dotnetcore/CAP · error · ArgumentException

Delay time span must be greater than 0 (Parameter…

Error message

Delay time span must be greater than 0 (Parameter 'delayTime')

What it means

An argument guard in the default ICapPublisher's PublishDelayAsync: the delayTime TimeSpan passed by the caller must represent a positive delay. Passing zero, a negative TimeSpan, or a default(TimeSpan) makes delayed publishing meaningless (it would be an immediate publish), so ArgumentException fires before any message is enqueued.

Solutions

1. Pass a positive TimeSpan, e.g. await publisher.PublishDelayAsync(TimeSpan.FromMinutes(5), "order.created", payload).
2. When delay is computed dynamically, guard it first: if (delay <= TimeSpan.Zero) use PublishAsync instead of PublishDelayAsync.

When it happens

Trigger: Thrown at src/DotNetCore.CAP/Internal/ICapPublisher.Default.cs:75 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of dotnetcore/CAP@e52b8508e5 (2026-09-14). Data as JSON: /api/errors/b96db367a5ed51af. Report an issue: GitHub.

Appendix: source

Thrown at src/DotNetCore.CAP/Internal/ICapPublisher.Default.cs:75

        await PublishInternalAsync(name, value, headers, null, cancellationToken).ConfigureAwait(false);
    }

    public async Task PublishAsync<T>(string name, T? value, string? callbackName = null,
        CancellationToken cancellationToken = default)
    {
        var headers = new Dictionary<string, string?>
        {
            { Headers.CallbackName, callbackName }
        };
        await PublishAsync(name, value, headers, cancellationToken).ConfigureAwait(false);
    }

    public async Task PublishDelayAsync<T>(TimeSpan delayTime, string name, T? value, IDictionary<string, string?> headers,
        CancellationToken cancellationToken = default)
    {
        if (delayTime <= TimeSpan.Zero)
        {
            throw new ArgumentException("Delay time span must be greater than 0", nameof(delayTime));
        }

        await PublishInternalAsync(name, value, headers, delayTime, cancellationToken).ConfigureAwait(false);
    }

    public async Task PublishDelayAsync<T>(TimeSpan delayTime, string name, T? value, string? callbackName = null,
        CancellationToken cancellationToken = default)
    {
        var header = new Dictionary<string, string?>
        {
            { Headers.CallbackName, callbackName }
        };

        await PublishDelayAsync(delayTime, name, value, header, cancellationToken).ConfigureAwait(false);
    }

    public void Publish<T>(string name, T? value, string? callbackName = null)
    {

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