sdd-spec-writer

sdd-spec-writer is an agent for Claude Code from gonzalezpazmonica/savia. It costs 103 tokens per session (1,412 once invoked), scanned A, original, MIT.

A specification-writing agent for Spec-Driven Development, a method where a detailed specification acts as the contract for implementation. It creates and checks specifications intended to be followed without further clarification.

In plain words
What is it for?
It helps turn work items into implementation-ready specifications, refine existing ones, and check whether they are precise enough for a coding agent.
Why use it?
It reduces guesswork between a requested task and its implementation by making requirements, project context, and expected behaviour explicit.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter; reads .claude/ paths; mentions CLAUDE.md.

Part of the pm-workspace plugin — 124 commands, 75 agents shipped together

Good fit It helps turn work items into implementation-ready specifications, refine existing ones, and check whether they are precise enough for a coding agent.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/gonzalezpazmonica/savia/sdd-spec-writer
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/gonzalezpazmonica/savia

Made for: Claude Code.

Or install pm-workspace, the plugin that ships this one along with the rest of its 124 commands, 75 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for sdd-spec-writer

README.md
[![agentmods](https://agentmods.dev/badge/agents/gonzalezpazmonica/savia/sdd-spec-writer/github.svg)](https://agentmods.dev/agents/gonzalezpazmonica/savia/sdd-spec-writer)
Your own site
<a href="https://agentmods.dev/agents/gonzalezpazmonica/savia/sdd-spec-writer"><img src="https://agentmods.dev/badge/agents/gonzalezpazmonica/savia/sdd-spec-writer/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for sdd-spec-writer

Your own site · 80×15
<a href="https://agentmods.dev/agents/gonzalezpazmonica/savia/sdd-spec-writer"><img src="https://agentmods.dev/badge/agents/gonzalezpazmonica/savia/sdd-spec-writer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 103 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,412 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00103 $0.01412
Opus 5 $0.00051 $0.00706
Sonnet 5 $0.00021 $0.00282
Haiku 4.5 $0.00010 $0.00141

Measured 6d ago against content hash 90490e47daba, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

sdd-spec-writer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.claude/agents/sdd-spec-writer.md · 149 lines

How it starts

The opening of the file, as written. The whole thing — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Eres el guardián de la calidad de las Specs SDD en este workspace. Tu trabajo es crear especificaciones que sirvan como contratos inequívocos: un desarrollador humano o un agente Claude debe poder implementar la tarea sin hacer ninguna pregunta adicional.

Principio fundamental

"Si el agente falla, la Spec no era suficientemente buena" — tu trabajo es que esto nunca ocurra.

Context Index

Before writing a spec, check projects/{project}/.context-index/PROJECT.ctx if it exists. Use [location] entries to find requirements, architecture, and business rules. Use [digest-target] entries to place the generated spec in the correct location.

Fuentes que siempre consultas antes de escribir

az boards item show --id $TASK_ID --output json    # datos de la Task en AzDO
az boards item show --id $PBI_ID --output json     # PBI padre

También:

  • .claude/skills/spec-driven-development/SKILL.md — metodología SDD completa
  • .claude/skills/spec-driven-development/references/spec-template.md — plantilla canónica
  • .claude/skills/spec-driven-development/references/layer-assignment-matrix.md — qué va a agente vs humano
  • projects/[proyecto]/CLAUDE.md — contexto del proyecto
  • projects/[proyecto]/RULES.md (o reglas-negocio.md) — reglas de negocio
  • Código fuente relevante (interfaces existentes, contratos, tests similares)

Decisión: ¿agente o humano?

Antes de escribir la spec, determinar developer_type:

→ Agente Claude si:

  • Task en capas Application, Infrastructure, o Domain con patrones claros
  • Sin interacción UI compleja (MVC/Blazor con lógica de estado compleja → humano)
  • Sin acceso a sistemas externos no documentados
  • Patrón repetible (Command Handler, Repository, Service, Unit Test)
  • Complejidad estimada ≤ 8h (SDD_DEFAULT_MAX_TURNS = 40)

→ Humano si:

  • Task tipo E1 (Code Review) — SIEMPRE humano, sin excepciones
  • Requiere decisiones de diseño no documentadas
  • Implica UI/UX con criterios estéticos subjetivos
  • Requiere conocimiento de sistemas legacy no documentados

Read the full file on GitHub · 149 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 149 lines · 103 tokens per session scan A 90490e47daba

Subscribe to this mod's changes

sdd-spec-writer is an agent published in the GitHub repository gonzalezpazmonica/savia (50 stars, last pushed today), licensed MIT. It adds 103 tokens to every session and 1,412 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-06.