# Send an event to a destination again **POST /delivery-attempts/{attempt}/replay** Asks for the event behind this attempt to be delivered to the same destination again. Needs `sending: write`. The same action as the retry button beside that attempt in the delivery portal. **It re-delivers the event, it does not resend the attempt.** What comes back is a *new* attempt against the same event and the same destination, numbered one higher and marked `manual: true`. The attempt this was called on is unchanged. Reach for it when a delivery failed for a reason you have since fixed and the delivery service has stopped retrying on its own. It is not the way to catch up after an outage: those retries happen without being asked, and replaying an event a consumer already processed is a duplicate they have to handle. A `202` means the delivery service has the request. The delivery happens after the response, and the attempt it produces appears in the log shortly afterwards rather than immediately. A destination that has been switched off answers `422`, since a disabled destination is skipped rather than queued. Switch it back on in the portal first. Takes no body: which event and which destination are both properties of the attempt. It does take `?newsletter=`, for the reason `GET /delivery-attempts/{attempt}` does. Leave it out if your credential reaches exactly one newsletter. ## Servers - Production. There is no separate sandbox host. : https://api.usecommune.com (Production. There is no separate sandbox host. ) ## Authentication methods - Api key - Oauth2 ## Parameters ### Headers - **Commune-Version** (string) The contract version this request is written against. Every version published so far is a release date (`YYYY-MM-DD`), which is why the examples look like one, but the value is an opaque identifier: match it against the versions this API publishes rather than parsing it, because a future one may not be only a date. An unknown value answers `400` with `invalid_version`. Omitting the header pins the request to the version that was current when the API key was issued, so an integration keeps working when a newer version ships. - **Idempotency-Key** (string) A value of your choosing naming the change this request is making. Send the same value again to retry the same request. Commune replays the answer the first attempt gave instead of making the change twice, and marks the replay with an `Idempotent-Replay: true` response header. Send a different value for a different change: a key reused for a request that differs in any way answers `409`, because replaying an answer to a question you did not ask is a wrong answer you could not detect. A UUID per change is the usual choice. Remembered for 24 hours, per credential, so two credentials choosing the same value never see each other's answers. Required, not optional. ### Path parameters - **attempt** (string) The delivery attempt's `id`, as `GET /newsletters/{newsletter}/delivery-attempts` returned it. Opaque, and minted by the delivery service rather than by Commune, so it is not a UUID and must not be parsed as one. ### Query parameters - **newsletter** (string) Which newsletter this request is for, by `id` or by `handle`. Most operations never need this. A credential reaches a list of newsletters, and an operation that acts on one of them normally works out which from the object in its path: an article, a thread, a subscriber and a key each belong to a newsletter, so naming one is naming the other. This parameter is for the operations whose subject is **not** a Commune object, where there is nothing to work it out from. Leave it out if your credential reaches exactly one newsletter, which is the usual case: it is that one. If your credential reaches several and you leave it out, the answer is `400` naming this parameter, because picking one for you would be picking wrong most of the time. `GET /newsletters` lists the newsletters your credential reaches, and is where the value for this comes from. ## Responses ### 202 The delivery service has the request. The delivery has not happened yet, so no attempt is returned; find it afterwards in the delivery log, filtered to the same event. #### Body: application/json (object) - **object** (string) Always `delivery_replay`. - **attempt** (object | null) The attempt that was replayed, not the one this makes. Always a `Ref`, and it is unchanged: it is a record of a delivery that already happened. - **event_id** (string) The event being delivered again. Filter the delivery attempt log by it to find the new attempt once the delivery service has made it. - **destination** (object | null) Where it is being delivered again. Always a `Ref`. ### 400 The request was malformed, and the same request will fail the same way until it is changed. `param` names the parameter or header at fault when there is exactly one, and `allowed_values` lists what it accepts when that is a finite set. The code is `bad_request` for every case below except the last. * **A query parameter**: one the operation does not have, a value outside its set, range or format (an unparseable cursor, an unknown `expand` path or `fields` name, an identifier that is not a UUID), or a required one left out, such as `q` on a search or `newsletter` when the credential reaches more than one. * **The request body**: not JSON, not the shape the operation reads, a property it does not write, or a value of the wrong type, length or format. `param` is absent here, since the body is not a parameter, and the message names the property. * **The `Idempotency-Key` header**, on an operation that changes something: missing, or a value this API will not store. * **An unrecognised `Commune-Version`**, which answers with its own code, `invalid_version`, because it is never fixed by changing the body. #### Body: application/json (object) - **error** (object) ### 401 No credential was presented, or it is malformed, unknown, revoked or expired, or it is an access token minted for a different audience. Every one of these answers identically, down to the wording and the headers, so a refusal never confirms that a string was once real. #### Headers - **WWW-Authenticate** (string) The authentication scheme this API accepts, and where to find out how to get a credential for it. Always `Bearer realm="Commune API", resource_metadata="https://api.usecommune.com/.well-known/oauth-protected-resource"`. `resource_metadata` is the RFC 9728 pointer to this API's protected resource metadata, which names the authorization server an OAuth client should send its user to. A client holding an API key can ignore it. The header carries no `error` parameter, not even `error="invalid_token"`, because it describes what this API accepts rather than what was wrong with the credential sent, and the reasons above are deliberately indistinguishable. There is no second scheme and no query-parameter fallback, because a credential that can travel in a URL ends up in access logs and referer headers. #### Body: application/json (object) - **error** (object) ### 402 The credential is allowed to do this but the newsletter's plan does not include it. Two surfaces can answer it: **insights**, the engagement and metrics operations, which are the only reads Commune reserves the right to meter, and **writing**, every operation that changes something. Every other read stays free on every plan, so a credential refused at one of these can still read everything else. The body names the plan the newsletter is on and the plans that would work. **This status is predictable and should not be how you discover it.** `GET /newsletters/{newsletter}/entitlements` answers the same question in advance, carrying the same plan list this puts in `allowed_values` and the same sentence it puts in `message`. Read it once at the start of a run rather than finding out in the middle of one. #### Body: application/json (object) - **error** (object) ### 403 The credential is valid but is not allowed to do this. Two codes answer with this status, and `error.code` says which. **`insufficient_scope`: it does not hold the permission.** The operation needs, say, `audience: read` on the newsletter addressed, and this credential holds less than that there. `allowed_values` carries the permission that was needed, and the message says what the credential does hold on that newsletter, because a credential granted the wrong family and a credential belonging to somebody whose standing on the team has narrowed look identical without it. The answer can differ per newsletter: the same credential may be allowed here and refused on the next one it reaches. The same code answers an operation that needs the **account permission** from a credential that does not carry it. That permission is about the person a credential belongs to rather than about any newsletter, so nothing granted on a newsletter adds up to it. It is granted on the credential itself, when a key is minted or when an authorization asks for `account:read`. And it answers a parameter the credential may send, but not with the value it sent: a filter a credential holding only `read` permissions may not use, or an `expand` path whose rows need a permission the operation does not. `param` names the parameter, and `allowed_values` carries what this credential may send instead, or is absent when it may send nothing there at all. **`forbidden`: it may not act here at all.** Either the credential does not reach the newsletter addressed, because it was never granted it or because the person it belongs to can no longer act on it, or it reaches no newsletter at all; `param` is `newsletter`, and `GET /newsletters` lists the ones it does reach. Or, on `DELETE /api-keys/{key}`, the credential named belongs to somebody else. Neither carries `allowed_values`, because there is no value to send instead. #### Body: application/json (object) - **error** (object) ### 404 No such resource, or the key is not allowed to know that it exists. Commune answers `404` rather than `403` where distinguishing the two would leak the existence of private content. #### Body: application/json (object) - **error** (object) ### 409 The request collided with something. On a write this is always the `Idempotency-Key`, in one of two ways, and the message says which. Either the key was already used for a **different** request, which is refused rather than answered with the earlier request's result. Or an earlier request using the same key has not finished, or never reported an outcome, in which case this one was not run and the key becomes usable again shortly. Nothing was changed by a request that answers this. #### Headers - **Retry-After** (integer) Seconds to wait before retrying, on the second case only. #### Body: application/json (object) - **error** (object) ### 422 The request is well formed and every value in it is legal, and the state of what it addresses refuses it anyway. The message says what about that state is in the way. #### Body: application/json (object) - **error** (object) ### 429 Too many requests. Back off and retry after the interval named by the `Retry-After` response header. One of the budgets in `RateLimit-Policy` ran out, and the `RateLimit-*` headers on this response say which and when it resets. #### Headers - **Retry-After** (integer) Seconds to wait before retrying. #### Body: application/json (object) - **error** (object) ### 500 Something failed inside Commune. The request may be retried. #### Body: application/json (object) - **error** (object) ### 503 A capability this operation depends on did not answer. Every other operation is unaffected, so back off on this one rather than on the API. Two parts of the API can answer this, because they are the only ones Commune cannot serve out of its own database. **Event delivery.** Destinations, the attempt log and the portal all live in the delivery service. It is never an empty answer instead, because a destination list or an attempt log that came back empty for this reason reads exactly like a newsletter that has registered no endpoints and sent nothing anywhere. **`sendArticleTest`.** A test copy is sent while the request is open, by Commune's sending service, and this answers when that service could not be reached or when the sending provider refused every address on the test, so nothing arrived. Nothing about the article changes either way, and the message says which of the two happened. #### Headers - **Retry-After** (integer) Seconds to wait before retrying. Absent in the one case that will not pass on its own, a deployment where event delivery is not available at all; the message says so, and retrying will not clear it. #### Body: application/json (object) - **error** (object) [Powered by Bump.sh](https://bump.sh)