tech-spec

tech-spec is a skill for Claude Code, Codex from sd0xdev/sd0x-harness. It costs 54 tokens per session (1,941 once invoked), scanned A, original, MIT.

A tool for creating and reviewing technical specifications: numbered documents that describe how a software feature should be designed and built.

In plain words
What is it for?
Use it to draft or update feature specifications, deepen a concept into a roadmap, and review a proposed technical design.
Why use it?
It gives developers a shared, reviewable plan before implementation begins and helps find unclear or missing details in an existing specification.

Skill for Claude CodeCodex

Part of the sd0x-dev-flow plugin — 98 skills, 16 agents, 5 hooks shipped together

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 skills/sd0xdev/sd0x-harness/tech-spec
Any agent
npx skills add sd0xdev/sd0x-harness --skill tech-spec
Clone the repo
git clone --depth 1 https://github.com/sd0xdev/sd0x-harness

Made for: Claude Code, Codex.

Or install sd0x-dev-flow, the plugin that ships this one along with the rest of its 98 skills, 16 agents, 5 hooks.

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 tech-spec

README.md
[![agentmods](https://agentmods.dev/badge/skills/sd0xdev/sd0x-harness/tech-spec.svg)](https://agentmods.dev/skills/sd0xdev/sd0x-harness/tech-spec)
Your own site
<a href="https://agentmods.dev/skills/sd0xdev/sd0x-harness/tech-spec"><img src="https://agentmods.dev/badge/skills/sd0xdev/sd0x-harness/tech-spec.svg" alt="Measured on agentmods" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,941 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. 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 $0.00054 $0.01941
Opus 5 $0.00027 $0.00971
Sonnet 5 $0.00011 $0.00388
Haiku 4.5 $0.00005 $0.00194

Measured yesterday against content hash 0f70763b3382, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

tech-spec 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 yesterday.

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.

skills/tech-spec/SKILL.md · 165 lines

How it starts

The opening of the file, as written. The whole thing — 165 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Tech Spec Skill

Trigger

  • Keywords: tech spec, technical specification, spec review, review spec, feature design

When NOT to Use

  • Creating request documents (use /create-request)
  • Code implementation (use feature-dev)
  • Architecture consulting (use /codex-architect)

Commands

Command Purpose When
/tech-spec Create or update tech spec Auto-detects create/update from filesystem state
/deep-analyze Deepen spec + roadmap After initial concept
/review-spec Review tech spec Spec confirmation

Context-Aware Mode (Upsert)

When invoked without a full requirement description, the skill auto-detects the target feature using the cascade in references/native-feature-resolution.md — this skill's own reference, and deliberately command-free.

This skill grants Bash(git:*) and not Bash(node:*), so the resolver script is not a command it may run — and it does not link the shared reference that teaches it, because a file of unrunnable commands inside this skill's reachable graph is the defect, not the annotation on it. The cascade needs nothing beyond $ARGUMENTS, git branch --show-current, git diff --name-only HEAD and a Glob over docs/features/*. What that does not produce is the four document source sets or scan_error — this skill consumes neither. A skill that needs the sets (/architecture, /tech-brief, /runbook, /ask) grants Bash(node:*) and reads the shared reference itself.

Canonical discovery is still owed, and testing one literal path does not deliver it. The spec may have been split into a folder or may carry a variant name, and docs/features/auto-loop-evolution/2-tech-spec/2-tech-spec.md in this repo is the live proof. Resolve it with a Glob over docs/features/<key>/, in this order — the first hit wins:

# Glob Meaning
1 docs/features/<key>/2-tech-spec.md Unsplit canonical spec
2 docs/features/<key>/2-tech-spec/2-tech-spec.md Split spec — the folder keeps the lifecycle prefix, the main file keeps the canonical filename (@rules/docs-numbering.md § Size Limit)
3 docs/features/<key>/2-tech-spec*.md, minus any hit matching -fp-brief.md or -tech-brief.md A variant (2-tech-spec-v2.md). The two suffixes are excluded because they are not specs: scripts/config/doc-taxonomy.json carries the same exclude_pattern for the same reason, and docs/features/seek-verdict/ holds a live 2-tech-spec-fp-brief.md that this glob would otherwise return as the canonical spec. Two or more remaining hits is ambiguity, not a match — report and take the Need Human exit rather than picking one

Read the full file on GitHub · 165 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. yesterday First seen · 165 lines · 54 tokens per session scan A 0f70763b3382

Subscribe to this mod's changes

tech-spec is a skill published in the GitHub repository sd0xdev/sd0x-harness (188 stars, last pushed yesterday), licensed MIT. It adds 54 tokens to every session and 1,941 once invoked, about $0.0003 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 2026-09-03.

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