304 tutorial and how to writing

Tutorial and How-To Writing

Purpose

Apply the Diátaxis framework to put each document in the right mode and write it well. Diátaxis splits docs into four kinds with different jobs: tutorials (learning-oriented, hold the reader's hand to a guaranteed success), how-to guides (task-oriented, get an experienced user through one real goal), reference (information-oriented, dry and complete), and explanation (understanding-oriented, the why). The most common documentation failure is mixing these modes in one page. This skill keeps them separate and makes every instructional step runnable and verified.

When to use

• Writing onboarding material that must take a beginner from zero to a working result.
• Writing a focused "how do I do X" guide for users who already know the basics.
• A page is confusing because it mixes teaching, recipes, theory, and reference at once.
• Step-by-step instructions exist but were never run and may be broken.
• Planning a docs section and deciding what kind of document each topic needs.

When not to use

• The need is an exhaustive parameter/endpoint listing (use api-reference-docs — that is the reference quadrant).
• The need is structuring the whole site/README (use readme-and-docs-structure).
• A one-line FAQ answer suffices and a full guide would be overkill.

Procedure

1. Classify the document by Diátaxis quadrant

Ask the reader's situation: are they learning (tutorial), trying to get a specific job done (how-to), looking something up (reference), or trying to understand (explanation)? Pick exactly one. If a draft serves two, split it.

2. For a tutorial: design a single guaranteed-success path

A tutorial is a lesson, not a menu. Choose one concrete outcome, remove all optional branches, and ensure every learner who follows it lands in the same working state. State prerequisites and the end result up front.

3. For a how-to: scope to one real task with assumed competence

A how-to assumes the reader knows the fundamentals and wants results. State the goal, list prerequisites, give the minimal ordered steps, and stop. Offer realistic variations ("if you use X instead of Y") but do not teach the basics.

4. Write runnable, verifiable steps

Each step is one action with a copy-pasteable command and an observable result the reader can check.

# Pattern for every step: action + expected, checkable result
mkdir demo && cd demo
python3 -m venv .venv && . .venv/bin/activate
pip install example-package
example-cli --version
# Expected: example-cli 2.3.0

5. Verify the whole path end to end from a clean state

# Run the entire tutorial/how-to in a throwaway environment, unmodified
( set -e; cd "$(mktemp -d)"; \
  echo "step 1..."; <command-1>; \
  echo "step 2..."; <command-2> )
echo "exit: $?"   # must be 0; any non-zero means a step is wrong

6. Add a verification and troubleshooting close

End with a "you should now see…" success check and a short troubleshooting list for the two or three most common failure points.

Concrete checks

• The document declares its Diátaxis type and stays in that one mode.
• A tutorial has exactly one outcome and no optional branches.
• A how-to is scoped to a single named task and does not teach fundamentals.
• Prerequisites (tools, versions, accounts) are stated before step 1.
• The end result is described up front so the reader knows the target.
• Every step is one action with a copy-pasteable command.
• Every step shows an observable, checkable result.
• The entire path was executed from a clean environment and exited 0.
• Commands use placeholder values for any secret or personal data.
• A final success check lets the reader confirm completion.
• A short troubleshooting section covers the top failure points.
• Explanation/theory is linked, not inlined, keeping the guide actionable.

Templates

# Tutorial: Build your first widget pipeline

By the end you will have a running pipeline that processes one sample file.

**Prerequisites:** Python 3.11+, a terminal, ~10 minutes.

## 1. Create and enter a clean workspace
    mkdir widget-tutorial && cd widget-tutorial
You should see an empty directory.

## 2. Install the toolkit
    python3 -m venv .venv && . .venv/bin/activate
    pip install widget-toolkit
Check: `widget --version` prints `widget 1.x`.

## 3. Run the pipeline on the sample
    widget run --input sample.csv --out result.json
Check: `result.json` exists and contains a `count` field.

## You did it
You now have a working pipeline. Next, see the [how-to: process your own data](../how-to/custom-input.md).

## Troubleshooting
- `command not found: widget` → the venv is not active; re-run `. .venv/bin/activate`.
- Empty `result.json` → confirm `sample.csv` is non-empty.

# How-to: Rotate the service API key

**Goal:** replace the active API key with zero downtime.
**Prerequisites:** admin access, the `service-cli` installed.

1. Create a new key:        `service-cli keys create --name rotated`
2. Deploy it as `SERVICE_API_KEY` (placeholder; never commit the value).
3. Verify traffic uses it:  `service-cli keys usage --name rotated` shows > 0.
4. Revoke the old key:      `service-cli keys revoke --name old`

Common issues & anti-patterns

• Mixing modes: a "tutorial" stuffed with reference tables and architecture theory, so the beginner stalls.
• Offering choices in a tutorial ("you can use A or B") — branching breaks the guaranteed path.
• How-to guides that re-teach installation the reader already did.
• Steps with no expected output, so the reader cannot tell if it worked.
• Instructions written from memory and never executed, so a step is subtly wrong.
• Hardcoded secrets, absolute machine paths, or environment-specific values in commands.
• A "quick" guide that grows into an unscoped everything-page.

Required output

Produce: (1) the Diátaxis classification and why; (2) the structured document with prerequisites, ordered runnable steps, and per-step expected results; (3) evidence the full path was run clean (exit 0); (4) a success check and troubleshooting section; (5) links out to reference/explanation rather than inlined theory.

Safety

• Run all steps in a throwaway directory/environment; never against production systems or real user data.
• Use placeholder credentials and relative or $HOME-based paths, never real secrets or absolute machine paths.
• Do not include destructive commands without an explicit warning and a safe default.
• Verify before publishing; never ship steps you have not executed.