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Custom Messages

Send custom Slack messages from within your workflow scripts using the slackMessage() function.

Prerequisites

The plugin must be enabled and configured for custom messages to work. See Quick Start if you haven't set up the plugin yet.

Basic Usage

Simple Text Messages

Send a simple text message:

include { slackMessage } from 'plugin/nf-slack'

workflow {
    slackMessage("đŸ”Ŧ Starting analysis for sample ${params.sample_id}")

    // Your workflow logic here
    MY_PROCESS(input_ch)

    slackMessage("✅ Analysis complete!")
}

Simple custom messages

Rich Formatted Messages

Adding Custom Fields

Create rich messages with custom fields:

include { slackMessage } from 'plugin/nf-slack'

workflow {
    slackMessage([
        message: "Analysis Results",
        fields: [
            [title: "Sample", value: params.sample_id, short: true],
            [title: "Status", value: "Success", short: true],
            [title: "Total Variants", value: "1,234", short: true],
            [title: "Duration", value: "2h 30m", short: true]
        ]
    ])
}

Message Structure

When using the map format, you can specify:

Property Type Description Required
message String Main message text Yes
fields List Array of field objects No

Field Structure

Each field in the fields array can have:

Property Type Description Required
title String Field label Yes
value String Field content Yes
short Boolean Show in column layout (default: false) No 
// Success message
slackMessage([
    message: "✅ Pipeline completed successfully"
])

// Error message
slackMessage([
    message: "❌ Quality control failed"
])

// Info message
slackMessage([
    message: "ℹī¸ Processing 100 samples"
])

// Warning message
slackMessage([
    message: "⚠ī¸ Low coverage detected"
])

Common Use Cases

Send Results Summary

Notify when analysis completes with summary statistics:

include { slackMessage } from 'plugin/nf-slack'

workflow {
    ANALYZE_DATA(input_ch)

    ANALYZE_DATA.out.results
        .map { sample, vcf, stats ->
            slackMessage([
                message: "Sample ${sample} analyzed",
                fields: [
                    [title: "Sample", value: sample, short: true],
                    [title: "Variants", value: stats.variant_count, short: true],
                    [title: "Quality", value: stats.mean_quality, short: true]
                ]
            ])
        }
}

Progress Updates

Send notifications at key workflow milestones:

include { slackMessage } from 'plugin/nf-slack'

workflow {
    slackMessage("🚀 Starting processing of ${sample_count} samples")

    QUALITY_CONTROL(input_ch).map { results ->
        slackMessage("✅ Quality control complete")
    }

    ALIGNMENT(QUALITY_CONTROL.out).map { results ->
        slackMessage("✅ Alignment complete")
    }

    VARIANT_CALLING(ALIGNMENT.out).map { results ->
        slackMessage("✅ Variant calling complete")
    }
}

Conditional Notifications

Send messages based on conditions:

include { slackMessage } from 'plugin/nf-slack'

workflow {
    QUALITY_CHECK(input_ch)
        .branch { sample, qc ->
            pass: qc.score >= 30
            fail: qc.score < 30
        }
        .set { qc_results }

    // Notify on failures
    qc_results.fail
        .map { sample, qc ->
            slackMessage([
                message: "⚠ī¸ Quality check failed for ${sample}",
                fields: [
                    [title: "Sample", value: sample, short: true],
                    [title: "Score", value: qc.score.toString(), short: true]
                ]
            ])
        }
}

Batch Notifications

Collect results and send a summary:

include { slackMessage } from 'plugin/nf-slack'

workflow {
    PROCESS_SAMPLES(input_ch)
        .collect()
        .map { results ->
            def total = results.size()
            def success = results.count { it.status == 'success' }
            def failed = results.count { it.status == 'failed' }

            slackMessage([
                message: "Batch processing complete",
                fields: [
                    [title: "Total Samples", value: total.toString(), short: true],
                    [title: "Successful", value: success.toString(), short: true],
                    [title: "Failed", value: failed.toString(), short: true]
                ]
            ])
        }
}

Next Steps