Feed screen standard

• The flag of what the feed simulates, such as the pair, then the feed's name.
• The line under the name: the key, the version and the engine, such as "EUR/USD · version 3 · Geometric".
• The status tag, then Start or Stop, then Edit and Delete.
• No access mark. The actions offered already say what the person may do.

• The edit dialog does not offer the engine. The engine changes on the process tab, where the process is converted with it.
• The add dialog offers the engine, so a new feed starts with one. A new feed opens on the process tab.
• Each field of the form can carry help, shown under it. A choice is explained by its option.
• Delete stops the feed, deletes its parts, then deletes the feed.

[ 2 unsaved changes ]        Engine [Geometric ▾]  [Add] [Discard] [Save]
┌─────────────────────────────────────────────────────────────────────┐
│ # Description            Profile   μ        σ        w      Share   │
│ 0 Primary · calibrated…  Normal    0        0.001    0.95   95.0%  ↑↓ Delete │
│ 1 Tail · 4x primary…     Custom    0        0.004    0.05    5.0%  ↑↓ Delete │
└─────────────────────────────────────────────────────────────────────┘
┌ Return distribution ─────────┐ ┌ Sample paths ────────────────┐
│ chart                        │ │ chart                        │
│                              │ │ price · ticks · paths · seed │
└──────────────────────────────┘ └──────────────────────────────┘
ⓘ The engine's note

• The toolbar holds the unsaved count, or "No unsaved changes.", the engine, and Add, Discard and Save. Buttons are one word.
• The list spans the full width. The previews sit side by side below it, and stack on a narrow screen. The engine's note sits under the previews.

• The list is read only. A row opens the part in a dialog.
• The description shows its name highlighted and its note subdued: the text before the first colon is the name. A long description ends in an ellipsis, with the whole text in its tooltip.
• Numbers are right aligned in the mono face.
• A computed column states what the engine does with the numbers. For FX, the Share column gives each weight as a percentage of the sum, and its header tooltip gives the sum. An engine that reads no shares has no such column.
• Every column header has a tooltip in the engine's terms, and every row a tooltip that says what one part means to the engine.
• Each row has ↑, ↓ and Delete. The first row cannot move up and the last cannot move down.

Nothing is written until Save, and what is not saved is visible:

Discard puts the saved process and engine back.

• The description is a text area of four lines, with a hint for the "Name: note" form.
• Each number has the engine's help under it, and the dialog refuses a value that is not a number or is negative before Done.
• Done puts the part back into the draft. It writes nothing.

Save is enabled while there are changes and no problems. It opens a dialog:

1. One line per kind of change: the engine change, such as "Engine: Geometric → Arithmetic.", and the counts added, changed and deleted.
2. The change reason and commentary, or the new record note when every change is new.
3. When the feed applies the change. A running feed keeps the process it started with, so the dialog says "The feed is running on the old mixture." and offers Restart it to apply, ticked. A stopped feed is told "It applies on start."

The save writes the feed's engine first, then deletes the removed parts, then writes the changed parts, all under one reason. A restart, when chosen, stops and starts the feed after the writes.

The engine decides what the numbers of a part mean. Changing it changes the meaning of the saved process, so the screen converts the draft with it:

• The screen asks the server to convert the draft. The conversion is never computed in the browser.
• The converted values show as unsaved changes. A notice says what was converted and at which price, and says when a preview price stood in for a feed with no fixed price.
• For FX, the server operation is convert_fx_mixture: μ and σ scale by the initial price between log-returns and price units; into the mean reverting engine only the first part stays, with κ from a 15 minute half-life and no μ; out of it the one part takes the whole weight.

• The previews read the draft, not the saved process, so a person judges a change before saving it.
• The distribution is drawn per part, dashed, and as the whole.
• The sample paths come from the server's simulation, with their settings under the chart: the initial price, the ticks, the paths and the seed with Reseed. The screen waits 300 ms after typing before it asks.
• Neither preview saves anything.

News of an action does not take a place in the page. A conversion that changed the person's numbers, such as a change of engine or a switch to Simple, shows as a toast. So does the sentence that says what the Simple answers make of the model (the curve slopes up, or the price has no trend), which a new answer replaces in the bottom right corner (ui/Toasts.tsx). It has a close button. Information leaves by itself after ten seconds, and a warning stays until the person closes it. A fact that stays true, such as an engine that can take a price below zero, is also marked where it applies: a Can go below zero tag beside the engine, with the full explanation as its tooltip. A closed toast is not lost, because the tag remains.

A process tab offers two ways to edit the same numbers. Advanced is the table above, the engine's own parameters. Simple is for a person who does not know the model, and it asks plain questions in place of the table.

• The choice is a switch on the toolbar. It is one choice for the whole web application, kept in the browser. A new person starts in Simple, and a person who picks Advanced stays in Advanced on every screen that offers both (EditingMode.tsx).
• A curve feed asks four questions: where rates are today, where they settle in the long run, how fast they come back (a half-life in years, with the words Slow, Medium and Fast), and how far they move in a year (basis points, with the words Calm, Normal and Stressed). A sentence under the answers says what they make of the curve: it slopes up, down or is flat. A line under the toolbar says in plain words what the engine does.
• The server converts both ways (synthetic.v1.ops.convert_ir_parameters; the FX mixture conversion, convert_fx_mixture, is its counterpart). Each engine reads σ in its own unit, and Black-Karasinski reads θ as a logarithm, so the screen never converts. An answer goes through the server and into the same draft the table edits. Save, Discard and the previews work the same from either mode.
• The same switch appears on the screens that draw ORE parameters, settings and convention terms, where it decides how much documentation shows rather than how a person edits. The choice is still one, and each screen names it in its own words; the ORE element and leaf screen standard states that meaning.
• Switching from Simple to Advanced loses nothing. A feed whose parameters have no simple form, such as a reversion speed of zero or a Two-Factor Gaussian feed with a second factor set by hand, shows the table in either mode, with a note that says why.
• A warning appears when the parameters allow a risk, such as a Cox-Ingersoll-Ross rate that can touch zero.
• A field whose value differs from the saved one is tinted, as a changed cell of the table is.
• The FX price behaviour tab offers the same switch (FxSimplePanel.tsx). Its questions are per hour, so they do not depend on the feed's rate: which way the price drifts, how far it moves, and how often it jumps; the mean-reverting engine asks how long the price takes to come half way back, and how far it moves. The server converts both ways (synthetic.v1.ops.convert_fx_simple). The simple form of a mixture is one primary component and, if the feed jumps, one jump regime that has no drift and is four times as wide.
• Switching to Simple never leaves a dead end. Values that the simple form states exactly stay as they are. Values that it only approximates, such as three hand-set components, or a second factor and a correlation set by hand, are converted to the closest simple form, and a notice says what changed: how many components became how many, the jump share, or the factors that were set. The change is only in the draft. Save writes it, and Discard brings the old values back. Values with no simple view at all, such as a reversion speed of zero, show the table with a note that says why.

The dashboard (DashboardTab.tsx) has five tiles and then one row for each provider.

• The tiles count the providers, the feeds running, the feeds stopped, the ids demanded and the ticks per minute. The two feed tiles count feeds one by one: a feed is in one of them and never in both.
• A provider row shows what it simulates, its FX and IR counts, its feeds, the state of its source, and the ids demanded of it that are not served. Demand starts a generator; Start and Stop on the row are the operator's test control.
• A banner counts the ids that are demanded and not served. Show them in the feed tree is gone; the row opens the Provider tab on that provider.

The Provider tab (ProviderTab.tsx) is the feeds of one provider.

• A provider combo at the top, then the provider's state, its feed count and Start and Stop, which act on the provider's feeds as the test control.
• A collection filter, drawn only when the provider holds more than one collection.
• An asset class combo: All, or one asset class. The grid is one plain list, with no group headers and no separator rows.
• The grid columns are underlying, enabled, name, engine, frequency and state. The underlying leads. A feed's state is Running or Stopped, and it is the feed's own run, not the state of its provider's source: the source can serve while this feed's generator does not run. The oresmd URI column is gone; the series is reached from the feed's page.
• There is no folder tree, no pick bar and no oresmd URI column. The lower folders were derived containers for asset class and instrument, and the grid groups by the same properties.
• A feed's page opens from a row. Its trail is Home, Market data, Synthetic, Provider, the provider and the folders, then the feed.