flowing v1.3.2

flowing

A lightweight DAG workflow runner for Claude's ephemeral containers. Declare steps, wire dependencies, run once — control flow lives in code, not in prose imperatives.

The problem it solves

Multi-step procedures are usually written as prose: "first fetch X, then validate Y, then if Z retry up to 3 times, otherwise skip ahead." An LLM reads and generates past prose like that — the gate is a suggestion, not a wall. Skipped validation, retries that never happen, branches taken on stale state.

A @task graph is structural instead. A step physically cannot run until its inputs are bound to its parameters. A gate that fires on missing or bad input can't be stepped over. The runner owns branching, retrying, validating, failure propagation, and parallelism; the LLM only supplies judgment at the leaves.

from flowing import task, Flow

@task
def fetch_data():
    return {"items": [1, 2, 3]}

@task(depends_on=[fetch_data])
def process(fetch_data):          # param name matches the dep's name
    return sum(fetch_data["items"])

@task(depends_on=[process])
def store(process):
    print(f"Result: {process}")

Flow(store).run()                 # topo-sorts into layers, parallel within a layer

Control-flow primitives

The distinctive part — branches and contracts as graph structure, not if statements buried in task bodies.

Primitive	What it does	Use for
when=	Predicate over dep values; falsy → task SKIPPED, skip cascades to dependents	Branch selection in the topology
validate=	Checks dep values before the body runs; raise → FAILED with no retry	Enforceable input contracts between steps
retry_until=	Predicate over the return value; falsy → retry, consuming the retry= budget	Self-correcting LLM steps (generate → check → regenerate)

retry_until= is distinct from retry= alone: retry= only retries on a raised exception, retry_until= retries on output shape.

Also handles

• Parallel execution — independent tasks in a layer run on a thread pool.
• Resume — run() → fix → resume() re-runs from the failure point, keeping succeeded tasks cached. override() injects a corrected value for a step resolved out-of-band.
• Detached side-effects — detached=True tasks (memory writes, notifications) run after the main DAG and never block it on failure.
• timeout_s=, retry= with exponential backoff, fail_fast=.

Layout

File	Audience	Contents
SKILL.md	Claude	Trigger, mental model, quick start, the three primitives, when / when-not-to-use
references/reference.md	Claude	Full API — every @task parameter, Flow methods, resume/override, detached auto-discovery, signature gotchas
scripts/flowing.py	—	The runner itself (no third-party dependencies)
tests/test_flowing.py	—	28 tests — python3 -m unittest tests.test_flowing
CHANGELOG.md	—	Version history

When to reach for it

Use it when a procedure has branches that matter, steps with input contracts, an LLM step that needs to converge, 3+ operations that can parallelize, or a pipeline where late failures shouldn't waste early work.

Skip it for a single sequential operation (just call the function), for a next step that needs open-ended reasoning about the prior result rather than a predicate (use a think loop), or for async / distributed workflows (this is single-container, thread-pool based).

Complements

• orchestrating-agents — parallel API instances and delegated sub-tasks. flowing orders and gates work within one container; orchestrating-agents fans work out across many.
• tiling-tree — MECE partitioning of a problem space. Tiling-tree decides what the branches are; flowing enforces the execution order once they exist.
• tracking-todos — a human-legible checklist for loose, evolving work. flowing is for procedures whose shape is known up front and worth encoding as a graph.

Skill folder: flowing

---

Release of flowing version 1.3.2

📥 Download & Install

⬇️ Download flowing.zip

To install:

1. Click the download link above (ignore the "Source code" archives below - they're auto-generated by GitHub)
2. Go to Claude.ai Skills Settings
3. Upload the downloaded ZIP file
4. Requires paid Claude Pro or Team account

See official documentation for more details.

Recent Changes

e2d9257 flowing v1.3.2: add human-facing README.md (#648)
0e39c46 docs: Update CHANGELOG.md for released skills