Technical Documentation & OpenAPI Spec Design

What it does

Technical Documentation & OpenAPI Spec Design is a Cursor skill: a SKILL.md playbook that AgenticKit installs at .cursor/skills/technical-docs. Cursor's agent loads it when the task matches the skill description, instead of stuffing the same rules into every chat.

Guidelines for writing developer-first documentation, OpenAPI 3.0 specs, interactive curl snippets, and Mermaid architecture diagrams.

OpenAPI 3.0, Markdown guides, Mermaid diagrams, and code sample generators. The file is domain knowledge, not a slash macro. You do not type it. The agent reads it when the job is technical docs.

Why it exists

Default Cursor has no memory of how your team ships code, schema, and tests. Founders paste the same conventions into chat, then watch the model drift on the next turn. This skill exists so those conventions live on disk and load only when relevant.

It ships in the Engineering Kit. It is wired to the API & Technical Documentation Writer (technical-writer) and Technical Lead & System Architect (tech-lead) agents. It is wired to the /write-docs: Technical Documentation & API Reference Writer and /release: Release Notes & Changelog Generator commands. That graph is the point: the skill is the standard, the agent is the role, the command is the trigger.

When to use it

• Use Technical Documentation & OpenAPI Spec Design when the work is specifically about openapi 3.0, markdown guides, mermaid diagrams, and code sample generators.
• Load it before a long session that will touch this surface more than once. A one-line edit does not need the full playbook.
• Use it on production SaaS work (multi-tenant apps, paid features, anything that will be reviewed) rather than a throwaway prototype.

When not to use it

• Do not treat the skill as a replacement for a slash command. Skills teach. Commands run a pipeline.
• Do not paste the whole SKILL.md into chat. If Cursor is not loading it, fix the description or invoke the matching command.
• Do not use it as a generic 'write better code' rule. Scope is this domain only.

Example workflow

1. Install the Engineering Kit so .cursor/skills/technical-docs lands in the repo.
2. Open a new Cursor agent chat pointed at the files this skill governs.
3. Ask the API & Technical Documentation Writer (technical-writer) to read the skill, or run /write-docs: Technical Documentation & API Reference Writer.
4. Review the first artifact against the practices below. If it violates one, stop and correct the file. Do not prompt 'just finish it'.
5. Commit the skill-guided files with the rest of the slice so the next session inherits the same standard.

Example usage

Example prompt: "Read .cursor/skills/technical-docs and apply it to this change. Do not invent extra conventions."

Or trigger the pipeline: /write-docs: Technical Documentation & API Reference Writer. That command is written to load this skill.

Check the output against: Maintain single source of truth for API contracts using OpenAPI 3.0 YAML/JSON

Example output

• The skill itself does not write a single output file. It changes what the agent is allowed to produce in code, schema, and tests.
• When you run /write-docs: Technical Documentation & API Reference Writer, expect repo files plus notes under docs/, not a chat-only answer.

Best practices

• Maintain single source of truth for API contracts using OpenAPI 3.0 YAML/JSON
• Provide copy-pasteable request and response examples for every endpoint
• Include interactive Mermaid architecture diagrams illustrating data flows
• Keep documentation synchronized with code changes during the feature PR review

Common mistakes

• Ignoring "Maintain single source of truth for API contracts using OpenAPI 3.0 YAML/JSON" and hoping a later prompt will clean it up.
• Copying the skill into .cursor/rules as always-on. That burns context and fights Cursor's load-on-match design.
• Running two overlapping skills that contradict each other in the same turn.
• Letting the agent skip tests or types because 'the skill is about architecture'.