# Moonfire NVR API Status: **current**. * [Summary](#summary) * [Endpoints](#endpoints) * [Authentication](#authentication) * [`POST /api/login`](#post-apilogin) * [`POST /api/logout`](#post-apilogout) * [`GET /api/`](#get-api) * [`GET /api/cameras//`](#get-apicamerasuuid) * [`GET /api/cameras///recordings`](#get-apicamerasuuidstreamrecordings) * [`GET /api/cameras///view.mp4`](#get-apicamerasuuidstreamviewmp4) * [`GET /api/cameras///view.mp4.txt`](#get-apicamerasuuidstreamviewmp4txt) * [`GET /api/cameras///view.m4s`](#get-apicamerasuuidstreamviewm4s) * [`GET /api/cameras///view.m4s.txt`](#get-apicamerasuuidstreamviewm4stxt) * [`GET /api/cameras///live.m4s`](#get-apicamerasuuidstreamlivem4s) * [`GET /api/init/.mp4`](#get-apiinitidmp4) * [`GET /api/init/.mp4.txt`](#get-apiinitidmp4txt) * [`GET /api/signals`](#get-apisignals) * [`POST /api/signals`](#post-apisignals) * [Request 1](#request-1) * [Request 2](#request-2) * [Request 3](#request-3) * [User management](#user-management) * [`GET /api/users/`](#get-apiusers) * [`POST /api/users/`](#post-apiusers) * [`GET /api/users/`](#get-apiusersid) * [`PATCH /api/users/`](#patch-apiusersid) * [`DELETE /api/users/`](#delete-apiusersid) * [Types](#types) * [UserSubset](#usersubset) * [Permissions](#permissions) * [Cross-site request forgery (CSRF) protection](#cross-site-request-forgery-csrf-protection) ## Summary A JavaScript-based web interface to list cameras and view recordings. Supports external analytics. In the future, this is likely to be expanded: * configuration support * commandline tool over a UNIX-domain socket (at least for bootstrapping web authentication) *Note:* italicized terms in this document are defined in the [glossary](glossary.md). Currently the API is considered an internal contract between the server and the UI which are bundled together. Thus, breaking changes in the API may happen in any release of Moonfire NVR, even a "minor" or "patch" release. From version 0.7.0 onward, API changes should be described in the [changelog](../CHANGELOG.md). Future work may introduce versioning to improve compatibility with externally developed tools. All requests for JSON data should be sent with the header `Accept: application/json` (exactly). ## Endpoints ### Authentication #### `POST /api/login` The request should have an `application/json` body containing a JSON object with `username` and `password` keys. On successful authentication, the server will return an HTTP 204 (no content) with a `Set-Cookie` header for the `s` cookie, which is an opaque, `HttpOnly` (unavailable to Javascript) session identifier. If authentication or authorization fails, the server will return a HTTP 403 (forbidden) response. Currently the body will be a `text/plain` error message; future versions will likely be more sophisticated. #### `POST /api/logout` The request should have an `application/json` body containing a `csrf` parameter copied from the `session.csrf` of the top-level API request. On success, returns an HTTP 204 (no content) responses. On failure, returns a 4xx response with `text/plain` error message. ### `GET /api/` Returns basic information about the server, including all cameras. Valid request parameters: * `days`: a boolean indicating if the days parameter described below should be included. * `cameraConfigs`: a boolean indicating if the `camera.config` and `camera.stream[].config` parameters described below should be included. This requires the `readCameraConfigs` permission. Example request URI (with added whitespace between parameters): ``` /api/?days=true &cameraConfigs=true ``` The `application/json` response will have a JSON object as follows: * `timeZoneName`: the name of the IANA time zone the server is using to divide recordings into days as described further below. * `serverVersion`: the version of the server in use, eg `0.7.0`. * `cameras`: a list of cameras. Each is a JSON object as follows: * `uuid`: in text format * `id`: an integer. The client doesn't ever need to send the id back in API requests, but camera ids are helpful to know when debugging by reading logs or directly examining the filesystem/database. * `shortName`: a short name (typically one or two words) * `description`: a longer description (typically a phrase or paragraph) * `config`: (only included if request parameter `cameraConfigs` is true) a JSON object describing the configuration of the camera. See doc comments on the `CameraConfig` type in [`server/db/json.rs`](../server/db.json.rs). * `streams`: a JSON object. Maps each configured stream type (valid types are `main`, `sub`, and `ext`), a JSON object describing the stream: * `id`: an integer. The client doesn't ever need to send the id back in API requests, but stream ids are helpful to know when debugging by reading logs or directly examining the filesystem/database. * `retainBytes`: the configured total number of bytes of completed recordings to retain. This is copied from the `config` to make it available when the client doesn't have permission to view the full configuration. * `minStartTime90k`: the start time of the earliest recording for this camera, in 90kHz units since 1970-01-01 00:00:00 UTC. * `maxEndTime90k`: the end time of the latest recording for this camera, in 90kHz units since 1970-01-01 00:00:00 UTC. * `totalDuration90k`: the total duration recorded, in 90 kHz units. This is no greater than `maxEndTime90k - maxStartTime90k`; it will be lesser if there are gaps in the recorded data. * `totalSampleFileBytes`: the total number of bytes of sample data (the `mdat` portion of a `.mp4` file). * `fsBytes`: the total number of bytes on the filesystem used by this stream. This is slightly more than `totalSampleFileBytes` because it also includes the wasted portion of the final filesystem block allocated to each file. * `days`: (only included if request parameter `days` is true) JSON object representing calendar days (in the server's time zone) with non-zero total duration of recordings for that day. Currently this includes uncommitted and growing recordings. This is likely to change in a future release for [#40](https://github.com/scottlamb/moonfire-nvr/issues/40). The keys are of the form `YYYY-mm-dd`; the values are objects with the following attributes: * `totalDuration90k` is the total duration recorded during that day. If a recording spans a day boundary, some portion of it is accounted to each day. * `startTime90k` is the start of that calendar day in the server's time zone. * `endTime90k` is the end of that calendar day in the server's time zone. It is usually 24 hours after the start time. It might be 23 hours or 25 hours during spring forward or fall back, respectively. * `config`: (only included if request parameter `cameraConfigs` is true) a JSON object describing the configuration of the stream. See doc comments on the `StreamConfig` type in [`server/db/json.rs`](../server/db.json.rs). * `signals`: a list of all *signals* known to the server. Each is a JSON object with the following properties: * `id`: an integer identifier. * `uuid`: a UUID identifier. * `shortName`: a unique, human-readable description of the signal * `cameras`: a map of associated cameras' UUIDs to the type of association: `direct` or `indirect`. See `db/schema.sql` for more description. * `type`: a UUID, expected to match one of `signalTypes`. * `days`: (only included if request parameter `days` is true) similar to `cameras.days` above. Values are objects with the following attributes: * `states`: an array of the total time (in 90,000ths of a second) the signal was state 1, state 2, and so on during the day. These may not sum to the entire day; if so, the rest of the day is in state 0 (`unknown`). * `signalTypes`: a list of all known signal types. * `uuid`: in text format. * `states`: an array of all possible states of the enumeration to more information about them. Each holds a JSON object: * `value`: an integer used to refer to this state, 1 or higher. Value 0 always means the `unknown` state. * `name`: a human-readable name of this state. * `motion`: if present and true, directly associated cameras will be considered to have motion when this signal is in this state. * `color` (optional): a recommended color to use in UIs to represent this state, as in the [HTML specification](https://html.spec.whatwg.org/#colours). * `permissions`: the caller's current `Permissions` object (defined below). * `user`: an object, present only when authenticated: * `name`: a human-readable name * `id`: an integer * `preferences`: a JSON object * `session`: an object, present only if authenticated via session cookie. * `csrf`: a cross-site request forgery token for use in `POST` requests. Example response: ```json { "timeZoneName": "America/Los_Angeles", "cameras": [ { "uuid": "fd20f7a2-9d69-4cb3-94ed-d51a20c3edfe", "shortName": "driveway", "description": "Hikvision DS-2CD2032 overlooking the driveway from east", "config": { "onvif_host": "192.168.1.100", "user": "admin", "password": "12345", }, "streams": { "main": { "retainBytes": 536870912000, "minStartTime90k": 130888729442361, "maxEndTime90k": 130985466591817, "totalDuration90k": 96736169725, "totalSampleFileBytes": 446774393937, "record": true, "days": { "2016-05-01": { "endTime90k": 131595516000000, "startTime90k": 131587740000000, "totalDuration90k": 52617609 }, "2016-05-02": { "endTime90k": 131603292000000, "startTime90k": 131595516000000, "totalDuration90k": 20946022 } } } } }, ... ], "signals": [ { "id": 1, "shortName": "driveway motion", "cameras": { "fd20f7a2-9d69-4cb3-94ed-d51a20c3edfe": "direct" }, "type": "ee66270f-d9c6-4819-8b33-9720d4cbca6b", "days": { "2016-05-01": { "endTime90k": 131595516000000, "startTime90k": 131587740000000, "states": [5400000] } } } ], "signalTypes": [ { "uuid": "ee66270f-d9c6-4819-8b33-9720d4cbca6b", "states": { 0: { "name": "unknown", "color": "#000000" }, 1: { "name": "off", "color": "#888888" }, 2: { "name": "on", "color": "#ff8888", "motion": true } } } ], "user": { "id": 1, "name": "slamb", "session": { "csrf": "2DivvlnKUQ9JD4ao6YACBJm8XK4bFmOc" } } } ``` ### `GET /api/cameras//` Returns information for the camera with the given URL. As in the like section of `GET /api/` with the `days` parameter set and the `cameraConfigs` parameter unset. Example response: ```json { "description": "", "streams": { "main": { "days": { "2016-05-01": { "endTime90k": 131595516000000, "startTime90k": 131587740000000, "totalDuration90k": 52617609 }, "2016-05-02": { "endTime90k": 131603292000000, "startTime90k": 131595516000000, "totalDuration90k": 20946022 } }, "maxEndTime90k": 131598273666690, "minStartTime90k": 131590386129355, "retainBytes": 104857600, "totalDuration90k": 73563631, "totalSampleFileBytes": 98901406 } }, "shortName": "driveway" } ``` ### `GET /api/cameras///recordings` Returns information about *recordings*. Valid request parameters: * `startTime90k` and and `endTime90k` limit the data returned to only recordings with wall times overlapping with the given half-open interval. Either or both may be absent; they default to the beginning and end of time, respectively. * `split90k` causes long runs of recordings to be split at the next convenient boundary after the given duration. * TODO(slamb): `continue` to support paging. (If data is too large, the server should return a `continue` key which is expected to be returned on following requests.) Returns a JSON object. Under the key `recordings` is an array of recordings in arbitrary order. Each recording object has the following properties: * `startId`. The id of this recording, which can be used with `/view.mp4` to retrieve its content. * `endId` (optional). If absent, this object describes a single recording. If present, this indicates that recordings `startId-endId` (inclusive) together are as described. Adjacent recordings from the same RTSP session may be coalesced in this fashion to reduce the amount of redundant data transferred. * `runStartId`. The id of the first recording in this run. * `firstUncommitted` (optional). If this range is not fully committed to the database, the first id that is uncommitted. This is significant because it's possible that after a crash and restart, this id will refer to a completely different recording. That recording will have a different `openId`. * `growing` (optional). If this boolean is true, the recording `endId` is still being written to. Accesses to this id (such as `view.mp4`) may retrieve more data than described here if not bounded by duration. Additionally, if `startId` == `endId`, the start time of the recording is "unanchored" and may change in subsequent accesses. * `openId`. Each time Moonfire NVR starts in read-write mode, it is assigned an increasing "open id". This field is the open id as of when these recordings were written. This can be used to disambiguate ids referring to uncommitted recordings. * `startTime90k`: the start time of the given recording, in the wall time scale. Note this may be less than the requested `startTime90k` if this recording was ongoing at the requested time. * `endTime90k`: the end time of the given recording, in the wall time scale. Note this may be greater than the requested `endTime90k` if this recording was ongoing at the requested time. * `videoSampleEntryId`: a reference to an entry in the `videoSampleEntries` object. * `videoSamples`: the number of samples (aka frames) of video in this recording. * `sampleFileBytes`: the number of bytes of video in this recording. * `hasTrailingZero`: the final frame of the final recording id described by this row (`endId` if present, otherwise `startId`) has a duration of 0. A frame's duration is calculated by subtracting its timestamp from the following frame's timestamp. When a run ends, there's no following frame and Moonfire NVR fills in a duration of 0. When using `/view.mp4`, it's not possible to append additional segments after such frames, as noted below. Under the property `videoSampleEntries`, an object mapping ids to objects with the following properties: * `width`: the stored width in pixels. * `height`: the stored height in pixels. * `pixelHSpacing`: the relative width of a pixel, as in a ISO/IEC 14496-12 section 12.1.4.3 `PixelAspectRatioBox`. If absent, assumed to be 1. * `pixelVSpacing`: the relative height of a pixel, as in a ISO/IEC 14496-12 section 12.1.4.3 `PixelAspectRatioBox`. If absent, assumed to be 1. * `aspectWidth`: the width component of the aspect ratio. (The aspect ratio can be computed from the dimensions and pixel spacing; it's included as a convenience.) * `aspectHeight`: the height component of the aspect ratio. The full initialization segment data for a given video sample entry can be retrieved at the URL `/api/init/.mp4`. Example request URI (with added whitespace between parameters): ``` /api/cameras/fd20f7a2-9d69-4cb3-94ed-d51a20c3edfe/main/recordings ?startTime90k=130888729442361 &endTime90k=130985466591817 ``` Example response: ```json { "recordings": [ { "startId": 1, "startTime90k": 130985461191810, "endTime90k": 130985466591817, "sampleFileBytes": 8405564, "videoSampleEntryId": 1, }, { "endTime90k": 130985461191810, ... }, ... ], "videoSampleEntries": { "1": { "width": 1280, "height": 720 } }, } ``` ### `GET /api/cameras///view.mp4` Requires the `viewVideo` permission. Returns a `.mp4` file, with an etag and support for range requests. The MIME type will be `video/mp4`, with a `codecs` parameter as specified in [RFC 6381][rfc-6381]. Expected query parameters: * `s` (one or more): a string of the form `START_ID[-END_ID][@OPEN_ID][.[REL_START_TIME]-[REL_END_TIME]]`. This specifies *segments* to include. The produced `.mp4` file will be a concatenation of the segments indicated by all `s` parameters. The ids to retrieve are as returned by the `/recordings` URL. The *open id* is optional and will be enforced if present; it's recommended for disambiguation when the requested range includes uncommitted recordings. The optional start and end times are in 90k units of wall time and relative to the start of the first specified id. These can be used to clip the returned segments. Note they can be used to skip over some ids entirely; this is allowed so that the caller doesn't need to know the start time of each interior id. If there is no key frame at the desired relative start time, frames back to the last key frame will be included in the returned data, and an edit list will instruct the viewer to skip to the desired start time. * `ts` (optional): should be set to `true` to request a subtitle track be added with human-readable recording timestamps. Example request URI to retrieve all of recording id 1 from the given camera: ``` /api/cameras/fd20f7a2-9d69-4cb3-94ed-d51a20c3edfe/main/view.mp4?s=1 ``` Example request URI to retrieve all of recording ids 1–5 from the given camera, with timestamp subtitles: ``` /api/cameras/fd20f7a2-9d69-4cb3-94ed-d51a20c3edfe/main/view.mp4?s=1-5&ts=true ``` Example request URI to retrieve recording id 1, skipping its first 26 90,000ths of a second: ``` /api/cameras/fd20f7a2-9d69-4cb3-94ed-d51a20c3edfe/main/view.mp4?s=1.26- ``` Note carefully the distinction between *wall duration* and *media duration*. It's normal for `/view.mp4` to return a media presentation with a length slightly different from the *wall duration* of the backing recording or portion that was requested. Bugs and limitations: * If the `s=` parameter references a recording id that doesn't exist when the server starts processing the `/view.mp4` request, the server will return a `404` with a text error message. This commonly happens when the oldest recording was deleted between the `/recordings` request and the `/view.mp4` request. The server probably should return a structured JSON document describing exactly which recordings have been deleted. For now, the client will have to retry from `/recordings` and again race against deletion. * If a recording is deleted after the server starts processing `/view.mp4` but before the request advances to the recording's byte position, the server will abruptly drop the HTTP connection. The client must then retry to see a proper 404 error. It'd be better if the server would prevent recordings from being deleted while there are `/view.mp4` requests in progress which reference them. * The final recording in every "run" ends with a frame that has duration 0. It's not possible to append additional segments after such a frame; the server will return a 400 error like `Invalid argument: unable to append recording 2/16672 after recording 2/16671 with trailing zero`. See also `hasTrailingZero` above, and [#178](https://github.com/scottlamb/moonfire-nvr/issues/178). ### `GET /api/cameras///view.mp4.txt` Returns a `text/plain` debugging string for the `.mp4` generated by the same URL minus the `.txt` suffix. ### `GET /api/cameras///view.m4s` Returns a `.mp4` suitable for use as a [HTML5 Media Source Extensions media segment][media-segment]. The MIME type will be `video/mp4`, with a `codecs` parameter as specified in [RFC 6381][rfc-6381]. Note that these can't include edit lists, so (unlike `/view.mp4`) the caller must manually trim undesired leading portions. This response will include the following additional headers: * `X-Prev-Media-Duration`: the total *media duration* (in 90 kHz units) of all *recordings* before the first requested recording in the `s` parameter. Browser-based callers may use this to place this at the correct position in the source buffer via `SourceBuffer.timestampOffset`. * `X-Runs`: the cumulative number of "runs" of recordings. If this recording starts a new run, it is included in the count. Browser-based callers may use this to force gaps in the source buffer timeline by adjusting the timestamp offset if desired. * `X-Leading-Media-Duration`: if present, the total duration (in 90 kHz units) of additional leading video included before the caller's first requested timestamp. This happens when the caller's requested timestamp does not fall exactly on a key frame. Media segments can't include edit lists, so unlike with the `/api/.../view.mp4` endpoint the caller is responsible for trimming this portion. Browser-based callers may use `SourceBuffer.appendWindowStart`. Expected query parameters: * `s` (one or more): as with the `.mp4` URL. It's recommended that each `.m4s` retrieval be for at most one Moonfire NVR recording. The fundamental reason is that the Media Source Extension API appears structured for adding a complete segment at a time. Large media segments thus impose significant latency on seeking. Additionally, because of this fundamental reason Moonfire NVR makes no effort to make multiple-segment `.m4s` requests practical: * There is currently a hard limit of 4 GiB of data because the `.m4s` uses a single `moof` followed by a single `mdat`; the former references the latter with 32-bit offsets. * There's currently no way to generate an initialization segment for more than one video sample entry, so a `.m4s` that uses more than one video sample entry can't be used. * The `X-Prev-Media-Duration` and `X-Leading-Media-Duration` headers only describe the first segment. Timestamp tracks (see the `ts` parameter to `.mp4` URIs) aren't supported today. Most likely browser clients will implement timestamp subtitles via WebVTT API calls anyway. ### `GET /api/cameras///view.m4s.txt` Returns a `text/plain` debugging string for the `.mp4` generated by the same URL minus the `.txt` suffix. ### `GET /api/cameras///live.m4s` Initiate a WebSocket stream for chunks of video. Expects the standard WebSocket headers as described in [RFC 6455][rfc-6455] and (if authentication is required) the `s` cookie. The server will send messages as follows: * text: a plaintext error message, followed by the end of stream. * binary: video data, repeatedly, as described below. * ping: every 30 seconds. Each binary message corresponds to one or more frames of video. The first message is guaranteed to start with a "key" (IDR) frame; others may not. The message will contain HTTP headers followed by by a `.mp4` media segment. The following headers will be included: * `X-Video-Sample-Entry-Id`: An id to use when fetching an initialization segment. * `X-Recording-Id`: the open id, a period, and the recording id of the recording these frames belong to. * `X-Recording-Start`: the timestamp (in Moonfire NVR's usual 90,000ths of a second) of the start of the recording. Note that if the recording is "unanchored" (as described in `GET /api/.../recordings`), the recording's start time may change before it is completed. * `X-Prev-Media-Duration`: as in `/.../view.m4s`. * `X-Runs`: as in `/.../view.m4s`. * `X-Media-Time-Range`: the relative media start and end times of these frames within the recording, as a half-open interval. The WebSocket will always open immediately but will receive messages only while the backing RTSP stream is connected. Example request URI: ``` /api/cameras/fd20f7a2-9d69-4cb3-94ed-d51a20c3edfe/main/live.m4s ``` Example binary message sequence: ``` Content-Type: video/mp4; codecs="avc1.640028" X-Recording-Id: 42.5680 X-Recording-Start: 130985461191810 X-Prev-Media-Duration: 10000000 X-Media-Time-Range: 5220058-5400061 X-Video-Sample-Entry-Id: 4 binary mp4 data ``` ``` Content-Type: video/mp4; codecs="avc1.640028" X-Recording-Id: 42.5681 X-Recording-Start: 130985461191822 X-Prev-Media-Duration: 10180003 X-Media-Time-Range: 0-180002 X-Video-Sample-Entry-Id: 4 binary mp4 data ``` ``` Content-Type: video/mp4; codecs="avc1.640028" X-Recording-Id: 42.5681 X-Recording-Start: 130985461191822 X-Prev-Media-Duration: 10360005 X-Media-Time-Range: 180002-360004 X-Video-Sample-Entry-Id: 4 binary mp4 data ``` These roughly correspond to the `.m4s` files available at the following URLs: * `/api/cameras/fd20f7a2-9d69-4cb3-94ed-d51a20c3edfe/main/view.m4s?s=5680@42.5220058-5400061` * `/api/cameras/fd20f7a2-9d69-4cb3-94ed-d51a20c3edfe/main/view.m4s?s=5681@42.0-180002` * `/api/cameras/fd20f7a2-9d69-4cb3-94ed-d51a20c3edfe/main/view.m4s?s=5681@42.180002-360004` However, there are two important differences: * The `/view.m4s` endpoint accepts offsets within a recording as wall durations; the `/live.m4s` endpoint's `X-Media-Time-Range` header returns them as media durations. Thus the URLs above are only exactly correct if the wall and media durations of the recording are identical. * The `/view.m4s` endpoint always returns a time range that starts with a key frame; `/live.m4s` messages may not include a key frame. Note: an earlier version of this API used a `multipart/mixed` segment instead, compatible with the [multipart-stream-js][multipart-stream-js] library. The problem with this approach is that browsers have low limits on the number of active HTTP/1.1 connections: six in Chrome's case. The WebSocket limit is much higher (256), allowing browser-side Javascript to stream all active camera streams simultaneously as well as making other simultaneous HTTP requests. ### `GET /api/init/.mp4` Returns a `.mp4` suitable for use as a [HTML5 Media Source Extensions initialization segment][init-segment]. The MIME type will be `video/mp4`, with a `codecs` parameter as specified in [RFC 6381][rfc-6381]. The `` should be a value previously extracted from the `X-Video-Sample-Entry-Id` header returned in a `.../live.m4s` response. An `X-Aspect` HTTP header will include the aspect ratio as width:height, eg `16:9` (most cameras) or `9:16` (rotated 90 degrees). This is redundant with the returned `.mp4` but is far easier to parse from Javascript. ### `GET /api/init/.mp4.txt` Returns a `text/plain` debugging string for the `.mp4` generated by the same URL minus the `.txt` suffix. ### `GET /api/signals` Returns an `application/json` response with state of every signal for the requested timespan. Valid request parameters: * `startTime90k` and and `endTime90k` limit the data returned to only events relevant to the given half-open interval. Either or both may be absent; they default to the beginning and end of time, respectively. This will return the current state as of the latest change (to any signal) before the start time (if any), then all changes in the interval. This allows the caller to determine the state at every moment during the selected timespan, as well as observe all events. Responses are several parallel arrays for each observation: * `times90k`: the time of each event. Events are given in ascending order. * `signalIds`: the id of the relevant signal; expected to match one in the `signals` field of the `/api/` response. * `states`: the new state. Example request URI (with added whitespace between parameters): ``` /api/signals ?startTime90k=130888729442361 &endTime90k=130985466591817 ``` Example response: ```json { "signalIds": [1, 1, 1], "states": [1, 2, 1], "times90k": [130888729440000, 130985424000000, 130985418600000] } ``` This represents the following observations: 1. time 130888729440000 was the last change before the requested start; signal 1 (`driveway motion`) was in state 1 (`off`). 2. signal 1 entered state 2 (`on`) at time 130985424000000. 3. signal 1 entered state 1 (`off`) at time 130985418600000. ### `POST /api/signals` Requires the `updateSignals` permission. Alters the state of a signal. A typical client might be a subscriber of a camera's built-in motion detection event stream or of a security system's zone status event stream. It makes a request on every event or on every 30 second timeout, predicting that the state will last for a minute. This prediction may be changed later. Writing to the near future in this way ensures that the UI never displays `unknown` when the client is actively managing the signal. Some requests may instead backfill earlier history, such as when a video analytics client starts up and analyzes all video segments recorded since it last ran. These will specify beginning and end times. The request should have an `application/json` body describing the change to make. It should be a JSON object with these attributes: * `csrf`: a CSRF token, required when using session authentication. * `signalIds`: a list of signal ids to change. Must be sorted. * `states`: a list (one per `signalIds` entry) of states to set. * `start`: the starting time of the change, as a JSON object of the form `{'base': 'epoch', 'rel90k': t}` or `{'base': 'now', 'rel90k': t}`. In the `epoch` form, `rel90k` is 90 kHz units since 1970-01-01 00:00:00 UTC. In the `now` form, `rel90k` is relative to current time and may be negative. * `end`: the ending time of the change, in the same form as `start`. The response will be an `application/json` body JSON object with the following attributes: * `time90k`: the current time. When the request's `startTime90k` is absent and/or its `endBase` is `now`, this is needed to know the effect of the earlier request. Example request sequence: #### Request 1 The client responsible for reporting live driveway motion has just started. It observes motion now. It records no history and predicts there will be motion for the next minute. Request: ```json { "signalIds": [1], "states": [2], "start": {"base": "now", "rel90k": 0}, "end": {"base": "now", "rel90k": 5400000} } ``` Response: ```json { "time90k": 140067468000000 } ``` #### Request 2 30 seconds later (half the prediction interval), the client still observes motion. It leaves the prior data alone and predicts the motion will continue. Request: ```json { "signalIds": [1], "states": [2], "start": {"base": "epoch", "rel90k": 140067468000000}, "end": {"base": "now", "rel90k": 5400000} } ``` Response: ```json { "time90k": 140067470700000 } ``` #### Request 3 5 seconds later, the client observes motion has ended. It leaves the prior data alone and predicts no more motion. Request: ```json { "signalIds": [1], "states": [2], "start": {"base": "now", "rel90k": 0}, "end": {"base": "now", "rel90k": 5400000} } } ``` Response: ```json { "time90k": 140067471150000 } ``` ### User management #### `GET /api/users/` Requires the `adminUsers` permission. Lists all users. Currently there's no paging. Returns a JSON object with a `users` key with an array of objects, each with the following keys: * `id`: a number. * `user`: a `UserSubset`. #### `POST /api/users/` Requires the `adminUsers` permission. Adds a user. Expects a JSON object as follows: * `csrf`: a CSRF token, required when using session authentication. * `user`: a `UserSubset` as defined below. Returns status 204 (No Content) on success. #### `GET /api/users/` Retrieves the user. Requires the `adminUsers` permission if the caller is not authenticated as the user in question. Returns a HTTP status 200 on success with a JSON `UserSubset`. #### `PATCH /api/users/` Updates the given user. Requires the `adminUsers` permission if the caller is not authenticated as the user in question. Expects a JSON object: * `csrf`: a CSRF token, required when using session authentication. * `update`: `UserSubset`, sets the provided fields. Field-specific notes: * `disabled`: requires `adminUsers` permission. * `password`: when updating the password, the previous password must be supplied as a precondition, unless the caller has `adminUsers` permission. * `permissions`: requires `adminUsers` permission. Note that updating a user's permissions currently neither adds nor limits permissions of existing sessions; it only changes what is available to newly created sessions. * `username`: requires `adminUsers` permission. * `precondition`: `UserSubset`, forces the request to fail with HTTP status 412 (Precondition failed) if the provided fields don't have the given values. Returns HTTP status 204 (No Content) on success. #### `DELETE /api/users/` Deletes the given user. Requires the `adminUsers` permission. Expects a JSON object body with the following parameters: * `csrf`: a CSRF token, required when using session authentication. Returns HTTP status 204 (No Content) on success. ## Types ### UserSubset A JSON object with any of the following parameters: * `disabled`, boolean indicating if all logins from the user are rejected. * `password` * on retrieval, a placeholder string to indicate a password is set, or null. * in preconditions, may be left absent to ignore, set to null to require no password, or set to a plaintext string. * in updates, may be left absent to keep as-is, set to null to disable session creation, or set to a plaintext string. * `permissions`, a `Permissions` as described below. * `preferences`, a JSON object which the server stores without interpreting. This field is meant for user-level preferences meaningful to the UI. * `username` ### Permissions A JSON object of permissions to perform various actions: * `adminUsers`: bool * `readCameraConfigs`: bool, read camera configs including credentials * `updateSignals`: bool * `viewVideo`: bool See endpoints above for more details on the contexts in which these are required. ## Cross-site request forgery (CSRF) protection The API includes several standard protections against [cross-site request forgery](https://en.wikipedia.org/wiki/Cross-site_request_forgery) attacks, in which a malicious third-party website convinces the user's browser to send requests on its behalf. The following protections apply regardless of method of authentication (session, no authentication + `allowUnauthenticatedPermissions`, or the browser proxying to a Unix socket with `ownUidIsPrivileged`): * The `GET` method is always "safe". Actions that have significant side effects require another method such as `DELETE`, `POST`, or `PUT`. This prevents simple hyperlinks from causing damage. * Mutations always require some non-default request header (e.g. `Content-Type: application/json`) so that a `
` will be rejected. * The server does *not* override the default [CORS](https://en.wikipedia.org/wiki/Cross-origin_resource_sharing) policy. Thus, cross-domain Ajax requests (via `XMLHTTPRequest` or `fetch`) should fail. * WebSocket upgrade requests are rejected if the `Origin` header is present and does not match `Host`. This is the sole protection against [Cross-Site WebSocket Hijacting (CSWSH)](https://christian-schneider.net/CrossSiteWebSocketHijacking.html). The following additional protections apply only when using session authentication: * Session cookies are set with the [`SameSite=Lax` attribute](samesite-lax), so that sufficiently modern web browsers will never send the session cookie on subrequests. (Note they still send session cookies when following links and on WebSocket upgrade. In these cases, we rely on the protections described above.) * Mutations use a `csrf` token, requiring the caller to prove it is able to read the `GET /api/` response. (This is subect to change. We may decide to implement these tokens in a way that doesn't require session authentication or decide they're entirely unnecessary.) [media-segment]: https://w3c.github.io/media-source/isobmff-byte-stream-format.html#iso-media-segments [init-segment]: https://w3c.github.io/media-source/isobmff-byte-stream-format.html#iso-init-segments [rfc-6381]: https://tools.ietf.org/html/rfc6381 [rfc-6455]: https://tools.ietf.org/html/rfc6455 [multipart-mixed-js]: https://github.com/scottlamb/multipart-mixed-js [samesite-lax]: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie/SameSite#lax