Conditions & boost engine

Player conditions

Player predicates are their own API — aincraft-org/conditions (dev.conditions:api|gson|paper, CalVer YY.M.D.REVISION). They are not a boost implementation detail.

Key facts:

Conditions evaluate against a Paper-free snapshot (player, living entity, block) — Condition never looks up a Player; Paper builds the ConditionContext.
JSON is vanilla loot-condition shaped; the serializer produces bytes.
Missing player / missing snapshot fields fail closed (false).
Unknown condition ids fail on read.
Paper adapters: from, fromLiving, fromBlock; modularjobs:* types provide job / job_level predicates through snapshot extras.
Kryo is not used for conditions or SerializableBoostData.

ConditionHandler SPI

Third-party condition ids register a ConditionHandler (JSON → DataBag arguments + ConditionContext.extras()). Party/region/profession extras stay out of ModularJobs — that is the SPI's job.

Databag storage

Primitive storage lives in mintychochip/databag (dev.databag:databag). Item boost data embeds as PDC BYTE_ARRAY:

Envelope v1 (DBAG + version + length-prefixed entries); unversioned v0 still reads.
Payload encodings that may change use setBytes(key, formatId, bytes) / getFormatted.
Unknown tags in v1+ skip; unknown envelope versions throw.

ModularJobs registers BoostPayloadHandler (format id 1) and fills modularjobs:job / modularjobs:job_level extras on evaluation.

Boost engine

BoostEngine aggregates three source families:

Passive item sources from inventory.
Active timed boosts for the player target (MySQL).
Upgrade-tree sources for the current job.

Offline players return no boosts. Evaluation builds a BoostContext (action type, progression, player UUID, world, payable, condition snapshot); each RuledBoostSource selects its highest-priority matching rule; boosts never double-apply the same source (identity: target + source).

Boost data model

BoostData is a sealed hierarchy: SerializableBoostData, ConsumableBoostData, PassiveBoostData, TimedBoostData. BoostSource (extends Keyed) is the primary modifier-source extension point: evaluate(BoostContext): List<Boost> + nullable description().

Condition builder API

Condition offers static factories (biome, world, resource, sneak, sprint, liquid, potion, weather) plus and/or/negate/compose combinators. ConditionFactory (via Bridge.bridge().conditionFactory()) includes the job / jobAny builders.

Enums that shape conditions:

Enum	Values
`LogicalOperator`	AND, OR, XOR, NAND, NOR, XNOR, IMPLIES
`RelationalOperator`	BigDecimal comparisons
`WeatherState`	THUNDERING, RAINING, CLEAR
`PlayerResourceType`	HEALTH, HUNGER, EXPERIENCE
`PotionConditionType`	DURATION, AMPLIFIER

Factories

Both BoostFactory and ConditionFactory are @Internal — reach them via Bridge; they create additive/multiplicative boosts and the full condition builder API. The transient boost-source registry (RegistryKeys.TRANSIENT_BOOST_SOURCES) is where plugins register custom sources.

Engine tests

The pure engine cases run without Bukkit; repository tests need a live MySQL. MockBukkit 26.2 covers listener/payment tests where a Bukkit service is needed.