agents: Skill for Claude Code

.agents/skills/sast-graphql/SKILL.md

sast-graphql is a skill for Claude Code, Codex from mtnyilmaz/agents. It costs 115 tokens per session (3,483 once invoked), scanned A, original, MIT.

A focused check for GraphQL injection, where user input changes the text or structure of a GraphQL query, mutation, or subscription instead of being passed as a value. GraphQL is an API format that lets clients request specific data through structured operations.

In plain words
What is it for?
Use it to inspect GraphQL clients, gateways, resolvers, and HTTP request bodies for operations assembled with concatenation or interpolation. It requires sast/architecture.md.
Why use it?
Building GraphQL operations by joining strings can let attackers add fields, directives, or other instructions to a request. This check finds unsafe operation construction and traces whether user input reaches it.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions subagents; installed under .agents/ (shared by several agents).

This is mtnyilmaz/agents's own configuration. It tells Claude Code and Codex how to work on agents itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything agents configures →

Reuse

Borrowing it

Nothing to install: this file belongs to mtnyilmaz/agents. 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/mtnyilmaz/agents/main/.agents/skills/sast-graphql/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/mtnyilmaz/agents

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 sast-graphql

README.md
[![agentmods](https://agentmods.dev/badge/skills/mtnyilmaz/agents/sast-graphql.svg)](https://agentmods.dev/skills/mtnyilmaz/agents/sast-graphql)
Your own site
<a href="https://agentmods.dev/skills/mtnyilmaz/agents/sast-graphql"><img src="https://agentmods.dev/badge/skills/mtnyilmaz/agents/sast-graphql.svg" alt="Measured on agentmods" height="20"></a>
Per session 115 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,483 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 2 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 5.1 $0.00115 $0.03483
Opus 5 $0.00057 $0.01741
Sonnet 5 $0.00023 $0.00697
Haiku 4.5 $0.00012 $0.00348

Measured 6d ago against content hash 59fb8942fcca, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

sast-graphql scanned grade A with 2 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 6d 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.

Sends data to an external URLlowData exfiltration

A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.

const data = await fetch('https://api.internal/graphql', { method: 'POST',

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

> - `JSON.stringify({ query: `...${userPart}...` })`, `axios.post(url, { query: builtFromInput })`
.agents/skills/sast-graphql/SKILL.md · 309 lines

How it starts

The opening of the file, as written. The whole thing — 309 lines — stays where its author put it; the contents beside it link to each section on GitHub.

GraphQL Injection Detection

You are performing a focused security assessment to find GraphQL injection vulnerabilities. This skill uses a two-phase approach with subagents: recon (confirm GraphQL usage and find every location where a GraphQL operation document is assembled unsafely) then taint (confirm whether user-supplied input reaches those assembly sites).

Prerequisites: sast/architecture.md must exist. Run the analysis skill first if it doesn't.


What is GraphQL Injection

GraphQL injection occurs when user-controlled data is embedded into the GraphQL document (the query, mutation, or subscription string) rather than passed only through the variables map. The parser then interprets attacker-controlled syntax — new fields, aliases, directives, or fragments — which can bypass intent, reach unauthorized resolvers, or change server-side behavior when that document is executed or forwarded.

The core pattern: unvalidated user input alters the structure or text of the GraphQL operation string passed to execute, graphql, a gateway client, or an HTTP body query field built from string operations.

What GraphQL Injection IS

  • Concatenating or interpolating user input into an operation string: `query { user(id: "${id}") { name } }`, "query { user(id: \"" + id + "\") { name } }"
  • Building the JSON query field for a downstream GraphQL HTTP request with string concat from request body or params
  • Forwarding req.body.query (or similar) into another interpolated template that wraps or extends the operation
  • Dynamic gql / graphql-tag template literals where a non-static expression changes document structure (not just a bound variable value inside a static document)
  • Server-side code that selects or assembles operation text from user input (including "persisted query" ID → document maps without allowlisting)
  • Wrappers around graphql.execute(), graphqlHTTP, Yoga/Apollo request pipeline where the first argument (document/source) is built from variables that could be user-influenced

Read the full file on GitHub · 309 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. 6d ago First seen · 309 lines · 115 tokens per session scan A 59fb8942fcca

Subscribe to this mod's changes

sast-graphql is a skill published in the GitHub repository mtnyilmaz/agents (6 stars, last pushed 3mo ago), licensed MIT. It adds 115 tokens to every session and 3,483 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 2 findings (sends data to an external url, makes network calls). 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

omni-mcp

Connect to the OmniRoute MCP server (110 tools, 3 transports: SSE/stdio/HTTP). Covers routing, cache, compression, memory, skills, providers, and audit tools across 33 permission scopes.

diegosouzapw/OmniRoute · 48 tokens

mem0-oss-to-platform

Plan and then execute a migration of a project from the mem0 open-source / self-hosted SDK (the local Memory class) to the mem0 Platform / hosted / managed SDK (the MemoryClient class). Use this whenever a developer wants to move, switch, or migrate their mem0 usage off OSS/self-hosted to the hosted API — e.g.…

mem0ai/mem0 · 273 tokens

agui-dotnet-protobuf

Use the protobuf wire transport (instead of the default Server-Sent Events) for an AG-UI connection with the AG-UI .NET SDK — a compact binary event stream negotiated via the Accept header. USE FOR: making an AGUIChatClient prefer protobuf by wiring an AGUIEventStreamHandler with ProtobufEventStreamFormatter (then…

ag-ui-protocol/ag-ui · 162 tokens

azure-mgmt-botservice-dotnet

Azure Resource Manager SDK for Bot Service in .NET. Management plane operations for creating and managing Azure Bot resources, channels (Teams, DirectLine, Slack), and connection settings. Triggers: "Bot Service", "BotResource", "Azure Bot", "DirectLine channel", "Teams channel", "bot management .NET", "create bot".

microsoft/skills · 78 tokens

fastapi-router-py

Create FastAPI routers with CRUD operations, authentication dependencies, and proper response models. Use when building REST API endpoints, creating new routes, implementing CRUD operations, or adding authenticated endpoints in FastAPI applications.

microsoft/skills · 46 tokens

telnyx-messaging-hosted-curl

Set up hosted SMS numbers, toll-free verification, and RCS messaging. Use when migrating numbers or enabling rich messaging features. This skill provides REST API (curl) examples.

team-telnyx/ai · 45 tokens