RaiseAttention 2026.2.161

a static exception flow analyser for python with lsp integration

RaiseAttention

[!WARNING] this project is vibe coded, as a test of Kimi K2.5. it isn't battle tested, so issues may arise. if you're willing to run into potential bugs, feel free to use it!

a static exception flow analyser for python that identifies unhandled exceptions in your codebase. i built this because i was tired of not knowing what exceptions functions might raise, especially when calling third-party code.

version 2026.2.14.

• usage
  • installation
  • cli
  • lsp server
• what does it do?
• features
• configuration
• licence

usage

installation

pip install raiseattention

nix users, rejoice: nix run github:markjoshwel/RaiseAttention

cli

check version:

raiseattention --version

analyse your project:

raiseattention check .

analyse a specific file:

raiseattention check src/main.py

for json output:

raiseattention check --json .

enable debug logging to see what the analyser is doing:

raiseattention check --debug .

full cli help:

raiseattention --help
raiseattention check --help

lsp server

start the lsp server for real-time editor integration:

raiseattention lsp

the server will give you errors when you're calling a function that may raise an exception. the laziest way to appease RaiseAttention is to wrap calls in a try: ... except Exception: block—but you probably shouldn't do that lol

what does it do?

RaiseAttention tracks exception flow through your code. it follows function calls transitively, so if a() calls b() which calls c() which raises ValueError, RaiseAttention will tell you that calling a() may raise ValueError.

def risky():
    raise ValueError("something went wrong")

def caller():
    risky()  # RaiseAttention: unhandled ValueError

def safe_caller():
    try:
        risky()  # no warning—handled by except ValueError
    except ValueError:
        pass

it also analyses external modules (stdlib and third-party):

import json

def parse_data(data: str) -> dict:
    return json.loads(data)  # RaiseAttention: unhandled JSONDecodeError, TypeError

the idea is that you won't have to worry about exceptions anymore live in the dark when it comes to whether any functions you use may raise exceptions you didn't expect.

features

• transitive exception tracking
  follows exceptions through call chains

• try-except detection
  understands which exceptions are handled at call sites

• external module analysis
  analyses stdlib and third-party packages

• higher-order function traversal
  tracks exceptions through map, filter, sorted, and other HOFs when you pass callable arguments

• native code detection
  reports PossibleNativeException for C extensions that can't be statically analysed (suppress with --no-warn-native)

• c extension stubs
  pre-computed exception signatures for stdlib C modules (6531 stubs for python 3.12)

• type constructor analysis
  detects exceptions from int(), float(), str(), etc. (e.g., int("not a number") raises ValueError)

• smart builtin filtering
  only flags builtins with interesting exceptions, skips noisy ones like len(), abs(), print()

• docstring heuristics
  checks __doc__ for "raises" keywords when static analysis isn't possible

• exception instance re-raise detection
  raise error from except Exception as error: is treated as re-raise, not a new exception

• inline ignore comments
  # raiseattention: ignore[ExceptionType] for line-specific suppression (pyright-style)

• ra shorthand
  # ra: ignore[Exception] works too (all case-insensitive)

• docstring-based suppression
  exceptions documented in parent docstrings are automatically suppressed

• lsp server
  real-time feedback in your editor

• debug logging
  see exactly what the analyser is doing with --debug

configuration

configuration is loaded from (in order of precedence):

1. default values
2. pyproject.toml [tool.raiseattention] section
3. .raiseattention.toml file
4. cli flags

example pyproject.toml:

[tool.raiseattention.analysis]
local_only = false    # set to true to skip external module analysis
warn_native = true    # set to false to suppress native code warnings

# control which builtins are analysed
ignore_include = ["str", "print"]  # always ignore these builtins
ignore_exclude = ["open"]          # never ignore this builtin (overrides ignore_include)

inline ignore comments

suppress specific exceptions on a single line:

import json

def parse_data(data: str) -> dict:
    return json.loads(data)  # raiseattention: ignore[JSONDecodeError]

multi-line statements work too:

result = some_function(
    arg1,
    arg2,
)  # raiseattention: ignore[ValueError, TypeError]

shorthand formats (all case-insensitive):

# raiseattention: ignore[ValueError]
# RaiseAttention: ignore[ValueError]
# ra: ignore[ValueError]
# RA: ignore[ValueError]

plain # raiseattention: ignore without brackets is invalid and will be reported as a warning.

docstring-based suppression

if a line raises an exception, RaiseAttention checks the closest parent function's docstring. if the docstring contains "raise" or "raises" and the exception class name, the diagnostic is suppressed:

def parse_config(path: str) -> dict:
    """may raise ValueError if config is invalid."""
    return json.loads(read_file(path))  # no diagnostic - ValueError is documented

cli flags

• --version
  show version (2026.2.14)

• --local
  analyse only first-party code (skip external modules)

• --strict
  enable strict mode (flags undocumented exceptions)

• --debug
  enable debug logging

• --no-warn-native
  suppress PossibleNativeException warnings

• --json
  output diagnostics as json

• --absolute
  use absolute paths in output

• --full-module-path
  show full module path for exceptions

workspace packages

this repository contains several packages:

• raiseattention (2026.2.14)
  main exception analyser

• libsoulsearching (0.1.0)
  virtual environment detection library

• libsightseeing (0.1.0)
  file finding with gitignore support

• standardstubber (2026.2.14, private)
  cpython stub generator

licence

RaiseAttention is free and unencumbered software released into the public domain. for more information, please refer to the UNLICENCE or https://unlicense.org.