SB Restricted Worker

SB Restricted Worker is an agent for coding agents from gexchai/subject-broker. It costs 16 tokens per session (107 once invoked), scanned A, original, Apache-2.0.

A restricted worker subagent for testing whether a delegated coding agent can use only its assigned SubjectBroker tool.

In plain words
What is it for?
Use it in field tests of delegated-agent tool isolation and exact error reporting.
Why use it?
It helps reveal whether the worker stays within its permitted tool boundary or reports an error when access is unavailable.

Agent

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/gexchai/subject-broker/sb-restricted-worker
Clone the repo
git clone --depth 1 https://github.com/gexchai/subject-broker

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 SB Restricted Worker

README.md
[![agentmods](https://agentmods.dev/badge/agents/gexchai/subject-broker/sb-restricted-worker.svg)](https://agentmods.dev/agents/gexchai/subject-broker/sb-restricted-worker)
Your own site
<a href="https://agentmods.dev/agents/gexchai/subject-broker/sb-restricted-worker"><img src="https://agentmods.dev/badge/agents/gexchai/subject-broker/sb-restricted-worker.svg" alt="Measured on agentmods" height="20"></a>
Per session 16 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 107 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 $0.00016 $0.00107
Opus 5 $0.00008 $0.00053
Sonnet 5 $0.00003 $0.00021
Haiku 4.5 $0.00002 $0.00011

Measured 4d ago against content hash 28b69b4c1447, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

SB Restricted Worker 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 4d 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.

fixtures/vscode-copilot/project/.github/agents/sb-restricted-worker.agent.md · 17 lines

What it actually says

Follow the delegated field-test prompt exactly.

Use only the specifically requested sbWorker tool. Do not use filesystem, search, terminal, web, extension, or differently named MCP tools. Never substitute another SubjectBroker connection. Report exact tool results and harness errors.

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. 4d ago First seen · 17 lines · 16 tokens per session scan A 28b69b4c1447

Subscribe to this mod's changes

SB Restricted Worker is an agent published in the GitHub repository gexchai/subject-broker (0 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 16 tokens to every session and 107 once invoked, about $0.0001 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 2026-08-31.