting.
/preflight debug
Toggles detailed provider output and detailed overlay mode.
/preflight reload
Reports config reload/live config behavior. Requires permission level 2.

Config highlights

Permission Preflight includes several config options for overlay behavior, networking, provider checks, and warnings.

Common options include:

enableOverlay
overlayPosition
showAllowed
showUnknownInNormalMode
showProviderInDetailedMode
showConfidenceInDetailedMode
useColorEmphasis
compactOverlay
maxReasonLength
enableChatWarnings
warningCooldownTicks
requestRateLimitPerSecond
cacheTtlTicks
maxInteractionReachBlocks
enableVanillaProvider
enableObservationProvider
enableClaimAdapters
debugLogging

Networking and safety

Permission Preflight is designed with multiplayer safety in mind.

Clients send requests only when needed.
The server validates target reach and current target information.
Clients cannot freely query arbitrary distant chunks or claims.
Requests are rate-limited.
Results are cached briefly.
Missing server support degrades gracefully.
Dedicated servers are supported.

Default networking behavior:

Request rate limit: 4 requests per second
Result cache time: 20 ticks

Recommended installation

Singleplayer: install on the client
Dedicated server: install on the server
Best multiplayer experience: install on both server and clients
Server-only: commands and server-side checks work, but clients without the mod will not see the HUD overlay
Client-only on a server without the mod: no server-authoritative results are available

Known limitations

Permission Preflight is designed to be helpful and conservative, not omniscient.

Known limitations:

Without direct claim-mod adapters, some claim permissions cannot be predicted before the first attempted action.
Some modded blocks may not expose enough vanilla information to classify every interaction perfectly.
High latency can briefly delay overlay updates.
Attack-entity checks are more limited than block and container checks.
Unknown results are normal when no provider can verify the action.

Version info

Minecraft: 1.20.1
Loader: Forge
Forge target: 47.4.20
Java: 17
Mod version: 1.0.0
Mod ID: permission_preflight
Creator: Iljas

PePr - Permission Preflight