api-utils

api-utils is a skill for Claude Code, Codex from magnusquest/startgg-mcp. It costs 37 tokens per session (3,533 once invoked), scanned A, a copy of api-utils, Apache-2.0.

A reference guide to utility functions exported by the @cyanheads/mcp-ts-core package, including formatting, parsing, security, and network helpers.

In plain words
What is it for?
Use it when building or maintaining an MCP server with these utilities, especially when you need to format data, parse files, sanitize input, limit requests, or make timed network requests.
Why use it?
It removes the need to search through source code to find method signatures, options, dependencies, and usage examples.

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/magnusquest/startgg-mcp/api-utils
Any agent
npx skills add magnusquest/startgg-mcp --skill api-utils
Clone the repo
git clone --depth 1 https://github.com/magnusquest/startgg-mcp

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 api-utils

README.md
[![agentmods](https://agentmods.dev/badge/skills/magnusquest/startgg-mcp/api-utils.svg)](https://agentmods.dev/skills/magnusquest/startgg-mcp/api-utils)
Your own site
<a href="https://agentmods.dev/skills/magnusquest/startgg-mcp/api-utils"><img src="https://agentmods.dev/badge/skills/magnusquest/startgg-mcp/api-utils.svg" alt="Measured on agentmods" height="20"></a>
Per session 37 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,533 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 91% copy Near-identical to another mod 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 $0.00037 $0.03533
Opus 5 $0.00018 $0.01767
Sonnet 5 $0.00007 $0.00707
Haiku 4.5 $0.00004 $0.00353

Measured 5d ago against content hash 6ab5c49f887a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

api-utils 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 5d 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.

Origin

This is a copy

91% identical to api-utils — 19 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/api-utils/SKILL.md · 170 lines

How it starts

The opening of the file, as written. The whole thing — 170 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Overview

Utility exports from @cyanheads/mcp-ts-core/utils. Utilities with complex APIs have dedicated reference files; simpler utilities are documented inline below.

Tier 3 = optional peer dependency. Install as needed (e.g., bun add js-yaml). All Tier 3 methods are async (lazy-load deps on first call).

References

Reference Path Covers
Formatting references/formatting.md markdown(), MarkdownBuilder, diffFormatter, tableFormatter, treeFormatter — builder patterns, option types, style variants, usage examples
Parsing references/parsing.md yamlParser, xmlParser, csvParser, jsonParser, pdfParser, dateParser, frontmatterParser — method signatures, option types, peer deps, Allow flags, PDF workflows
Security references/security.md sanitization, RateLimiter, IdGenerator — config types, method details, sensitive fields, usage examples

@cyanheads/mcp-ts-core/utils — network

Export API Notes
fetchWithTimeout (url, timeoutMs, context: RequestContext, options?: FetchWithTimeoutOptions) -> Promise<Response> Wraps fetch with AbortController timeout. FetchWithTimeoutOptions extends RequestInit (minus signal) and adds rejectPrivateIPs?: boolean and signal?: AbortSignal (external cancellation). SSRF protection: blocks RFC 1918, loopback, link-local, CGNAT, cloud metadata. DNS validation on Node; hostname-only on Workers. Manual redirect following (max 5) with per-hop SSRF check.

@cyanheads/mcp-ts-core/utils — pagination

Export API Notes
extractCursor (params?) -> string | undefined Extracts opaque cursor string from MCP request params. Checks params.cursor then params._meta.cursor. Returns undefined when no cursor is present. Does not decode.
paginateArray <T>(items, cursorStr, defaultPageSize, maxPageSize, context: RequestContext) -> PaginatedResult<T> Decodes cursor, slices array, returns { items, nextCursor?, totalCount }. nextCursor omitted on last page. Throws McpError(InvalidParams) on invalid cursor.
encodeCursor (state: PaginationState) -> string Encodes { offset, limit, ...extra } to opaque base64url string.
decodeCursor (cursor, context: RequestContext) -> PaginationState Decodes opaque base64url cursor. Throws McpError(InvalidParams) if malformed.

Read the full file on GitHub · 170 lines

Files

What ships with it

3 files 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. 5d ago First seen · 170 lines · 37 tokens per session scan A 6ab5c49f887a

Subscribe to this mod's changes

api-utils is a skill published in the GitHub repository magnusquest/startgg-mcp (1 stars, last pushed 4mo ago), licensed Apache-2.0. It adds 37 tokens to every session and 3,533 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 91% identical to api-utils, differing in 19 lines, and is treated as a copy.

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