diff --git a/crates/codescythe/analyze.rs b/crates/codescythe/analyze.rs
index 54c0837..6ab7e98 100644
--- a/crates/codescythe/analyze.rs
+++ b/crates/codescythe/analyze.rs
@@ -86,9 +86,10 @@ pub fn analyze_path(
     config: &CodescytheConfig,
     options: AnalysisOptions,
 ) -> Result<Analysis> {
-    let cwd = cwd
-        .canonicalize()
-        .with_context(|| format!("failed to resolve {}", cwd.display()))?;
+    let cwd = normalize_path(cwd);
+    if !cwd.exists() {
+        anyhow::bail!("analysis root does not exist: {}", cwd.display());
+    }
     let project_files = discover_project_files(&cwd, config)?;
     let entry_files = discover_entry_files(&cwd, config, &project_files)?;
     let entry_set = entry_files.iter().cloned().collect::<HashSet<_>>();
diff --git a/crates/codescythe_cli/BUILD.bazel b/crates/codescythe_cli/BUILD.bazel
index 8602813..738dc4d 100644
--- a/crates/codescythe_cli/BUILD.bazel
+++ b/crates/codescythe_cli/BUILD.bazel
@@ -1,4 +1,5 @@
 load("@rules_rs//rs:rust_binary.bzl", "rust_binary")
+load("@rules_rs//rs:rust_test.bzl", "rust_test")
 load(
     ":release_binary.bzl",
     "release_binary_darwin_arm64",
@@ -20,6 +21,19 @@ rust_binary(
     ],
 )
 
+rust_test(
+    name = "codescythe_cli_test",
+    srcs = ["main.rs"],
+    crate_name = "codescythe_cli_test",
+    edition = "2024",
+    deps = [
+        "//crates/codescythe",
+        "@crates//:anyhow",
+        "@crates//:clap",
+        "@crates//:serde_json",
+    ],
+)
+
 release_binary_linux_amd64(
     name = "release_binary_linux_amd64",
     srcs = [":codescythe"],
diff --git a/crates/codescythe_cli/main.rs b/crates/codescythe_cli/main.rs
index a24b5c3..d538bcc 100644
--- a/crates/codescythe_cli/main.rs
+++ b/crates/codescythe_cli/main.rs
@@ -1,4 +1,8 @@
-use std::{path::PathBuf, process::ExitCode};
+use std::{
+    env,
+    path::{Path, PathBuf},
+    process::ExitCode,
+};
 
 use anyhow::Result;
 use clap::Parser;
@@ -9,8 +13,8 @@ struct Args {
     #[arg(short, long)]
     config: Option<PathBuf>,
 
-    #[arg(short = 'C', long, default_value = ".")]
-    directory: PathBuf,
+    #[arg(short = 'C', long)]
+    directory: Option<PathBuf>,
 
     #[arg(long)]
     fix: bool,
@@ -40,8 +44,8 @@ fn main() -> ExitCode {
 
 fn run() -> Result<bool> {
     let args = Args::parse();
-    let cwd = args.directory.canonicalize()?;
     let config = args.config.as_deref();
+    let cwd = analysis_root(args.directory.as_deref(), config)?;
 
     if args.fix {
         let result = codescythe::run_and_fix(&cwd, config)?;
@@ -119,3 +123,43 @@ fn print_text_report(analysis: &codescythe::Analysis) {
         }
     }
 }
+
+fn analysis_root(directory: Option<&Path>, config: Option<&Path>) -> Result<PathBuf> {
+    if let Some(directory) = directory {
+        return Ok(directory.to_path_buf());
+    }
+
+    if let Some(parent) = config
+        .and_then(Path::parent)
+        .filter(|parent| !parent.as_os_str().is_empty())
+    {
+        return Ok(parent.to_path_buf());
+    }
+
+    Ok(env::current_dir()?)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn derives_analysis_root_from_config_parent_without_directory() {
+        let root = Path::new("/tmp/runfiles/_main");
+        let config = root.join("codescythe.json");
+
+        let analysis_root = analysis_root(None, Some(&config)).unwrap();
+
+        assert_eq!(analysis_root, root);
+    }
+
+    #[test]
+    fn explicit_directory_overrides_config_parent() {
+        let directory = Path::new("/tmp/runfiles/_main");
+        let config = Path::new("/tmp/runfiles/_main/pplx/frontend/codescythe.json");
+
+        let analysis_root = analysis_root(Some(directory), Some(config)).unwrap();
+
+        assert_eq!(analysis_root, directory);
+    }
+}
diff --git a/crates/codescythe_napi/lib.rs b/crates/codescythe_napi/lib.rs
index a3a39aa..34ad95d 100644
--- a/crates/codescythe_napi/lib.rs
+++ b/crates/codescythe_napi/lib.rs
@@ -13,8 +13,8 @@ pub struct RunOptions {
 #[napi]
 pub fn analyze(options: Option<RunOptions>) -> napi::Result<String> {
     let options = options.unwrap_or_default();
-    let cwd = cwd(options.cwd)?;
     let config = options.config.as_deref().map(PathBuf::from);
+    let cwd = cwd(options.cwd, config.as_deref())?;
     let analysis = codescythe::run(&cwd, config.as_deref()).map_err(to_napi_error)?;
     serde_json::to_string(&analysis).map_err(to_napi_error)
 }
@@ -22,8 +22,8 @@ pub fn analyze(options: Option<RunOptions>) -> napi::Result<String> {
 #[napi]
 pub fn fix(options: Option<RunOptions>) -> napi::Result<String> {
     let options = options.unwrap_or_default();
-    let cwd = cwd(options.cwd)?;
     let config = options.config.as_deref().map(PathBuf::from);
+    let cwd = cwd(options.cwd, config.as_deref())?;
     let result = codescythe::run_and_fix(&cwd, config.as_deref()).map_err(to_napi_error)?;
     serde_json::to_string(&result).map_err(to_napi_error)
 }
@@ -38,10 +38,15 @@ impl Default for RunOptions {
     }
 }
 
-fn cwd(value: Option<String>) -> napi::Result<PathBuf> {
+fn cwd(value: Option<String>, config: Option<&std::path::Path>) -> napi::Result<PathBuf> {
     match value {
         Some(path) => Ok(PathBuf::from(path)),
-        None => std::env::current_dir().map_err(to_napi_error),
+        None => config
+            .and_then(std::path::Path::parent)
+            .filter(|parent| !parent.as_os_str().is_empty())
+            .map(PathBuf::from)
+            .map(Ok)
+            .unwrap_or_else(|| std::env::current_dir().map_err(to_napi_error)),
     }
 }
 
diff --git a/packages/codescythe/npm_smoke.ts b/packages/codescythe/npm_smoke.ts
index 7734101..624017b 100644
--- a/packages/codescythe/npm_smoke.ts
+++ b/packages/codescythe/npm_smoke.ts
@@ -15,11 +15,11 @@ type Analysis = {
 };
 
 type NativeBinding = {
-  analyze(options: {cwd: string}): string;
+  analyze(options: {config?: string; cwd?: string}): string;
 };
 
 type Codescythe = {
-  analyze(options: {cwd: string}): Analysis;
+  analyze(options: {config?: string; cwd?: string}): Analysis;
 };
 
 const repoRoot = process.cwd();
@@ -53,6 +53,12 @@ describe('@perplexity/codescythe npm package', () => {
     assertFixtureAnalysis(analysis);
   });
 
+  it('uses the config parent as the cwd when cwd is omitted', () => {
+    const codescythe = smokeRequire('@perplexity/codescythe') as Codescythe;
+    const analysis = codescythe.analyze({config: path.join(fixture, 'codescythe.json')});
+    assertFixtureAnalysis(analysis);
+  });
+
   it('runs the public package bin', () => {
     const binResult = childProcess.spawnSync(
       process.execPath,
@@ -75,6 +81,29 @@ describe('@perplexity/codescythe npm package', () => {
     assert.equal(binResult.status, 1, binResult.stderr || binResult.stdout);
     assertFixtureAnalysis(JSON.parse(binResult.stdout) as Analysis);
   });
+
+  it('runs the public package bin from the config parent', () => {
+    const binResult = childProcess.spawnSync(
+      process.execPath,
+      [
+        '--experimental-transform-types',
+        path.join(mainPackageDir, 'bin/codescythe.ts'),
+        '--json',
+        '--config',
+        path.join(fixture, 'codescythe.json'),
+      ],
+      {
+        encoding: 'utf8',
+        env: {
+          ...process.env,
+          NODE_PATH: nodeModules,
+        },
+      },
+    );
+
+    assert.equal(binResult.status, 1, binResult.stderr || binResult.stdout);
+    assertFixtureAnalysis(JSON.parse(binResult.stdout) as Analysis);
+  });
 });
 
 function packageDirFromEnv(name: string): string {