API & MCP

Everything a person can do on Ohmforge Sound Level (WAV → Leq, LAeq, Lmax), a program or AI agent can do with the same inputs and get the identical result.

HTTP API

POST https://ohmforgesoundlevel.usefulweb.app/api/v1/calculate – run Ohmforge Sound Level (WAV → Leq, LAeq, Lmax)
GET https://ohmforgesoundlevel.usefulweb.app/api/v1/tool – inputs, output schema, examples
OpenAPI 3.1: /openapi.json · /openapi.yaml
Errors: application/problem+json; 422 includes per-field errors.

Ohmforge Sound Level (WAV → Leq, LAeq, Lmax)

Measures a WAV recording like a sound level meter: equivalent continuous levels with A, C and no (Z) frequency weighting, maximum levels with Fast (125 ms) and Slow (1 s) time weighting, minimum, C-weighted peak and the statistical levels L10, L50 and L90, plus a level-over-time chart. Without calibration the levels are relative to a full-scale sine; with an offset from a reference meter they read dB SPL. Same engine as the sound level meter in Ohmforge's Pocket instruments.

Inputs of Ohmforge Sound Level (WAV → Leq, LAeq, Lmax)
Field	Type	Default	Description
`file` (required)	file	—	WAV recording. PCM 8/16/24/32-bit or 32-bit float, 8 to 192 kHz, up to 10 minutes. Stereo is mixed to mono. Processed in memory and not kept.
`offset`	number	0	Calibration offset. Added to every level. 0 = uncalibrated (dB relative to a full-scale sine). Get it by recording a known level, e.g. a 94 dB calibrator or a reference meter.
`channel`	select (0, 1, 2)	"0"	Channel

Every result contains

inputs (normalised, defaults applied), summary, result (validated against the published schema), units, assumptions, sources, warnings, computedAt and links.

MCP (Model Context Protocol)

Streamable HTTP endpoint: https://ohmforgesoundlevel.usefulweb.app/mcp – protocol revisions 2026-07-28 (stateless) and 2025-11-25 / 2025-06-18 / 2025-03-26 (initialize handshake).
Tools: ohmforge_sound_level
Local stdio connector: node src/mcp-stdio.ts --tool=ohmforge-sound-level

{
  "mcpServers": {
    "ohmforge-sound-level": { "type": "http", "url": "https://ohmforgesoundlevel.usefulweb.app/mcp" }
  }
}