async-snmp

A lightweight TypeScript wrapper around the Node.js net-snmp library that exposes Promise-friendly helpers and a small session manager.

Why this package

• Converts net-snmp's callback APIs into Promise/async-friendly helpers.
• Provides a session manager that reuses net-snmp sessions per-IP and supports SNMPv3 credentials.
• TypeScript-first with declaration output so consumers get types.

Install

This package expects net-snmp to be available at runtime. Install it as a peer or runtime dependency in your project:

npm install net-snmp

Quick usage

The package uses a singelton snmpManager to manage sessions instead of closing them after each use. You can configure credentials for the snmp user in two ways:

1. Environment variable: SNMP_USER_CONFIG (JSON string)
2. Provide a per-session override when calling getSession(ip, userConfig)

Example — programmatic default config:

SNMP_USER_CONFIG='{"name":"operator","level":3,"authProtocol":3,"authKey":"auth","privProtocol":2,"privKey":"priv"}'

The JSON fields map to the SnmpUserConfig shape used by net-snmp:

• name — username
• level — numeric snmp.SecurityLevel (e.g. authPriv)
• authProtocol — numeric snmp.AuthProtocols (e.g. sha)
• authKey — authentication key/password
• privProtocol — numeric snmp.PrivProtocols (e.g. aes)
• privKey — privacy/encryption key

If SNMP_USER_CONFIG is not set, the package falls back to reasonable defaults for development (see types in source).

Usage examples

Simple SNMP GET:

import { snmpGet } from "async-snmp";

async function readSysDescr() {
  const varbinds = await snmpGet("192.168.1.1", ["1.3.6.1.2.1.1.1.0"]);
  console.log(varbinds[0].value.toString());
}

Simple SNMP SET:

import { snmpSet } from "async-snmp";
import type { Varbind } from "net-snmp";

const vb: Varbind[] = [
  { oid: "1.3.6.1.2.1.1.5.0", type: 4, value: "newName" }, // example
];

async function setSysName() {
  const result = await snmpSet("192.168.1.1", vb);
  console.log("Set result:", result);
}

Notes

• These helpers use an internal session manager that will reuse sessions per-IP.
• For per-call or per-session credential overrides you can modify the session manager usage in source or extend the API; by default the package uses SNMP_USER_CONFIG as the manager's default credentials.
• The package expects net-snmp available at runtime (listed as a peer dependency). Install it in your project.

Troubleshooting

• If TypeScript complains about import/export vs CommonJS, ensure tsconfig.json uses module: "nodenext" and package.json has "type": "module" when targeting ESM.
• Do not attempt to bundle net-snmp if it relies on native components; mark it external in bundlers.

Contributing

PRs are welcome. If you change public API shape, update examples in this README. Add small focused commits and include tests for behavioral changes when possible.

License

MIT