# OmniRoute Compression Strategy Selector Modes: Off, Lite, Standard, Aggressive, Ultra, RTK, and Stacked

> Explore OmniRoute's compression strategy selector modes: Off, Lite, Standard, Aggressive, Ultra, RTK, and Stacked. Understand how to optimize performance with this versatile feature.

- Repository: [Diego Rodrigues de Sa e Souza/OmniRoute](https://github.com/diegosouzapw/OmniRoute)
- Tags: deep-dive
- Published: 2026-07-07

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**OmniRoute's compression strategy selector supports seven distinct modes—`off`, `lite`, `standard`, `aggressive`, `ultra`, `rtk`, and `stacked`—which are defined in [`open-sse/services/compression/types.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/services/compression/types.ts) and selected via the `selectMode` function in [`strategySelector.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/strategySelector.ts) based on combo overrides, auto-trigger thresholds, or global defaults.**

OmniRoute implements a sophisticated prompt-compression pipeline that automatically selects the optimal **compression strategy selector mode** for each request. The open-source repository defines these modes as a TypeScript union type, allowing developers to balance token savings against processing latency through explicit configuration or automatic heuristics.

## How the Strategy Selector Determines the Active Mode

The selection logic resides in **[`open-sse/services/compression/strategySelector.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/services/compression/strategySelector.ts)** within the **`selectMode`** function. According to the OmniRoute source code, the selector evaluates configuration in the following strict priority order:

1. **Explicit compression combo assignment** – A specific combo can force a designated mode.
2. **Combo-level override** – Individual combos may override the system default.
3. **Auto-trigger thresholds** – When request token counts exceed configured limits (e.g., 4,000 tokens), the selector automatically enables a higher-saving mode.
4. **Configured default mode** – The global default stored in the database.
5. **`off`** – When no configuration applies, compression is disabled.

This hierarchy ensures that explicit developer configurations take precedence over automatic heuristics while maintaining fallback safety.

## The Seven Compression Strategy Selector Modes

The **`CompressionMode`** type in **[`open-sse/services/compression/types.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/services/compression/types.ts)** defines seven operational levels. Each mode represents a specific trade-off between computational latency and token reduction efficiency.

### `off` – No Compression Applied

The **`off`** mode disables all compression processing. Requests pass through the pipeline unmodified, incurring zero processing overhead. This mode serves as the default fallback when no compression configuration exists or when latency requirements are absolute.

### `lite` – Fast Lightweight Optimization

The **`lite`** mode implements five inexpensive techniques: whitespace collapse, system-prompt deduplication, tool-result compression, redundant-content removal, and image-URL replacement. According to the implementation in **[`open-sse/services/compression/lite.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/services/compression/lite.ts)**, this mode achieves approximately 10–15% token savings with less than 1 millisecond of added latency, making it ideal for high-throughput applications where minimal overhead is critical.

### `standard` – Balanced Compression Pipeline

The **`standard`** mode activates the full compression pipeline defined in **[`open-sse/services/compression/caveman.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/services/compression/caveman.ts)**. It applies a broader mix of semantic and syntactic transformations than `lite`, offering significantly higher token savings while maintaining reasonable latency characteristics suitable for most production workloads.

### `aggressive` – High-Efficiency Token Reduction

The **`aggressive`** mode employs heavier transformations including deep semantic condensation to maximize token reduction. As implemented in the core compression engine, this mode incurs additional latency compared to `standard` but delivers substantially higher compression ratios for complex prompts.

### `ultra` – Maximum Compression for Large Payloads

The **`ultra`** mode utilizes all available compression techniques plus extra heuristics to achieve maximum token savings. According to the OmniRoute source code, this mode is specifically designed for very large prompts where latency is less critical than minimizing token count, processing content through the most intensive pathways in [`caveman.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/caveman.ts).

### `rtk` – Rule-Based Terminal Output Compression

The **`rtk`** mode invokes the Rule-Based Terminal Tool (RTK) engine located in **`open-sse/services/compression/engines/rtk/`**. This specialized mode parses terminal tool output, removes ANSI noise, deduplicates lines, and optionally preserves raw output for authenticated recovery. Unlike general content modes, `rtk` targets specific tool-output formats for deterministic compression.

### `stacked` – Layered Multi-Engine Composition

The **`stacked`** mode enables composition of multiple compression engines, such as combining `caveman` with `rtk` for layered processing. This mode supports complex workloads requiring different compression strategies for distinct content sections within a single request.

## Configuring Compression Modes in Practice

Developers interact with these modes through the compression API endpoints defined in **`src/app/api/settings/compression/`**. The following examples demonstrate how to leverage the strategy selector programmatically.

**Setting a Global Default Mode**

```typescript
import { getCompressionConfig, updateCompressionConfig } from '@omniroute/client';

// Retrieve current configuration
const config = await getCompressionConfig();
console.log('Current default:', config.defaultMode);

// Update global default to 'lite'
await updateCompressionConfig({ defaultMode: 'lite' });

```

**Forcing a Mode via Combo Configuration**

Combos can enforce specific modes regardless of global settings:

```typescript
// Combo definition stored in the database
const comboConfig = {
  id: 'combo-fast-001',
  name: 'High-Speed Processing',
  providers: ['openai/gpt-4o-mini'],
  compressionMode: 'lite'  // Forces lite mode for this combo
};

```

**Auto-Trigger Implementation**

The selector automatically escalates compression when token thresholds are exceeded:

```typescript
// Logic based on the selectMode implementation in strategySelector.ts
function selectMode(requestTokens: number, config: CompressionConfig): CompressionMode {
  if (requestTokens > config.autoTriggerThreshold) {
    return 'standard';  // Auto-escalate from default to standard
  }
  return config.defaultMode;
}

```

## Summary

- OmniRoute defines **seven compression strategy selector modes** in [`open-sse/services/compression/types.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/services/compression/types.ts): `off`, `lite`, `standard`, `aggressive`, `ultra`, `rtk`, and `stacked`.
- The **`selectMode`** function in [`strategySelector.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/strategySelector.ts) chooses modes based on strict priority: combo assignment > combo override > auto-trigger > default > off.
- **`lite`** mode provides sub-millisecond latency with 10–15% savings, while **`ultra`** mode maximizes compression for large payloads at higher latency cost.
- **`rtk`** mode offers specialized terminal-output processing, and **`stacked`** enables multi-engine composition for complex workflows.
- Configuration occurs via the API endpoints in `src/app/api/settings/compression/`, supporting both global defaults and per-combo overrides.

## Frequently Asked Questions

### What is the default compression mode if I don't configure anything?

OmniRoute defaults to the **`off`** mode when no configuration exists. The `selectMode` function falls back to this state when it cannot find a combo assignment, override, or auto-trigger threshold that applies to the current request.

### How does the `lite` mode achieve such low latency?

The **`lite`** mode limits processing to five cheap syntactic transformations—whitespace collapse, system-prompt deduplication, tool-result compression, redundant-content removal, and image-URL replacement—without performing expensive semantic analysis. This constrained scope, implemented in [`open-sse/services/compression/lite.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/services/compression/lite.ts), keeps processing time under 1 millisecond while delivering approximately 10–15% token savings.

### Can I use multiple compression modes simultaneously?

Yes, through the **`stacked`** mode, which composes multiple engines such as `caveman` and `rtk` to apply different compression strategies to different parts of a request. This layered approach allows sophisticated pipelines where, for example, general content undergoes semantic compression while terminal output receives rule-based processing.

### When should I choose `aggressive` over `standard` mode?

Select **`aggressive`** mode when your prompts contain substantial redundant semantic content and you prioritize token savings over response latency. According to the source implementation in [`open-sse/services/compression/caveman.ts`](https://github.com/diegosouzapw/OmniRoute/blob/main/open-sse/services/compression/caveman.ts), this mode activates deeper semantic condensation algorithms that require more processing time but yield significantly higher compression ratios than `standard`.