diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 187cd46..1b799e3 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -26,14 +26,11 @@ jobs:
             python -m pip install --upgrade pip
             pip install .[lint]
 
-        - name: Run Black
-          run: black --check .
+        - name: Run ruff format
+          run: ruff format --check .
 
-        - name: Run isort
-          run: isort --check-only .
-
-        - name: Run flake8
-          run: flake8 .
+        - name: Run ruff check
+          run: ruff check .
 
         - name: Run mdformat
           run: mdformat . --check
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 58166e7..330b247 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -4,22 +4,12 @@ repos:
     hooks:
     -   id: check-yaml
 
--   repo: https://github.com/PyCQA/isort
-    rev: 6.0.0
+-   repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.14.10
     hooks:
-      - id: isort
-
--   repo: https://github.com/psf/black
-    rev: 25.1.0
-    hooks:
-      - id: black
-        name: black
-
--   repo: https://github.com/pycqa/flake8
-    rev: 7.1.2
-    hooks:
-    -   id: flake8
-        additional_dependencies: [flake8-breakpoint, flake8-print, flake8-pydantic, flake8-type-checking]
+    -   id: ruff
+        args: [--fix, --exit-non-zero-on-fix]
+    -   id: ruff-format
 
 -   repo: https://github.com/pre-commit/mirrors-mypy
     rev: v1.15.0
diff --git a/ape_solidity/compiler.py b/ape_solidity/compiler.py
index ef792b6..5ff03d3 100644
--- a/ape_solidity/compiler.py
+++ b/ape_solidity/compiler.py
@@ -301,7 +301,10 @@ def get_import_remapping(self, project: Optional[ProjectManager] = None) -> dict
         return remapping
 
     def get_compiler_settings(
-        self, contract_filepaths: Iterable[Path], project: Optional[ProjectManager] = None, **kwargs
+        self,
+        contract_filepaths: Iterable[Path],
+        project: Optional[ProjectManager] = None,
+        **kwargs,
     ) -> dict[Version, dict]:
         pm = project or self.local_project
         paths = _validate_can_compile(contract_filepaths)
@@ -341,9 +344,15 @@ def _get_settings_from_version_map(
         settings: dict = {}
         for solc_version, sources in version_map.items():
             version_settings: dict[str, Union[Any, list[Any]]] = {
-                "optimizer": {"enabled": config.optimize, "runs": config.optimization_runs},
+                "optimizer": {
+                    "enabled": config.optimize,
+                    "runs": config.optimization_runs,
+                },
                 "outputSelection": {
-                    str(get_relative_path(p, pm.path)): {"*": OUTPUT_SELECTION, "": ["ast"]}
+                    str(get_relative_path(p, pm.path)): {
+                        "*": OUTPUT_SELECTION,
+                        "": ["ast"],
+                    }
                     for p in sorted(sources)
                 },
                 **kwargs,
@@ -415,18 +424,10 @@ def get_standard_input_json_from_settings(
             if solc_version >= Version("0.6.9"):
                 arguments["base_path"] = pm.path
 
-            vers_settings["outputSelection"] = {
-                k: v for k, v in vers_settings["outputSelection"].items() if (pm.path / k).is_file()
-            }
-
             if missing_sources := [
                 x for x in vers_settings["outputSelection"] if not (pm.path / x).is_file()
             ]:
-                # See if the missing sources are from dependencies (they likely are)
-                # and cater the error message accordingly.
                 if dependencies_needed := [x for x in missing_sources if str(x).startswith("@")]:
-                    # Missing dependencies. Should only get here if dependencies are found
-                    # in import-strs but are not installed (not in project or globally).
                     missing_str = ", ".join(dependencies_needed)
                     raise CompilerError(
                         f"Missing required dependencies '{missing_str}'. "
@@ -434,11 +435,11 @@ def get_standard_input_json_from_settings(
                         "in an ape-config.yaml or using the `ape pm install` command."
                     )
 
-                # Otherwise, we are missing project-level source files for some reason.
-                # This would only happen if the user passes in unexpected files outside
-                # of core.
                 missing_src_str = ", ".join(missing_sources)
-                raise CompilerError(f"Sources '{missing_src_str}' not found in '{pm.name}'.")
+                raise CompilerError(
+                    f"Sources '{missing_src_str}' not found in '{pm.name}' "
+                    f"(project path: {pm.path})."
+                )
 
             sources = {
                 x: {"content": (pm.path / x).read_text(encoding="utf8")}
@@ -461,8 +462,8 @@ def compile(
     ) -> Iterator[ContractType]:
         pm = project or self.local_project
         settings = settings or {}
-        paths = [p for p in contract_filepaths]  # Handles generator.
-        source_ids = [f"{get_relative_path(p.absolute(), pm.path)}" for p in paths]
+        paths = [(p if Path(p).is_absolute() else pm.path / p) for p in contract_filepaths]
+        source_ids = [f"{get_relative_path(Path(p).absolute(), pm.path)}" for p in paths]
         _validate_can_compile(paths)
 
         # Compile in an isolated env so the .cache folder does not interfere with anything.
@@ -500,7 +501,10 @@ def _compile(
             logger.info(log_str)
             cleaned_version = Version(solc_version.base_version)
             solc_binary = get_executable(version=cleaned_version)
-            arguments: dict = {"solc_binary": solc_binary, "solc_version": cleaned_version}
+            arguments: dict = {
+                "solc_binary": solc_binary,
+                "solc_version": cleaned_version,
+            }
 
             if solc_version >= Version("0.6.9"):
                 arguments["base_path"] = pm.path
diff --git a/pyproject.toml b/pyproject.toml
index 8991fa8..8beb45f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,16 +9,6 @@ plugins = ["pydantic.mypy"]
 [tool.setuptools_scm]
 write_to = "ape_solidity/version.py"
 
-# NOTE: you have to use single-quoted strings in TOML for regular expressions.
-# It's the equivalent of r-strings in Python.  Multiline strings are treated as
-# verbose regular expressions by Black.  Use [ ] to denote a significant space
-# character.
-
-[tool.black]
-line-length = 100
-target-version = ['py39', 'py310', 'py311', 'py312', 'py313']
-include = '\.pyi?$'
-
 [tool.pytest.ini_options]
 addopts = """
     -p no:ape_test
@@ -35,12 +25,21 @@ fuzzing: Run Hypothesis fuzz test suite
 install: Tests that will install a solc version (slow)
 """
 
-[tool.isort]
-line_length = 100
-force_grid_wrap = 0
-include_trailing_comma = true
-multi_line_output = 3
-use_parentheses = true
+[tool.ruff]
+target-version = "py310"
+line-length = 100
+
+[tool.ruff.lint.pydocstyle]
+convention = "google"
+
+[tool.ruff.lint.isort]
+known-first-party = ["ape_solidity"]
+
+[tool.ruff.format]
+quote-style = "double"
+line-ending = "auto"
+indent-style = "space"
+docstring-code-format = true
 
 [tool.mdformat]
 number = true
diff --git a/setup.cfg b/setup.cfg
deleted file mode 100644
index 0bcc87f..0000000
--- a/setup.cfg
+++ /dev/null
@@ -1,10 +0,0 @@
-[flake8]
-max-line-length = 100
-ignore = E704,W503,PYD002,TC003,TC006
-exclude =
-	*.venv*
-	venv*
-	docs
-	build
-	tests/node_modules
-type-checking-pydantic-enabled = True
diff --git a/setup.py b/setup.py
index abc7899..258e350 100644
--- a/setup.py
+++ b/setup.py
@@ -12,14 +12,10 @@
         "pytest-benchmark",  # For performance tests
     ],
     "lint": [
-        "black>=25.1.0,<26",  # Auto-formatter and linter
+        "ruff>=0.14.10",  # Linter and auto-formatter
         "mypy>=1.15.0,<2",  # Static type analyzer
         "types-requests",  # Needed for mypy type shed
         "types-setuptools",  # Needed for mypy type shed
-        "flake8>=7.1.2,<8",  # Style linter
-        "flake8-pydantic",  # For detecting issues with Pydantic models
-        "flake8-type-checking",  # Detect imports to move in/out of type-checking blocks
-        "isort>=5.13.2,<6",  # Import sorting linter
         "mdformat>=0.7.22",  # Auto-formatter for markdown
         "mdformat-gfm>=0.3.5",  # Needed for formatting GitHub-flavored markdown
         "mdformat-frontmatter>=0.4.1",  # Needed for frontmatters-style headers in issue templates
diff --git a/tests/test_compiler.py b/tests/test_compiler.py
index c0e3c9f..f3617ac 100644
--- a/tests/test_compiler.py
+++ b/tests/test_compiler.py
@@ -432,7 +432,10 @@ def test_get_version_map_importing_more_constrained_version(project, compiler):
 
     actual = compiler.get_version_map((path,), project=project)
     expected_version = Version("0.8.12+commit.f00d7308")
-    expected_sources = ("ImportSourceWithEqualSignVersion", "SpecificVersionWithEqualSign")
+    expected_sources = (
+        "ImportSourceWithEqualSignVersion",
+        "SpecificVersionWithEqualSign",
+    )
     assert expected_version in actual
 
     actual_ids = [x.stem for x in actual[expected_version]]
@@ -1070,3 +1073,19 @@ def test_compile_code(project, compiler):
     assert actual.ast is not None
     assert len(actual.runtime_bytecode.bytecode) > 0
     assert len(actual.deployment_bytecode.bytecode) > 0
+
+
+def test_compile_relative_path_from_other_cwd(project, compiler, tmp_path, monkeypatch):
+    # Regression: a relative source path must be resolved against the
+    # project root, not the current working directory.
+    monkeypatch.chdir(tmp_path)
+    actual = [c for c in compiler.compile(("contracts/CompilesOnce.sol",), project=project)]
+    assert len(actual) == 1
+    assert actual[0].name == "CompilesOnce"
+    assert actual[0].source_id == "contracts/CompilesOnce.sol"
+
+
+def test_compile_missing_source_raises_clear_error(project, compiler, monkeypatch):
+    monkeypatch.chdir(project.path)
+    with pytest.raises(CompilerError, match=r"not found in .*project path:"):
+        list(compiler.compile(("contracts/DoesNotExist.sol",), project=project))