---

name: hail description: "Use Hail for scalable genomic Tables, MatrixTables, VariantDatasets, Hail Batch DAGs, and hailctl setup or cloud workflow troubleshooting." disable-model-invocation: true metadata: disco-role: operating license: MIT

Hail

Use this repo skill when a task mentions Hail, hail, hailtop, hailctl, genomic Table or MatrixTable workflows, VCF/PLINK/BGEN imports, sparse GVCF or VariantDataset workflows, Hail Batch DAGs, or Hail backend setup and troubleshooting.

First Checks

• Install the public hail distribution in Python 3.10 or newer, then verify import hail as hl, import hailtop, and python -m hailtop.hailctl --help from a neutral working directory.
• Read references/repo-provenance.md before deciding whether this skill is current for a local Hail checkout.
• Read references/package-map.md for the package layout, public APIs, and how the sub-skills divide responsibilities.
• Read references/inspection-facts.md for verified signatures, dependency constraints, packaged resources, and hailctl command families.
• Run or adapt scripts/check_hail_environment.py for safe import, version, CLI, Java, PySpark, packaged-resource, and optional local-init diagnostics.
• Use references/troubleshooting.md for cross-cutting install/import/backend issues before diving into workflow-specific troubleshooting.

Route by User Goal

User goal or signal	Read
Install Hail, debug import hail, choose hl.init backend, configure logs/tmp/reference/requester-pays, or fix Java/Spark/JAR startup failures	sub-skills/setup-and-backends/SKILL.md
Build Hail Table pipelines, import delimited data, key/join annotations, aggregate rows, inspect schemas, or fix expression-index errors	sub-skills/tables-and-expressions/SKILL.md
Work with dense genotype MatrixTables, VCF/PLINK/BGEN import/export, sample/variant QC, splitting, PCA, association tests, VEP, loci, calls, or reference genomes	sub-skills/genomics-analysis/SKILL.md
Use hail.vds, sparse GVCF/VariantDataset workflows, local alleles, reference blocks, VDS combiner, to_dense_mt, or VDS QC	sub-skills/variant-datasets/SKILL.md
Build hailtop.batch DAGs, choose LocalBackend vs ServiceBackend, use hailctl batch/config/auth/dataproc/hdinsight/describe, or debug Batch/CLI cloud configuration	sub-skills/batch-and-cli/SKILL.md

Safe Workflow Defaults

• Start with setup: verify the installed package, working directory, Java/PySpark, hailctl, and backend choice before debugging workflow code.
• For local examples, prefer backend='local' or hailtop.batch.LocalBackend; treat cloud Batch, Dataproc, HDInsight, requester-pays data, and service billing as explicit user choices.
• Convert large external genomic inputs to Hail native formats (.ht, .mt, .vds) once, then iterate on native reads instead of reparsing VCF/PLINK/BGEN/GVCF inputs.
• Keep dense MatrixTable workflows and sparse VDS/GVCF workflows separate until a task explicitly asks for conversion.
• Use describe(), schema inspection, tiny previews, dry-run templates, and the bundled diagnostics before running expensive writes, exports, Batch submissions, or densification.

Important Boundaries

• This skill covers user-facing Hail Python, Hailtop, Hail Batch, and packaged hailctl workflows. It does not cover Hail monorepo service deployment, release automation, Kubernetes infrastructure, or maintainer-only cloud operations.
• Do not tell future agents to open original repository docs, tests, notebooks, or scripts. Use the bundled references and scripts in this skill.
• Do not put credentials, billing projects, bucket names, private paths, or local environment details into reusable examples; use placeholders and ask the user for their values.
• Native repo tests and cloud examples are verification evidence, not runtime dependencies. Run only safe, short, credential-free native checks when verifying this skill.

Bundled Helpers

• scripts/check_hail_environment.py inspects installed Hail/Hailtop imports, version metadata, hailctl, Java, PySpark, and packaged resources without initializing an expensive backend by default.
• sub-skills/tables-and-expressions/scripts/table_pipeline_template.py prints or dry-runs a self-contained Table pipeline template.
• sub-skills/genomics-analysis/scripts/matrixtable_recipe_template.py prints or dry-runs a dense MatrixTable analysis template.
• sub-skills/variant-datasets/scripts/vds_recipe_template.py prints or dry-runs a VDS workflow template.
• sub-skills/batch-and-cli/scripts/batch_local_smoke.py constructs a local-only Batch smoke/template and supports help or dry-run checks before execution.