fetch

fetch is a skill for Claude Code, Codex from SECBLOK/belay. It costs 1 tokens per session (15 once invoked), scanned A, original, AGPL-3.0.

A local security layer for AI coding agents such as Claude Code, Codex, and Cursor. It checks tool calls to block dangerous commands, secret leaks, and prompt injection, without sending data to the cloud by default.

In plain words
What is it for?
Use it to protect coding-agent tool calls across supported agents and MCP integrations.
Why use it?
It reduces the risk that an agent will run harmful commands, expose credentials, or follow malicious instructions from its inputs.

Skill for Claude CodeCodex

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/secblok/belay/underdeclared_net_skill
Any agent
npx skills add SECBLOK/belay --skill underdeclared_net_skill
Clone the repo
git clone --depth 1 https://github.com/SECBLOK/belay

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.

agentmods badge for fetch

README.md
[![agentmods](https://agentmods.dev/badge/skills/secblok/belay/underdeclared_net_skill.svg)](https://agentmods.dev/skills/secblok/belay/underdeclared_net_skill)
Your own site
<a href="https://agentmods.dev/skills/secblok/belay/underdeclared_net_skill"><img src="https://agentmods.dev/badge/skills/secblok/belay/underdeclared_net_skill.svg" alt="Measured on agentmods" height="20"></a>
Per session 1 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 15 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin unknown 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 $0.00001 $0.00015
Opus 5 $0.00000 $0.00008
Sonnet 5 $0.00000 $0.00003
Haiku 4.5 $0.00000 $0.00002

Measured 3d ago against content hash d412575b5940, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

fetch 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 3d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (run.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skillscan/tests/corpus/malicious/underdeclared_net_skill/SKILL.md · 6 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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. 3d ago First seen · 6 lines · 1 tokens per session scan A d412575b5940

Subscribe to this mod's changes

fetch is a skill published in the GitHub repository SECBLOK/belay (4 stars, last pushed 29d ago), licensed AGPL-3.0. It adds 1 tokens to every session and 15 once invoked, about $0.0000 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.

Related

Other skills, from other repositories

implementing-llm-guardrails-for-security

Implements input and output validation guardrails for LLM-powered applications to prevent prompt injection, data leakage, toxic content generation, and hallucinated outputs. Builds a security validation pipeline using NVIDIA NeMo Guardrails Colang definitions, custom Python validators for PII detection and content…

xalgorix/xalgorix · 143 tokens

zugashield

7-layer AI security + ML detection for OpenClaw. Covers all 10 OWASP Agentic AI risks — prompt injection, tool misuse, memory poisoning, data exfiltration, and more — across ALL channels (Signal, Telegram, Discord, WhatsApp, web) simultaneously.

Zuga-Technologies/ZugaShield · 61 tokens

exploiting-excessive-data-exposure-in-api

Tests APIs for excessive data exposure where endpoints return more data than the client application needs, relying on the frontend to filter sensitive fields. The tester intercepts API responses and analyzes them for leaked PII, internal identifiers, debug information, or sensitive business data that the UI does not…

xalgorix/xalgorix · 114 tokens

exploiting-jwt-algorithm-confusion-attack

Exploits JWT algorithm confusion vulnerabilities where the server's token verification library accepts the algorithm specified in the JWT header rather than enforcing a fixed algorithm. The tester manipulates the alg header to switch from RS256 to HS256 (using the RSA public key as the HMAC secret), sets alg to none…

xalgorix/xalgorix · 116 tokens

implementing-api-rate-limiting-and-throttling

Implements API rate limiting and throttling controls using token bucket, sliding window, and fixed window algorithms to protect against brute force attacks, credential stuffing, resource exhaustion, and API abuse. The engineer configures per-user, per-IP, and per-endpoint rate limits using Redis-backed counters, API…

xalgorix/xalgorix · 114 tokens

performing-api-inventory-and-discovery

Performs API inventory and discovery to identify all API endpoints in an organization's environment including documented, undocumented, shadow, zombie, and deprecated APIs. The tester uses passive traffic analysis, active scanning, DNS enumeration, JavaScript analysis, and cloud resource inventory to build a…

xalgorix/xalgorix · 100 tokens