# Hooktheory — Wrapped API

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>
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> |---|---|---|---|
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> Search through 65,000+ songs to discover their music theory details like chords, melody notes, keys, tempos, and meters. Break down any song into its individual sections and examine the exact notes used in each part.

**Category:** Music | **Website:** [www.hooktheory.com/theorytab](https://www.hooktheory.com/theorytab) | **Docs:** [parse.bot/marketplace/5483984b-7030-4e96-a4eb-a3b2686b72bb/hooktheory-com-api](https://parse.bot/marketplace/5483984b-7030-4e96-a4eb-a3b2686b72bb/hooktheory-com-api)

Pay-per-use API proxy for Locus Pro. Each call burns credits from your workspace balance.

## Access

**Base URL:** `https://api.beta.paywithlocus.com/api/wrapped/credits/hooktheory/`
**Auth:** `Authorization: Bearer <LOCUS_CREDITS_SECRET_KEY>` (an `lcr_` secret key or a scoped `lcac_` agent credential)
**Required header:** `Idempotency-Key: <fresh UUID per call>`. A retry with the same key replays the stored result without a new charge.
**Response:** the provider response after any endpoint-specific normalization. `X-Locus-Credits-Charged` carries the charge and `X-Locus-Credits-Balance` the remaining balance. Insufficient credits return `402` before the provider is called.
**Pricing:** estimated costs below are USD. Locus debits the credit equivalent at your workspace rate.

Full call contract: https://docs.paywithlocus.com/api-reference/introduction

> Using a Pay With Locus wallet key (`claw_` prefix)? Wallet routes are documented separately: https://docs.paywithlocus.com/wrapped-apis/for-agents

## Endpoints

### Get section notes

Retrieve full music theory data for a specific song section including chords (root, type, inversion, duration, applied intervals), melody notes (scale degree, octave, beat, duration), key signatures, tempos, time signatures, and YouTube sync points. Requires a section_id obtained from get_song_sections.

**Estimated cost:** Metered

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `section_id` | string | Yes | Section ID from get_song_sections endpoint (e.g. 'ROmNOXDjngN') |

```bash
curl -X POST https://api.beta.paywithlocus.com/api/wrapped/credits/hooktheory/get-section-notes \
  -H "Authorization: Bearer $LOCUS_CREDITS_SECRET_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{"section_id":"<string>"}'
```

### Get song sections

Retrieve all sections (intro, verse, chorus, bridge, etc.) for a specific song identified by artist and song URL slugs. Returns section IDs required by the get_section_notes endpoint. Slugs are lowercase hyphenated forms of the artist/song name.

**Estimated cost:** Metered

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `artist` | string | Yes | Artist URL slug (e.g. 'queen', 'the-beatles') |
| `song` | string | Yes | Song URL slug (e.g. 'bohemian-rhapsody', 'let-it-be') |

```bash
curl -X POST https://api.beta.paywithlocus.com/api/wrapped/credits/hooktheory/get-song-sections \
  -H "Authorization: Bearer $LOCUS_CREDITS_SECRET_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{"artist":"<string>","song":"<string>"}'
```

### Search songs

Full-text search over Hooktheory's TheoryTab database of 65,000+ songs. Matches song titles and artist names. Returns chord progressions (absolute and relative notation), key signatures, section types, and YouTube IDs. Paginated via offset/limit.

**Estimated cost:** Metered

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `limit` | integer | No | Maximum number of results to return (max 200) |
| `offset` | integer | No | Offset for pagination |
| `query` | string | Yes | Search keyword (song name, artist, etc.) |

```bash
curl -X POST https://api.beta.paywithlocus.com/api/wrapped/credits/hooktheory/search-songs \
  -H "Authorization: Bearer $LOCUS_CREDITS_SECRET_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{"limit":"<integer>","offset":"<integer>","query":"<string>"}'
```

## Next steps

- [All wrapped API providers](https://beta.paywithlocus.com/wapi/index.md): pick another provider.
- [Find and call tools](https://beta.paywithlocus.com/agent/tools.md): price ceilings, async results, and errors.
- [Credits and billing](https://beta.paywithlocus.com/agent/billing.md): what a call costs and how to add credits.
- [Agent docs index](https://beta.paywithlocus.com/agent/index.md): every Locus agent page.