title	API Debug Env
emoji	🔧
colorFrom	blue
colorTo	green
sdk	docker
pinned	false

API Debug Environment

A real-world OpenEnv environment where AI agents learn to debug broken HTTP API requests.

Built for the Scaler × Meta PyTorch × HuggingFace OpenEnv Hackathon 2026.

---

What This Environment Does

An AI agent is given a broken HTTP request and a task description. It interacts with a live mock REST API running inside the same container, reads the real HTTP error responses (401, 422, 429, 500), and iteratively fixes its requests — adjusting headers, methods, body types, and authentication flows — until it receives a successful 200 response.

Every step produces a real HTTP call. The grader is fully deterministic: no LLM, no fuzzy matching. The reward is derived entirely from HTTP status codes and response schema matching.

---

Environment Summary

Property	Value
Framework	OpenEnv (openenv-core 0.2.3)
Tasks	3 difficulty levels — 9 tasks total
Max Steps per Episode	5
Reward Range	0.0 – 1.0
Grader	Fully deterministic (no LLM)
Mock API	Internal FastAPI router, same container
Port	7860 (HF Spaces)

---

Action Space

The agent sends a structured HTTP request at each step.

Field	Type	Description
method	str	HTTP method — GET, POST, PUT, DELETE, PATCH
url	str	Endpoint path e.g. /mock_api/users
headers	dict	Request headers e.g. {"Authorization": "Bearer token"}
body	dict	Request body — null for GET requests
query_params	dict	URL query parameters e.g. {"q": "python"}

---

Observation Space

After each step the agent receives:

Field	Type	Description
task_id	str	Current task — easy, medium, or hard
task_description	str	Plain-English description of what needs to be fixed
broken_request	dict	The original broken request shown at episode start
last_status_code	int	HTTP status from last step (0 = not yet tried)
last_response_headers	dict	Response headers from last step
last_response_body	str	Raw response body from last step
step_feedback	str	Human-readable hint based on last error
current_score	float	Running reward 0.0–1.0
reward	float	Reward for the last step
done	bool	Whether the episode has ended
attempt	int	Current step number

---

Tasks

Easy — Auth and Header Errors

Simple fixes to authentication headers and request format.

Task ID	Bug	What the Agent Needs to Fix
easy_auth	Missing Authorization header	Add Authorization: Bearer demo_token_123 to GET /mock_api/users
easy_content_type	Wrong Content-Type: text/plain	Change to application/json and add {"name": "book"} body to POST /mock_api/items
easy_query_param	Missing ?q= query param	Add q=python to GET /mock_api/search

Medium — Method and Body Errors

Requires understanding API semantics and request structure.

Task ID	Bug	What the Agent Needs to Fix
medium_wrong_method	GET instead of POST	Change method to POST on /mock_api/orders
medium_type_mismatch	product_id: "five" (string)	Fix to integer 5 in body
medium_nested_field	address: "123 Main St" (string)	Fix to dict {"street": "123 Main St", "city": "NY"}

Hard — Rate Limiting and Multi-step Auth

Requires multi-step reasoning and handling stateful API behaviour.

Task ID	Bug	What the Agent Needs to Fix
hard_token_exchange	Stale/expired Bearer token	First POST to /mock_api/auth/token to get a fresh token, then use it on GET /mock_api/protected
hard_rate_limit	No backoff after 429	After receiving 429, include X-Retry-After: 2 header on next request
hard_pagination	Never follows cursor	Call GET /mock_api/logs?cursor=<value> until has_more is false

---

Reward Function

reward = schema_match_score × attempt_bonus
attempt_bonus = max(0.0, 1.0 − (attempt / max_steps) × 0.15)

Agents are rewarded more for solving tasks in fewer steps. Partial credit is given at every step:

HTTP Status Received	Partial Reward	Meaning
0	0.00	Request never sent / connection error
401 / 403 / 404	0.05	Hit the endpoint, auth failed
405 / 415	0.10	Auth ok, wrong method or content-type
422	0.15	Auth ok, body validation failed
429	0.20	Hit endpoint, needs rate limit handling
200 (schema mismatch)	0.70	Right status, wrong response structure
200 (schema match)	0.85–1.00	Correct — higher reward for fewer attempts

---

Mock API Endpoints

All endpoints are mounted at /mock_api/ inside the same container — no external calls, fully reproducible.

Method	Path	What it Does	Common Error
GET	/mock_api/users	Returns user list	401 if no Bearer token
POST	/mock_api/items	Creates an item	415 if wrong Content-Type, 422 if no name
GET	/mock_api/search	Search results	422 if no ?q= param
POST	/mock_api/orders	Creates an order	405 if GET, 422 if wrong types
POST	/mock_api/profile	Updates profile	422 if address is not a dict
POST	/mock_api/auth/token	Issues a token	401 if wrong credentials
GET	/mock_api/protected	Protected resource	401 if token not from /auth/token
GET	/mock_api/rate_limited	Rate-limited resource	429 after 3 requests without X-Retry-After
GET	/mock_api/logs	Paginated log entries	Returns cursor — must follow chain

---

API Endpoints (OpenEnv)

Method	Path	Description
GET	/health	Health check — returns {"status": "ok"}
POST	/reset	Start new episode. Body: {"task_id": "easy"}
POST	/step	Execute action. Body: {"action": {...}}
GET	/state	Get current episode state
GET	/docs	Auto-generated Swagger UI

---

Quick Start

Connect to the deployed Space

from client import APIDebugEnv
from models import APIAction

with APIDebugEnv(base_url="https://ProthamD-api-debug-env.hf.space").sync() as env:
    # Start an episode
    obs = env.reset(task_id="easy")
    print(obs.task_description)
    print(obs.broken_request)

    # Fix the request and step
    result = env.step(APIAction(
        method="GET",
        url="/mock_api/users",
        headers={"Authorization": "Bearer demo_token_123"},
        body=None,
        query_params={}
    ))
    print(result.reward)       # 0.85+
    print(result.observation.step_feedback)

Install the client

pip install git+https://huggingface.co/spaces/ProthamD/api-debug-env

Run locally with Docker

docker pull registry.hf.space/ProthamD-api-debug-env:latest
docker run -p 7860:7860 registry.hf.space/ProthamD-api-debug-env:latest

---

Run the Baseline Inference Script

# Set environment variables
export API_BASE_URL=https://router.huggingface.co/v1
export MODEL_NAME=mistralai/Mistral-7B-Instruct-v0.3
export HF_TOKEN=hf_your_token_here
export ENV_URL=https://ProthamD-api-debug-env.hf.space

# Run
python inference.py

Expected log format

[START] task=easy env=api_debug_env model=mistralai/Mistral-7B-Instruct-v0.3
[STEP] step=1 action={"method":"GET","url":"/mock_api/users",...} reward=0.05 done=false error=null
[STEP] step=2 action={"method":"GET","url":"/mock_api/users","headers":{"Authorization":"Bearer demo_token_123"},...} reward=0.92 done=true error=null
[END] success=true steps=2 score=0.920 rewards=0.05,0.92

---

Project Structure

api_debug_env/
├── inference.py              ← Baseline inference script (root, mandatory)
├── models.py                 ← APIAction, APIObservation, APIState
├── client.py                 ← APIDebugEnv(EnvClient)
├── openenv.yaml              ← Environment manifest
├── pyproject.toml            ← Package config
├── Dockerfile                ← HF Spaces Dockerfile (port 7860)
├── tasks/
│   ├── easy.py               ← 3 easy tasks
│   ├── medium.py             ← 3 medium tasks
│   ├── hard.py               ← 3 hard tasks
│   └── registry.py           ← TASK_REGISTRY dict
├── graders/
│   └── grader.py             ← Deterministic reward logic
└── server/
    ├── app.py                ← FastAPI app with create_app()
    ├── api_debug_environment.py  ← Environment logic
    ├── mock_api.py           ← Internal mock REST API router
    └── requirements.txt

---

Setup from Source

git clone https://huggingface.co/spaces/ProthamD/api-debug-env
cd api-debug-env

pip install openenv-core fastapi uvicorn httpx pydantic openai python-dotenv

# Windows
$env:PYTHONPATH = "path\to\api-debug-env"

# Linux/Mac
export PYTHONPATH=$(pwd)

uvicorn server.app:app --host 0.0.0.0 --port 7860

Test it:

curl http://localhost:7860/health
curl -X POST http://localhost:7860/reset \
  -H "Content-Type: application/json" \
  -d '{"task_id": "easy"}'

---

Environment Variables

Variable	Required	Description
API_BASE_URL	Yes	LLM API endpoint e.g. https://router.huggingface.co/v1
MODEL_NAME	Yes	Model identifier e.g. mistralai/Mistral-7B-Instruct-v0.3
HF_TOKEN	Yes	HuggingFace token with inference access
ENV_URL	No	Override environment URL (default: localhost)

---

Why API Debugging?

Debugging broken HTTP requests is one of the most common real-world developer tasks. Every backend developer, DevOps engineer, and API integrator does this daily. Unlike existing OpenEnv environments (games, code execution, financial simulations), there was no environment for this domain.

Key advantages of this domain for RL training:

• Deterministic grading — HTTP status codes are binary, no LLM judge needed
• Rich partial reward signal — agent gets meaningful feedback at every step
• Stateful multi-turn reasoning — hard tasks require chaining multiple requests
• Real-world transferability — skills learned here apply directly to production debugging

---

License

MIT

Author

Pratham Dey (ProthamD) — IIEST Shibpur, Information Technology