diff --git a/packages/core/src/analysis/aggregate.ts b/packages/core/src/analysis/aggregate.ts
index 1c3fbac..2087622 100644
--- a/packages/core/src/analysis/aggregate.ts
+++ b/packages/core/src/analysis/aggregate.ts
@@ -1,10 +1,6 @@
 import type { CoreAnalysis, CoreAnalysisInput } from '../types/core.js';
 import type { PluginResult } from '../types/plugin.js';
-import { firstNonEmptyLine } from '../utils/text.js';
-
-function unique(values: string[]): string[] {
-  return [...new Set(values.filter((value) => value.trim().length > 0))];
-}
+import { firstNonEmptyLine, uniqueNonEmptyStrings } from '../utils/text.js';
 
 function pickLeadResult(
   pluginResults: PluginResult<unknown, unknown>[],
@@ -50,7 +46,7 @@ function buildLikelyCauses(
     );
   }
 
-  return unique(causes).slice(0, 5);
+  return uniqueNonEmptyStrings(causes).slice(0, 5);
 }
 
 function buildNextSteps(
@@ -70,7 +66,10 @@ function buildNextSteps(
       : 'Re-run the command with more verbose logging if the failure is still ambiguous.',
   ];
 
-  return unique([...pluginSuggestions, ...genericSteps]).slice(0, 6);
+  return uniqueNonEmptyStrings([...pluginSuggestions, ...genericSteps]).slice(
+    0,
+    6,
+  );
 }
 
 export function aggregateCoreAnalysis(
@@ -85,7 +84,7 @@ export function aggregateCoreAnalysis(
     keySnippet: leadResult?.keySnippet ?? input.signals.snippet,
     likelyCauses: buildLikelyCauses(input, pluginResults),
     nextSteps: buildNextSteps(input, pluginResults),
-    relatedFiles: unique([
+    relatedFiles: uniqueNonEmptyStrings([
       ...input.signals.relatedFiles,
       ...pluginResults.flatMap((result) => result.relatedFiles ?? []),
     ]).slice(0, 10),
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index 132f692..88483e1 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -49,5 +49,12 @@ export {
 } from './utils/fs.js';
 export { shortHash } from './utils/hash.js';
 export { toJson } from './utils/json.js';
+export {
+  firstNonEmptyLine,
+  normalizeDiagnosticMessage,
+  readAnalysisLogText,
+  unique,
+  uniqueNonEmptyStrings,
+} from './utils/text.js';
 export type { E2FPaths } from './utils/paths.js';
 export { getE2FPaths } from './utils/paths.js';
diff --git a/packages/core/src/parser/extract.ts b/packages/core/src/parser/extract.ts
index bb62d13..74d5307 100644
--- a/packages/core/src/parser/extract.ts
+++ b/packages/core/src/parser/extract.ts
@@ -1,3 +1,4 @@
+import { unique } from '../utils/text.js';
 import type {
   CandidateSnippet,
   ExtractedSignals,
@@ -10,10 +11,6 @@ const FILE_PATTERN =
 const GENERIC_PATH_PATTERN =
   /(?:^|[\s("'`])((?:\.{0,2}\/)?(?:[\w@%+=:,.-]+\/)+[\w@%+=,.-]+)(?:[:(]\d+(?::\d+)?)?/g;
 
-function unique<T>(values: T[]): T[] {
-  return [...new Set(values)];
-}
-
 function scoreSegment(segment: LogSegment): number {
   const text = segment.text;
   let score = 0;
diff --git a/packages/core/src/utils/text.ts b/packages/core/src/utils/text.ts
index 63cec42..67eb9dc 100644
--- a/packages/core/src/utils/text.ts
+++ b/packages/core/src/utils/text.ts
@@ -25,3 +25,7 @@ export function readAnalysisLogText(input: CoreAnalysisInput): string {
 export function unique<T>(values: T[]): T[] {
   return [...new Set(values)];
 }
+
+export function uniqueNonEmptyStrings(values: string[]): string[] {
+  return unique(values.filter((value) => value.trim().length > 0));
+}
diff --git a/packages/mcp/src/tools/tool-utils.ts b/packages/mcp/src/tools/tool-utils.ts
index 6cbee47..568bda9 100644
--- a/packages/mcp/src/tools/tool-utils.ts
+++ b/packages/mcp/src/tools/tool-utils.ts
@@ -1,3 +1,7 @@
+import { uniqueNonEmptyStrings } from '@error2fix/core';
+
+export const unique = uniqueNonEmptyStrings;
+
 export function makeToolText(result: {
   ok: boolean;
   error?: { message: string };
@@ -25,10 +29,6 @@ export function truncate(
   return `${text.slice(0, Math.max(0, maxChars - 3)).trimEnd()}...`;
 }
 
-export function unique(values: string[]): string[] {
-  return [...new Set(values.filter((value) => value.trim().length > 0))];
-}
-
 function scoreFailureExcerpt(
   excerpt: string,
   relatedFiles: string[],