--- title: "API reference" description: "501 endpoints across 33 resources, generated from the OpenAPI 2026-06-20 specification." canonical_url: "https://twominutebilling.com/help/developers/api-reference" --- # API reference > 501 endpoints across 33 resources, generated from the OpenAPI 2026-06-20 specification. 501 endpoints across 33 resources, generated from the OpenAPI 2026-06-20 document the typed SDK is built from. Every example reads the base URL and key from your shell: set `TMBILLING_URL` to your deployment and `TMBILLING_API_KEY` to a key from **Settings → API keys**. Writes send a fresh `Idempotency-Key`, so a retried request never runs twice. Multi-tenant subscription billing. Account hierarchy: Organization → Business → Customer → Subscription. Authenticate with `Authorization: Bearer `; every write accepts an `Idempotency-Key`. Money is integer minor units + ISO currency. **Unknown parameters.** A body or query key the endpoint does not define — at any depth — answers **400** `invalid_request_error` with `message: "Unknown parameter: "` (e.g. `items[0].qty`) and `param` naming the first one; nothing is written. Values inside `metadata` and `custom_fields`, and top-level `cf_` custom-field keys, are free-form. **Rate limits.** Requests are counted per API key in fixed one-minute windows. Every authenticated response carries `X-RateLimit-Limit`, `X-RateLimit-Remaining` and `X-RateLimit-Reset` (unix seconds, when the window and the allowance reset), so a client can back off before it is refused. Over the limit answers **429** with `error.type = "rate_limit_error"` and a `Retry-After` header in seconds — wait that long rather than retrying immediately. The ceiling applies per key, so an organization's integrations do not consume each other's allowance; it is set per organization, so ask us to raise it rather than sharding across keys. A 429 means nothing was processed: the request is safe to retry unchanged, and with an `Idempotency-Key` it is safe to retry even if you are unsure. Some actions also have their own, tighter limit (team invites, webhook resends and test sends, ad hoc emails, invoice collect/retry, checkout coupon codes); the 429 message names it. **List filtering.** Paginated lists filter with `[]=` — e.g. `?created_at[after]=2026-09-01&status[in]=paid,posted`. There is no `filters` parameter: each filterable field is documented as its own query parameter, and any query key that is neither a filter nor a documented one is a **400** rather than a silently ignored no-op. Most operators take one scalar; four do not — `in`/`not_in` take a comma-separated set, `between` exactly two comma-separated values (both ends inclusive), `in_last`/`in_next` a positive number of DAYS, and `is_present` takes `true` or `false`. Dates are ISO-8601. Sorting is `sort_by[asc]=` or `sort_by[desc]=`. **Request ids.** Every response carries a `Request-Id` header (`req_…`). Requests your API keys make, and writes made in the dashboard, are kept in the request log: open one with `GET /v1/request_logs/{id}` to see what was sent and what was answered. Reads are kept 30 days, writes 90 days. ## Resources
Resource Endpoints
Organization 25
Analytics 6
Businesses 27
Catalog 49
Customers 26
Payment Methods 24
Subscriptions 51
Invoices 31
Entitlements 12
Integrations 9
HubSpot 19
Webhooks 50
Payment Intents 8
Custom Fields 5
Report dashboards 14
List views 5
Reference 3
Tax 10
Payments 5
Payment Instructions 5
Payment Links 4
Reason Codes 4
Dunning Policies 5
Receipts 3
Payment Requests 7
Comments 5
Transfers 2
Usage 13
Model prices 10
Credits 17
Usage controls 31
Customer segments 8
Metadata Rules 8
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