Plan Your Dependencies Before They Plan Your Project

A good Open Source idea can feel small at first: a helpful app, a simple library, a dashboard, a browser extension, a set of tools for a community group. Then planning begins, and the project quietly grows around things you do not fully control.

Maybe you need a third-party API. Maybe the project depends on a dataset that is hard to update. Maybe it assumes a hosted service will stay free. Maybe only one person understands a key part of the stack.

That is why dependency planning belongs in Planning & Scoping. Before you build, you need to know what your project relies on, how risky those dependencies are, and what you will do if they change. This is especially important for public-benefit software, where users may not have money, time, fast devices, or easy alternatives.

Why This Stage Matters

Open Source projects that serve education, accessibility, security, and civic needs often operate with limited time and support. A hidden dependency can become a hidden cost.

For example, imagine an Open Source reading practice app for adult learners. The core idea is simple: teachers assign short passages, learners listen to audio, and the app tracks progress locally or in a low-cost backend. But the plan may depend on several things:

• A text-to-speech service or browser feature
• A library for offline storage
• A set of reading passages with clear usage rights
• A hosting provider
• A volunteer who can help with accessibility testing

None of those are automatically bad. The problem is not having dependencies. The problem is not naming them until they break.

Step 1: List Every Dependency You Can See

Start with a plain list. Do not judge anything yet. Write down everything your project needs in order to work.

Use these categories:

• Code dependencies: frameworks, packages, SDKs, command-line tools, browser APIs, build tools
• Data dependencies: public datasets, content libraries, translation files, maps, school data, vulnerability feeds
• Service dependencies: hosting, email, authentication, analytics, storage, notification services, payment-free API tiers
• Hardware and platform dependencies: phones, screen readers, low-end laptops, specific browsers, operating systems
• People dependencies: maintainers, domain experts, testers, designers, translators, community partners
• Process dependencies: review steps, data updates, content moderation, release approvals, documentation updates

The goal is to make the invisible visible. If your project cannot function without it, it belongs on the list.

Step 2: Mark What You Control

Next to each dependency, mark how much control you have over it.

• High control: code you write, documentation you maintain, simple configuration you own
• Medium control: Open Source libraries you can fork if needed, public data you can cache, services you can replace with effort
• Low control: proprietary APIs, free service tiers, external organizations, closed platforms, one volunteer with unique knowledge

This is not about avoiding every low-control dependency. Sometimes a third-party service is the right choice. But low-control dependencies should affect your scope.

If a free API is required for the first version, write that down clearly. If a project depends on one person manually updating data every week, that is part of the plan, not a side note.

Step 3: Identify the Failure Mode

For each important dependency, ask: what happens if this stops working?

Be specific. Avoid vague notes like “could be a problem.” Instead, write the actual failure mode.

• If the text-to-speech API changes pricing, audio playback stops for learners.
• If the offline storage library is abandoned, the app may fail in newer browsers.
• If the dataset is not updated, users may see outdated or unsafe information.
• If the only accessibility tester leaves, screen reader support may drift without anyone noticing.

This step helps you see which risks are annoying and which risks can harm the usefulness of the project.

For public-benefit Open Source, failure modes matter because users may depend on the tool in real settings: a classroom, a clinic, a library, a mutual aid group, or a small nonprofit. Planning should respect that.

Step 4: Choose a Strategy for Each Key Dependency

Once you know the risk, choose a simple strategy. You do not need a complex risk management system. You need clear decisions.

• Accept it: The risk is small enough for now. Note it and move on.
• Reduce it: Use a smaller library, cache data, add tests, document setup, or choose a simpler stack.
• Replace it: Pick a dependency you control more directly.
• Delay it: Keep the dependency out of the first build until you know it is necessary.
• Design around it: Make the app still useful when the dependency is unavailable.

In the reading app example, you might decide that text-to-speech is helpful but not required for the first version. The first scope could support human-recorded audio uploads and plain text display. Browser text-to-speech can be added later after testing. That one decision can make the first version easier to build and less fragile.

Step 5: Turn Dependency Choices Into Scope Rules

Dependency planning is only useful if it changes the project plan. Convert your decisions into scope rules that guide development.

Here are examples:

• The first version will not require paid external APIs.
• The app must work without analytics or tracking services.
• Core content must be usable offline after first load.
• Authentication will be optional until there is a clear need for accounts.
• Any required dataset must have a documented update process.
• No feature can depend on one undocumented manual step.

These rules help you say no without getting stuck in debate. They also help future contributors understand why the project is shaped the way it is.

Step 6: Write a Small Dependency Table

Add a short dependency table to your planning notes, project brief, or README draft. Keep it simple enough that you will actually maintain it.

• Name: What is the dependency?
• Type: Code, data, service, platform, person, or process
• Needed for: What feature or workflow uses it?
• Control level: High, medium, or low
• Failure mode: What breaks if it changes?
• Decision: Accept, reduce, replace, delay, or design around

For a small project, ten rows may be enough. The point is not to predict every future problem. The point is to avoid being surprised by the obvious ones.

A Simple Planning Checklist

• Have you listed code, data, service, platform, people, and process dependencies?
• Do you know which dependencies are outside your control?
• Can the core project still work if a nice-to-have service disappears?
• Are any important tasks dependent on one person’s private knowledge?
• Have dependency risks changed the first version’s scope?
• Have you documented the decisions where contributors can find them?

This kind of planning supports sustainability. It helps developers build Open Source tools that are easier to maintain, easier to explain, and more reliable for the people who need them.

TL;DR

Before you build, list what your project depends on. Include code, data, services, platforms, people, and processes. Mark what you control, name what can fail, and choose a strategy for each important dependency. Then turn those choices into clear scope rules. A project with fewer hidden dependencies is easier to build, easier to sustain, and more likely to serve communities well.