TraceKit Python SDK Setup

When To Use

Use this skill when the user asks to:

• Add TraceKit to a Python application
• Add observability or APM to a Python service
• Instrument a Django, Flask, or FastAPI app with distributed tracing
• Configure TraceKit API keys in a Python project
• Debug production Python services with live breakpoints
• Set up code monitoring in a Python app

Non-Negotiable Rules

1. Never hardcode API keys in code. Always use os.getenv("TRACEKIT_API_KEY") or os.environ["TRACEKIT_API_KEY"].
2. Always call tracekit.init() before creating the app — initialization must happen before framework setup so auto-instrumentation patches are applied.
3. Always include a verification step confirming traces appear in https://app.tracekit.dev/traces.
4. Always enable code monitoring (enable_code_monitoring=True) — it is TraceKit's differentiator.

Detection

Before applying this skill, detect the project type:

1. Check for Python project files — requirements.txt, pyproject.toml, or Pipfile confirms this is a Python project.
2. Detect framework by scanning dependencies or imports:
   • django in dependencies/imports => Django framework (use Django branch)
   • flask in dependencies/imports => Flask framework (use Flask branch)
   • fastapi in dependencies/imports => FastAPI framework (use FastAPI branch)
3. Only ask the user if multiple frameworks are detected or if no project file is found.

Step 1: Environment Setup

Set the TRACEKIT_API_KEY environment variable. This is the only required secret.

Add to your .env file or environment:

export TRACEKIT_API_KEY=ctxio_your_api_key_here

The OTLP endpoint is hardcoded in the SDK init — no need to configure it separately.

Where to get your API key:

1. Log in to TraceKit
2. Go to API Keys page
3. Generate a new key (starts with ctxio_)

Do not commit real API keys. Use .env files, deployment secret managers, or CI variables.

Step 2: Install SDK

pip install tracekit-apm

Framework-specific extras are available:

pip install tracekit-apm[flask]    # For Flask
pip install tracekit-apm[django]   # For Django
pip install tracekit-apm[fastapi]  # For FastAPI
pip install tracekit-apm[all]      # All frameworks

This installs the TraceKit Python SDK with built-in OpenTelemetry support, framework middleware, and code monitoring.

Step 3: Initialize TraceKit

Add initialization at the top of your application entry point, before creating the framework app:

import tracekit
import os

# Initialize TraceKit — MUST be before app creation
client = tracekit.init(
    api_key=os.getenv("TRACEKIT_API_KEY"),
    service_name="my-python-service",
    endpoint="https://app.tracekit.dev/v1/traces",
    enable_code_monitoring=True,
)

Key points:

• service_name should match your service's logical name (e.g., "api-gateway", "user-service")
• enable_code_monitoring=True enables live breakpoints and snapshots in production
• Call tracekit.init() before Flask(__name__), FastAPI(), or Django's MIDDLEWARE setup

Step 4: Framework Integration

Choose the branch matching your framework. Apply one of the following.

Branch A: Flask

# app.py
from flask import Flask, request, jsonify
import tracekit
from tracekit.middleware.flask import init_flask_app
import os

# Initialize TraceKit (before app creation!)
client = tracekit.init(
    api_key=os.getenv("TRACEKIT_API_KEY"),
    service_name="my-flask-app",
    endpoint="https://app.tracekit.dev/v1/traces",
    enable_code_monitoring=True,
)

# Create Flask app
app = Flask(__name__)

# Add TraceKit middleware (auto-traces all routes!)
init_flask_app(app, client)

@app.route("/api/users/<int:user_id>")
def get_user(user_id):
    return jsonify({"id": user_id, "name": "Alice"})

if __name__ == "__main__":
    app.run(port=5000)

Order matters: tracekit.init() then Flask(__name__) then init_flask_app(app, client) then route definitions.

Branch B: Django

Add TraceKit initialization to your Django settings and middleware.

1. Initialize in settings.py:

# settings.py
import tracekit
import os

# Initialize TraceKit at Django startup
client = tracekit.init(
    api_key=os.getenv("TRACEKIT_API_KEY"),
    service_name="my-django-app",
    endpoint="https://app.tracekit.dev/v1/traces",
    enable_code_monitoring=True,
)

2. Add middleware to MIDDLEWARE:

# settings.py
MIDDLEWARE = [
    'tracekit.middleware.django.TracekitDjangoMiddleware',
    # ... other middleware (keep TraceKit first for complete request tracing)
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    # ...
]

Order matters: Place TracekitDjangoMiddleware at the top of MIDDLEWARE to trace the full request lifecycle.

Branch C: FastAPI

# main.py
from fastapi import FastAPI
import tracekit
from tracekit.middleware.fastapi import init_fastapi_app
import os

# Initialize TraceKit (before app creation!)
client = tracekit.init(
    api_key=os.getenv("TRACEKIT_API_KEY"),
    service_name="my-fastapi-app",
    endpoint="https://app.tracekit.dev/v1/traces",
    enable_code_monitoring=True,
)

# Create FastAPI app
app = FastAPI()

# Add TraceKit middleware (auto-traces all routes!)
init_fastapi_app(app, client)

@app.get("/api/users/{user_id}")
async def get_user(user_id: int):
    return {"id": user_id, "name": "Alice"}

Order matters: tracekit.init() then FastAPI() then init_fastapi_app(app, client) then route definitions.

Step 5: Error Capture

Capture errors explicitly in except blocks:

try:
    result = some_operation()
except Exception as e:
    tracekit.capture_exception(e)
    # handle the error...

Step 5b: Snapshot Capture (Code Monitoring)

For programmatic snapshots, use the snapshot client directly — do not call through the SDK wrapper. The SDK uses stack inspection internally to identify the call site. Adding extra layers shifts the frame and causes snapshots to report the wrong source location.

Create a thin wrapper module (e.g., app/breakpoints.py):

_snapshot_client = None


def init(sdk):
    """Store the snapshot client. No-op when sdk is None."""
    global _snapshot_client
    if sdk is not None:
        _snapshot_client = sdk.snapshot_client()


def capture(name: str, data: dict):
    """Fire a code monitoring snapshot. No-op when tracing is disabled."""
    if _snapshot_client is None:
        return
    _snapshot_client.check_and_capture(name, data)

Initialize after SDK setup:

from app.breakpoints import init as init_breakpoints
init_breakpoints(sdk)

Use at call sites:

from app.breakpoints import capture

capture("payment-failed", {"order_id": order.id, "error": str(e)})

See the tracekit-code-monitoring skill for the full pattern across all languages.

Step 6: Verification

After integrating, verify traces are flowing:

1. Start your application with TRACEKIT_API_KEY set in the environment.
2. Hit your endpoints 3-5 times — e.g., curl http://localhost:5000/api/users/1 (Flask) or curl http://localhost:8000/api/users/1 (FastAPI/Django).
3. Open https://app.tracekit.dev/traces.
4. Confirm new spans and your service name appear within 30-60 seconds.

If traces do not appear, see Troubleshooting below.

Troubleshooting

Traces not appearing in dashboard

• Check TRACEKIT_API_KEY: Ensure the env var is set in the runtime environment. Print it: print(os.getenv("TRACEKIT_API_KEY")).
• Check outbound access: Your service must reach https://app.tracekit.dev/v1/traces. Verify with: curl -X POST https://app.tracekit.dev/v1/traces (expect 401 — means the endpoint is reachable).
• Check init order: tracekit.init() must be called before creating the Flask/FastAPI app or before Django processes the first request. If init happens too late, auto-instrumentation patches miss early imports.

Init order wrong

Symptoms: Server starts fine but no traces appear despite traffic.

Fix: Move tracekit.init() to the very top of your entry module, before importing route modules or creating the app object.

# DO: Init before app creation
tracekit.init()
app = Flask(__name__)

# DON'T: Import route modules before tracekit.init()

Missing environment variable

Symptoms: None API key warning on startup, or traces are rejected by the backend.

Fix: Ensure TRACEKIT_API_KEY is set in your .env file (loaded via python-dotenv), virtualenv activation script, Docker Compose, or deployment config.

Django middleware order

Symptoms: Partial traces or missing request context.

Fix: Place 'tracekit.middleware.django.TracekitDjangoMiddleware' as the first entry in MIDDLEWARE.

Service name collisions

Symptoms: Traces appear under the wrong service in the dashboard.

Fix: Use a unique service_name per deployed service. Avoid generic names like "app" or "server".

Next Steps

Once your Python app is traced, consider:

• Code Monitoring — Set live breakpoints and capture snapshots in production without redeploying (already enabled via enable_code_monitoring=True)
• Distributed Tracing — Connect traces across multiple services for full request visibility
• Frontend Observability — Add @tracekit/browser to your frontend for end-to-end trace correlation

References

• Python SDK docs: https://app.tracekit.dev/docs/languages/python
• TraceKit docs root: https://app.tracekit.dev/docs
• Dashboard: https://app.tracekit.dev
• Quick start: https://app.tracekit.dev/docs/quickstart