# Instruction Reference

Use this section when you need precise behavior for built-in Instructions that run inside Action-style instruction lists.

Instructions are useful when a graph node owns the flow step, but the work inside that step should be configured as a reusable operation. If you need a graph-level flow route, start with [Flow Node Kinds](/flow-core-docs/documentation/reference/flow-node-kinds.md) instead.

## Start With

| If you want to...                                        | Read                                                                                                                                              |
| -------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------- |
| Branch inside an instruction list                        | [Check Instruction](https://github.com/HaikunHuang/FlowCore/blob/main/reference/instructions/instruction-check.md)                                |
| Wait inside an instruction list until a condition passes | [Wait Until Check Instruction](https://github.com/HaikunHuang/FlowCore/blob/main/reference/instructions/instruction-wait-until-check.md)          |
| Wait for a named signal inside an instruction list       | [Wait Signal Instruction](https://github.com/HaikunHuang/FlowCore/blob/main/reference/instructions/instruction-wait-signal.md)                    |
| Query timer state from another chain or graph            | [Get Timer Status Instruction](https://github.com/HaikunHuang/FlowCore/blob/main/reference/instructions/instruction-get-timer-status.md)          |
| Read or find `GameObjectGuid` tag membership             | [GameObjectGuid Tags Instructions](https://github.com/HaikunHuang/FlowCore/blob/main/reference/instructions/instruction-game-object-guid-tags.md) |

## Pages

* [Check Instruction](https://github.com/HaikunHuang/FlowCore/blob/main/reference/instructions/instruction-check.md): Evaluate a condition group once and choose a branch result inside an instruction list.
* [GameObjectGuid Tags Instructions](https://github.com/HaikunHuang/FlowCore/blob/main/reference/instructions/instruction-game-object-guid-tags.md): Check tag membership or find registered `GameObjectGuid` targets by tag query.
* [Get Timer Status Instruction](https://github.com/HaikunHuang/FlowCore/blob/main/reference/instructions/instruction-get-timer-status.md): Query timer progress, running state, completion, elapsed, and remaining values.
* [Wait Signal Instruction](https://github.com/HaikunHuang/FlowCore/blob/main/reference/instructions/instruction-wait-signal.md): Pause an instruction list until a matching signal arrives or times out.
* [Wait Until Check Instruction](https://github.com/HaikunHuang/FlowCore/blob/main/reference/instructions/instruction-wait-until-check.md): Poll a condition group until it passes or the configured timeout resolves.

## Related

* [Built-in Catalog Overview](/flow-core-docs/documentation/reference/built-in-catalog-overview.md)
* [Action Node](https://github.com/HaikunHuang/FlowCore/blob/main/reference/nodes/node-action.md)
* [Invoke and Reject Modes](/flow-core-docs/documentation/reference/invoke-and-reject-modes.md)


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# Agent Instructions: Querying This Documentation

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Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
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Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.