API reference

Solar lucky-imaging stacker. All paths are relative to the server's data root. Version 0.5.0 of the document; licence GPL-3.0-or-later.

The narrative guide, with examples and the security model, is in The API. The machine-readable document is openapi.json, and a running server serves it at /api/v1/openapi.json.

All paths below are relative to /api/v1.

Operations

`GET /captures/frame`

One frame of a capture as an auto-stretched 8-bit greyscale PNG.

Parameter	In	Type	Required	Description
`path`	query	string	yes	Capture path relative to the data root.
`index`	query	integer	no	Frame index (default 0).
`channel`	query	ChannelArg	no	`r`, `g`, `b` or `lum` (default) for Bayer captures.
`max_width`	query	integer	no	Downscale to at most this width (16 to 8192).
`bayer`	query	string	no	Bayer handling, as for jobs: `auto` (default), `none` or a pattern.
`bit_depth`	query	integer (int32)	no	Bits per sample instead of the SER header's.
`endian`	query	string	no	`little` or `big`.
`flip_rows`	query	boolean	no	Read the rows bottom to top.

Status	Meaning	Body
200	8-bit greyscale PNG	`image/png`

`POST /captures/inspect`

Header information for a .ser, .avi or video capture, without reading frames.

Request body:

application/json: InspectRequest

Status	Meaning	Body
200	OK	`application/json`: CaptureInfo

`GET /docs`

A small HTML page that lists the operations of the OpenAPI document; needs no token.

Needs no token.

Status	Meaning	Body
200	OK	`text/html`

`GET /health`

Liveness probe. Always answers {"status":"ok"}; needs no token.

Needs no token.

Status	Meaning	Body
200	OK	`application/json`: Health

`GET /jobs`

Remembered jobs, oldest first. The newest 100 finished jobs are kept.

Status	Meaning	Body
200	OK	`application/json`: array of JobView

`POST /jobs`

Queue a stack. Answers 202 with the job; poll it or follow its events.

Request body:

application/json: JobRequest

Status	Meaning	Body
202	Accepted	`application/json`: JobView
429	queue full (`queue_full`)	`application/json`: ErrorEnvelope

`GET /jobs/{id}`

One job: state, stage, progress, timings and summary.

Parameter	In	Type	Required	Description
`id`	path	integer (int64)	yes	job id

Status	Meaning	Body
200	OK	`application/json`: JobView
404	unknown job id	`application/json`: ErrorEnvelope

`DELETE /jobs/{id}`

Cancel a queued or running job, or forget a finished one.

A finished job's output file stays on disk.

Parameter	In	Type	Required	Description
`id`	path	integer (int64)	yes	job id

Status	Meaning	Body
202	cancellation requested	`application/json`: JobView
204	finished job forgotten
404	unknown job id	`application/json`: ErrorEnvelope

`GET /jobs/{id}/events`

WebSocket stream of job events: a snapshot, then state and progress messages.

The server closes the stream after the final state message.

Parameter	In	Type	Required	Description
`id`	path	integer (int64)	yes	job id

Status	Meaning	Body
101	WebSocket; text frames are JobEvent JSON

`GET /jobs/{id}/preview.png`

An 8-bit PNG of the result (square-root stretch). Only once the job has succeeded.

Parameter	In	Type	Required	Description
`id`	path	integer (int64)	yes	job id
`max_width`	query	integer	no	Downscale to at most this width (16 to 8192; stored previews are at most 2048 wide).

Status	Meaning	Body
200	PNG preview	`image/png`
409	the job has not succeeded (`not_ready`)	`application/json`: ErrorEnvelope

`GET /jobs/{id}/result`

The written TIFF or FITS file, streamed. Only once the job has succeeded.

Parameter	In	Type	Required	Description
`id`	path	integer (int64)	yes	job id

Status	Meaning	Body
200	the stacked TIFF, PNG or FITS file
409	the job has not succeeded (`not_ready`)	`application/json`: ErrorEnvelope

`GET /jobs/{id}/sunspots.csv`

The sunspot table of a finished job that asked for sunspots, as CSV.

Parameter	In	Type	Required	Description
`id`	path	integer (int64)	yes	job id

Status	Meaning	Body
200	one row per spot	`text/csv`
404	the job did not ask for sunspots (`sunspots_missing`)	`application/json`: ErrorEnvelope
409	the job has not succeeded (`not_ready`)	`application/json`: ErrorEnvelope

`GET /jobs/{id}/sunspots.png`

The sunspot overlay of a finished job that asked for sunspots: the flattened disc with penumbra, umbra and group numbers drawn on it.

Parameter	In	Type	Required	Description
`id`	path	integer (int64)	yes	job id

Status	Meaning	Body
200	overlay PNG	`image/png`
404	the job did not ask for sunspots (`sunspots_missing`)	`application/json`: ErrorEnvelope
409	the job has not succeeded (`not_ready`)	`application/json`: ErrorEnvelope

`GET /openapi.json`

This API as an OpenAPI document.

Status	Meaning	Body
200	OpenAPI 3 document

`GET /presets`

GET /presets: the filter presets, their recommended settings and colours.

Status	Meaning	Body
200	OK	`application/json`: PresetList

`GET /presets/{id}/lut`

A preset's colour table as a file other programs read.

Parameter	In	Type	Required	Description
`id`	path	string	yes	preset id, see `GET /presets`
`format`	query	string	no	`cube` (default), `csv`, `imagej` or `png`.
`size`	query	integer	no	Entries, 2 to 4096 (default 256; an `imagej` table always has 256).
`invert`	query	boolean	no	Invert before colouring.
`strength`	query	number (float)	no	Mix of colour and grey, 0 to 1 (default 1).

Status	Meaning	Body
200	the table: a .cube, .csv, ImageJ .lut or a PNG strip
404	no such preset	`application/json`: ErrorEnvelope
422	a bad format, size or strength	`application/json`: ErrorEnvelope

`GET /version`

Server version, backend availability, limits and whether a token is required.

The GPU is probed once, on first use.

Status	Meaning	Body
200	OK	`application/json`: VersionInfo

Schemas

AlignmentSummary

Global alignment: the method that ran, why, and its confidence.

Field	Type	Required	Description
`confidence`	number (float), may be null	no	Mean confidence of the frames, 0 to 1. Absent when it was not measured.
`confidence_min`	number (float), may be null	no	Least confidence of any frame, 0 to 1.
`fallbacks`	integer	yes	Frames that wanted the limb fit but were aligned by phase correlation.
`limb`	array of number (float), may be null	no	Fitted limb of the reference: centre x, centre y and radius, pixels.
`method`	string	yes	What ran: `limb` or `phase`.
`reason`	string	yes	Why, in a sentence (for `auto`, whether the full disc was in view).
`requested`	string	yes	What `config.align` asked for: `auto`, `phase` or `limb`.
`sampled`	boolean	yes	The confidence comes from a sample of the frames (a GPU run).

AutoApSummary

What automatic alignment points chose and what they were based on.

Field	Type	Required	Description
`arcsec_per_pixel`	number (float), may be null	no	Image scale from the fitted limb, arcseconds per pixel. Absent when there was no limb.
`search_radius`	integer	yes	Search radius around the global shift, pixels.
`size`	integer	yes	Window edge, pixels.
`step`	integer	yes	Distance between window centres, pixels.
`text`	string	yes	The choice in a sentence.
`warp_px`	number (float), may be null	no	Local warp of the seeing, pixels (root mean square distance of an alignment point's shift from its frame's median). Absent when too few points locked.

BackendArg

Compute backend request.

One of auto, cpu, gpu.

Backends

Backend availability.

Field	Type	Required	Description
`cpu`	CpuInfo	yes	CPU reference path.
`gpu`	GpuInfo	yes	wgpu path.

BuildDetails

How the server binary was built.

Field	Type	Required	Description
`built`	string	yes	Build time, UTC.
`commit`	string	yes	Short git commit hash (`unknown` outside a git checkout).
`dirty`	boolean	yes	Built from a tree with uncommitted changes.
`profile`	string	yes	Cargo profile.
`rust`	string	yes	Compiler version.
`target`	string	yes	Target triple.
`wgpu`	string	yes	wgpu version.

Calibration masters for a job. Each path is relative to the data root and names a master file (FITS, from helia calibrate) or raw calibration frames to build one from (a SER, AVI or FITS file, or a folder of them).

Field	Type	Required	Description
`bad_pixels`	string, may be null	no	Bad-pixel map: a FITS map from `helia calibrate`, or a text file with an `x y` pair (from 0, top-left) on each line.
`bias`	string, may be null	no	Master bias, or bias captures. Only used with `scale_dark`.
`combine`	string	no	How frames are combined into a master: `median`, `sigma` or `sigma:K`. Default `sigma`. Default `"sigma"`.
`cosmetic`	boolean	no	Without `bad_pixels`, find the hot pixels of the dark and the cold ones of the flat and correct them. Default `true`. Default `true`.
`dark`	string, may be null	no	Master dark, or dark captures.
`displaced`	string, may be null	no	Captures of the Sun at many places on the sensor, to solve a flat from when there is no `flat` (self-calibration: dust and fringes included). The dark is taken off first. Excludes `flat`.
`flat`	string, may be null	no	Master flat, or flat captures.
`flat_dark`	string, may be null	no	Dark captures at the exposure of the flats, when `flat` is captures.
`scale_dark`	boolean	no	Scale the dark by the ratio of the exposures (read from the `SharpCap` sidecar of the capture). Default `false`.

CaptureInfo

Header information for a capture.

Field	Type	Required	Description
`bayer`	string, may be null	no	Bayer pattern (`rggb` ...) when raw colour.
`bit_depth`	integer (int32)	yes	Bits per sample.
`codec`	string, may be null	no	Video codec (`h264`, ...), for video read through ffmpeg.
`colour`	string	yes	Pixel layout: `mono`, `bayer`, `rgb`, `bgr`, or `video` for compressed video, which ffmpeg converts to luminance or one colour channel.
`detection`	DetectionInfo or null	no
`effective`	EffectiveInfo	yes	What Helia decodes the capture with, and where each value came from.
`format`	string	yes	`ser`, `avi`, or the extension of a video read through ffmpeg (`mp4`, `mov`, `mkv`, `webm`, `m4v`; also `avi` for a compressed AVI).
`fourcc`	string, may be null	no	AVI `FourCC`.
`frame_rate`	number (double), may be null	no	Frames per second, for video.
`frames`	integer	yes	Number of frames.
`header`	SerHeaderInfo or null	no
`height`	integer (int32)	yes	Height in pixels.
`instrument`	string, may be null	no	SER instrument string.
`notices`	array of NoticeInfo	yes	What to tell the user about how the file was read.
`observer`	string, may be null	no	SER observer string.
`overrides`	array of string	yes	The overrides in force, as command-line flags.
`path`	string	yes	Capture path relative to the data root.
`quality_note`	string, may be null	no	Quality caveat when the input is lossy video, for example "lossy 8-bit 4:2:0 video (h264): fine for quick results, SER/AVI raw captures keep more detail".
`recommended`	Recommended	yes	The settings a job would use if none were given.
`sidecar`	SidecarInfo or null	no
`telescope`	string, may be null	no	SER telescope string.
`timestamps`	boolean, may be null	no	SER per-frame timestamps present.
`width`	integer (int32)	yes	Width in pixels.

ChannelArg

Colour plane taken from a Bayer capture.

One of r, g, b, lum.

ChannelSummary

How red and blue were registered to green in a true-colour stack.

Field	Type	Required	Description
`applied`	boolean	yes	The plane was moved. False when the shift was too small, too large or not trustworthy.
`channel`	string	yes	`red` or `blue`.
`confidence`	number (float)	yes	Confidence of the correlation, 0 to 1.
`shift`	array of number (float)	yes	Shift measured, pixels: `[dx, dy]`.

CpuInfo

CPU availability (always true).

Field	Type	Required	Description
`available`	boolean	yes	Always true.

DebayerArg

Demosaicing method.

One of bilinear, mhc.

DetectionInfo

The test for a hidden Bayer mosaic.

Field	Type	Required	Description
`frames_used`	integer	yes	Frames measured.
`pattern`	string, may be null	no	Pattern found, for `mosaic`.
`position_means`	array of number (double)	yes	Mean level (0 to 1) of the pixels at even x/even y, odd x/even y, even x/odd y and odd x/odd y.
`reason`	string, may be null	no	Why it could not tell, for `inconclusive`.
`red_blue_basis`	string, may be null	no	How red was told from blue, for `mosaic`.
`region`	array of integer	yes	Area measured: x, y, width, height.
`spread`	number (double)	yes	(largest - smallest) / average of the four means.
`verdict`	string	yes	`mosaic`, `mono` or `inconclusive`.

EffectiveInfo

What Helia decodes the capture with.

Field	Type	Required	Description
`bayer`	SourcedText	yes	Bayer pattern (`rggb` ...), or `none` for mono.
`bit_depth`	SourcedNumber	yes	Bits per sample.
`byte_order`	SourcedText	yes	Byte order of 16-bit samples: `little` or `big`.
`flip_rows`	SourcedFlag	yes	Rows are read bottom to top.

ErrorBody

Machine-readable error body.

Field	Type	Required	Description
`code`	string	yes	Stable `snake_case` identifier, safe to match on.
`message`	string	yes	Human-readable explanation.

ErrorEnvelope

Envelope returned for every non-2xx response.

Field	Type	Required	Description
`error`	ErrorBody	yes	The error.

GpuInfo

GPU availability.

Field	Type	Required	Description
`adapter`	string, may be null	no	Adapter description.
`available`	boolean	yes	A GPU backend can be created (a software adapter counts).
`software`	boolean	yes	The adapter is a software rasteriser.

GranulationSummary

Granulation statistics of the stack (helia measure, the quality report).

Field	Type	Required	Description
`arcsec_per_pixel`	number (float), may be null	no	Image scale, arcseconds per pixel (absent without a fitted limb).
`cell_diameter_px`	number (float)	yes	Mean diameter of whole granules, pixels.
`cell_pitch_px`	number (float)	yes	Mean spacing of granules, pixels.
`cutoff_freq`	number (float), may be null	no	Diffraction cut-off `D / lambda` in cycles per pixel; needs `aperture_mm` and a fitted limb.
`lines`	array of string	yes	The report in lines, as the command line prints it.
`resolved_freq`	number (float)	yes	Highest frequency (cycles per pixel) above 1% of the peak power.
`rms_contrast`	number (float)	yes	Standard deviation over mean of the flattened disc-centre region (a fraction, 0.04 is 4%).
`rolloff_freq`	number (float)	yes	Spatial frequency (cycles per pixel) where the noise-subtracted power spectrum has fallen to 10% of its peak.

Health

Liveness probe.

Field	Type	Required	Description
`status`	string	yes	Always `ok`.

InspectRequest

POST /captures/inspect body.

Field	Type	Required	Description
`bayer`	string, may be null	no	`auto` (default), `none`, `rggb`, `grbg`, `gbrg` or `bggr`: see what an override would change.
`bit_depth`	integer (int32), may be null	no	Bits per sample instead of the SER header's (1 to 16).
`endian`	string, may be null	no	`little` or `big`, instead of the SER header flag.
`flip_rows`	boolean	no	Read the rows bottom to top.
`path`	string	yes	Capture path relative to the data root.

JobConfig

The same knobs as helia stack.

Field	Type	Required	Description
`align`	string	no	How whole frames are aligned: `auto` (fit the solar limb when the full disc is in view and the fit is confident, else phase correlation), `phase`, or `limb`. The choice and its confidence come back in `summary.alignment`. Default `"auto"`.
`align_channels`	boolean	no	With `colour: "true"`, register red and blue to green (atmospheric dispersion). Default `true`. Default `true`.
`ap_auto`	boolean	no	Choose the alignment point size, spacing and search range from the image scale (the fitted limb) and the seeing (a probe of a dozen frames). Excludes `ap_size`; needs `multipoint`. What was chosen comes back in `summary.auto_ap`. Default `false`.
`ap_passes`	integer (int32), may be null	no	Alignment point passes, 1 or 2. 2 stacks once and measures the points again against that stack. Default 1; needs `multipoint`.
`ap_size`	integer, may be null	no	Alignment point size in pixels (8 to 1024). Absent: chosen from the image size.
`ap_smooth`	boolean	no	Replace alignment point shifts that disagree with their neighbours by the neighbours' median. Needs `multipoint`. Default `false`.
`aperture_mm`	number (float), may be null	no	Telescope aperture in millimetres, for the diffraction cut-off in `summary.granulation` and for `r0` in `summary.seeing`.
`autocrop`	boolean	no	Crop the result to the solar disc plus `autocrop_margin`, FITS too. A capture without a clear disc is left uncropped; `summary.crop` is then absent. Default `false`.
`autocrop_margin`	number (float), may be null	no	Margin of `autocrop` as a percentage of the disc radius, 0 to 200. Default 10.
`backend`	BackendArg	no	Compute backend. Default `"auto"`.
`bayer`	string	no	`auto`, `none`, `rggb`, `grbg`, `gbrg` or `bggr`. `auto` trusts the file's header, but checks a SER file labelled mono for a hidden Bayer mosaic and debayers when it finds one. `none` treats the frames as mono whatever the header says; a pattern forces it. Default `"auto"`.
`bit_depth`	integer (int32), may be null	no	Bits per sample instead of the SER header's (1 to 8 read one byte per pixel, 9 to 16 two). SER only.
`calibration`	CalibrationConfig or null	no
`channel`	ChannelArg or null	no
`colour`	string, may be null	no	Colour of the output: `auto` (the preset in force), `mono`, a preset id, or `true`. `true` is true colour from a raw colour camera: red, green and blue stacked on one alignment, channels aligned, white balanced, written as an RGB TIFF or PNG or a three-plane FITS cube; it needs a Bayer capture and excludes `channel`, `invert` and `colour_strength`. The other looks colour a `.tif` or `.png` from the mono stack, and FITS output is mono and unaltered for them. Absent: the `preset`'s colours if one was given, else mono.
`colour_strength`	number (float)	no	Mix of colour and grey, 0 to 1. Default `1.0`.
`debayer`	DebayerArg	no	Demosaicing method. Default `"mhc"`.
`detect_overlay`	boolean	no	Look for burned-in text (a `SharpCap` timestamp) and mask it. Default `true`.
`disc_mask`	boolean	no	Fit the limb and place alignment points on the disc only. Default `true`.
`edits`	array of object	no	Further edits, applied in order after `sharpen`: objects with an `op` of `unsharp`, `wavelet`, `deconvolve`, `denoise`, `levels`, `curve`, `crop`, `rotate`, `flip` or `resize` and that operation's parameters (see the sharpening and adjustments page of the user guide). Unset parameters take their defaults. Default `[]`.
`endian`	string, may be null	no	Byte order of 16-bit samples instead of the SER header flag: `little` or `big`. SER only.
`exclude`	array of Region	no	Rectangles to keep alignment and scoring off. They are flattened in every frame and so are flat in the result. Burned-in timestamps are found automatically (see `detect_overlay`). Default `[]`.
`flatten`	string, may be null	no	Flatten the disc's limb darkening before anything else: `model` (divide by the fitted law) or `profile` (divide by the measured azimuthal median). Outside the limb nothing changes. It runs first, so `sharpen` and `edits` see flat contrast. A capture with no clear disc is left as it is and `summary.limb_darkening` is absent.
`flip_rows`	boolean	no	Read the rows bottom to top. SER only. Default `false`.
`invert`	boolean	no	Invert before colouring (shows filaments and prominences). Default `false`.
`keep`	string, may be null	no	Share (`"25%"`) or count (`"500"`) of frames to keep. Default `25%`.
`keep_frames`	integer, may be null	no	Number of frames to keep; excludes `keep`.
`limb_law`	string, may be null	no	The limb-darkening law fitted to the stack and used by `flatten`: `linear`, `quadratic` (the default) or `neckel` (five terms). The fit comes back in `summary.limb_darkening` whether or not `flatten` is set.
`metric`	MetricArg	no	Frame ranking metric. Default `"gradient"`.
`multipoint`	boolean	no	Multi-point alignment; `false` is global alignment only. Default `true`.
`preset`	string, may be null	no	Filter preset (`ha`, `cak`, `cah`, `mg`, `na`, `he-d3`, `hbeta`, `white`; see `GET /presets`): its channel and frame share apply wherever `channel` and `keep` are absent, and a `.tif` or `.png` output is coloured with it. Absent: the filter is detected from the file name, folder, sidecar or header, for the settings only.
`prominence_band`	integer	no	Pixels outside the fitted limb where alignment points are still allowed; 0 keeps them on the disc. Default `0`.
`robust`	RobustArg or null	no
`robust_k`	number (float), may be null	no	Threshold of `robust` in standard deviations. Default 2.5 for `sigma`, 1.345 for `huber`, 2 for `winsor`.
`seeing`	boolean	no	Estimate the seeing from the capture (`summary.seeing`): the Fried parameter from the spectral ratio, which needs `aperture_mm`, and a relative alignment point motion index. Default `false`.
`sharpen`	string, may be null	no	Sharpening of the stack: `wavelet` (Registax-style layers, the usual choice), `unsharp`, `rl` (Richardson-Lucy) or `none`, with the recommended values of the filter in force. Absent: `none`. It runs first, on the mono image, before `edits` and before any colour.
`sharpen_fits`	boolean	no	Apply `sharpen` and `edits` to FITS output too. By default a FITS file is the unsharpened stack. Default `false`.
`sigma_clip`	number (float), may be null	no	Sigma clipping threshold in standard deviations; off when absent. Same as `robust: "sigma"` with `robust_k`.
`site`	string, may be null	no	Observing site as `"lat,lon,alt"` (degrees north, degrees east, metres), written to a FITS output as `OBSGEO-X/Y/Z`. Absent: the server's `HELIA_SITE` environment variable, else the keywords are left out.
`sunspots`	SunspotsConfig or null	no
`white_balance`	string, may be null	no	White balance of `colour: "true"`: `auto` (make the disc centre neutral), `off` (the sensor's own balance) or `"R,G,B"` gains such as `"1.9,1,1.5"`. Default `auto`. Only with `colour: "true"`.

JobEvent

Message on the /events WebSocket.

One of:

Full job view, sent once on connect. Fields: job (JobView), type = snapshot.
State change. Fields: error (ErrorBody or null), job (integer (int64)), state (JobState), type = state.
Progress tick. Fields: job (integer (int64)), progress (number (float)), stage_progress (number (float)), stage (string), type = progress.

JobRequest

POST /jobs body.

Field	Type	Required	Description
`config`	JobConfig	no	Stacking settings.
`input`	string	yes	Capture path (`.ser` or `.avi`), relative to the data root.
`output`	string	yes	Output path; `.tif`/`.tiff` or `.fits`/`.fit`/`.fts`.
`overwrite`	boolean	no	Replace an existing output file.

JobState

Lifecycle state.

One of queued, running, succeeded, failed, cancelled.

JobSummary

What a finished stack contains.

Field	Type	Required	Description
`alignment`	AlignmentSummary	yes	How whole frames were aligned, and how confident that was.
`alignment_points_active`	integer, may be null	no	Active alignment points (multi-point only).
`alignment_points_total`	integer, may be null	no	Alignment points in the grid (multi-point only).
`auto_ap`	AutoApSummary or null	no
`bayer`	string, may be null	no	Bayer pattern the frames were decoded with (`rggb` ...); absent for mono.
`bayer_source`	string	yes	Where that came from: `header`, `sidecar`, `detection` or `override`.
`calibration`	array of string	yes	The calibration masters applied, one line each, and any warning about them (a flat with rings, a dark that could not be scaled). Empty when the job had no `calibration`.
`colour`	string, may be null	no	How the output was coloured, in words; absent for a mono output.
`crop`	Region or null	no
`edited`	boolean	yes	The edits were applied to the pixels of the output.
`edits`	array of string	yes	The edits recorded in the output file, one line each. For FITS output without `sharpen_fits` this is the note that the file is unedited.
`filter`	string, may be null	no	Preset id in force (chosen or detected), if any.
`filter_source`	string, may be null	no	Where the filter was read from (`chosen`, or the text it was found in).
`frames`	integer	yes	Frames in the capture.
`granulation`	GranulationSummary or null	no
`height`	integer	yes	Output height.
`kept`	integer	yes	Frames in the kept set.
`limb_darkening`	LimbSummary or null	no
`notices`	array of string	yes	Things worth knowing about how the capture was read, such as a Bayer mosaic found in a file whose header says mono.
`registered`	integer	yes	Frames registered.
`seeing`	SeeingSummary or null	no
`sunspots`	SunspotsSummary or null	no
`true_colour`	TrueColourSummary or null	no
`width`	integer	yes	Output width.

JobView

Public view of a job.

Field	Type	Required	Description
`backend`	string, may be null	no	Backend used.
`config`	JobConfig	yes	The settings in force.
`created_at`	integer (int64)	yes	Creation time, Unix milliseconds.
`error`	ErrorBody or null	no
`finished_at`	integer (int64), may be null	no	End time, Unix milliseconds.
`id`	integer (int64)	yes	Job id.
`input`	string	yes	Input path relative to the data root.
`output`	string	yes	Output path relative to the data root.
`progress`	number (float)	yes	Approximate overall progress, 0 to 1.
`queue_position`	integer, may be null	no	Position among queued jobs (0 is next), while queued.
`run_seconds`	number (float), may be null	no	Seconds spent running so far or in total.
`stage`	string, may be null	no	Current stage name, once running.
`stage_progress`	number (float)	yes	Progress within the current stage, 0 to 1.
`started_at`	integer (int64), may be null	no	Start time, Unix milliseconds.
`state`	JobState	yes	State.
`summary`	JobSummary or null	no
`timings`	array of StageTiming	yes	Per-stage wall times of a finished run.

LicenceDetails

Licensing of the software.

Field	Type	Required	Description
`copyright`	string	yes	Copyright line.
`licence`	string	yes	SPDX licence identifier.
`source`	string	yes	Source code location.

LimbSummary

A limb-darkening law fitted to the stack's azimuthal median profile.

Field	Type	Required	Description
`coefficients`	array of number (float)	yes	The coefficients, `I(mu) / I(1) = 1 - sum c_k (1 - mu^k)` for `neckel`, `1 - u (1 - mu) - u2 (1 - mu)^2` for the others.
`law`	string	yes	`linear`, `quadratic` or `neckel`.
`limb_level`	number (float)	yes	The law at the limb as a share of the disc centre.
`names`	array of string	yes	Names of the coefficients, in order (`u1`, `u2`, or `a1` to `a5`).
`radius_px`	number (float)	yes	Fitted disc radius, pixels.
`rms`	number (float)	yes	Root mean square departure of the profile from the law, as a share of the centre intensity.
`text`	string	yes	The fit in a sentence.

Limits

Server limits.

Field	Type	Required	Description
`active_jobs`	integer	yes	Jobs queued or running now.
`max_body_bytes`	integer	yes	Request body limit in bytes.
`max_queue`	integer	yes	Queued plus running jobs allowed.
`workers`	integer	yes	Concurrent jobs.

MetricArg

Sharpness metric.

One of gradient, laplacian.

NoticeInfo

A message about how the capture was understood.

Field	Type	Required	Description
`level`	string	yes	`info` or `warning`.
`text`	string	yes	The message.

PresetColour

The colour parameters of a preset.

Field	Type	Required	Description
`exponents`	array of number (float)	yes	Per-channel exponent (red, green, blue).
`gains`	array of number (float)	yes	Per-channel gain (red, green, blue).
`gamma`	number (float)	yes	Tone exponent applied before colouring (below 1 brightens).
`mid_grey_rgb`	array of integer (int32)	yes	What a mid-grey (0.5) becomes, 8-bit red, green, blue.

PresetList

GET /presets body.

Field	Type	Required	Description
`presets`	array of PresetView	yes	Every preset.

PresetSharpen

The recommended sharpening values of a preset (what sharpen in a job uses for this filter).

Field	Type	Required	Description
`denoise`	number (float)	yes	Wavelet denoise strength.
`reason`	string	yes	Why they are what they are.
`rl_iterations`	integer (int32)	yes	Richardson-Lucy iterations.
`rl_tv`	number (float)	yes	Richardson-Lucy total-variation weight.
`unsharp_amount`	number (float)	yes	Unsharp mask amount.
`unsharp_threshold`	number (float)	yes	Unsharp mask threshold (image units, 0 to 1).
`wavelet_gains`	array of number (float)	yes	Wavelet gain of layers 1 to 6.
`wavelet_noise`	array of number (float)	yes	Wavelet noise threshold of layers 1 to 6, in noise sigmas.

PresetView

One filter preset.

Field	Type	Required	Description
`channel`	string	yes	Bayer channel stacked (`r`, `g`, `b` or `lum`).
`colour`	PresetColour	yes	Colour parameters. Colour is presentation, not measurement.
`hue`	string	yes	Hue in words.
`id`	string	yes	Id to give as `preset` or `colour` in a job: `ha`, `cak`, ...
`keep_percent`	number (float)	yes	Share of frames kept, percent.
`name`	string	yes	Plain name.
`reason`	string	yes	Why the recommendations are what they are.
`sharpen`	PresetSharpen	yes	Recommended sharpening values.
`summary`	string	yes	One line on what it is for.
`wavelength`	string	yes	Wavelength as printed in the docs.

Field	Type	Required	Description
`ap_size`	integer	yes	Alignment point size in pixels.
`channel`	string	yes	Bayer channel it would stack (`r`, `g`, `b`, `lum`).
`filter`	string, may be null	no	Preset id detected from the file name, folder, sidecar or SER header.
`filter_source`	string, may be null	no	The text the filter was read from.
`keep_percent`	number (float)	yes	Share of frames it would keep, percent.

Region

A rectangle of the frame, in pixels from the top-left corner.

Field	Type	Required	Description
`h`	integer	yes	Height; at least 1.
`w`	integer	yes	Width; at least 1.
`x`	integer	yes	Left edge.
`y`	integer	yes	Top edge.

RobustArg

Outlier-robust combination of the frames at each pixel.

One of none, sigma, huber, winsor.

SeeingSummary

Seeing estimated from the capture.

Field	Type	Required	Description
`d_over_r0`	number (float), may be null	no	`D / r0` from the spectral ratio; needs `aperture_mm`.
`frames`	integer	yes	Frames followed (spread over the whole capture).
`grade`	string, may be null	no	`excellent`, `good`, `fair`, `poor` or `bad`, from `r0_500nm_cm`.
`lines`	array of string	yes	The report in lines, as the command line prints it.
`motion_arcsec`	number (float), may be null	no	The same in arcseconds, with a fitted limb.
`motion_px`	number (float), may be null	no	RMS differential motion between neighbouring alignment points, per axis, pixels. A relative index, not `r0`.
`r0_500nm_cm`	number (float), may be null	no	Fried parameter at 500 nm, centimetres.
`r0_cm`	number (float), may be null	no	Fried parameter at the capture's wavelength, centimetres.
`tiles`	integer	yes	Tiles of the disc followed.

SerHeaderInfo

A SER header exactly as written in the file, decoded.

Field	Type	Required	Description
`colour_id`	integer (int32)	yes	`ColorID` as stored.
`colour_meaning`	string	yes	Its meaning (`MONO`, `BAYER_RGGB` ...).
`date_time`	string, may be null	no	`DateTime` (local) decoded; absent when unset.
`date_time_utc`	string, may be null	no	`DateTimeUTC` decoded; absent when unset.
`file_id`	string	yes	`FileID`.
`frame_count`	integer (int32)	yes	Frame count.
`height`	integer (int32)	yes	Height in pixels.
`instrument`	string	yes	Instrument.
`little_endian`	boolean	yes	`LittleEndian` flag as stored.
`lu_id`	integer (int32)	yes	`LuID`.
`observer`	string	yes	Observer.
`pixel_depth`	integer (int32)	yes	Bits per sample.
`telescope`	string	yes	Telescope.
`timestamps`	TimestampInfo or null	no
`width`	integer (int32)	yes	Width in pixels.

SidecarInfo

SharpCap sidecar contents that Helia uses.

Field	Type	Required	Description
`bayer_hint`	string, may be null	no	Bayer pattern implied by the sidecar.
`colour_space`	string, may be null	no	`Colour Space` value.
`frame_count`	integer, may be null	no	Frame count from the sidecar.
`path`	string	yes	Sidecar path relative to the data root.
`raw_colour`	boolean, may be null	no	Whether the sidecar says the data is raw colour.
`sections`	array of string	yes	Section headings (camera model).

SourcedFlag

A switch and where its setting came from.

Field	Type	Required	Description
`source`	string	yes	`header`, `sidecar`, `detection` or `override`.
`value`	boolean	yes	The value.

SourcedNumber

A number Helia uses and where it came from.

Field	Type	Required	Description
`source`	string	yes	`header`, `sidecar`, `detection` or `override`.
`value`	integer (int32)	yes	The value.

SourcedText

A value Helia uses and where it came from.

Field	Type	Required	Description
`source`	string	yes	`header`, `sidecar`, `detection` or `override`.
`value`	string	yes	The value.

StageTiming

Wall time of one stage.

Field	Type	Required	Description
`seconds`	number (float)	yes	Seconds.
`stage`	string	yes	Stage name.

SunspotGroupRow

One group of sunspots.

Field	Type	Required	Description
`area_msh`	number (float)	yes	Corrected, millionths of the hemisphere.
`cmd_deg`	number (float)	yes	Area-weighted central meridian distance, degrees.
`id`	integer	yes	Number from 1, largest first.
`lat_deg`	number (float)	yes	Area-weighted latitude, degrees north.
`lon_deg`	number (float), may be null	no	Area-weighted Carrington longitude, degrees (needs `time`).
`projected_msh`	number (float)	yes	As seen, millionths of the visible hemisphere.
`spots`	integer	yes	Spots in it.
`umbra_msh`	number (float)	yes	Umbrae corrected, millionths of the hemisphere.
`umbrae`	integer	yes	Umbrae in it.

SunspotRow

One sunspot.

Field	Type	Required	Description
`area_msh`	number (float)	yes	Corrected for foreshortening, millionths of the hemisphere.
`cmd_deg`	number (float)	yes	Central meridian distance, degrees, west positive.
`group`	integer	yes	Its group.
`id`	integer	yes	Number from 1.
`lat_deg`	number (float)	yes	Heliographic latitude, degrees north.
`lon_deg`	number (float), may be null	no	Carrington longitude, degrees (needs `time`).
`mu`	number (float)	yes	Cosine of the angle from disc centre.
`penumbra_px`	integer	yes	Penumbra pixels.
`projected_msh`	number (float)	yes	As seen, millionths of the visible hemisphere.
`umbra_msh`	number (float)	yes	Umbra corrected, millionths of the hemisphere.
`umbra_px`	integer	yes	Umbra pixels.
`umbrae`	integer	yes	Umbrae in it.
`x`	number (float)	yes	Centroid, pixels.
`y`	number (float)	yes	Centroid, pixels, top row 0.

SunspotsConfig

Tuning of the sunspot detection; every field is optional.

Field	Type	Required	Description
`celestial_north_up`	boolean	no	The image has celestial north up: add the position angle P of the Sun at the capture time to `north_angle_deg`. Default `false`.
`group_gap_deg`	number (float), may be null	no	Spots closer than this on the Sun, degrees, form one group. Default 3.
`max_area`	number (float), may be null	no	Largest spot, millionths of the hemisphere; bigger dark regions are left out as a cloud or vignette. Default 6000.
`min_area`	number (float), may be null	no	Smallest spot, millionths of the hemisphere. Default 2.
`mirror`	boolean	no	The image is a mirror image. Default `false`.
`north_angle_deg`	number (float), may be null	no	Counter-clockwise angle from the top of the image to solar north, degrees. Default 0.
`penumbra`	number (float), may be null	no	Penumbra threshold, a share of the quiet disc (0 to 1). Default 0.88.
`umbra`	number (float), may be null	no	Umbra threshold, a share of the quiet disc (0 to 1). Default 0.55.
`wolf_k`	number (float), may be null	no	Observer factor k of the Wolf number. Default 1.

SunspotsSummary

Sunspots on the stack: counts, areas and the table.

Field	Type	Required	Description
`area_msh`	number (float)	yes	Everything corrected for foreshortening, millionths of the hemisphere.
`b0_deg`	number (float), may be null	no	Heliographic latitude of the disc centre, degrees (needs `time`).
`disc`	array of number (float)	yes	Disc centre x, centre y and radius the positions are measured on, pixels.
`group_table`	array of SunspotGroupRow	yes	One row per group.
`groups`	integer	yes	Sunspot groups, `g`.
`k`	number (float)	yes	The observer factor used.
`l0_deg`	number (float), may be null	no	Carrington longitude of the disc centre, degrees (needs `time`).
`lines`	array of string	yes	The report in lines, as the command line prints it.
`notes`	array of string	yes	Things to be careful about.
`p_deg`	number (float), may be null	no	Position angle of the solar axis, degrees (needs `time`).
`projected_msh`	number (float)	yes	Everything as seen, millionths of the visible hemisphere.
`spot_table`	array of SunspotRow	yes	One row per spot.
`spots`	integer	yes	Individual spots, `s` (umbrae and pores).
`time`	string, may be null	no	Capture time used, ISO 8601 UTC; absent when the capture had none.
`umbra_msh`	number (float)	yes	Umbrae corrected, millionths of the hemisphere.
`wolf`	number (float)	yes	Relative Wolf number `k (10 g + s)`.

TimestampInfo

SER trailer timestamps.

Field	Type	Required	Description
`count`	integer	yes	How many.
`first`	string, may be null	no	First, UTC.
`last`	string, may be null	no	Last, UTC.

TrueColourSummary

What a true-colour job did.

Field	Type	Required	Description
`channels`	array of ChannelSummary, may be null	no	Red and blue against green; absent when `align_channels` was off.
`gains`	array of number (float)	yes	Gains applied to red, green and blue, including the common scale that keeps the picture inside white.
`notes`	array of string	yes	The notes written into the file's history, including warnings (a channel held at the largest automatic gain, a shift not applied).

VersionInfo

/version response.

Field	Type	Required	Description
`api`	string	yes	API version in the URL prefix.
`auth_required`	boolean	yes	Whether a token is required.
`backends`	Backends	yes	Backends.
`build`	BuildDetails	yes	Build record.
`licence`	LicenceDetails	yes	Copyright and licence.
`limits`	Limits	yes	Limits.
`name`	string	yes	Package name.
`version`	string	yes	Package version.

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