> ## Documentation Index
> Fetch the complete documentation index at: https://wiki.latch.bio/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

> The Latch Python SDK is an open-source toolchain to define serverless bioinformatics workflows with plain python and deploy associated no-code interfaces using single command.

## What is the Latch SDK?

The Python SDK lets you define computational workflows in Python, package them into Docker images, and run them on LatchBio's managed infrastructure.\
It provides:

* A Python API for defining **tasks** (individual steps) and **workflows** (task graphs)
* Instant no-code interfaces for accessibility and publication
* Containerization and versioning of every registered change
* Reliable and scalable managed cloud infrastructure
* Single line definition of arbitrary resource requirements (eg. CPU, GPU) for serverless execution
* Programmatic API endpoints for running workflows

## Workflows as DAGs

A **workflow** is a series of connected **tasks**, represented internally as a [directed acyclic graph](https://en.wikipedia.org/wiki/Directed_acyclic_graph) (DAG).

Each **task** is a Python function that:

* Declares its inputs via function parameters
* Returns outputs that can be passed to downstream tasks
* Contains any processing logic (Python or subprocess calls to other tools)

Example:

```python theme={null}
@small_task
def assembly_task(read1: LatchFile, read2: LatchFile) -> LatchFile:
    # run bowtie2...
    return LatchFile("covid_assembly.sam", "latch:///covid_assembly.sam")

@workflow
def assemble_and_sort(read1: LatchFile, read2: LatchFile) -> LatchFile:
    sam = assembly_task(read1=read1, read2=read2)
    return sort_bam_task(sam=sam)
```

## Next Steps

* Visit [Quick Start](/workflows/sdk/python/quick-start) to upload your first Python workflow in under 5 minutes.
* Visit [Tutorial](/workflows/sdk/python/authorizing-your-own-workflow) to understand how to author your workflow in details.
* Visit [UI](/workflows/sdk/ui/latch-metadata) for more details on how to customize your workflow interface.