Write Docs

Writing Prefect Documentation

This guide covers everything needed to write, update, and test Prefect documentation pages. For structural context (directory layout, navigation, links, local dev commands), see docs/AGENTS.md.

Page types

Each section of the docs serves a distinct purpose. Place new content in the right section and match its tone and structure.

Get Started (v3/get-started/)

Onboarding pages for new users. Content should be linear, opinionated, and get the reader to a working result as fast as possible. Use <Steps> for sequential instructions and <Tabs> to offer Cloud vs. self-hosted paths. Minimize explanation — link to Concepts for deeper understanding.

Concepts (v3/concepts/)

Explain what something is and why it matters. Concepts pages define Prefect's mental model — flows, tasks, states, deployments, events, work pools, etc. Start with a short code example showing the concept in action, then explain the underlying model, lifecycle, and relationships to other concepts. Link to How-to Guides for step-by-step instructions. Do not provide exhaustive procedural walkthroughs here.

How-to Guides (v3/how-to-guides/)

Task-oriented pages that show how to accomplish a specific goal. Each page should solve one problem (e.g., "How to write and run a workflow", "How to set up retries"). Structure as a series of actionable steps with code examples. Meet the reader where they are — do not assume familiarity with Prefect internals. Use the smallest amount of Prefect-specific jargon possible, and explain or link terms when they are unavoidable.

Guides are organized into the following categories:

• workflows/ — Writing, running, and customizing flows and tasks: retries, caching, concurrency, logging, testing, runtime info, state hooks, and artifacts.
• deployments/ — Creating, scheduling, running, and versioning deployments, including prefect.yaml configuration and flow code storage.
• deployment_infra/ — Running workflows on specific infrastructure: Docker, Kubernetes, serverless platforms (AWS ECS, Azure ACI, GCP Cloud Run), Modal, Coiled, Prefect Managed, and local processes. Also covers work pool management.
• automations/ — Setting up event-driven automations: creating automations and triggers, chaining deployments via events, custom notifications, and accessing event payloads in flows.
• cloud/ — Prefect Cloud-specific operations: connecting to Cloud, managing workspaces and users, creating webhooks, and troubleshooting.
• configuration/ — Configuring the Prefect environment: managing settings, storing secrets, and using variables.
• ai/ — Using Prefect with AI tooling, such as the Prefect MCP server.
• migrate/ — Upgrading from older Prefect versions or migrating from other tools like Airflow.
• self-hosted/ — Running the Prefect server yourself via Docker Compose, the CLI, or on Windows.

Advanced (v3/advanced/)

In-depth pages for experienced users covering topics like transactions, interactive workflows, infrastructure-as-code, scaling self-hosted deployments, and custom API integrations. These assume familiarity with core concepts and how-to patterns. They can be longer and more detailed than how-to guides.

Examples (v3/examples/)

Auto-generated — do not edit directly. Each page is generated from a standalone Python file in the repo's top-level examples/ directory by generate_example_pages.py. To add an example, create a new .py file in examples/ with YAML frontmatter in comments and run just generate-examples. See contribute/docs-contribute.mdx for the full process.

Integrations (integrations/)

Each integration (e.g., prefect-aws, prefect-gcp) has its own subdirectory. The index.mdx covers installation, credential setup (blocks), and key capabilities. Additional pages cover specific workers, tasks, or SDK reference. Follow the existing pattern: "Why use it" section, prerequisites, install instructions, blocks setup, then per-service usage sections.

API Reference (v3/api-ref/)

Auto-generated — do not edit directly. Covers the Python SDK (python/), CLI commands (cli/), and REST API (rest-api/). CLI pages use <ResponseField> and <Accordion> components for arguments and options.

Release Notes (v3/release-notes/)

Changelogs organized by product surface: oss/ for open-source releases, cloud/ for Prefect Cloud, integrations/ for integration packages.

Contribute (contribute/)

Guides for contributors: how to set up the dev environment, write docs, develop integrations, and follow code style conventions.

Adding vs. updating content

When to update an existing page vs. create a new one

• Update an existing page when the new content is a variation, option, or closely related technique for something the page already covers. For example, a new retry strategy belongs on the existing retries page, not a new page.
• Create a new page when the content addresses a distinct goal that doesn't fit naturally into any existing page. A good test: if the page title would need to become vague or a compound sentence to accommodate the new content, it deserves its own page.
• When in doubt, prefer extending an existing page. Fewer, more comprehensive pages are easier for readers to discover than many small, fragmented ones.

When to add a new category or section

• Create a new subdirectory only when you have multiple pages (or a clear roadmap for multiple pages) that share a theme not covered by any existing category. A single page does not justify a new category — place it in the closest existing one.
• Before creating a category, check whether the content fits in an existing one. For example, a guide about running flows on a new cloud platform belongs in deployment_infra/, not a new category named after that platform.
• New categories must also be added as a group in the navigation.tabs section of docs/docs.json, with an index.mdx page for the group overview.

Page templates

Starter templates live in this skill directory. Copy one as the basis for a new page and fill in the bracketed placeholders:

• How-to guide — template-howto.mdx
• Concept page — template-concept.mdx

Adjust headings and sections to fit the content — the templates show the expected shape, not a rigid format.

Keywords for searchability

Every page should include a keywords array in its frontmatter. Keywords feed Mintlify's search index and help readers find pages using terms that don't appear in the title or description.

keywords: ["retry", "retries", "error handling", "fault tolerance"]

• Include 3-5 lowercase terms a reader might search for.
• Use synonyms and shorthand readers would actually type (e.g., "k8s" is wrong in prose but useful as a keyword alongside "Kubernetes").
• Don't repeat words already in title or description — those are indexed automatically.

Registering pages in navigation

Every new page must be added to docs/docs.json under navigation.tabs or it won't appear in the sidebar. Add the page path (without .mdx) to the appropriate group:

{
  "tab": "How-to Guides",
  "pages": [
    "v3/how-to-guides/index",
    {
      "group": "Workflows",
      "pages": [
        "v3/how-to-guides/workflows/write-and-run",
        "v3/how-to-guides/workflows/retries"
      ]
    }
  ]
}

• Each tab has a "tab" display name and either "pages" or "groups".
• Groups can nest: a group's "pages" array can contain strings (page paths) or nested {"group": ..., "pages": [...]} objects.
• Place new pages at a logical position within the existing group — typically at the end, unless ordering matters for the reader.

Mintlify components

Use these components (not standard Markdown admonition syntax):

<Note>Important information.</Note>
<Warning>Caution about potential issues.</Warning>
<Tip>Helpful suggestion.</Tip>
<Info>Additional context.</Info>

<Accordion title="Expandable section">
  Content hidden until clicked.
</Accordion>

<Tabs>
  <Tab title="Option A">Content for A</Tab>
  <Tab title="Option B">Content for B</Tab>
</Tabs>

<Steps>
  <Step title="First step">Instructions</Step>
  <Step title="Second step">Instructions</Step>
</Steps>

<CardGroup cols={3}>
  <Card title="Title" icon="icon" href="/v3/path">
    Description text.
  </Card>
</CardGroup>

<CodeGroup>
```bash pip
pip install prefect

uv pip install prefect

Reusable snippets

Snippets live in snippets/ and are imported with JSX:

import ComponentName from '/snippets/path.mdx'

<ComponentName />

Always check for an existing snippet before writing duplicate content. Key snippets to know about:

• snippets/installation.mdx — Standard Prefect install instructions (used in v3/get-started/install.mdx). Use this instead of writing ad-hoc install blocks.
• snippets/resource-management/ — Consistent "manage this resource via CLI / API / Terraform / Helm" callouts. Import the relevant variant when documenting a Prefect resource.

Code blocks

Code blocks support language hints, filenames, line highlighting, and expandable sections:

```python my_flow.py
from prefect import flow

@flow
def hello():
    print("Hello!")
```

```bash {3} [expandable]
prefect deploy --all
prefect work-pool create my-pool --type process
prefect worker start --pool my-pool
```

Mark code blocks that should not be tested with the comment {/* pmd-metadata: notest */} on the line before the code block.

Prefer minimal, runnable snippets that produce a visible result (printed output, a return value, or a logged message). Avoid placeholder names like foo/bar in user-facing examples — use realistic names that reflect the domain (e.g., process_order, customer_id).

Code example testing

Python code blocks in .mdx files are automatically extracted and executed as tests using pytest-markdown-docs. Tests run in CI against a live Prefect server and are parallelized with pytest-xdist (up to 6 workers). All test configuration — fixtures, skip lists, and injected globals — lives in docs/conftest.py.

How it works

By default, every fenced Python code block in an .mdx file is treated as an independent test. The plugin extracts the block, executes it, and fails if it raises an exception. Each block runs in its own namespace unless continuation is used (see below).

Running tests locally

There is no just command for markdown tests. Run them manually:

# Start a Prefect server in the background
PREFECT_HOME=$(pwd) uv run prefect server start &

# Run the markdown doc tests
PREFECT_API_URL="http://127.0.0.1:4200/api" uv run --group markdown-docs pytest docs/ -m markdown-docs

pmd-metadata directives

Control test behavior with {/* pmd-metadata: <directive> */} comments placed on the line immediately before a code fence.

notest — Skip this code block entirely. Use when code is illustrative, incomplete, or requires setup that cannot be provided in the test environment.

{/* pmd-metadata: notest */}
```python
# This block will not be tested
prefect deploy --some-hypothetical-flag

**`continuation`** — Share state (imports, variables, function definitions) from preceding code blocks on the same page. Without this, each block starts with a clean namespace. Use when a multi-step example is split across blocks for readability.

```mdx
```python
from prefect import flow

@flow
def my_workflow() -> str:
    return "Hello, world!"

{/* pmd-metadata: continuation */}

my_workflow()  # Can reference the function defined above

**`fixture:<name>`** — Inject a pytest fixture defined in `conftest.py` as a global in the code block. Use when a block needs mocking (e.g., HTTP calls).

```mdx
{/* pmd-metadata: fixture:mock_post_200 */}
```python
import requests
response = requests.post(endpoint, headers=headers, json=data)
assert response.status_code == 200

### Global imports

The `pytest_markdown_docs_globals` hook in `conftest.py` injects a small set of globals into every code block automatically: `Mapped`, `Run`, `Union`, `mapped_column`, `sa`. You do not need to import these in doc examples.

### Autouse fixtures

Two fixtures are applied to every test automatically (defined in `conftest.py`):

- `mock_runner_start` — Mocks `prefect.cli.flow.Runner.start` so flow-serving examples don't actually start a long-running process.
- `mock_base_worker_submit` — Mocks `BaseWorker.submit` and `KubernetesWorker.submit` so worker examples don't attempt real infrastructure calls.

### Skipped files

Some files are skipped entirely via the `SKIP_FILES` dict in `conftest.py`. Common reasons include needing database fixtures, block cleanup, live network calls, or async contexts. Additionally:

- All files under `v3/api-ref/python/` are auto-skipped (generated reference docs).
- All files under `v3/examples/` are auto-skipped (tested separately in their source repo).

When adding a new page that genuinely cannot be tested, add it to `SKIP_FILES` with a reason rather than marking every block with `notest`.

## Images

Place images in `v3/img/` organized by section (e.g., `v3/img/ui/`, `v3/img/concepts/`). Reference them with absolute paths:

```mdx
![Description](/v3/img/ui/screenshot.png)

• Always include meaningful alt text that describes what the image shows.
• Use compressed PNG or WebP format to keep page load times fast.
• Avoid committing unnecessarily large screenshots; crop to the relevant area.

Linting

Docs are linted with Vale using Google style, Vale defaults, and custom Prefect rules. Run locally:

just lint

Or manually: vale --glob='**/*.{md,mdx}' .

Tone and style

• Use second person ("you") and active voice in present tense.
• Avoid first person ("I", "we") and marketing language ("powerful", "seamless", "best-in-class").
• Be direct and concise. Shorter sentences are easier to scan.
• Follow the Google developer documentation style guide as the baseline.

Examples of preferred phrasing:

When introducing a concept, lead with what the reader can do, not what the feature is:

• Before: "The retry mechanism is a configurable system that allows flows to recover from transient failures."
• After: "Add retries to your flow to recover automatically from transient failures."

Quality checklist

Before considering a page complete, verify:

1. The page opens with appropriate context: for how-to guides, a single-sentence scope line (or jump straight into steps if the title already establishes the goal); for concepts and advanced pages, an opening paragraph that defines the topic and why it matters.
2. Prerequisites (tools, access, prior knowledge) are called out up front.
3. The page includes at least one cross-link to a related Concept or How-to page.
4. All code blocks are runnable and tested, or explicitly marked with {/* pmd-metadata: notest */} with a reason.
5. Frontmatter includes keywords with 3-5 search terms not already in the title or description.
6. The page is registered in docs/docs.json navigation.

Common mistakes

• Using # (H1) in the body — the frontmatter title already renders as H1.
• Using relative links or including .mdx in link paths.
• Using Markdown admonitions (> **Note:**) instead of Mintlify components (<Note>).
• Inconsistent heading hierarchy (jumping from H2 to H4).
• Missing description or keywords in frontmatter — both improve search discoverability.
• First-person pronouns ("I", "we") — use "you" or imperative voice.
• Wrong terminology casing: "Prefect cloud" (should be "Prefect Cloud"), "Prefect Server" (should be "Prefect server"), "k8s" (should be "Kubernetes"), "infra" (should be "infrastructure").
• Forgetting to register a new page in docs/docs.json — the page won't appear in nav.
• Forgetting to add a redirect in docs/docs.json when moving or renaming a page.
• Overusing <Note>/<Tip>/<Warning> — reserve for genuinely important callouts, not every paragraph.

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