[READ] Describe the connected FLECS world; call it first to test the link.

Returns:

• rest_url: the FLECS REST API this server talks to.

• build_info: FLECS version, compiler, enabled addons and build flags (flecs.core.BuildInfo), or null if unavailable.

• world_summary: live counters such as entity, table, component and query counts, frame count, fps, target fps, time scale and uptime (flecs.stats.WorldSummary), or null if the stats module is not imported.

• notes: why a section is null, if any.

Fails if the FLECS REST API cannot be reached.

[READ] Get one entity with its tags, relationship pairs and component values.

Returns the FLECS entity JSON: 'parent', 'name', 'tags' (list), 'pairs' (relationship -> target), 'components' (component -> value; null when the component has no reflection data) and, when requested, 'id', 'type_info', 'inherited', 'matches' and doc info. Names use full paths.

Errors when the entity does not exist. Use flecs_query to find entities.

[READ] Get the value of a single component of an entity.

Returns {entity, component, value}; 'value' is the component serialized by FLECS reflection (usually an object of members, e.g. {"x": 10, "y": 20}). Errors when the entity does not have the component, when the id is a tag (no data) or when it cannot be resolved.

[READ] Find entities with a query written in the FLECS query language.

Syntax cheat sheet (terms are comma separated and all must match):

• 'Position, Velocity' entities with both components

• 'Position, !Velocity' ... without Velocity

• 'Position, ?Mass' Mass is optional

• 'Planet || Moon' either tag

• '(ChildOf, Sun)' children of entity Sun

• '!(flecs.core.ChildOf, *)' root entities

• '(Likes, *)' / '(Likes, $x)' wildcard / variable pair target

• 'Position, Mass(up)' Mass on an ancestor (ChildOf)

• 'SpaceShip, $this ~= "Uss"' name contains "Uss"

• 'IsA(_, *)' instances of any prefab Use full paths (e.g. 'transform.Position') when names are ambiguous.

Returns {page, results, type_info?}. Each result has 'parent', 'name' and, depending on options, 'id', 'fields' ({values, ids, sources, is_set} per query term), 'vars' or, with table=true, 'tags'/'pairs'/'components'. page = {offset, limit, returned, may_have_more}; when may_have_more is true, call again with offset += limit. Invalid queries return the FLECS parser error (with position) so the query can be fixed.

[READ] Return what an existing named query, system or observer matches now.

Useful to check which entities a system processes. Same result format as flecs_query: {page, results, type_info?}.

[READ] Explain how FLECS parses and plans a query, without returning results.

Returns 'query_info' (resolved terms: operator, source, traversal flags), 'field_info' (id, type and member schema per field), 'query_plan' (the FLECS query plan as text) and optionally 'query_profile'. Use it to debug queries that match nothing or match too much. Invalid queries return the FLECS parser error.

[READ] Get the reflection schema (members, types, units) of a component type.

Returns {component, has_reflection, schema}. 'schema' maps member names to [type, {unit, ...}] descriptors, e.g. {"x": ["float"], "y": ["float"]}. has_reflection is false (and schema null) when the type has no reflection data, in which case FLECS cannot serialize or set its value.

[READ] List the component, tag and pair ids in use, with storage statistics.

Each entry has 'name', 'entity_count', 'entity_size', 'tables' (table ids), 'traits' (e.g. Exclusive, CanToggle, (OnDelete,Remove)), 'type' (size, alignment, which lifecycle hooks are set; absent for tags), 'sparse' (for sparse components) and 'memory' when the stats module is imported. Includes FLECS builtin ids and wildcard records. Returns {total, offset, limit, components}; total counts matches after filtering. Use flecs_get_type_info for a component's member schema.

[READ] List named queries, systems and observers with evaluation statistics.

Each entry has 'name' (usable with flecs_run_named_query), 'kind' (Query, System or Observer), 'expr' (the query expression), 'results' and 'count' (current matches), 'eval_count', 'eval_time', 'eval_mode', 'cache_kind', 'batched', 'empty_tables', 'plan_size' and, when the stats module is imported, 'memory'. FLECS evaluates every query to produce this list, which can take a while in very large worlds. Returns {total, offset, limit, queries}.

[READ] Get world performance statistics from the FLECS stats module.

'metrics' maps names such as 'performance.fps', 'performance.frame_time', 'entities.count', 'tables.count', 'queries.system_count', 'commands.add_count' and 'memory.alloc_count' to {avg, min, max, brief}. Times are in seconds. Requires the FLECS application to import the stats module (FlecsStats); returns an explanatory error otherwise.

[READ] Get per-system timing statistics from the FLECS stats module.

'entries' contains one object per system: 'name', 'disabled', 'time_spent' and (for non-task systems) 'matched_entity_count' and 'matched_table_count', each metric as {avg, min, max}. With a pipeline, sync points ('multi_threaded', 'immediate', 'time_spent', 'commands_enqueued') are interleaved in execution order. Times are in seconds. Requires the stats module (FlecsStats).