blare for Python

Production failures to Slack, Discord and Teams. One line of setup, no server, no spam.

pip install blare

import blare

blare.init()

BLARE_SINKS=https://hooks.slack.com/services/T000/B000/xxxx
BLARE_ENV=production

That is the whole installation. From then on every logger.error(...), every unhandled exception and every framework 500 becomes a chat alert — grouped so that one broken endpoint is one message rather than eight hundred.

Check it before you need it:

python -m blare --send

What is captured

# FastAPI
from blare.integrations.asgi import BlareASGIMiddleware

app.add_middleware(BlareASGIMiddleware)

# Flask
from blare.integrations.flask import install

install(app)

# Django, in AppConfig.ready()
from blare.integrations.django import install

install()

# Celery
from blare.integrations.celery import install

install()

Why it does not flood the channel

Identical failures are fingerprinted together and one alert per problem goes out per five minute window. The suppressed occurrences are not lost — they arrive as a count on the next alert:

🟠 OperationalError: connection pool exhausted — 847 times in the last 5 min

There is also a hard ceiling of 20 alerts an hour, and the number dropped by it is reported on the next alert that gets through.

Settings

Every setting is an environment variable, documented in SPEC.md section 2. The ones most people touch:

Running more than one host? Set BLARE_STATE to a Redis URL, or each host deduplicates on its own and a ten-replica deployment sends ten alerts for one outage.

Privacy

Local variables, request bodies, response bodies and environment variable values are never collected, in any configuration. Everything that does leave the process is scanned for credentials first — bearer tokens, JWTs, AWS keys, GitHub and Slack tokens, private keys, URL passwords, card numbers — and keys named password, token, secret and friends are replaced wholesale. See SPEC.md section 6.

Testing your own code

blare.init(sinks=[], synchronous=True)  # captures, sends nowhere
blare.stats()  # {'delivered': .., 'suppressed': ..}

Or set BLARE_DRY_RUN=true to render alerts to stderr and send nothing.

Development

uv venv && . .venv/bin/activate
uv pip install -e ".[dev]"
pytest
ruff check .

The suite reads the shared fixtures in ../conformance/, so behaviour cannot drift from the spec or from the other language ports.

Apache-2.0. Implements spec version 1.