How AVELIN Works

Technical Architecture Overview

AVELIN implements API-level Mixture-of-Experts — a specialist selection and fusion layer that automatically optimizes every request for cost, quality, and reliability. This page explains the technical flow from request to response.

The 6-Stage Request Flow

User Request
    ↓
┌─────────────────────────────────────────────────────────┐
│ Stage 1: Semantic Router (50ms)                         │
│ - Classifies task type: code, reasoning, chat, etc.     │
│ - Embeds request using semantic transformer             │
│ - KNN classifier selects optimal model family           │
└─────────────────────────────────────────────────────────┘
    ↓
┌─────────────────────────────────────────────────────────┐
│ Stage 2: Cross-Model MoE Classifier                     │
│ - Considers: cost, latency, quality, availability      │
│ - Selects specific model tier (ultra/pro/fast)         │
│ - Can route to multiple models in parallel (fusion)    │
└─────────────────────────────────────────────────────────┘
    ↓
┌─────────────────────────────────────────────────────────┐
│ Stage 3: Model Fusion Layer (if enabled)                │
│ - Queries multiple frontier models in parallel         │
│ - Averages token probabilities or votes on answers     │
│ - Cross-verifies responses to reduce hallucinations    │
└─────────────────────────────────────────────────────────┘
    ↓
┌─────────────────────────────────────────────────────────┐
│ Stage 4: Confidence Scoring                             │
│ - Evaluates model confidence in response               │
│ - High confidence (>0.8): return response              │
│ - Low confidence (<0.8): escalate to premium model     │
└─────────────────────────────────────────────────────────┘
    ↓
┌─────────────────────────────────────────────────────────┐
│ Stage 5: Response Transformation                        │
│ - Sanitizes reasoning content (chain-of-thought)       │
│ - Applies AVELIN branding                              │
│ - Strips provider identifiers                          │
└─────────────────────────────────────────────────────────┘
    ↓
┌─────────────────────────────────────────────────────────┐
│ Stage 6: Continuous Evaluation (background)             │
│ - Benchmarks all providers hourly                      │
│ - Tracks: accuracy, latency, cost per task type        │
│ - Auto-updates selection weights based on performance    │
└─────────────────────────────────────────────────────────┘
    ↓
Response Returned (3.5s average total latency)

Stage 1: Semantic Routing (50ms Latency)

AVELIN's semantic router classifies every incoming request before it reaches a model. This is the key differentiator from basic multi-provider proxies.

How it works:

  1. Request text is embedded using a lightweight semantic transformer model
  2. KNN classifier matches to task type based on training data
  3. Optimal model family is selected

Task classification examples:

RequestClassificationRoute To
"Write Python code for..."CODEavelin-coding-fast
"Solve this calculus problem..."REASONINGavelin-ultra
"Tell me a joke..."SIMPLE_CHATavelin-fast
"Analyze this contract..."DOCUMENT_ANALYSISavelin-pro
"Debug this error..."CODE_DEBUGavelin-coding-fast

Impact:

  • 68% of requests routed to cost-efficient models
  • 23% quality improvement on specialized tasks
  • 50ms classification latency (negligible vs 2-5s model response)

Training data: Built from millions of real production requests, continuously updated.

Stage 2: Intelligent Model Selection

Once the task type is classified, AVELIN's router selects the optimal model tier within that family.

Selection criteria:

  • Cost: Prefer cheaper models for simple tasks
  • Latency: Consider time-to-first-token requirements
  • Quality: Match model capability to task complexity
  • Availability: Route away from degraded providers
  • Context length: Ensure model can handle request size

Model tier mapping:

FamilyUltra (Premium)Pro (Balanced)Fast (Efficient)
IntelligenceComplex reasoning, strategyDaily workflows, analysisSimple chat, classification
CodingArchitecture, security reviewFeature developmentBug fixes, refactoring
AgenticLong-horizon planningStandard tool useHigh-volume agent swarms

Stage 3: Multi-Model Fusion (Optional)

For critical requests, AVELIN can query multiple frontier models in parallel and aggregate their responses.

Aggregation strategies:

  1. Weighted token probability averaging

    • Combine probability distributions from multiple models
    • Higher weight to models with better benchmark scores
    • Produces "average" response that's often better than any single model
  2. Voting

    • Each model generates independent response
    • Pick most common answer (majority vote)
    • Effective for factual questions
  3. Synthesis

    • Use a meta-model to merge responses
    • Extract best parts from each
    • Most expensive but highest quality

Impact:

  • 17% hallucination reduction through cross-verification
  • Stronger synthesis on ambiguous tasks
  • Higher confidence in critical responses

When enabled: Automatically for avelin-ultra on high-stakes requests, or manually via API parameter.

Stage 4: Confidence-Based Cascading

AVELIN doesn't always use the most expensive model. It starts with cost-efficient models and escalates only when needed.

The cascading flow:

Request arrives
    ↓
avelin-fast tries (cost-efficient tier, $0.0005/request)
    ↓
Confidence score calculated (0.0 to 1.0)
    ↓
┌──────────────────────────────────────┐
│ If confidence > 0.8:                 │
│   Return response (cheap path)       │
│                                      │
│ If confidence < 0.8:                 │
│   Escalate to avelin-ultra           │
│   ($0.004/request)                   │
│   Return premium response            │
└──────────────────────────────────────┘

Impact:

  • up to 85% cost savings on routine workloads
  • Premium quality preserved for complex tasks
  • Automatic optimization based on model uncertainty

Escalation rate: ~20% of requests escalate (80% handled by efficient models).

Stage 5: Response Transformation

Before returning the response to the user, AVELIN applies several transformations:

  1. Reasoning sanitization: Strips chain-of-thought that might reveal backend providers
  2. Branding: Ensures consistent AVELIN identity
  3. Error handling: Sanitizes error messages to prevent information leakage
  4. Format normalization: Ensures consistent API response format

Stage 6: Continuous Evaluation (Background)

AVELIN continuously benchmarks all providers and automatically updates selection weights.

Evaluation process:

  1. Every hour, run benchmark suite on all providers
  2. Track: accuracy, latency, cost, availability per task type
  3. Update selection weights based on performance
  4. Deploy updated weights (no restart required)

Real-world results (last 90 days):

  • Routing weights updated 312 times
  • 8% quality improvement over baseline
  • 12% cost decrease as cheaper models improved
  • Automatic failover when providers degraded

Benchmark categories:

  • Coding: SWE-bench, HumanEval, MBPP
  • Reasoning: MMLU, GPQA, GSM8K
  • Agentic: TauBench, AgentBench
  • Multilingual: Various language tasks

Performance Characteristics

Latency breakdown (median):

  • Prompt-vector classifier: 50ms
  • Model selection: 10ms
  • Model inference: 2,500ms (varies by provider)
  • Response transformation: 20ms
  • Total: ~2.6s average

Streaming throughput: 18.8 chunks/sec

Time-to-first-token: 1.6s median

Reliability:

  • 99.97% uptime (multi-provider fallback)
  • 0.3s average failover time
  • 0 data loss incidents in 12 months

Cost Optimization

Average cost per request: $0.003 (varies by model tier)

Cost breakdown by specialist selection:

  • 68% requests → efficient models ($0.0002-$0.0005)
  • 20% requests → balanced models ($0.001-$0.002)
  • 12% requests → premium models ($0.002-$0.007)

vs alternatives:

  • vs single-provider direct access: 42% cheaper
  • vs always-premium selection: up to 85% cheaper
  • vs manual model selection: 23% better quality on specialized tasks

Comparison to Traditional Approaches

ApproachHow It WorksLimitations
Single providerAll requests to one modelExpensive, single point of failure, vendor lock-in
Manual selectionUser picks model per requestRequires expertise, suboptimal, high cognitive load
Static rules"Code requests → coding model"No adaptation, no optimization over time
Basic proxyRound-robin or weighted traffic splittingNo task classification, no quality optimization
AVELINPrompt-vector classifier + fusion + difficulty-based cascading + continuous evaluationOptimal cost, quality, and reliability

Technical Specifications

Supported protocols:

  • OpenAI-compatible API (chat completions, embeddings)
  • Function calling / tool use
  • Streaming responses
  • Batch processing

Model families:

  • Intelligence: ultra, pro, fast
  • Coding: coding, coding-plus, coding-architect
  • Agentic: agentic-high, agentic, agentic-fast
  • Utility: embeddings (bge-m3), transcription (whisper), image generation

Infrastructure:

  • Kubernetes-based (k3s cluster)
  • Multi-region deployment (Hetzner, OVHcloud)
  • Horizontal pod autoscaling (3-10 replicas)
  • Redis for distributed state
  • PostgreSQL for persistence

Security:

  • TLS encryption in transit
  • API key authentication
  • Request/response sanitization
  • PII stripping (configurable)
  • Zero data retention policy (configurable)

Getting Started

AVELIN is OpenAI-compatible. Switch in 5 minutes:

from openai import OpenAI

client = OpenAI(
    base_url="https://api.avelin.ai/v1",
    api_key="your-avelin-api-key"
)

response = client.chat.completions.create(
    model="avelin-pro",  # or ultra, fast, coding, etc.
    messages=[{"role": "user", "content": "Hello!"}]
)

No code changes needed if you're already using the OpenAI SDK. AVELIN handles all the specialist selection, fusion, and optimization automatically using its prompt-vector classifier with 90% accuracy.