pipelines

name	pipelines
description	This skill should be used when the user asks to "create pipeline", "lint pipeline", "build schema", "sync template", "release pipeline", "validate params", or any `nf-core pipelines` operation. Covers the full nf-core pipeline lifecycle including Nextflow strict syntax validation (Q2 2026 deadline).
version	0.1.0

nf-core Pipelines

Full pipeline lifecycle: create, lint, schema, sync, and release.

Read ${CLAUDE_PLUGIN_ROOT}/shared/conventions.md for nf-core conventions and package manager setup.

---

nf-core Migration Roadmap

Update this table as Nextflow and nf-core evolve. Last updated: Feb 2026.

Feature	Enforce?	Allow in Linting	In Template	Required	Notes
Strict syntax	ENFORCE	—	Q2 2026	Q2 2026	CRITICAL deadline. Run nextflow lint .
Version topics in modules	ENFORCE	Q4 2025	Mid-2026	Mid-2026	Already allowed by linting
Workflow output	Don't enforce	—	Mid-2026	Q4 2026	Coming soon
Static types & records	Don't enforce	Mid-2026	Q4 2026	Q2 2027	Gradual rollout
New process syntax	Don't enforce	Mid-2026	Q4 2026	Q2 2027	Gradual rollout

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Quick Commands

Replace <cmd> with the configured package manager prefix (see Setup in conventions.md).

Action	Command
Create pipeline	<cmd> nf-core pipelines create
Strict syntax lint	<cmd> nextflow lint .
Community lint	<cmd> nf-core pipelines lint
Lint with auto-fix	<cmd> nf-core pipelines lint --fix
Build schema	<cmd> nf-core pipelines schema build
Lint schema	<cmd> nf-core pipelines schema lint
Validate params	<cmd> nf-core pipelines schema validate <pipeline> params.json
Check sync status	<cmd> nf-core pipelines sync --show
Run sync	<cmd> nf-core pipelines sync
Run tests	<cmd> nf-test test

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Create Pipeline

Naming Rules

• Lowercase only: rnaseq not RNAseq
• No punctuation: methylseq not methyl-seq
• Descriptive: Name should indicate data type or analysis
• Unique: Check existing pipelines at https://nf-co.re/pipelines

Commands

# Interactive (recommended)
<cmd> nf-core pipelines create

# Non-interactive
<cmd> nf-core pipelines create --name mypipeline --description "Description" --author "Name"

# From template YAML
<cmd> nf-core pipelines create --template-yaml template.yml

# Custom organization
<cmd> nf-core pipelines create --org myorg

Template Features

Feature	Description	Default
github	GitHub integration, CI	Yes
ci	Continuous integration	Yes
igenomes	iGenomes reference config	Yes
multiqc	MultiQC report	Yes
fastqc	FastQC quality control	Yes
nf_schema	Parameter validation	Yes
codespaces	GitHub Codespaces	No
slackreport	Slack notifications	No

Generated Structure

nf-core-mypipeline/
├── .github/              # GitHub Actions, templates
├── assets/               # Email templates, logos
├── bin/                  # Custom scripts
├── conf/                 # base.config, modules.config, test.config
├── docs/                 # usage.md, output.md
├── lib/                  # Groovy libraries
├── modules/              # local/ and nf-core/
├── subworkflows/         # local/ and nf-core/
├── workflows/            # Main workflow
├── main.nf               # Entry point
├── nextflow.config       # Main config
├── nextflow_schema.json  # Parameter schema
└── CHANGELOG.md

Git Branches

• master/main: Stable releases only
• dev: Active development
• TEMPLATE: Vanilla template for sync

---

Lint Pipeline

Nextflow Strict Syntax (CRITICAL — Q2 2026 Deadline)

Always run strict syntax lint first. All nf-core pipelines must pass by Q2 2026.

<cmd> nextflow lint .
<cmd> nextflow lint main.nf workflows/ modules/

What it checks:

• Errors: for/while loops, switch, imports, top-level classes, unquoted env, addParams
• Warnings: Channel. uppercase, implicit closure params, shell: blocks

nf-core Community Lint

<cmd> nf-core pipelines lint
<cmd> nf-core pipelines lint --fix          # Auto-fix (requires clean git)
<cmd> nf-core pipelines lint --dir /path    # Specific directory
<cmd> nf-core pipelines lint -k files_exist # Specific tests only

Complete Linting Workflow

1. Run nextflow lint . — fix all errors, then warnings
2. Run nf-core pipelines lint — fix FAILED, then WARNED
3. Run nf-core pipelines lint --fix — apply auto-fixes
4. Verify both pass with zero errors

Common Lint Categories

Category	Description
files_exist	Required files (LICENSE, CITATIONS.md, etc.)
files_unchanged	Template files not to modify
nextflow_config	Config validation (manifest, params, profiles)
schema_lint	nextflow_schema.json structure
pipeline_todos	TODO comments to address
version_consistency	Version numbers match across files

Configuring .nf-core.yml Exceptions

lint:
  pipeline_todos: false         # Disable test
  files_exist:
    - CODE_OF_CONDUCT.md        # Skip specific file
  files_unchanged:
    - .github/CONTRIBUTING.md

Common Lint Fixes

Missing files (files_exist): Create LICENSE, CODE_OF_CONDUCT.md, CITATIONS.md.

Schema issues (schema_lint): Run <cmd> nf-core pipelines schema build.

Config issues (nextflow_config): Ensure complete manifest with name, version, nextflowVersion, etc.

TODOs (pipeline_todos): Remove or implement TODO comments.

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Schema Management

Build/Update Schema

<cmd> nf-core pipelines schema build          # Generate from nextflow.config
<cmd> nf-core pipelines schema build --web-only  # Web interface only

Adding a Parameter

1. Add param to nextflow.config params { } block
2. Run <cmd> nf-core pipelines schema build
3. Set type, description, constraints in prompts or web UI

Parameter Types

Type	Example	Use Case
string	"value"	Text, paths, enums
integer	10	Whole numbers
number	0.05	Decimals
boolean	true/false	Flags

Standard Parameter Groups

1. Input/output options: --input, --outdir
2. Reference genome options: --genome, --fasta
3. Process skipping options: --skip_* flags
4. Max job request options: --max_cpus, --max_memory, --max_time

Samplesheet Schema

Define samplesheet columns in assets/schema_input.json:

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "array",
  "items": {
    "type": "object",
    "required": ["sample", "fastq_1"],
    "properties": {
      "sample": { "type": "string", "pattern": "^\\S+$" },
      "fastq_1": { "type": "string", "format": "file-path", "exists": true },
      "fastq_2": { "type": "string", "format": "file-path", "exists": true }
    }
  }
}

Reference from nextflow_schema.json:

"input": {
  "type": "string",
  "format": "file-path",
  "schema": "assets/schema_input.json"
}

Generate Samplesheet from FASTQs

echo "sample,fastq_1,fastq_2,strandedness" > samplesheet.csv
for f in *_R1.fastq.gz; do
    sample=$(basename "$f" _R1.fastq.gz)
    echo "${sample},$(pwd)/${f},$(pwd)/${sample}_R2.fastq.gz,auto"
done >> samplesheet.csv

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Template Sync

How It Works

1. TEMPLATE branch contains vanilla nf-core template with your pipeline metadata
2. Sync updates TEMPLATE with latest template version
3. PR opens from TEMPLATE to dev
4. Merge after reviewing and resolving conflicts

master ────────────────────► (releases only)
dev ────●─────●─────●──────► (active development)
        │     ▲
        │     │ merge sync PR
TEMPLATE ●────●─────────────► (template updates)

Commands

<cmd> nf-core pipelines sync                    # Run sync (creates PR)
<cmd> nf-core pipelines sync --no-pull-request  # No PR
<cmd> nf-core pipelines sync --make-template-branch  # Recreate TEMPLATE

Resolving Merge Conflicts

• nextflow.config: Keep custom params, take structural changes
• CI workflows: Take template version, add back custom jobs
• README.md: Merge carefully, keep custom content

Fixing Broken TEMPLATE Branch

git branch -D TEMPLATE
git fetch origin TEMPLATE:TEMPLATE
# Or recreate:
<cmd> nf-core pipelines sync --make-template-branch

---

Release Preparation

Release Checklist

1. Version: Update manifest.version in nextflow.config (semver: MAJOR.MINOR.PATCH)
2. CHANGELOG.md: Add version section with date, categorize (Added/Changed/Fixed)
3. Documentation: docs/usage.md, docs/output.md, README.md up to date
4. Schema: nextflow_schema.json matches all params (<cmd> nf-core pipelines schema build)
5. Lint: nextflow lint . zero errors, nf-core pipelines lint all pass
6. Tests: <cmd> nf-test test all pass, CI green
7. Modules: All updated to latest versions
8. Containers: Versioned (no :latest), Docker and Singularity work
9. Citations: CITATIONS.md lists all tools with DOIs

Version Numbering

Change Type	Bump	Example
Breaking changes	MAJOR	1.0.0 → 2.0.0
New features	MINOR	1.0.0 → 1.1.0
Bug fixes	PATCH	1.0.0 → 1.0.1

Release Process

# 1. Ensure dev is up to date
git checkout dev && git pull origin dev

# 2. Run full validation
<cmd> nextflow lint .
<cmd> nf-core pipelines lint
<cmd> nf-test test

# 3. Update version in nextflow.config and CHANGELOG.md
# 4. Commit and push
git commit -m "Prepare release X.Y.Z"
git push origin dev

# 5. Create release PR (dev → master)
gh pr create --base master --head dev --title "Release X.Y.Z"

# 6. After merge, tag release
git checkout master && git pull
git tag -a X.Y.Z -m "Release X.Y.Z"
git push origin X.Y.Z