forge-ops-tracker

Python error reporting client for ForgeOps. Requires Python 3.9+. It captures unhandled and explicitly reported exceptions, builds a backtrace, scrubs likely PII, and delivers events to ForgeOps over HTTP without blocking the request or process that raised them.

Installation

pip install forge-ops-tracker

For Django or Flask integration, install the matching extra:

pip install "forge-ops-tracker[django]"
pip install "forge-ops-tracker[flask]"

For outbound HTTP span capture (see Distributed tracing below), install the requests extra too:

pip install "forge-ops-tracker[requests]"

Configuration

Set a DSN (from a project's settings page in ForgeOps), either via the FORGE_OPS_DSN environment variable or explicitly:

import forge_ops_tracker

forge_ops_tracker.init(
    dsn="https://<api_key>@getforgeops.net/api/v1/events",  # or leave unset to read FORGE_OPS_DSN
    release="...",
    environment="production",
)

Call init() once at startup: Django's settings.py, or right after creating a Flask app. Any Configuration attribute can be overridden by keyword.

Django

# settings.py
import forge_ops_tracker

forge_ops_tracker.init(dsn="https://<api_key>@getforgeops.net/api/v1/events")

MIDDLEWARE = [
    ...,
    "django.contrib.auth.middleware.AuthenticationMiddleware",  # if not already there
    "forge_ops_tracker.integrations.django.ForgeOpsTrackerBreadcrumbContextMiddleware",
    "forge_ops_tracker.integrations.django.ForgeOpsTrackerTracingMiddleware",
    "forge_ops_tracker.integrations.django.ForgeOpsTrackerMiddleware",
    "forge_ops_tracker.integrations.django.ForgeOpsTrackerSessionTrackingMiddleware",
    "forge_ops_tracker.integrations.django.ForgeOpsTrackerPerformanceTrackingMiddleware",
    "forge_ops_tracker.integrations.django.ForgeOpsTrackerUserContextMiddleware",
]

Flask

from flask import Flask
import forge_ops_tracker
from forge_ops_tracker.integrations.flask import init_flask

forge_ops_tracker.init(dsn="https://<api_key>@getforgeops.net/api/v1/events")

app = Flask(__name__)
init_flask(app)

What gets reported automatically, and what doesn't

An exception that crashes a request needs no further wiring at all. The Django middleware's process_exception hook and Flask's got_request_exception signal both fire for anything that propagates uncaught out of a view, then let the framework handle it exactly as if this client weren't installed.

An exception your own code catches and handles is different: neither integration ever sees it, since it never propagates far enough to reach either hook:

try:
    charge_card(order)
except CardError as e:
    logger.warning("card declined: %s", e)
    # ForgeOps never sees this: caught locally, never reaches the
    # middleware/signal at all.

There's no application-wide hook that reports an exception while still letting your own except block handle it: report it explicitly instead, right at the catch site:

except CardError as e:
    forge_ops_tracker.capture_exception(e, context={"order_id": order.id})
    logger.warning("card declined: %s", e)

Called with no arguments, capture_exception() picks up whichever exception is currently being handled (same as a bare raise inside an except: block), so it usually reads as just forge_ops_tracker.capture_exception() from inside the block that already caught it.

Outside a web request (scripts, management commands, workers)

init() also installs a sys.excepthook wrapper by default (Configuration.install_excepthook, True unless set otherwise), which reports anything that crashes the whole interpreter: a plain script, a Django management command, a worker's own top-level loop: with no wiring needed, the same "unhandled needs no wiring" case the Django/Flask integrations cover for web requests. It still calls whatever sys.excepthook was already installed afterward, so it never changes program behavior. This does not catch a web request's unhandled exception under a real WSGI server (Gunicorn/uWSGI catch that themselves per-request, long before it would ever reach the interpreter level): that's what the Django/Flask integrations are for.

Delivery happens on a background thread with a bounded queue and a short per-request HTTP timeout (Configuration.timeout, 2s default). Every failure mode: network errors, timeouts, a full queue, a malformed DSN: is caught and dropped rather than raised, so a broken or unreachable tracker can never take down the host app. The worker thread starts lazily, on first push, not at import time: Gunicorn (prefork) and uWSGI commonly fork worker processes after the application has already loaded, which would leave an eagerly-started thread dead in every forked child; starting fresh on first push means each forked worker gets its own live thread regardless of when it was forked relative to import.

Identifying users

forge_ops_tracker.capture_exception(error, user={"id": user.id, "email": user.email})

Or set_user(id=None, email=None, username=None) to attach it for the rest of the current thread (a WSGI request, a background worker, a console session) rather than passing it to every capture_exception() call by hand:

forge_ops_tracker.set_user(id=request.user.id, email=request.user.email)

Thread-local, not global: a WSGI server (Django/Flask's own deployment model) runs one request per thread, so this is the right isolation boundary; not correct under an ASGI/asyncio deployment, where several requests can share one OS thread, but this SDK has no async integration today for that gap to matter yet. id/email/username are all independently optional; call set_user() with none of them to clear whatever was set, e.g. once a request finishes. Shows up on an issue's own detail page, and as its own affected-users count alongside the regular event count.

Automatic detection, if you're using either integration above:

• Django: ForgeOpsTrackerUserContextMiddleware (see the Django snippet above; must be listed after django.contrib.auth.middleware.AuthenticationMiddleware, or whatever else sets request.user) reads request.user when it's present and is_authenticated, and calls set_user() for you: pk for id (present on every model instance, regardless of your own AUTH_USER_MODEL), email if the attribute exists, and get_username() (correct even with a custom USERNAME_FIELD) if it does. A no-op for an app with no such middleware installed at all.
• Flask: init_flask() detects Flask-Login if it's installed and configured (a genuinely optional dependency this package never requires): id comes from current_user.get_id() (the only thing Flask-Login's own UserMixin actually guarantees); email/username are read as plain optional attributes, since Flask-Login itself guarantees neither, the common convention most apps' own User model follows regardless. A no-op if Flask-Login isn't installed, isn't configured (no LoginManager attached to this app), or nobody's logged in.

Both compose with the manual API above rather than replacing it: call set_user() yourself afterward (e.g. for a custom auth setup neither integration can detect, or to override what was auto-detected) and it wins for the rest of that request.

Breadcrumbs

A trail of what happened right before an error, on by default, no setup needed beyond the Django/Flask integration above: every SQL query (Django's own ORM automatically; any tracked SQLAlchemy engine too) and request/controller lifecycle is recorded automatically, and shows up alongside the error on an issue's own detail page.

forge_ops_tracker.init(
    dsn="...",
    track_breadcrumbs=False,  # opt out of the automatic sources entirely
    max_breadcrumbs=30,       # oldest entry dropped once this many have accumulated in one trail
)

Add your own by hand, regardless of whether the automatic sources are on:

forge_ops_tracker.add_breadcrumb("charged card", category="billing", data={"order_id": order.id})

category defaults to "custom", level to "info" ("debug"/"info"/"warning"/"error" are the four levels the automatic sources themselves use too), and data to {}. Works outside a request entirely too (a background task, a console session): the trail it adds to is created lazily on whatever context calls it, the same "works standalone, no specific setup required" shape set_user() already has, rather than silently doing nothing with no active request/task around it.

Each request or Celery task gets its own fresh, bounded trail (a ring buffer capped at max_breadcrumbs, oldest entry dropped once full), scoped with a contextvars.ContextVar rather than the thread-local set_user() above uses: a plain WSGI worker thread behaves identically either way, but this also stays correctly isolated under a Celery worker's own thread pool (which, unlike its prefork processes, does reuse one OS thread across many unrelated task runs) and any future asyncio/ASGI integration, where several requests could otherwise interleave on a single OS thread as separate asyncio Tasks. Unlike the affected user above, a breadcrumb's message/data is scrubbed for likely PII: console-style/query/request trail entries are exactly the kind of free text (a bind parameter showing up in a message, a URL with a token in it) the scrubber exists to catch, not a deliberately-structured field the way user is.

Celery tasks (with init_celery() from the section above) get their own automatic "job" category breadcrumb too, recorded at the very start of the task, before its own body even runs: this is deliberate, not an oversight, since Celery fires task_failure (which is what actually reports a task's exception) before task_postrun, so a breadcrumb only added once the task finishes would never make it into that same task's own failure report.

in_app backtrace frames

Python runs interpreted directly from real .py files on disk, so file-path matching against Configuration.app_root is a straightforward prefix comparison against those on-disk paths. Defaults to the current working directory; set it explicitly if that doesn't match your app's actual layout (a WSGI server started from a different directory than your app's root, for instance). Standard-library and installed-package (site-packages/dist-packages) frames are never marked in_app, regardless of app_root.

PII scrubbing

By default, the message, backtrace, and any context/tags you attach are scanned for likely personal data (email addresses, formatted SSNs/credit cards, known API key/token formats, and anything under a suspiciously-named key like password, api_key, or ssn) and redacted before the payload ever leaves this process. ForgeOps itself scrubs again on arrival regardless, so this is a second, earlier layer, not the only one. The user attached via user=/ set_user() above is a deliberate exception: it's never scrubbed, since redacting it would defeat the whole point of identifying users in the first place.

To disable it:

forge_ops_tracker.init(dsn="...", scrub_pii=False)

Source context

By default, each in-app backtrace frame (never a standard-library or installed-package frame) is captured along with the 5 lines of source on either side of the culprit line, read straight off disk at raise-time, so an issue's detail page can show the actual code that broke, not just a file:line:method reference. This never applies to a frame outside your configured app_root, and it fails silently (no context, not an exception) for any file that can't be read for whatever reason.

This is a real, deliberate exception to "off by default is safer": literal source code is being transmitted, not just a reference to it, and the real protection here is not this flag. Every project on ForgeOps has its own setting (on by default, off durably and immediately once an org owner turns it off, regardless of what any individual app's own capture_source_context is still set to) that governs whether the server will ever actually store what a client sends. Set this to False if you'd rather this client never even attempt the disk read in the first place:

forge_ops_tracker.init(dsn="...", capture_source_context=False)

Session tracking (release health)

By default, every request through the Django/Flask integrations is counted as a session: crash-free unless an unhandled exception (or a 5xx response, for Django, where the exception has already been converted to a response by the time this client ever sees the request) actually affects it, giving ForgeOps a crash-free rate per release to show alongside the errors themselves, not just the errors on their own. Counted in-process and flushed as a small periodic aggregate on a background thread (never one network call per request), the same delivery philosophy as everything else in this client: a broken or unreachable tracker never affects the host app either way.

forge_ops_tracker.init(
    dsn="...",
    track_sessions=False,       # opt out entirely
    session_flush_interval=30,  # seconds; default 60
)

Requires a ForgeOps plan that includes release health; on a plan that doesn't, the periodic flushes are simply rejected server-side and dropped, exactly like any other delivery failure.

Performance monitoring

By default, the Django/Flask integrations also time every request, so a dashboard widget on ForgeOps can show which parts of your app are actually slow, not just which ones raise. Bucketed by transaction ("GET /users/<int:id>", the matched URL pattern rather than the literal path, so a distinct user id doesn't explode into its own separate transaction) and flushed as a small periodic aggregate per transaction on the same kind of background thread session tracking above uses.

Each aggregate also carries a small latency histogram (a count per fixed latency bucket: 50, 100, 250, 500, 1000, 2500, 5000 and 10000ms, plus an overflow bucket), so ForgeOps can show an approximate p50/p95/p99 per transaction, not just an average. Percentiles are accurate to the width of whichever bucket a duration falls into; the SDK never stores the individual durations.

forge_ops_tracker.init(
    dsn="...",
    track_performance=False,        # opt out entirely
    performance_flush_interval=30,  # seconds; default 60
)

Requires a ForgeOps plan that includes performance monitoring; on a plan that doesn't, the periodic flushes are simply rejected server-side and dropped, exactly like any other delivery failure.

Database queries and Celery tasks

The same automatic instrumentation, on the same track_performance flag, also covers:

• Database queries, for Django automatically (no extra step beyond the middleware above) and for any SQLAlchemy engine (Flask-SQLAlchemy included) with one extra call:

  from forge_ops_tracker.integrations.sqlalchemy import track_sqlalchemy_queries
  
  db = SQLAlchemy(app)
  track_sqlalchemy_queries(db.engine)
  

  Bucketed by "<VERB> <table>" ("SELECT auth_user", "INSERT INTO orders"), not the raw SQL text: a low-cardinality name in the same spirit as the request transaction name above, and never a literal value even where a query's own parameters aren't already placeholder-bound.

• Celery tasks, via a separate integration (Celery is an optional dependency, same as Django/Flask):

  from forge_ops_tracker.integrations.celery import init_celery
  
  init_celery()
  

  Bucketed by the task's own registered name ("myapp.tasks.send_email"). This is also this SDK's only error-reporting integration for Celery: a task that raises is reported the same way an unhandled Django/Flask request exception already is, no separate wiring needed.

Each shows up as its own kind ("controller", "job", "query") on the same performance dashboard dataset, so "slowest queries" and "slowest tasks" are just a filtered version of the same widget builder "slowest transactions" already uses.

Distributed tracing

For one slow request, the Django/Flask integrations (via ForgeOpsTrackerTracingMiddleware and init_flask() respectively, both installed above) capture its full nested call tree: the controller/view span, plus every database query, outbound HTTP call, and manually-wrapped span nested under it, so ForgeOps can render a waterfall for that one request.

This is the whole point of the feature, so it's worth being explicit about: a request's own trace is only ever built, let alone sent, once its own root span's duration crosses a threshold, decided entirely client-side before a single byte goes over the wire. A normal, fast request costs nothing extra.

forge_ops_tracker.init(
    dsn="...",
    track_tracing=False,             # opt out entirely
    trace_capture_threshold_ms=500,  # milliseconds; default 1000
)

Database queries nest in automatically, the same way they do for performance monitoring above (Django's ORM with no extra step; any engine passed to track_sqlalchemy_queries). Outbound HTTP calls made via requests nest in too, with one extra call:

from forge_ops_tracker.integrations.requests import init_requests

init_requests()

Every span name ("GET api.stripe.com", "SELECT orders") is low-cardinality by design, the same as every transaction name elsewhere in this SDK: never a raw URL path, query string, or SQL literal, since any of those can carry a customer's own id or a secret.

There's no way to auto-detect "this is a logically distinct service layer" the way a SQL query or an outbound HTTP call already has a real hook to extend, so wrap your own service-layer code by hand to have it show up as its own span:

with forge_ops_tracker.span("PaymentService.charge"):
    charge_card(order)

Also works as a decorator (@forge_ops_tracker.span("PaymentService.charge")), and kind= accepts "controller", "service" (the default), "database", "http", "job", or "other". A no-op outside of a request currently being traced (a plain script, a fast request that's already finished) or with track_tracing off: it just runs the wrapped code and records nothing, never raising.

Requires a ForgeOps plan that includes distributed tracing; on a plan that doesn't, a captured trace is simply rejected server-side and dropped, exactly like any other delivery failure.

Known gap: there's no Redis integration yet. Unlike SQLAlchemy or requests, this SDK has no existing hook of its own to extend for Redis, and neither redis-py's Redis class nor execute_command is a stable enough surface to wrap without real Redis-specific testing; a Redis call inside a traced request just won't show up as its own span for now.

Custom metrics and infrastructure monitoring

Two explicit calls (nothing is automatic, so there is no track_* flag): a business event you name yourself, and a reading from one of your own hosts.

forge_ops_tracker.capture_metric("signup")           # value defaults to 1.0: a bare counter
forge_ops_tracker.capture_metric("payment", 49.0)    # a real magnitude; it may be negative (a refund)

forge_ops_tracker.capture_infrastructure_metric("cpu", 0.42)                      # hostname defaults to server_name
forge_ops_tracker.capture_infrastructure_metric("disk", 0.81, hostname="db-1")
forge_ops_tracker.flush_metrics()                    # optional: send right now

Each capture is buffered and flushed as one batch every metric_flush_interval / infrastructure_metric_flush_interval seconds (60 by default) on a background thread, and once more when the process exits normally, which is what a short-lived cron script relies on; call flush_metrics() yourself if it might exit another way (os._exit, a kill). Every entry is stored as it was captured (a signup is a row, not a running total), so a count or sum you compute later is exact. Both are a no-op when the client isn't enabled for the environment.

A failed delivery keeps every entry for the next flush, and an entry captured while a delivery is in flight is kept too (the Ruby gem's own buffer loses it). The buffer holds at most 1000 entries per kind and drops further ones until a flush succeeds, since a plan without the feature rejects every flush and would otherwise grow it for as long as the process lives. A NaN or infinite value is dropped at capture: it is not valid JSON and would make the server reject the whole batch behind it. Requires a ForgeOps plan that includes custom metrics / infrastructure monitoring.

Running the tests

cd sdks/python
python3 -m venv .venv
./.venv/bin/pip install -e ".[test]"
./.venv/bin/python -m pytest
./.venv/bin/ruff check src tests