Compress Before You Prompt: How a 74K-Star Token-First Architecture Is Making AI Coding Agents Smarter, Cheaper, and Actually Honest A developer-built project that has accumulated over 74,000 GitHub stars in under a year introduces a "token-first" architecture that compresses code, documents, and conversation history before they reach an AI coding agent's context window. The approach reports 60-80% token cost reductions on real-world code understanding tasks with higher accuracy than uncompressed baselines, and sharply lower hallucination rates because agents work from compressed, high-fidelity representations of actual code rather than inventing function signatures and imports. Originally published on tamiz.pro https://tamiz.pro/insights/token-first-architecture-ai-coding-agents-compression . The context window is the new bottleneck. Every AI coding agent you've used — whether it's a local CLI assistant, a cloud IDE copilot, or an autonomous refactor bot — is fundamentally constrained by the same problem: models have finite context, but codebases are infinite in complexity. The result is a brutal engineering tradeoff. Stuff more context in, and you pay exponentially more per token while quality degrades from attention dilution. Stuff less in, and your agent hallucinates APIs, invents dependencies, and confidently writes code that doesn't compile against your actual codebase. A project that has accumulated over 74,000 GitHub stars in under a year offers a radically different approach. Instead of treating the context window as a fill-to-capacity resource, it treats token budget as a scarce asset to be managed — compressing code, documents, and conversation history before they ever reach the model. This "token-first" architecture inverts the traditional prompt engineering paradigm: rather than asking "what should I put in the prompt?", it asks "what is the minimum information the model needs, expressed in the most information-dense form possible?" The results are striking. Benchmarks show 60-80% token cost reduction on real-world code understanding tasks, with higher accuracy than uncompressed baselines. More importantly, hallucination rates drop dramatically — the agent stops inventing function signatures, fake imports, and nonexistent methods because it's working with surgically compressed, high-fidelity representations of actual code. This article dissects the architecture, explains the compression pipeline in detail, and walks through the engineering decisions that make this approach viable at scale. Modern LLMs advertise context windows of 128K to 200K tokens. This sounds generous until you realize what actually goes into a coding agent's context: | Context Component | Typical Token Cost | Notes | |---|---|---| | System prompt + tool definitions | 2,000–5,000 | Fixed overhead | | Conversation history | 5,000–20,000 | Grows linearly with turns | | Repository structure file tree | 3,000–10,000 | For medium projects | | Referenced source files | 10,000–50,000 | The biggest variable | | Documentation / README | 2,000–8,000 | Often low signal | | Linting/test output | 1,000–5,000 | Noisy | A single "refactor this module" request can consume 80,000+ tokens of context, leaving almost no room for the model's actual reasoning. Worse, attention mechanisms don't handle uniform token importance well — a 50,000-token context with only 3,000 relevant tokens produces measurably worse outputs than a focused 5,000-token context. The traditional approach has been retrieval augmentation : use a vector database to find "relevant" chunks and stuff them in. This helps, but it's blunt. Vector similarity doesn't understand code semantics — a function named calculate might match a completely unrelated calculate in another module. And once chunks are in the context window, they're immutable. The model sees them all with equal weight. The token-first architecture introduces a compression layer between the raw codebase and the model. Instead of feeding source files directly into the prompt, every piece of code passes through a multi-stage pipeline that reduces token count while preserving semantic fidelity. Here's the high-level data flow: ┌─────────────────────────────────────────────────────────────────┐ │ AI Coding Agent Runtime │ ├─────────────────────────────────────────────────────────────────┤ │ │ │ ┌──────────┐ ┌──────────────┐ ┌───────────────────────┐ │ │ │ Raw │───▶│ Compression │───▶│ Token Budget │ │ │ │ Codebase│ │ Pipeline │ │ Allocator │ │ │ └──────────┘ └──────────────┘ └───────────┬───────────┘ │ │ │ │ │ │ │ │ ▼ ▼ │ │ │ ┌──────────────┐ ┌───────────────────────┐ │ │ │ │ AST Parser │ │ Context Assembly │ │ │ │ │ + Indexer │ │ + Prompt Builder │ │ │ │ └──────────────┘ └───────────┬───────────┘ │ │ │ │ │ │ │ ▼ │ │ │ ┌───────────────┐ │ │ │ │ LLM Backend │ │ │ │ │ Any Model │ │ │ │ └───────────────┘ │ │ ▼ │ │ ┌──────────┐ │ │ │ Git / │ │ │ │ FS │ │ │ └──────────┘ │ └─────────────────────────────────────────────────────────────────┘ The key architectural insight is that compression happens before any model call. The pipeline is deterministic, fast typically under 50ms for a 2,000-line file , and produces representations that are dramatically more information-dense than raw source code. The compression pipeline consists of four stages, each targeting a different class of redundancy: Raw source code contains massive redundancy from a semantic perspective. Consider this TypeScript function: // Original: 187 tokens export async function processUserData userId: string, options: ProcessOptions = { includeHistory: false, maxRecords: 100, timeout: 5000 }: ProcessOptions : Promise