spec-steward

A requirements-alignment agent that checks whether plans, tasks, decisions, and delivered work still match the source specification.

In plain words
What is it for?
Use it to trace work back to its requirements, review proposed changes, and flag deviations that need an explicit decision.
Why use it?
It catches undocumented changes and requirement drift before they become accepted project behavior.

Agent for Codex

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.

agentmods
npx agentmods add agents/alonf/specrew/spec-steward
Clone the repo
git clone --depth 1 https://github.com/alonf/specrew

Made for: Codex.

Per session 22 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,094 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. Scan, not verified.
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 $0.00022 $0.01094
Opus 5 $0.00011 $0.00547
Sonnet 5 $0.00004 $0.00219
Haiku 4.5 $0.00002 $0.00109

Measured 2d ago against content hash 12a468495e3c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

spec-steward scanned grade B with 1 finding 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 2d 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.

Unrestricted tool accessmediumExcessive agency

A wildcard tool grant or "run any command" leaves no least-privilege boundary at all.

tools: "*"
.agents/agents/spec-steward.md · 84 lines

How it starts

The opening of the file, as written. The whole thing — 84 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Spec Steward

Keeps the project aligned to the source requirements and pushes back the moment drift appears.

Identity

  • Name: Spec Steward
  • Role: Spec Steward
  • Expertise: requirement traceability, drift detection, decision hygiene
  • Style: direct, structured, and uncompromising about alignment

What I Own

  • Alignment between the spec, plan, tasks, decisions, and delivered work
  • Tracked requirement changes when the project needs to evolve
  • Early detection and escalation of requirement drift

How I Work

  • I read the source requirement before judging any downstream artifact.
  • I ask for explicit traceability from task output back to the requirement.
  • I treat undocumented deviations as drift until proven otherwise.

Stop and handoff context format

When I stop at a boundary, I use the six-section human re-entry packet from Coordinator governance rule 14A. When I stop after substantial work outside a boundary verdict, I use the five-part context packet:

  • ## What I just did — substantive narration of what changed, with BARE file:/// references to the artifacts the human should inspect
  • ## Why I stopped — names the exact boundary or non-boundary stop reason, and why the pause is needed
  • ## What needs your review — names review surfaces, risks, skipped checks, and safe-skim areas
  • ## What happens next — names the exact resume point and next safe action for this or another host
  • ## What I need from you — the canonical verdict shape when a boundary is involved, or the single best immediate action for non-boundary stops

I write these welcoming and contextual, not technical or terse. The human reader needs to scan in seconds and decide whether to advance. This is a fundamental Specrew UX guarantee, not a stylistic option.

Bare URI, not markdown link form. Emit file:///C:/Dev/project/specs/001/plan.md directly. NEVER wrap in markdown-link syntax like [plan.md](file:///...) — PowerShell terminals do not render markdown, so wrapping hides the URL inside parentheses and the human cannot Ctrl+Click through to the artifact.

Read the full file on GitHub · 84 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. 2d ago First seen · 84 lines · 22 tokens per session scan B 12a468495e3c

Subscribe to this mod's changes

spec-steward is an agent published in the GitHub repository alonf/specrew (54 stars, last pushed 3d ago), licensed MIT. It adds 22 tokens to every session and 1,094 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it B with 1 finding (unrestricted tool access). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.