# List trade credit ledger `GET /api/v1/trade-credit-ledger` The movements behind outstanding_minor: the append-only record of every charge against a buyer's credit and every settlement of it. THE SIGN IS THE MEANING. A positive amount_minor draws credit down, a negative one frees it, and the plain sum of the column IS the outstanding balance. Taking an absolute value turns a reconciliation into gross turnover reported as debt. reference_type and reference_id are the pair a movement is idempotent on, and they are OPAQUE STRINGS WITH NO DECLARED ENUM. Match on them, do not switch on them: the checkout flow that will be the main producer does not exist yet, so there is no vocabulary to freeze and none is being invented. ?customer_id narrows it to one buyer. Omit it to walk the whole store in one ordered pass, which is what an accounts-receivable reconciliation wants. APPEND ONLY AT THE DATABASE GRANT, not by convention: no code path in this platform can update or delete a movement, which is what makes this a tamper-evident trail rather than a cache of the balance. ## Query parameters - `customer_id` (string) — Restrict the page to one buyer's movements. Omit it to walk the whole store's ledger newest first, which is what an accounts-receivable reconciliation wants and what the dashboard's own per-customer view cannot do. - `limit` (integer) — Rows per page. Out of range is a 400 rather than a silent clamp, so a client asking for more than 100 learns it did not get it. - `after` (string) — The next_cursor from the previous page. Opaque: decode nothing from it and construct nothing by hand, since its encoding is not part of this contract. Omit it to read the first page. ## Responses - `200` — Success - `400` — The request was refused before any state changed. `code` is one of: `invalid_body`, a write body this route will not take. `reason` partitions it and `field` names the key when one key is at fault. `invalid_query`, a query parameter, including limit and after. `invalid_text`, a NUL byte or bytes that are not valid UTF-8 anywhere in the path, the query or the body. Strip control characters before sending. `idempotency_key_required`, a write sent without the Idempotency-Key header. `invalid_request`, an Idempotency-Key longer than 255 bytes. Routes add their own codes for rules only they know. Switch with a default arm. - `401` — No credential, or one this API does not accept. `code` is always `unauthorized`. THE BODY IS DELIBERATELY UNINFORMATIVE. An expired key, a revoked key, a publishable key, a key belonging to another merchant and a key that never existed are all refused with the same bytes, so this response cannot be used to probe which keys exist. Check the key's state in the dashboard rather than inferring it here. Send the key as `Authorization: Bearer ` or as `X-API-Key: `. It is never accepted in a query string. - `403` — The key lacks the read_offline_payments scope. `code` is `insufficient_scope` and the message names the scope to ask the merchant for. - `429` — Too many requests. `code` is `rate_limited`. Two limits apply independently: one on the credential and the route family, one on the client address. The headers describe whichever has less left, so honouring Retry-After always clears the window that bound. - `default` — Any status this operation does not list, in the same envelope. A 5xx means the request may or may not have applied. Retry it with the SAME Idempotency-Key: that is the only way to find out without risking a duplicate, and it is what the key is for. A few 4xx conditions arrive here rather than as a listed status because they depend on the merchant's plan or on a module being wired: 402 when a quota or a plan limit is reached, and 503 when a capability the route needs is not configured on this deployment. Both carry a `code` naming which. ## Example ```bash curl --request GET \ --url 'https://api.mercemur.com/api/v1/trade-credit-ledger' \ --header 'Authorization: Bearer ' ```