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sdd-spec

Writes SDD delta specifications with RFC 2119 requirements and Given/When/Then scenarios.

Updated Mar 7, 2026
Search Tags:#specification#requirements#sdd#openspec#given-when-then#rfc2119#delta spec
One-click install
npx skills add https://github.com/albersg/dotfiles --skill sdd-spec-albersg
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: sdd-spec
Source: https://github.com/albersg/dotfiles/tree/main/dotfiles-opencode/.opencode/skills/sdd-spec
Command: npx skills add https://github.com/albersg/dotfiles --skill sdd-spec-albersg

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? It turns an approved change proposal into structured, testable specifications, eliminating ambiguity about what behavior is being added, modified, removed, or renamed before implementation begins. ## Core Features & Use Cases - Delta Spec Authoring: Produces ADDED, MODIFIED, REMOVED, and RENAMED requirement sections that merge cleanly into existing specs at archive time. - Testable Scenarios: Every requirement includes Given/When/Then scenarios covering happy paths and edge cases, ready to convert into automated tests. - Multi-Mode Persistence: Supports engram, openspec, hybrid, and none artifact store modes, reading the proposal's Capabilities section to map domains to spec files. - Use Case: After an orchestrator approves a change proposal for a new authentication flow, this sub-agent reads the proposal, writes delta specs per affected domain, and returns a coverage summary for the design phase. ## Quick Start Delegate to the sdd-spec sub-agent with the change name and artifact store mode to generate delta specifications from the approved proposal.

Frequently Asked Questions about sdd-spec

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I write delta specs in an SDD workflow?▼

Read the proposal's Capabilities section to identify affected domains, then write ADDED, MODIFIED, REMOVED, or RENAMED requirement sections per domain. Each requirement uses RFC 2119 keywords and at least one Given/When/Then scenario.

What is the difference between a delta spec and a full spec?▼

A delta spec describes changes to existing behavior using ADDED/MODIFIED/REMOVED/RENAMED sections, while a full spec defines a brand-new domain with a Purpose section and complete requirements. New capabilities get full specs; modified capabilities get deltas.

Why must MODIFIED requirements copy the entire existing requirement block?▼

The archive step replaces the requirement in main specs with the MODIFIED block. A partial block loses scenarios that were not copied, so the full requirement plus all scenarios must be pasted and then edited.

Can this skill run standalone or only through an orchestrator?▼

It is delegate-only: the orchestrator must invoke the dedicated sdd-spec sub-agent rather than executing the instructions inline. The sub-agent receives the change name and artifact store mode as inputs.

What artifact store modes does the spec phase support?▼

Four modes are supported: engram (single concatenated artifact), openspec (filesystem convention), hybrid (both), and none (return result only without creating project files).

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