A shared governance profile for Specsmith agents. It defines required checks, permissions, execution rules, and links between requirements, tests, and code changes.

Use it when setting up or governing agents that need preflight checks, controlled permissions, context limits, testing traceability, and related safeguards.

It gives agents a consistent set of safety and tracking rules instead of leaving those decisions to each task.

How layer1labs/specsmith configures Claude Code and Codex

Reuse

Borrowing it

Nothing to install: this file belongs to layer1labs/specsmith. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/layer1labs/specsmith/main/.agents/skills/agent-core/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/layer1labs/specsmith

Made for: Claude Code, Codex.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/layer1labs/specsmith/agent-core/github.svg)](https://agentmods.dev/skills/layer1labs/specsmith/agent-core)

Your own site

<a href="https://agentmods.dev/skills/layer1labs/specsmith/agent-core"><img src="https://agentmods.dev/badge/skills/layer1labs/specsmith/agent-core/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/layer1labs/specsmith/agent-core"><img src="https://agentmods.dev/badge/skills/layer1labs/specsmith/agent-core.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 624 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.

Model	Per session	Once invoked
Fable 5.1	$0.00000	$0.00624
Opus 5.5	$0.00000	$0.00250
Sonnet 5.5	$0.00000	$0.00125
Haiku 4.5	$0.00000	$0.00062

Measured 2mo ago against content hash cfa2e0c9607b, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

agent-core 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 2mo 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.

.agents/skills/agent-core/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SKILL.md

Agent Core Profile

Requirements Covered

Governance Requirements

REQ-012: Least-Privilege Agent Permissions
REQ-217: Agent Permissions Check
REQ-220: Policy Guardrails
REQ-244: Context Window Sizing
REQ-245: Live Context Fill Indicator
REQ-246: Auto Context Compression
REQ-247: Hard Context Ceiling

Core Principle

The agent-core profile defines the fundamental capabilities and governance rules that all Specsmith agents must follow. This profile ensures that agents operate within the bounds of the Specsmith governance framework while maintaining the flexibility to adapt to different project contexts.

Profile Characteristics

Minimal Required Skills

preflight-gate
governed-agent-loop
requirement-author
testcase-author
traceability-auditor
context-pack-compiler
token-budget-auditor
skill-composer

Governance Compliance

All agents using this profile must:

Run preflight checks before any action that could have side effects
Follow the governed-agent-loop execution pattern
Maintain traceability between requirements, tests, and code changes
Compose skills dynamically based on context
Track token usage and budget efficiency

Implementation Details

Core Loop Execution

Detect Specsmith project context
Run session bootstrap procedures
Emit governance anchor
Classify user intent (read-only, change, release, destructive, research, planning)
For non-read-only actions, run preflight
Load only required context and skills
Execute smallest scoped action
Run verification gates
Record evidence
Save through Specsmith

Context Management

Build minimal context packs from project state, requirements, work items, ESDB records, and relevant skills
Never inject the whole repository when a scoped context is sufficient
Prefer requirement IDs, test IDs, recent WIs, and relevant files
Exclude stale, low-confidence, tombstoned, or contradicted ESDB records
Include stop conditions and known hazards
Track token budget and context utilization

Read the full file on GitHub · 85 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.

2mo ago First seen · 85 lines · 0 tokens per session scan A cfa2e0c9607b

Subscribe to this mod's changes

agent-core is a skill published in the GitHub repository layer1labs/specsmith (8 stars, last pushed 1mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 624 tokens. 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 2026-08-31.

Building agents ai-agents ai-assisted-development ai-governance context-compression developer-tools governance-as-code

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