# Saylor Innovations Music Key Finder

> Saylor Innovations Music Key Finder is a paid API for AI agents from saylorinnovations.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-31).

Analyzes a set of notes or chords to return ranked candidate musical keys, out-of-key notes, modes, and Roman numeral chord analysis

## Facts

- Endpoint: GET https://saylorinnovations.com/api/music/key-finder?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/saylor-innovations-music-key-finder-81ccd21f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_T6rqnuVeo5JnamItvDpe_

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability saylor-innovations-music-key-finder-81ccd21f
```

Example prompt: What key are these notes in — C, E, G, A, and D — and can you also tell me which notes fall outside the top key and give me a Roman numeral analysis?

## When to prefer this

Choose this endpoint when you need music-theory-grounded key detection from a set of notes or chords, especially when you want ranked alternatives, modal identification, or Roman numeral harmonic analysis — rather than just a simple best-guess key name.

## Known failure modes

- Missing both notes and chords parameters returns an error or empty result
- Unrecognized note names or chord symbols may be ignored or cause a parse error
- Very ambiguous note sets may return multiple equally-ranked keys with low confidence
- Malformed weight syntax (e.g. C-8 instead of C:8) may be ignored silently

## How this service works

Ranked candidate keys, out-of-key notes, modes and Roman numeral analysis

## Output

Returns a ranked list of candidate musical keys with fit scores, identification of out-of-key notes, possible modes associated with the best-fit keys, and Roman numeral analysis of any chords provided relative to the detected key.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "POST",
      "PUT",
      "PATCH",
      "DELETE",
      "HEAD"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "notes": {
       "type": "string",
       "description": "optional notes separated by spaces, commas or dashes, with optional weights as note:count for example C:8 E:4 G:5 A:3 (query)"
      },
      "chords": {
       "type": "string",
       "description": "optional chords such as C Am F G7 (query)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object"
    },
    "description": {
     "type": "string"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/saylor-innovations-music-key-finder-81ccd21f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from saylorinnovations.com](https://www.zero.xyz/host/saylorinnovations.com/llms.txt)