# TraconRunBudgetExceededException > Tracon documentation. Tracon is a .NET package family that adds a control > plane on Microsoft Agent Framework, published as NuGet packages that run > inside your own ASP.NET Core application. > > Page: https://tracon.dev/api/tracon.traconrunbudgetexceededexception/ > Summary: TraconRunBudgetExceededException: Thrown when a run tree's budget runs out: its token or cost budget between two model turns, or a workflow step or function node that the budget refuses to start.
Namespace Tracon · Assembly Tracon.Abstractions.dll
Thrown when a run tree's budget runs out: its token or cost budget between two model turns, or a workflow step or function node that the budget refuses to start. ```csharp public sealed class TraconRunBudgetExceededException : TraconException, ISerializable ```
Inheritance
object ← Exception ← TraconException ← TraconRunBudgetExceededException
Implements
ISerializable
Inherited Members
TraconException.ErrorType, Exception.GetBaseException(), Exception.ToString(), Exception.GetType(), Exception.TargetSite, Exception.Message, Exception.Data, Exception.InnerException, Exception.HelpLink, Exception.Source, Exception.HResult, Exception.StackTrace, object.GetType(), object.ToString(), object.Equals(object?), object.Equals(object?, object?), object.ReferenceEquals(object?, object?), object.GetHashCode()
## Remarks Thrown by the wrapper installed inside the tool-call loop, one layer before the raw provider client; Microsoft Agent Framework's function-invoking client does not catch it, so it propagates out of `AIAgent.RunAsync`/`RunStreamingAsync` and fails the run. This is a different fault from [AgentRunBudget](/api/tracon.agentrunbudget/) refusing to reserve a *new child run* ([AgentRunBudget.TryReserveRun](/api/tracon.agentrunbudget/#Tracon_AgentRunBudget_TryReserveRun)): for agent delegation that refusal is returned to the model as an ordinary tool result and the calling agent can recover; this exception ends the run that hit it. A workflow step has no calling model to recover, so there the refused reservation throws this exception too, and the workflow run ends `Failed` with the same class as any other budget exhaustion. A workflow function node is refused the same way, at its start, when the tree's cost or time budget is already spent (the token budget does not stop a node). The message says "Could not start function node" and names the setting to raise. A node that is already running is never stopped by it, and the refusal is not retried. A tool call is refused at its start when the tree's token, cost or time budget is spent. The exception does not leave the tool: its message becomes the tool's result ("… The tool call did not start."), a streaming run records the call as failed, and the run ends at its next model call. A tool call that has started is never stopped. ## Constructors ### TraconRunBudgetExceededException\(\) Creates a new error. ```csharp public TraconRunBudgetExceededException() ``` ### TraconRunBudgetExceededException\(string\) Creates a new error. ```csharp public TraconRunBudgetExceededException(string message) ``` #### Parameters `message` [string](https://learn.microsoft.com/dotnet/api/system.string) The error message. ### TraconRunBudgetExceededException\(string, Exception\) Creates a new error. ```csharp public TraconRunBudgetExceededException(string message, Exception innerException) ``` #### Parameters `message` [string](https://learn.microsoft.com/dotnet/api/system.string) The error message. `innerException` [Exception](https://learn.microsoft.com/dotnet/api/system.exception) The underlying error. ## Fields ### RunBudgetExceededErrorType The stable value written to [TraconException.ErrorType](/api/tracon.traconexception/#Tracon_TraconException_ErrorType). ```csharp public const string RunBudgetExceededErrorType = "run_budget_exceeded" ``` #### Field Value [string](https://learn.microsoft.com/dotnet/api/system.string) ## Properties ### ErrorType Gets the stable error type name written to the run record. ```csharp public override string ErrorType { get; } ``` #### Property Value [string](https://learn.microsoft.com/dotnet/api/system.string) #### Remarks Defaults to the full name of the exception type, so today's behaviour does not change. A derived type overrides this member when the record has to be machine readable — for example [TraconContentFilteredException](/api/tracon.traconcontentfilteredexception/) writes `content_filtered`. Reports and alert rules can rely on this stable name instead of an assembly name. The value is written to `RunError.Type` and **carries no secret**.