---
title: "Idle economy progression: API"
package: "@phaser-ae/incremental"
tier: Pro
version: 3.0.0-4
released: 2026-10-14
updated: 2026-10-19
description: "The rules of an idle tycoon game: business ladders and mine pipelines with enormous costs, timed cycles, managers, upgrades, prestige and capped catch-up."
url: https://phaser.io/packs/incremental/api
site: Phaser - https://phaser.io
---

# Idle economy progression: API

`@phaser-ae/incremental` — Seeded business ladders and mine pipelines with huge-number costs, cycles, managers, upgrades, prestige and bounded catch-up.

## The pack

### `incremental`

```ts
function incremental(): Pack<{ incremental: typeof rules }, { largeNumbers: unknown }>
```

Install renderer-independent timed businesses and serial mine economies backed by enormous decimal values.

## Helpers

### `createIncremental`

```ts
function createIncremental(definition: IncrementalDefinition): IncrementalGame
```

Create an independent idle economy from public scenario data.

### `generateIncremental`

```ts
function generateIncremental(options: IncrementalGenerationOptions): IncrementalDefinition
```

Generate varied economic decisions: costs, milestones, ownership gates and initial bottleneck change with seed.

### `solveIncremental`

```ts
function solveIncremental(definition: IncrementalDefinition, budget = 4000): { status: 'solved' | 'budget-exhausted'; actions: IncrementalAction[]; elapsedSeconds: number }
```

Bounded constructive economic plan. A replay-validated witness, not an optimal-strategy or difficulty proof.

## Classes

### `IncrementalGame`

```ts
class IncrementalGame
```

Reusable pure idle economy. Actions validate atomically. The run is a kernel history over a base state: undo, redo
and saves replay the retained commands, and consecutive advances are merged into one command.

- `constructor(definition: IncrementalDefinition)`
- `get definition(): IncrementalDefinition` — Scenario copy; callers cannot alter the economy during a run.
- `get state(): IncrementalState` — Current visible state copy.
- `locked(id: string): string` — Ownership gate explanation, or empty text when open.
- `cost(id: string, amount = 1): LargeNumber` — Total geometric cost for a bounded bulk purchase; conservatively rounded upward.
- `maxAffordable(id: string): number` — Maximum affordable purchase, found by bounded binary search without Number conversion of money.
- `payout(id: string): LargeNumber` — Income per cycle after ownership, milestones, upgrades and retained prestige.
- `rate(id: string): LargeNumber` — Theoretical sustained throughput, irrespective of manual/automated running status.
- `bottleneck(): string | null` — Weakest transport/production stage; all stages are required to sustain a mine.
- `prestigeGain(): LargeNumber` — Additional prestige points available; total-run threshold avoids repeated reset farming.
- `apply(action: IncrementalAction): { ok: boolean; reason: string }` — Apply an action atomically; rejection never consumes money, time or history.
- `undo(): boolean` — Undo the last command (consecutive elapsed advances form one command).
- `redo(): boolean` — Redo an undone command.
- `reset(): void` — Fresh run, discarding local history and prestige.
- `snapshot(): IncrementalSnapshot` — Bounded serializable timeline.
- `restore(s: IncrementalSnapshot): void` — Validate the complete save and all redo commands by replaying them before replacing anything.
- `hint(): { action: IncrementalAction; explanation: string }` — Practical visible-information hint, including purchasing, automation and starting manual cycles.

## Types

### `IncrementalAction`

```ts
type IncrementalAction = { kind: 'buy'; id: string; amount?: number | 'max' } | { kind: 'start' | 'manager' | 'upgrade'; id: string } | { kind: 'advance'; seconds: number } | { kind: 'prestige' }
```

Commands recorded in snapshots; advance accepts explicit host-supplied seconds.

### `IncrementalDefinition`

```ts
interface IncrementalDefinition
```

Public scenario definitions; amounts are decimal strings, never unsafe Number values.

- `id: string` — Stable scenario identity.
- `kind: 'business' | 'mine'` — Independent payout cycles or a serial fluid production pipeline.
- `seed: number` — Visible seed used by the scenario generator.
- `difficulty: 'easy' | 'medium' | 'hard'` — Economic constraints preset.
- `startingCash: string` — Initial spendable currency.
- `target: string` — Run income needed to finish the short-session objective.
- `prestigeBase: string` — Base income threshold for earning prestige points.
- `catchUpCap: number` — Maximum supplied elapsed time per advance, in seconds.
- `generators: IncrementalGenerator[]` — Ordered businesses or production/transport stages.

### `IncrementalGenerationOptions`

```ts
interface IncrementalGenerationOptions
```

Seeded economic generation controls.

- `seed: number` — Unsigned 32-bit seed.
- `kind?: 'business' | 'mine'` — Business ladder or mine pipeline.
- `difficulty?: 'easy' | 'medium' | 'hard'` — Default medium; changes growth costs, prerequisites and objective.
- `count?: number` — Business count from two to six; mines always use three distinct stages.
- `magnitude?: number` — Scale all currency/throughput by ten to this power, from zero to one million.

### `IncrementalGenerator`

```ts
interface IncrementalGenerator
```

A priced producer with milestones, a manager and a permanent-for-this-run upgrade.

- `id: string` — Unique ID, stable through the run.
- `name: string` — Display name.
- `initial: number` — Initial unit count.
- `cost: string` — First unit cost. Later units cost cost times growth raised to owned units.
- `growth: string` — Geometric unit-cost multiplier, strictly greater than one.
- `income: string` — Income per owned unit per cycle, or throughput over cycleMs in a pipeline.
- `cycleMs: number` — Positive whole milliseconds per cycle; manual pipeline work lasts this long.
- `managerCost: string` — Manager purchase cost, automating this producer.
- `unlock?: { id: string; units: number }` — Optional ownership requirement for opening the producer.
- `milestones: number[]` — Ownership thresholds each multiply production by two.
- `upgradeCost: string` — Cost of the producer's one-time threefold production upgrade.

### `IncrementalSnapshot`

```ts
interface IncrementalSnapshot
```

Versioned save with a bounded undo timeline; all boundaries validate through replay.

- `version: 1` — Save format version.
- `definition: IncrementalDefinition` — Complete public immutable scenario.
- `base: IncrementalState` — State at the start of the retained history.
- `commands: IncrementalAction[]` — Coalesced accepted commands, including redo commands beyond cursor.
- `cursor: number` — Number of applied commands.

### `IncrementalState`

```ts
interface IncrementalState
```

Copied, JSON-safe mutable state; no game amounts are ordinary numbers.

- `cash: string` — Spendable currency.
- `earned: string` — Income earned since the latest prestige.
- `lifetime: string` — Income earned across all runs.
- `prestige: string` — Retained prestige points. Each gives a 25 percent production bonus.
- `resets: number` — Number of accepted prestige resets.
- `elapsedMs: number` — Supplied simulated milliseconds since the latest prestige.
- `cappedSeconds: number` — Cumulative time excluded by catch-up caps.
- `won: boolean` — Short-session target has been reached; free play remains available.
- `producers: Record<string, { units: number; manager: boolean; upgraded: boolean; remainingMs: number; stock: string }>` — Unit ownership, automation, progress and queued incoming material by producer ID.

---

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