arcasdk AGENTS.md

A set of instructions for using Arca SDK, a TypeScript monorepo—a repository containing several related packages—to connect Node.js programs to Argentina’s tax services.

In plain words
What is it for?
It helps build electronic invoices, query taxpayer records, check service status, create PDF invoices, and use other ARCA web services.
Why use it?
It clarifies which package to install, how the current SDK differs from the older package, and how authentication and service calls are configured.

Instructions file for CodexOpenCode

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 instructions/ralcorta/arcasdk/agents-md
Clone the repo
git clone --depth 1 https://github.com/ralcorta/arcasdk

Made for: Codex, OpenCode.

Per session 954 This file is loaded in full into every session.
When invoked 954 The same file — it is already loaded in full.
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 $0.00954 $0.00954
Opus 5 $0.00477 $0.00477
Sonnet 5 $0.00191 $0.00191
Haiku 4.5 $0.00095 $0.00095

Measured 2d ago against content hash f1f0755910f1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

arcasdk AGENTS.md 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 2d 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.

AGENTS.md · 105 lines

How it starts

The opening of the file, as written. The whole thing — 105 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Arca SDK — guía para agentes de código

Monorepo TypeScript para integrar Web Services de ARCA (ex AFIP) en Node.js.

Paquetes publicados

Paquete Uso
@arcasdk/core WSAA, facturación electrónica (WSFE), padrones, FCE, WSFEX, servicio genérico SOAP
@arcasdk/pdf PDF de comprobantes (A, B, C, E, M)

Importante: el paquete legacy afip.ts en npm es la versión anterior. El desarrollo actual es @arcasdk/core.

Instalación (consumidor)

npm i @arcasdk/core
# opcional PDF
npm i @arcasdk/pdf

Uso mínimo

import { Arca } from "@arcasdk/core";

const arca = new Arca({
  cuit: 20111111112,
  cert: process.env.AFIP_CERT!, // PEM o ruta al .crt
  key: process.env.AFIP_KEY!,   // PEM o ruta al .key
  production: false,            // homologación
});

const status = await arca.electronicBillingService.getServerStatus();
const invoice = await arca.electronicBillingService.createNextVoucher({ /* ... */ });
const taxpayer = await arca.registerScopeFourService.getTaxpayerDetails(20111111111);

Punto de entrada API

Servicios en Arca

Propiedad Web service
electronicBillingService WSFE — facturas, NC, ND, CAEA
wsfexService WSFEX — exportación
wsfecredService WSFECRED — factura de crédito MiPyMEs
registerScopeFourService Padrón alcance 4
registerScopeFiveService Padrón alcance 5
registerScopeTenService Padrón alcance 10
registerScopeThirteenService Padrón alcance 13
registerInscriptionProofService Constancia de inscripción
genericService Cualquier WSDL/SOAP de ARCA

Credenciales y entorno

  • Homologación: certificado de testing emitido en el portal ARCA (production: false o omitido).
  • Producción: certificado de producción + production: true.
  • El CUIT del contexto debe coincidir con el del certificado.
  • WSAA gestiona tickets automáticamente; en serverless usar ticketStorage custom o handleTicket: true con credenciales pre-obtenidas.
  • Ver docs/credential_management.md y docs/config.md.

Read the full file on GitHub · 105 lines

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. 2d ago First seen · 105 lines · 954 tokens per session scan A f1f0755910f1

Subscribe to this mod's changes

arcasdk AGENTS.md is an instructions file published in the GitHub repository ralcorta/arcasdk (166 stars, last pushed 25d ago), licensed MIT. It adds 954 tokens to every session, about $0.0048 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 2026-08-30.

Related

Other instructions, from other repositories

api-gateway CLAUDE.md

Instructions for membrane/api-gateway, covering claude.md, working principles, 1. think before coding, 2. simplicity first and 3. surgical changes.

membrane/api-gateway · 2,566 tokens

symfony-flex-backend CLAUDE.md

Instructions for tarlepp/symfony-flex-backend, covering what is this?, table of contents ᐞ, ai documentation map ᐞ, version sources of truth ᐞ and project architecture ᐞ.

tarlepp/symfony-flex-backend · 4,046 tokens

symfony-flex-backend copilot-instructions.md

Instructions for tarlepp/symfony-flex-backend, covering what is this?, table of contents ᐞ, purpose ᐞ, architecture rules ᐞ and php and symfony rules ᐞ.

tarlepp/symfony-flex-backend · 1,927 tokens

data-api-builder copilot-instructions.md

Copilot instructions for Azure/data-api-builder, covering data api builder (dab) - copilot instructions, project overview, key technologies, project structure and building and testing.

Azure/data-api-builder · 2,070 tokens

huaweicloud-devkit AGENTS.md

Instructions for huaweicloud/huaweicloud-devkit, covering agents.md — huaweicloud devkit, commands, architecture, skill naming: meta vs service and file naming: design docs vs implementation.

huaweicloud/huaweicloud-devkit · 2,174 tokens

korean-law-alio-mcp CLAUDE.md

Instructions for scvcoder/korean-law-alio-mcp, covering claude.md, structure, commands, alio 공공기관 내부규정 일괄 수집 (배치) and 보고서형 공시 카테고리 (reportgbn=y) — 단체협약/임금협약/노사협의회.

scvcoder/korean-law-alio-mcp · 3,809 tokens