fasthep-flow 2026.6.1

Dependency-light FAST-HEP graph workflow core.

fasthep-flow

fasthep-flow provides the core FAST-HEP workflow language and execution engine.

It is responsible for:

• workflow compilation
• execution planning
• runtime orchestration
• registry/profile loading
• backend interfaces
• artifact lifecycle management

The Python import namespace is:

import hepflow

Scope

fasthep-flow is intentionally lightweight and domain-agnostic.

It does not implement:

• ROOT IO
• histogram filling
• HEP-specific transforms
• plotting/rendering
• experiment-specific analysis logic

Those capabilities are provided by companion FAST-HEP packages.

Recommended companion packages

For High Energy Physics (HEP) workflows, most users will also want:

• fasthep-carpenter

  • HEP analysis transforms
  • ROOT/awkward sources and writers
  • histogramming
  • cutflows
  • object reconstruction helpers

• fasthep-curator

  • dataset inspection
  • schema snapshots
  • diagnostics
  • runtime hooks

• fasthep-render

  • plotting
  • tables
  • reports
  • render styles

• fasthep-cli

  • the fasthep command-line interface

Alternatively, install the meta package:

pip install fasthep

Installation

Core workflow package only:

pip install fasthep-flow

Development environment:

pixi install
pixi run ci

Minimal example

from hepflow.api import compile_author_file, run_author_file

compile_author_file(
    "analysis/author.yaml",
    work_dir="build/example",
)

run_author_file(
    "analysis/author.yaml",
    outdir="build/example",
)

Design principles

fasthep-flow focuses on:

• small and composable interfaces
• explicit workflow compilation stages
• registry-driven extensibility
• backend-independent execution planning
• reproducible workflow artifacts
• minimal domain assumptions

The long-term goal is to make the workflow layer reusable beyond High Energy Physics.

Documentation

Main FAST-HEP documentation:

• https://fast-hep.github.io

API documentation for this package:

• https://fasthep-flow.readthedocs.io/en/latest/

Repository

Main FAST-HEP repository and project links:

• https://github.com/FAST-HEP/fasthep

Contributing

Contribution guidelines, development setup, and project-wide documentation are maintained centrally in the main FAST-HEP repository.

Legacy branch

The pre-split prototype implementation is preserved in the legacy branch.

The new main branch contains the split-package architecture.

Status

FAST-HEP is currently in active pre-alpha development.

Interfaces may still evolve rapidly while the package split and stabilization work continues.