# Invoke and Reject Modes ## Summary Invoke and Reject modes define what a chain returns when a node cannot continue normally. They are the small return rules behind busy nodes, failed Guards, disabled pass gates, and control inputs. Use this page when a graph looks correct but a chain stops, queues, bypasses a node, or disappears as Invalid. ## Use When * A Guard rejects and you need to know whether the chain should stop loudly or end as Invalid. * A node is already running and a second chain reaches it. * A control input such as Abort or Invalid appears to cancel a running chain. * A BT leaf, Flow node, or subgraph behaves differently than expected after rejection. ## FlowInvokeMode (Node Busy) FlowInvokeMode controls what happens when a node that can be busy receives another incoming chain. | Value | Meaning | Runtime outcome | | ------- | ------------------------------- | -------------------------------------------------------------------------- | | Abort | Stop immediately. | The incoming chain ends at that node. | | Queue | Wait and resume in order. | The incoming chain is delayed until the node is free. | | Bypass | Use the node's bypass behavior. | The node is skipped or an alternate output is used, depending on the node. | | Invalid | Mark the branch invalid. | The branch ends as Invalid without running the busy node. | ## FlowNodeRejectResult (Guard Reject) FlowNodeRejectResult controls the return value when a Guard or node-level rejection fails. | Value | Meaning | Runtime outcome | | ------- | -------------------------------- | ------------------------------------------------------------------ | | Abort | Reject ends execution. | The chain ends at that Guard or rejecting node. | | Invalid | Reject marks the branch invalid. | The branch ends as Invalid and can be interpreted by parent logic. | ## Where These Are Configured | Place | Setting | What it affects | | --------------------------------------------- | ---------------------------------------------- | ----------------------------------------------------------------- | | Guard group | Reject Result | What the node returns when the Guard fails. | | Nodes with busy behavior | FlowInvokeMode or node-specific invoke setting | What happens when another chain enters while the node is running. | | Once, Gate, Gather Timeout, and similar nodes | Reject Result | What the node returns when its own rule rejects. | | Flow control inputs | Enable, Disable, Abort, Invalid | Per-node pass state or cancellation of matching active chains. | ## Examples | Scenario | Recommended mode | Why | | -------------------------------------------------------------------------- | ---------------- | -------------------------------------------------------------------------------------- | | A button can be pressed repeatedly, but the animation should finish first. | Queue or Bypass | Queue preserves every press; Bypass ignores extra work. | | A cutscene step must not overlap itself. | Abort or Bypass | Abort makes overlap visible as a stopped chain; Bypass keeps the graph calm. | | A Guard checks whether an optional target exists. | Invalid | Invalid lets the branch end quietly when the optional target is absent. | | A Guard protects a required runtime object. | Abort | Abort makes the missing requirement easier to notice while debugging. | | A selector-style flow needs failed options to fall through. | Invalid | Invalid communicates "this branch did not match" rather than "the whole chain failed." | ## Control Inputs Flow nodes with control inputs expose **Enable**, **Disable**, **Abort**, and **Invalid** in a dedicated control-port section. **BTRoot** exposes them as Flow control inputs. BT non-root nodes do not expose control inputs. * **Enable** and **Disable** toggle the per-node **Pass Enabled** gate. They do not change the node's Enabled flag. * When Pass Enabled is off, incoming chains end as **Invalid** and the node does not execute. * On Flow nodes, **Abort** and **Invalid** control inputs cancel all matching active chains, then return their own result. * A chain matches when the node is the chain Root, or when the node is the current executing node, including Wait. * Matching also applies inside SubFlowGraph execution. Control inputs in subgraphs can cancel chains started within that subgraph runtime. * If no active chain matches, the control input still returns Abort or Invalid, but no other chain is affected. * Control inputs are non-flow signals. They apply side effects and return Invalid unless a node explicitly cancels the chain. ## Debugging Reads | What you see | Read it as | Check | | --------------------------------------------------------- | --------------------------------------------------------------- | --------------------------------------------------------------- | | The node is highlighted but the next node never runs. | The chain may have returned Abort or Invalid. | Guard result, Reject Result, busy behavior, and control inputs. | | A repeated event stops responding while a node is active. | The busy behavior may be Abort, Bypass, or Invalid. | FlowInvokeMode and whether the node is still running. | | A branch ends without an error-looking signal. | Invalid may be doing exactly what it is designed to do. | Whether the branch is optional or expected to fall through. | | A control input cancels more than expected. | Multiple active chains may match the same root or current node. | Chain root, current executing node, and Start New Chain usage. | ## Constraints * Bypass is node-specific. Some nodes skip work; others route to an alternate output. * Invalid ends the current branch. It is intentionally quieter than Abort. * BT leaf guards map Invalid to Success and Abort to Abort. * Start New Chain works inside SubFlowGraph and creates an independent chain within the subgraph runtime. * Node pages define the exact return mapping for each node. ## Related * [Flow Node Kinds](/flow-core-docs/documentation/reference/flow-node-kinds.md) * [Node Reference](/flow-core-docs/documentation/reference/nodes.md) * [Lifecycle and Dataflow](/flow-core-docs/documentation/runtime-guide/lifecycle-and-dataflow.md) * [Graph Debugging](/flow-core-docs/documentation/troubleshooting/graph-debugging.md) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. 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