Comparison

SpecTrail and requirements tools: authored and derived.

Requirements management tools are built for teams that write requirements first and trace them to the work. SpecTrail starts from the code, derives the specification and keeps it current. The two approaches suit different teams, and some teams use both.

Comparison · 5 minute read

Two ways to get a specification

The first way is to write it. People decide what the product should do, record it as requirements, link the requirements to design, work and tests, and keep the links current as the project moves. Requirements management tools are built for this approach, and it gives a team a deliberate, reviewed statement of intent.

The second way is to derive it. The code already holds the truth about what the product does, so a tool reads it and writes the specification in plain language, with the code and the tests behind each statement. People review and edit the result. SpecTrail takes this approach.

	Authored requirements tools	SpecTrail
It starts from	Requirements that people write	The code that is running
Creating the document	Written and organised by people	Drafted from the repository, then reviewed and edited by people
Staying current	Through the team’s process and discipline	Each merged change is checked against the document
Links to code and tests	Created and maintained by the team	Marks on each statement show the code and tests behind it
Fits best when	Requirements come first, with formal approval before building starts	Code moves fast and the document must describe what is actually built

When an authored tool is the right fit

A programme with a long design phase and formal sign-off before any code is written needs a place for those requirements and their approvals. The requirements are the plan, and the plan is worth recording carefully. An authored tool is designed for exactly that.

When a derived specification fits

The code moves faster than the document. Daily releases and AI agents change the product faster than anyone can edit a requirements database.
There is no document yet. A growing startup or an inherited codebase has a product and no specification, and a draft derived from the code is a fast place to start.
The document has to match what is built. Auditors, regulators and customers ask what the product does, and the answer should describe the running product.
Nobody has time to maintain it. A specification that is updated by reading the code needs no upkeep from the team.

Using both

Intent and fact are different things, and a mature team can value both. The authored requirements say what the product should do. The derived specification says what it does. Reading the two side by side makes any difference between them visible, and SpecTrail’s flags show when a merged change moves the product away from the specification, so that a person can decide whether the change or the document should win.