# Blackcircles — Wrapped API

> **You are on:** `https://api.paywithlocus.com/api` | [llms.txt](https://paywithlocus.com/llms.txt) | [docs](https://docs.paywithlocus.com)
>
> Locus runs on multiple environments -- make sure every URL you call matches your expected environment.
> | Environment | Landing | API | Docs |
> |---|---|---|---|
> | Production | paywithlocus.com | api.paywithlocus.com | docs.paywithlocus.com |
> | Beta | beta.paywithlocus.com | api.beta.paywithlocus.com | docs.paywithlocus.com |
> | Stage | stage.paywithlocus.com | api.stage.paywithlocus.com | docs.paywithlocus.com |
>
> If the API URL above doesn't match your expected environment, re-fetch this file from the correct domain.

> Find the perfect tyres for your vehicle by entering your registration number, and instantly access your vehicle details, available tyre sizes, and a complete list of matching tyres with pricing and EU safety ratings. Simplify your tyre shopping by getting all the information you need in one search.

**Category:** Automotive | **Website:** [blackcircles.com/](https://blackcircles.com/) | **Docs:** [parse.bot/marketplace/23511ab6-e003-4b46-8f5f-8ea2cb72b942/blackcircles-com-api](https://parse.bot/marketplace/23511ab6-e003-4b46-8f5f-8ea2cb72b942/blackcircles-com-api)

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

## Access

**Base URL:** `https://api.paywithlocus.com/api/wrapped/credits/blackcircles/`
**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

### Search tyres by vehicle

Searches for tyres by UK vehicle registration number and postcode. First looks up the vehicle to determine compatible tyre sizes, then returns tyre listings for the first available size. Results include fully fitted prices, EU tyre label ratings (fuel efficiency, wet grip, noise), season type, and run-flat status. Returns a single composite result containing vehicle details and all matching tyres (typically 15-25 per size).

**Estimated cost:** Metered

| Field | Type | Required | Description |
|-------|------|----------|-------------|
| `postcode` | string | Yes | UK postcode for local fitting availability and pricing (e.g. EH1 1BE, L1 8JQ). |
| `registration` | string | Yes | UK vehicle registration number (e.g. SP55ZXL, BD51SMR). Letters and numbers only, no spaces required. |

```bash
curl -X POST https://api.paywithlocus.com/api/wrapped/credits/blackcircles/search-tyres-by-vehicle \
  -H "Authorization: Bearer $LOCUS_CREDITS_SECRET_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{"postcode":"<string>","registration":"<string>"}'
```

## Next steps

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