Spaces:
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title: Token Optimiser Environment
emoji: π€
colorFrom: indigo
colorTo: purple
sdk: docker
app_port: 8000
pinned: false
tags:
- openenv
base_path: /web
π€ Prompt & Response Token Optimization Environment
An OpenEnv-compatible RL environment that trains agents to minimize LLM API token usage while preserving semantic quality β reducing AI inference costs at scale.
β οΈ Hackathon Status β Action Required
Submission #6 failed Phase 2 validation. All fixes have been applied and pushed. Someone needs to resubmit from the dashboard before 12 April 2026, 11:59 PM IST.
What was fixed (latest commits)
| Commit | Fix |
|---|---|
c7fe490 |
Fixed openenv.yaml β tasks had wrong format (plain strings, no grader field) |
3dde704 |
Each task now has its own grader function (grade_redundancy_stripping, etc.) |
24eb57f |
Fixed fallback simulate domain responses + hard task always returns JSON |
Bugs fixed in server/token_optimiser_environment.py
- Easy task fallback β format check was
"brief explanation"(never matched"plain_brief"), response was about machine learning instead of photosynthesis - Medium task fallback β response was about solar/renewable energy instead of Python vs JavaScript
- Hard task fallback β JSON only returned when compression ratio β€ 0.6; now always returns valid JSON with all 5 required keys
- Keyword scorer β added photosynthesis-domain keywords (plants, sunlight, co2, oxygen, etc.)
Updated baseline (no HF_TOKEN)
| Task | Before | After fix |
|---|---|---|
| Easy | 0.657 | ~0.75 |
| Medium | 0.673 | ~0.49 |
| Hard | 0.137 | ~0.60 |
Medium score may vary with the rule-based optimizer; with a real LLM it should score higher.
Checklist before resubmit
-
openenv.yamlhas 3 tasks with correctgraderfields - All 3 grader functions exist and are importable
- Fallback responses match actual task domains
-
inference.pyruns all 3 task rounds (TASK_EVAL_ROUNDS = 3) - Resubmit from dashboard β https://openenv.scaler.com (or wherever the dashboard is)
π Introduction
Large Language Model APIs charge per token. Verbose prompts and unconstrained responses waste tokens and money. This environment trains an AI agent to rewrite verbose prompts into concise, efficient versions that:
- Use fewer input tokens
- Guide the LLM toward shorter, correctly-formatted responses
- Preserve the full semantic meaning and intent of the original request
- Respect output format constraints (free text, bullet points, JSON)
The agent learns real-world prompt engineering β a critical skill for production LLM systems where cost efficiency matters at scale.
ποΈ Architecture
token_optimiser/
βββ inference.py # Hackathon evaluation script
βββ models.py # Pydantic data models (Action / Observation / State)
βββ client.py # Async WebSocket EnvClient
βββ openenv.yaml # OpenEnv deployment config
βββ Dockerfile # Root-level multi-stage build
βββ pyproject.toml # Package config & dependencies
βββ uv.lock # Locked dependencies
βββ server/
βββ app.py # FastAPI server (WebSocket + HTTP)
βββ token_optimiser_environment.py # Core RL environment logic
βββ requirements.txt # Server dependencies
π§ How It Works
Action Space
The agent submits a TokenOptimiserAction containing its optimized version of the original prompt:
class TokenOptimiserAction(Action):
optimized_prompt: str # Agent's rewritten, token-efficient prompt
Observation Space
After each step, the agent receives a TokenOptimiserObservation:
class TokenOptimiserObservation(Observation):
llm_response: str # Actual LLM response to the optimized prompt
input_tokens: int # Token count of the optimized prompt
output_tokens: int # Token count of the LLM response
reward: float # Step reward (0.0 β 1.0)
State Space
class TokenOptimiserState(State):
original_prompt: str # The verbose task prompt the agent must optimize
task_difficulty: str # "easy" | "medium" | "hard"
task_index: int # Index in task bank
π Tasks
π’ Easy β Redundancy Stripping
Original: "Could you possibly help me understand, if it's not too much trouble, what the word 'photosynthesis' means? I would really appreciate it if you could explain it to me in simple terms that are easy to understand."
Goal: Strip politeness filler and redundancy to a single direct question without formatting
Expected optimized: "What does photosynthesis mean? Be brief."
Max output: 30 tokens
π‘ Medium β Constraint Injection
Original: "I'm looking for information about the main differences between Python and JavaScript programming languages. Could you give me a thorough breakdown covering things like typing, use cases, performance, syntax style, and ecosystem so I can decide which one to learn first?"
Goal: Compress input AND inject format + exactly 5 bullet point counts into prompt
Expected optimized: "Compare Python and JavaScript (typing, use cases, performance, syntax, ecosystem) in exactly 5 bullet points."
Max output: 120 tokens
π΄ Hard β Multi-Key JSON Extraction
Original: "We need you to analyze our e-commerce platform data and provide strategic insights. Specifically: first identify which product categories are performing best by revenue, second tell us which geographic regions show the most growth potential, third identify which customer segments respond best to promotions, fourth suggest how we should allocate our Q3 marketing budget across channels, and fifth flag any market risks we should be watching. Please be thorough in your analysis and provide detailed reasoning for each point."
Goal: Compress 82-word multi-intent prompt and force structured JSON output with 5 exact required keys
Expected optimized: "Analyze e-commerce data based on revenue, growth regions, responsive segments, Q3 budget, and market risks. Output strictly as JSON with keys: top_categories, growth_regions, responsive_segments, budget_allocation, risks_watch."
Max output: 200 tokens
π Reward Function
Hybrid grading β combines token efficiency + LLM-as-judge semantic scoring:
| Component | Weight | Description |
|---|---|---|
| Token Efficiency | 0.0 β 0.40 | Tokens saved vs. reference (input + output combined) |
| Semantic Quality | 0.0 β 0.30 | LLM judge rates response quality 0β10 |
| Format Compliance | 0.0 β 0.20 | Response matches required format (bullets / JSON / brief) |
| Length Penalty | β0.10 | Output exceeds 2Γ max token budget |
reward = token_efficiency + (semantic_score Γ 0.3) + format_score + length_penalty
reward = clamp(reward, 0.0, 1.0)
| Score | Meaning |
|---|---|
| 0.0 | Meaning lost, system failure, or no optimization |
| 0.3 β 0.5 | Token reduction achieved but quality degraded |
| 0.6 β 0.8 | Good balance of compression and quality |
| 0.9 β 1.0 | Optimal: minimal tokens, correct format, meaning preserved |
βοΈ Setup & Installation
Prerequisites
- Python 3.10+
uv(recommended) orpip- A Hugging Face account with a token that has Inference Providers permission
1. Clone and Install
git clone <your-repo-url>
cd token_optimiser
# Install with uv (recommended)
uv sync
# Or with pip
pip install -e .
2. Set Environment Variables
# Required
export HF_TOKEN="hf_your_token_here"
# Optional (these are the defaults)
export API_BASE_URL="https://router.huggingface.co/v1"
export MODEL_NAME="Qwen/Qwen2.5-72B-Instruct"
export SERVER_URL="http://localhost:8000"
On Windows (PowerShell):
$env:HF_TOKEN = "hf_your_token_here"
HF Token Permissions: Your token must have "Make calls to Inference Providers" enabled.
Create/edit at β https://huggingface.co/settings/tokens
π Running Locally
Step 1 β Start the Environment Server
# Terminal 1
uv run uvicorn server.app:app --host 0.0.0.0 --port 8000
Expected output:
INFO: Application startup complete.
INFO: Uvicorn running on http://0.0.0.0:8000
Step 2 β Run the Inference Script
# Terminal 2
uv run inference.py
Expected output:
[START] task=token_optimization env=token_optimiser model=Qwen/Qwen2.5-72B-Instruct
[STEP] step=1 action='...' reward=0.71 done=false error=null
[STEP] step=4 action='...' reward=0.70 done=false error=null
[STEP] step=7 action='...' reward=0.17 done=false error=null
[END] success=false steps=9 score=0.487 rewards=0.71,0.66,0.60,0.70,0.68,0.64,0.17,0.14,0.10
π Baseline Performance
Current reproducible local baseline, measured with HF_TOKEN unset and the deterministic fallback path against the three-task cycle:
| Task | Score |
|---|---|
| Easy | 0.657 |
| Medium | 0.673 |
| Hard | 0.137 |
| Aggregate | 0.487 |
When HF_TOKEN is available, inference.py uses the OpenAI client against the Hugging Face router and can be rerun to regenerate model-backed scores.
Step 3 β (Optional) Run via Docker
# Build
docker build -t token-optimiser-env .
# Run
docker run -p 8000:8000 \
-e HF_TOKEN=$HF_TOKEN \
-e API_BASE_URL=$API_BASE_URL \
token-optimiser-env
π Using the Python Client
import asyncio
from token_optimiser import TokenOptimiserEnv, TokenOptimiserAction
async def main():
async with TokenOptimiserEnv(base_url="http://localhost:8000") as env:
# Reset β get the task
result = await env.reset()
state = await env.state()
print(f"Task: {state.original_prompt}")
print(f"Difficulty: {state.task_difficulty}")
# Agent submits an optimized prompt
result = await env.step(
TokenOptimiserAction(optimized_prompt="Explain machine learning briefly.")
)
print(f"LLM Response: {result.observation.llm_response}")
print(f"Reward: {result.reward}")
print(f"Tokens β in: {result.observation.input_tokens}, out: {result.observation.output_tokens}")
asyncio.run(main())
βοΈ Deployment
Deploy to Hugging Face Spaces using the OpenEnv CLI:
openenv push
π§ Environment Variables Reference
| Variable | Default | Description |
|---|---|---|
HF_TOKEN |
(required) | Hugging Face API key with Inference Providers permission |
API_BASE_URL |
https://router.huggingface.co/v1 |
LLM endpoint URL |
MODEL_NAME |
Qwen/Qwen2.5-72B-Instruct |
Model used for responses and judging |
SERVER_URL |
http://localhost:8000 |
Environment server URL (for inference.py) |
LOCAL_IMAGE_NAME |
(optional) | Docker image name β auto-spins container if set |
π¦ Dependencies
openenv-coreβ₯ 0.2.2 β RL environment frameworkopenaiβ LLM API client (routed through HF)fastapi+uvicornβ Environment serverpydanticv2 β Data model validation
See pyproject.toml for the full pinned dependency list.
π License
BSD License β see source files for details.