agent-builder

agent-builder is a skill for Claude Code from synaptiai/synapti-marketplace. It costs 241 tokens per session (6,205 once invoked), scanned B, original, Apache-2.0.

A generator for role-specific instructions and permissions for software agents. It reads organizational design documents and can format the result for Claude Code, OpenAI Agents SDK, Anthropic Agent SDK, CrewAI, or a custom setup.

In plain words
What is it for?
Use it to create system prompts, tool permissions, capability declarations, and self-review checklists for a specific organizational role.
Why use it?
It turns broad organizational decisions into a focused description of one agent’s job, authority, tools, and self-checks. This helps prevent an agent from receiving more access or responsibility than its role requires.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: agent in frontmatter; reads .claude/ paths; mentions CLAUDE.md.

Part of the ai-first-org-design-kit plugin — 15 skills shipped together

Good fit Use it to create system prompts, tool permissions, capability declarations, and self-review checklists for a specific organizational role.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/synaptiai/synapti-marketplace/agent-builder
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.

Any agent
npx skills add synaptiai/synapti-marketplace --skill agent-builder
Clone the repo
git clone --depth 1 https://github.com/synaptiai/synapti-marketplace

Made for: Claude Code.

Or install ai-first-org-design-kit, the plugin that ships this one along with the rest of its 15 skills.

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 agent-builder

README.md
[![agentmods](https://agentmods.dev/badge/skills/synaptiai/synapti-marketplace/agent-builder/github.svg)](https://agentmods.dev/skills/synaptiai/synapti-marketplace/agent-builder)
Your own site
<a href="https://agentmods.dev/skills/synaptiai/synapti-marketplace/agent-builder"><img src="https://agentmods.dev/badge/skills/synaptiai/synapti-marketplace/agent-builder/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 agent-builder

Your own site · 80×15
<a href="https://agentmods.dev/skills/synaptiai/synapti-marketplace/agent-builder"><img src="https://agentmods.dev/badge/skills/synaptiai/synapti-marketplace/agent-builder.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 241 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,205 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. 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 $0.00241 $0.06205
Opus 5 $0.00120 $0.03102
Sonnet 5 $0.00048 $0.01241
Haiku 4.5 $0.00024 $0.00620

Measured 9d ago against content hash e7bfa38f2447, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade B, and why

agent-builder 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 9d 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.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

chmod 700 "$HOME/.ai-first-kit" "$HOME/.ai-first-kit/projects" "$HOME/.ai-first-kit/projects/$SLUG" "$HOME/.ai-first-kit/projects/$SLUG/agents" 2>/dev/null
plugins/ai-first-org-design-kit/skills/agent-builder/SKILL.md · 494 lines

How it starts

The opening of the file, as written. The whole thing — 494 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Builder

You are an Agent Configuration Engineer — you take organizational design artifacts and produce role-specific agent system prompts, tool permissions, and capability declarations for any framework. Not generic organizational primers — role-specific operating instructions that make an agent embody a particular function in the organization.

The AGENT-PRIMER.md is an employee handbook. This skill produces job descriptions. An agent needs both.

Read ../../shared/concepts.md for Work Modes and the Specification Stack before proceeding.

Work through these steps in order, announcing each step as you begin it:

Persona

  • Role-specific, not generic. An employee handbook is not a job description. Every output is scoped to one role.
  • Authority-scoped. Every agent gets exactly the authority its role requires — no more, no less.
  • Framework-flexible. The core output is platform-agnostic markdown. Framework exports are optional formatting.
  • Security-aware. Never expose holdouts or political maps. Agent configs get visible gate criteria only.

Pre-Flight

# Derive stable project slug from git repo root (not leaf dir, to prevent cross-repo collisions)
REPO_ROOT=$(git rev-parse --show-toplevel 2>/dev/null)
if [ -n "$REPO_ROOT" ]; then
  SLUG=$(basename "$REPO_ROOT" | tr '[:upper:]' '[:lower:]' | tr ' ' '-' | head -c 40)
else
  SLUG=$(echo "${PWD##*/}" | tr '[:upper:]' '[:lower:]' | tr ' ' '-' | head -c 40)
fi
[ -z "$SLUG" ] && SLUG="default"
mkdir -p "$HOME/.ai-first-kit/projects/$SLUG/agents"
chmod 700 "$HOME/.ai-first-kit" "$HOME/.ai-first-kit/projects" "$HOME/.ai-first-kit/projects/$SLUG" "$HOME/.ai-first-kit/projects/$SLUG/agents" 2>/dev/null
echo "Project: $SLUG"

# Check required artifacts
ROLES=$(ls -t "$HOME/.ai-first-kit/projects/$SLUG"/roles-*.md 2>/dev/null | head -1)
GENOME=$(ls "$HOME/.ai-first-kit/projects/$SLUG/genome/00-identity/VALUES.md" 2>/dev/null)
AUTH_MATRIX=$(ls "$HOME/.ai-first-kit/projects/$SLUG/governance/AUTHORITY-MATRIX.md" 2>/dev/null)
BOUNDARIES=$(ls "$HOME/.ai-first-kit/projects/$SLUG/governance/HARD-BOUNDARIES.md" 2>/dev/null)
ESCALATION=$(ls "$HOME/.ai-first-kit/projects/$SLUG/governance/ESCALATION-PROTOCOLS.md" 2>/dev/null)
GATES=$(ls "$HOME/.ai-first-kit/projects/$SLUG/gates/INDEX.md" 2>/dev/null)
SPECS=$(ls "$HOME/.ai-first-kit/projects/$SLUG/specs/"*.md 2>/dev/null | head -5)
PRIMER=$(ls "$HOME/.ai-first-kit/projects/$SLUG/AGENT-PRIMER.md" 2>/dev/null)
AGENT_INDEX=$(ls "$HOME/.ai-first-kit/projects/$SLUG/agents/INDEX.md" 2>/dev/null)

[ -n "$ROLES" ] && echo "ROLES: $ROLES" || echo "ROLES: missing"
[ -n "$GENOME" ] && echo "GENOME: found" || echo "GENOME: missing"
[ -n "$AUTH_MATRIX" ] && echo "AUTHORITY MATRIX: found" || echo "AUTHORITY MATRIX: missing"
[ -n "$BOUNDARIES" ] && echo "HARD BOUNDARIES: found" || echo "HARD BOUNDARIES: missing"
[ -n "$ESCALATION" ] && echo "ESCALATION: found" || echo "ESCALATION: missing"
[ -n "$GATES" ] && echo "GATES: found" || echo "GATES: missing"
[ -n "$SPECS" ] && echo "SPECS: found" || echo "SPECS: missing"
[ -n "$PRIMER" ] && echo "PRIMER: found" || echo "PRIMER: missing"
[ -n "$AGENT_INDEX" ] && echo "EXISTING AGENTS: found" || echo "EXISTING AGENTS: none"

# Check for registered Claude Code agents
CC_AGENT_COUNT=$(ls .claude/agents/*.md 2>/dev/null | wc -l | tr -d ' ')
[ "$CC_AGENT_COUNT" -gt 0 ] 2>/dev/null && echo "CLAUDE CODE AGENTS: $CC_AGENT_COUNT registered" || echo "CLAUDE CODE AGENTS: none"

Read the full file on GitHub · 494 lines

Files

What ships with it

1 file 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. 9d ago First seen · 494 lines · 241 tokens per session scan B e7bfa38f2447

Subscribe to this mod's changes

agent-builder is a skill published in the GitHub repository synaptiai/synapti-marketplace (6 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 241 tokens to every session and 6,205 once invoked, about $0.0012 per session on Opus 5. A static security scan graded it B with 1 finding (asks for root). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.