Backend Python

API-09 · Logs and prints should not receive secrets, credentials or whole request payloads

OPS-02 · The user confirms credential-named values written as literals, or secret environment reads with a literal fallback

API-06 · The user confirms disabling CSRF protection for cookie-authenticated requests (csrf_exempt, middleware removed, insecure CSRF settings)

PY-06 · Validation and authorization never rely on assert (removed under python -O)

API-01 · Request payload fields should go through a validator before domain use, not be read raw

API-04 · Serializers and forms list the fields they expose instead of "__all__"

API-05 · The user confirms mapping a raw request payload onto persistent objects (unrestricted ** expansion, __dict__ update, setattr loop)

API-07 · Bound-value placeholders are never quoted inside SQL text ('%s')

API-07 · The user confirms SQL built by interpolating values or identifiers into the query text

API-08 · eval/exec, shell=True, os.system, pickle and unsafe YAML loading need a demonstrated trusted input

API-08 · Request data never reaches eval/exec, a shell, or an unsafe deserializer

TYP-06 · A cast or annotation on untrusted input is not validation; parse it at runtime

API-10 · The user confirms outbound URLs, file paths or upload names taken from the request without a visible guard

IO-08 · TLS certificate verification stays on in production code (configure trust roots instead)

ENV-06 · The user authorizes tooling changes that add ignores or exclusions, lower strictness or thresholds, narrow test selection or drop a check

TST-08 · The user confirms new skips and expected failures, and removed test functions

TYP-04 · Type and lint suppressions name the diagnostic and justify the exception; no blanket suppression

TYP-01 · Public production functions should annotate their parameters and return type (None included)

TYP-03 · Any and opaque containers should stay at external boundaries and be narrowed before domain use

PY-03 · An exception handler propagates unexpected failure or implements an explicit recovery, never a silent success

PY-04 · Broad exception catches should be boundary handlers that keep diagnostics and failure semantics

PY-05 · An exception translated in a handler keeps the original as its cause (raise … from err)

IO-01 · Async functions do not call blocking sleep, HTTP, subprocess or socket APIs on the event-loop thread

IO-02 · A coroutine created by a statement is awaited or handed to a managed task facility

IO-03 · Background tasks have an owner that keeps a reference, observes failure and cancels them on shutdown

IO-04 · Async code re-raises CancelledError unless it owns the cancelled task

DB-06 · Loops should not issue one ORM query per item where batch loading preserves semantics

IO-05 · Outbound calls keep a finite effective timeout (requests and urlopen have none by default; timeout=None disables it)

IO-06 · HTTP, database and cloud clients are created once and reused, not inside loops

IO-07 · Files, sockets and streamed responses are closed on every path (context manager) or explicitly handed over

IO-09 · Retries are bounded (stop condition, backoff); a loop does not retry a failing operation forever

OPS-05 · In-process caches are bounded and owned (no unbounded @cache, no lru_cache on methods)

ARC-01 · Modules the project declared framework-independent import no framework, persistence or transport package at runtime

ARC-08 · Importing a module should not reach the network, write data or start tasks and processes

PY-01 · Parameters never default to a shared mutable object (list, dict, set, deque…)

PY-07 · No return, break or continue inside finally (it silently discards the pending exception or return)

PY-09 · Imports name what they use (no wildcard import outside package re-exports)

PY-10 · Instants are timezone-aware (no utcnow, utcfromtimestamp or argument-less now)

OPS-04 · Error responses expose a stable safe error, not the raw exception or a traceback

DB-01 · Several ORM writes in one function run inside one transaction (Django autocommit commits each separately)

DB-02 · Side effects that depend on a write (mail, tasks, events, HTTP) are scheduled after commit

DB-03 · A database error is not caught and swallowed inside the transaction it broke (use an inner savepoint)

DB-04 · Uniqueness under concurrency is a database constraint; an exists() pre-check before create races

DB-05 · Read-modify-write of a persisted counter or balance should be atomic (F() expression, lock or version check)

DB-07 · A persisted model change ends the turn with its migration (Django apps with migrations/, Alembic projects)

DB-08 · The user confirms editing a migration that already existed before this session (applied history)

DB-08 · Migrations use historical models (apps.get_model, op.get_bind), not the application's live models

DB-09 · Destructive, locking or non-null migration operations need a rollout plan (locks, batches, old/new code compatibility)

DB-10 · Data migrations declare their reverse, or state that they are irreversible and how to recover

ENV-05 · New syntax and stdlib APIs stay within the oldest Python version the project declares (requires-python)

OPS-01 · Configuration is read from the environment and validated at one boundary, not across the code

OPS-03 · Production modules carry no debugger traps or diagnostic prints (CLIs and entry points may print)

ENV-03 · A newly imported third-party package should be declared in the project's dependency manifest

ENV-04 · Changed dependency declarations end the turn with their lock or compiled constraints updated

OPS-07 · An ImportError fallback is tied to a supported version or a declared optional dependency, not invented compatibility

TST-03 · Test assertions compare behavior with an independent expectation, not a value with itself or a constant

TST-05 · Unit and contract tests do not reach external hosts; live suites are declared separately

TST-07 · Tests synchronize on events or control the clock instead of sleeping

PY-02 · Production functions implement reachable behavior instead of pass, Ellipsis or a stub-marked constant

TST-10 · A final message claiming passing checks needs a successful check after Claude's last edit

TST-10 · Records, per session, Claude's edits and the checks (pytest, type checker, linter) that succeeded after them

Records the work tree when a prompt starts, the baseline of the end-of-turn checks (TYP-02, DB-07, ENV-04)

TYP-02 · Claude does not end a turn with type-checker errors it introduced (unresolved imports, syntax, Optional access, unused coroutines included)