API Reference

The Go backend exposes methods to the TypeScript frontend through auto-generated Wails bindings. These are imported from frontend/wailsjs/go/service/AppService.

All methods are bound via the Wails Bind option in main.go and are available as async functions in the frontend.

`EvaluateAll`

function EvaluateAll(input: string): Promise<string[]>;

Evaluates every line of the input string. Each line is processed independently. Variables persist across lines. Empty lines and comment lines (#, //) return empty strings. Lines ending with : (labels) also return empty strings.

Parameters:

input — Multi-line string, lines separated by \n

Returns:

string[] — Array of result strings, one per line. Empty string for no result or evaluation errors.

Limits:

Input length: max 10,000 characters per line
Evaluation timeout: 5 seconds per call (returns ["Error: evaluation timed out"])

Example:

const results = await svc.EvaluateAll('x = 10\nx * pi\ntwenty five + 3');
// results: ["x = 10", "31.4159", "28"]

`EvaluateLine`

function EvaluateLine(input: string): Promise<string>;

Evaluates a single line of natural-language arithmetic. Variables are preserved across calls. Empty lines, comment lines (#, //), and label lines (ending with :) return an empty string.

Parameters:

input — Single line string

Returns:

string — Result string, or empty string on error/unsupported input.

Limits:

Input length: max 10,000 characters
Evaluation timeout: 5 seconds (returns "Error: evaluation timed out")

`GetVariables`

function GetVariables(): Promise<Record<string, number>>;

Returns all currently defined variables as a map of name to value.

Returns:

Record<string, number> — Object with variable names as keys (lowercase) and float64 values.

Example:

await svc.EvaluateAll('x = 42\ny = 100');
const vars = await svc.GetVariables();
// vars: { x: 42, y: 100 }

`ClearVariables`

function ClearVariables(): Promise<void>;

Clears all stored variables and resets the last-result context tracker.

`GetHistory`

interface HistoryEntry {
  input: string;
  output: string;
}

function GetHistory(): Promise<HistoryEntry[]>;

Returns the evaluation history — each entry records the input line and its computed result.

Returns:

HistoryEntry[] — Array of { input, output } objects, ordered chronologically (oldest first).

`ClearHistory`

function ClearHistory(): Promise<void>;

Clears all stored history entries.

`GetSteps`

interface Step {
  operation: string;
  expression: string;
  result: string;
}

interface EvalDetail {
  result: string;
  steps: Step[];
}

function GetSteps(input: string): Promise<EvalDetail>;

Evaluates a single expression and returns the intermediate computation steps. Does not modify engine state (no side effects on history or variables).

Parameters:

input — Single expression string

Returns:

EvalDetail with:
- result — The final result string
- steps — Ordered array of Step objects showing each parser-level reduction

Step fields:

operation — The operation type (e.g. "+", "×", "÷", "^", "mod")
expression — The sub-expression being reduced
result — The result of that reduction

Limits:

Input length: max 10,000 characters
Evaluation timeout: 5 seconds

Example:

const detail = await svc.GetSteps('2 + 3 * 4');
// detail.result: "14"
// detail.steps: [
//   { operation: "×", expression: "3 * 4", result: "12" },
//   { operation: "+", expression: "2 + 12", result: "14" }
// ]

`EvaluateGraph`

interface Point {
  x: number;
  y: number;
}

interface GraphResult {
  points: Point[];
  expression: string;
  from: number;
  to: number;
}

function EvaluateGraph(input: string): Promise<GraphResult | null>;

Evaluates a graphing expression (plot, graph, y = syntax) and returns 200 sampled points across the expression's range.

Parameters:

input — Graphing expression (e.g. "plot x^2", "graph sin(x) from -5 to 5")

Supported prefixes:

plot <expr> — e.g. plot x^2
graph <expr> — e.g. graph sin(x)
y = <expr> — e.g. y = 2*x + 3

Range specifiers:

from N to N at the end of the expression — e.g. plot x^2 from -5 to 5
Default range: -10 to 10

Returns:

GraphResult | null — Object with:
- points — Array of 200 { x, y } sampled points
- expression — The cleaned expression (prefix and range stripped)
- from — Start of the x range
- to — End of the x range
Returns null if the input is not a graph expression or evaluation fails.

Limits:

Evaluation timeout: 5 seconds

Example:

const graph = await svc.EvaluateGraph('plot x^2 from -2 to 2');
// graph.points: [{ x: -2, y: 4 }, { x: -1.98, y: 3.9204 }, ...]
// graph.expression: "x^2"
// graph.from: -2
// graph.to: 2

`ReorderNotes`

function ReorderNotes(noteIDs: string[]): Promise<void>;

Updates the position of notes to match the given order. All note IDs in the array must exist in the database.

Parameters:

noteIDs — Array of note ID strings in the desired display order

Example:

await svc.ReorderNotes(['uuid-3', 'uuid-1', 'uuid-2']);

`UpdateCurrencyRates`

interface CurrencyCacheInfo {
  cached: boolean;
  updatedAt: number; // Unix timestamp in milliseconds
  source: string; // "live", "cache", or "hardcoded"
}

function UpdateCurrencyRates(): Promise<CurrencyCacheInfo>;

Fetches live exchange rates from exchangerate-api.com. Falls back to cached rates on network failure. Rates are stored in the SQLite currency_cache table and applied to the calculator engine.

Returns:

CurrencyCacheInfo with:
- cached — true if rates are available (live or cached)
- updatedAt — Unix timestamp in milliseconds of when rates were last updated
- source — "live" if freshly fetched, "cache" if using cached rates, "hardcoded" if no cache exists

Error handling:

Returns an error if the fetch fails and no cached rates are available

`GetCurrencyCacheInfo`

function GetCurrencyCacheInfo(): Promise<CurrencyCacheInfo>;

Returns the current currency cache status without attempting a refresh.

Returns:

CurrencyCacheInfo — Same structure as UpdateCurrencyRates, but source is "hardcoded" when no cache exists.

`GetDataDir`

function GetDataDir(): Promise<string>;

Returns the application data directory path.

Returns:

string — The data directory path (e.g. ~/.config/neostore/linesolv on Linux/macOS, %APPDATA%/neostore/linesolv on Windows)

`GetSettings`

interface SettingsData {
  theme: string;
  font_size: string;
  font_family: string;
  shortcut_overrides: string; // JSON string
  opacity: string; // "0.30" to "1.00"
  line_numbers_enabled: string; // "true" or "false"
  autocomplete_enabled: string; // "true" or "false"
  animations_enabled: string; // "true" or "false"
  toast_enabled: string; // "true" or "false"
  result_panel_enabled: string; // "true" or "false"
  line_wrap_enabled: string; // "true" or "false"
  ui_style: string; // e.g. "default", "glass", "material"
  theme_manually_set: string; // "true" or "false" — whether user manually selected a theme
  noise: string; // "true" or "false" — background noise animation
  context_menu_notes: string; // "true" or "false"
  context_menu_folders: string; // "true" or "false"
  drag_and_drop: string; // "true" or "false"
  confirm_dialog: string; // "true" or "false"
}

function GetSettings(): Promise<SettingsData>;

Returns the current application settings loaded from config.toml.

Returns:

SettingsData with theme name, font size, font family, shortcut overrides as a JSON string, opacity, line numbers toggle, autocomplete toggle, animations toggle, toast toggle, result panel toggle, line wrap toggle, UI style, theme manual override, noise animation, context menu toggles (notes/folders), drag-and-drop toggle, and confirm dialog toggle.

Valid theme values (17 built-in): dark, light, neon, red, obsidian, plasma, blood, midnight, aurora, mono, frost, prism, lavender, sage, warm-light, claude-dark, claude-light

Plugin themes are also valid — their IDs are defined in each plugin's plugin.json manifest.

Valid ui_style values (7 built-in): default, nothing, glass, material, alivated, neon, claude

`SaveSettings`

function SaveSettings(settings: SettingsData): Promise<void>;

Saves application settings to config.toml. In the frontend, settings auto-save on every change with a 50ms debounce and apply immediately (real-time pattern).

Parameters:

settings — SettingsData object with the values to persist

`GetAppVersion`

function GetAppVersion(): Promise<string>;

Returns the current application version string (e.g. "0.17.0").

`CheckForUpdate`

interface UpdateInfo {
  update_available: boolean;
  current_version: string;
  latest_version: string;
  download_url: string;
}

function CheckForUpdate(): Promise<UpdateInfo>;

Checks the GitHub repository for a newer version by fetching the .version file from the main branch.

Returns:

UpdateInfo with:
- update_available — true if the remote version differs from the local version
- current_version — The local app version
- latest_version — The remote version string
- download_url — URL to the releases page

`GetDeleteWithoutConfirm` / `SetDeleteWithoutConfirm`

function GetDeleteWithoutConfirm(): Promise<boolean>;
function SetDeleteWithoutConfirm(v: boolean): Promise<void>;

Gets or sets the "Don't ask again" preference for note deletion confirmation. Stored in config.toml under [behavior] -> delete_without_confirm.

Note Management Methods

function GetAllNotes(): Promise<Note[]>;
function CreateNote(): Promise<Note>;
function CreateNoteInFolder(folderID: string): Promise<Note>;
function GetNote(id: string): Promise<Note>;
function RenameNote(id: string, name: string): Promise<void>;
function DeleteNote(id: string): Promise<void>;
function SaveNoteContent(id: string, content: string): Promise<void>;
function ExportNote(id: string, format: string): Promise<string>;
function ExportNoteToFile(id: string, format: string): Promise<string>;
function ImportNoteFromFile(): Promise<Note>;
function UpdateNoteIcon(id: string, icon: string): Promise<void>;
function MoveNoteToFolder(noteID: string, folderID: string): Promise<void>;

Where Note is:

interface Note {
  id: string;
  name: string;
  content: string;
  icon: string; // Emoji or icon identifier
  createdAt: number; // Unix timestamp in milliseconds
  updatedAt: number; // Unix timestamp in milliseconds
  position: number; // Sort order
}

CreateNote() generates a random fancy name (e.g. "Amber Fox")
CreateNoteInFolder(folderID) creates a note inside the specified folder
UpdateNoteIcon(id, icon) sets the emoji/icon for a note
MoveNoteToFolder(noteID, folderID) moves a note into the specified folder
ExportNoteToFile() opens a native Save As dialog; supported formats: lv, txt, md, json, toml, pdf
ImportNoteFromFile() opens a native Open file dialog; supported formats: lv, txt, md, json, toml, pdf

Folder Management Methods

function CreateFolder(name: string, parentID: string): Promise<Folder>;
function GetAllFolders(): Promise<Folder[]>;
function RenameFolder(id: string, name: string): Promise<void>;
function DeleteFolder(id: string): Promise<void>;
function MoveFolder(id: string, newParentID: string): Promise<void>;
function UpdateFolderIcon(id: string, icon: string): Promise<void>;
function UniqueFolderName(parentID: string): Promise<string>;
function ReorderFolders(folderIDs: string[]): Promise<void>;

Where Folder is:

interface Folder {
  id: string;
  name: string;
  parentId: string; // Empty string for root-level folders
  icon: string; // Emoji or icon identifier
  position: number; // Sort order
  createdAt: number; // Unix timestamp in milliseconds
  updatedAt: number; // Unix timestamp in milliseconds
}

CreateFolder(name, parentID) creates a folder; pass "" for parentID to create at root level
UniqueFolderName(parentID) returns an auto-generated unique name for a new folder within the given parent
ReorderFolders(folderIDs) updates folder positions to match the given order

`GetAutocompleteKeywords`

function GetAutocompleteKeywords(): Promise<string[]>;

Returns all available autocomplete keywords — built-in function names, constant names, and user-defined variable names. Used by the frontend AutocompletePopup to suggest completions as the user types.

Returns:

string[] — Sorted array of keyword strings (e.g. ["abs", "acos", "asin", "atan", "avg", "cbrt", ...])

Documentation Methods

function GetDocList(): Promise<string[]>;
function GetDocContent(name: string): Promise<string>;

GetDocList() — Returns sorted list of embedded documentation file names
GetDocContent(name) — Returns the raw Markdown content of a documentation file

Docs are embedded at build time via Go's embed package from the docs/ directory.

Plugin Methods

`GetPlugins`

function GetPlugins(): Promise<PluginInfo[]>;

Returns all loaded plugins with their manifest data and enabled state.

Returns:

PluginInfo[] — Array of plugin info objects:

interface PluginInfo {
  name: string;
  version: string;
  description: string;
  author: string;
  homepage?: string;
  dir: string; // Full path to the plugin directory
  enabled: boolean;
  error?: string; // Error message if the plugin failed to load
  functions?: FunctionDef[];
  themes?: ThemeDef[];
  variables?: VariableDef[];
}

interface FunctionDef {
  name: string;
  description: string;
  args: number; // -1 = variadic
  min_args: number;
  max_args: number; // -1 = unlimited
  expression?: string; // Math expression using a,b,c... as args
  builtin?: string; // Pre-defined operation name
  examples?: string[];
}

interface ThemeDef {
  id: string;
  label: string;
  colors: Record<string, string>; // 14 CSS custom properties
}

interface VariableDef {
  name: string;
  description: string;
  value: number;
}

`ReloadPlugins`

function ReloadPlugins(): Promise<void>;

Rescans the plugins directory, re-reads all manifests, and re-registers enabled plugin functions/variables/themes with the calculator engine.

`SetPluginEnabled`

function SetPluginEnabled(name: string, enabled: boolean): Promise<void>;

Enables or disables a plugin by name. Persists the state to state.json and re-registers all plugin functions.

Parameters:

name — Plugin name (case-insensitive)
enabled — true to enable, false to disable

`InstallPlugin`

function InstallPlugin(pluginsDir: string, pluginDir: string, manifestJSON: string): Promise<void>;

Installs a plugin by writing its manifest to the plugins directory, then triggers a rescan.

Parameters:

pluginsDir — Path to the plugins directory (obtained from GetPluginsDir())
pluginDir — Subdirectory name for the plugin (e.g. "finance")
manifestJSON — The plugin.json content as a JSON string

`RemovePlugin`

function RemovePlugin(pluginsDir: string, pluginDir: string): Promise<void>;

Removes a plugin directory entirely and triggers a rescan.

Parameters:

pluginsDir — Path to the plugins directory
pluginDir — Subdirectory name of the plugin to remove

`GetPluginsDir`

function GetPluginsDir(): Promise<string>;

Returns the absolute path to the plugins directory.

`GetPluginThemes`

function GetPluginThemes(): Promise<ThemeDef[]>;

Returns all themes from currently enabled plugins.

Usage from TypeScript

import * as svc from '../wailsjs/go/service/AppService';

// Evaluate all lines in a note
const results = await svc.EvaluateAll('42\n10 inches in cm\nx = 5');

// Evaluate a single expression
const result = await svc.EvaluateLine('sqrt(144)');

// Get variables
const vars = await svc.GetVariables();
// vars: { x: 5 }

// Get step-by-step breakdown
const detail = await svc.GetSteps('2 + 3 * 4');
console.log(detail.result); // "14"
console.log(detail.steps); // [{ operation: "×", ... }, { operation: "+", ... }]

// Graph a function
const graph = await svc.EvaluateGraph('plot sin(x) from 0 to 6.2832');
if (graph) {
  console.log(graph.points.length); // 200
}

// Get history
const history = await svc.GetHistory();
// history: [{ input: "42", output: "42" }, ...]

// Clear everything
await svc.ClearVariables();
await svc.ClearHistory();

// Currency rates
const info = await svc.UpdateCurrencyRates();
console.log(info.source); // "live" or "cache"

// Notes
const notes = await svc.GetAllNotes();
const note = await svc.CreateNote();
const folderNote = await svc.CreateNoteInFolder('folder-uuid');
await svc.SaveNoteContent(note.id, '2 + 2\npi * 2');
await svc.RenameNote(note.id, 'My Calculations');
await svc.UpdateNoteIcon(note.id, '\u{1F4C8}');
await svc.MoveNoteToFolder(note.id, 'folder-uuid');
await svc.ReorderNotes([note.id]);

// Folders
const folder = await svc.CreateFolder('Work', '');
const folders = await svc.GetAllFolders();
await svc.RenameFolder(folder.id, 'Personal');
await svc.UpdateFolderIcon(folder.id, '\u{1F4C1}');
await svc.MoveFolder(folder.id, 'parent-folder-uuid');
const uniqueName = await svc.UniqueFolderName('');
await svc.ReorderFolders([folder.id]);
await svc.DeleteFolder(folder.id);

// Autocomplete keywords
const keywords = await svc.GetAutocompleteKeywords();

// Plugins
const plugins = await svc.GetPlugins();
await svc.SetPluginEnabled('finance', true);
await svc.ReloadPlugins();
const pluginsDir = await svc.GetPluginsDir();
await svc.InstallPlugin(pluginsDir, 'my-plugin', JSON.stringify(manifest));
await svc.RemovePlugin(pluginsDir, 'my-plugin');

// Settings
const settings = await svc.GetSettings();
await svc.SaveSettings({ ...settings, theme: 'neon' });

// Toggle result panel and line wrap
await svc.SaveSettings({ ...settings, result_panel_enabled: 'false', line_wrap_enabled: 'true' });

// Data directory
const dir = await svc.GetDataDir();

// Documentation
const docs = await svc.GetDocList();
const content = await svc.GetDocContent('user-guide.md');

Error Handling

All Go errors result in an empty string (or empty array) being returned to the frontend. No error messages are propagated to the user through the API layer.

The frontend should wrap every Wails binding call in try/catch to handle cases where:

The Wails runtime is not yet initialized (e.g. during app startup)
The Go backend encountered an unexpected error
A timeout occurred (5-second evaluation limit)

try {
  const result = await svc.EvaluateLine('2 + 2');
  if (result === '') {
    // Expression was invalid or timed out
  }
} catch (e) {
  // Wails runtime not initialized or communication error
}

Evaluation Limits

Limit	Value
Max input length	10,000 characters per line
Max nested parentheses	~100 levels
Evaluation timeout	5 seconds per call
Max graph points	200 sampled points

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API Reference

EvaluateAll

EvaluateLine

GetVariables

ClearVariables

GetHistory

ClearHistory

GetSteps

EvaluateGraph

ReorderNotes

UpdateCurrencyRates

GetCurrencyCacheInfo

GetDataDir

GetSettings

SaveSettings

GetAppVersion

CheckForUpdate

GetDeleteWithoutConfirm / SetDeleteWithoutConfirm

Note Management Methods

Folder Management Methods

GetAutocompleteKeywords

Documentation Methods

Plugin Methods

GetPlugins

ReloadPlugins

SetPluginEnabled

InstallPlugin

RemovePlugin

GetPluginsDir

GetPluginThemes

Usage from TypeScript

Error Handling

Evaluation Limits

`EvaluateAll`

`EvaluateLine`

`GetVariables`

`ClearVariables`

`GetHistory`

`ClearHistory`

`GetSteps`

`EvaluateGraph`

`ReorderNotes`

`UpdateCurrencyRates`

`GetCurrencyCacheInfo`

`GetDataDir`

`GetSettings`

`SaveSettings`

`GetAppVersion`

`CheckForUpdate`

`GetDeleteWithoutConfirm` / `SetDeleteWithoutConfirm`

`GetAutocompleteKeywords`

`GetPlugins`

`ReloadPlugins`

`SetPluginEnabled`

`InstallPlugin`

`RemovePlugin`

`GetPluginsDir`

`GetPluginThemes`