diff --git a/review-enrichment/src/analyzers/complexity-delta.ts b/review-enrichment/src/analyzers/complexity-delta.ts
index a8536d54ea..3431e62766 100644
--- a/review-enrichment/src/analyzers/complexity-delta.ts
+++ b/review-enrichment/src/analyzers/complexity-delta.ts
@@ -27,7 +27,9 @@
 // that file, never a crash -- checked via plain truthiness, NEVER a strict `=== null` compare (see
 // reconstruct-old-content.ts's own doc comment: an empty string is falsy but `!== null`, so a strict-null check
 // would wrongly treat a brand-new file's "" as valid before-content).
-import type { EnrichRequest, ComplexityDeltaFinding } from "../types.js";
+import type { AnalyzerDiagnostics, EnrichRequest, ComplexityDeltaFinding } from "../types.js";
+import type { AnalysisContext } from "../analysis-context.js";
+import { boundedFetchText } from "../external-fetch.js";
 import { githubHeaders } from "../github-headers.js";
 import { reconstructOldContent } from "./reconstruct-old-content.js";
 import { isJsTsPath, scanContentForComplexity } from "./complexity.js";
@@ -41,36 +43,13 @@ const MAX_FETCH_BYTES = 1_000_000;
 
 interface ScanOptions {
   signal?: AbortSignal;
+  analysis?: Pick<AnalysisContext, "fetchText">;
+  diagnostics?: AnalyzerDiagnostics;
 }
 
-async function readBoundedText(resp: Response, signal?: AbortSignal): Promise<string | null> {
-  const length = Number(resp.headers.get("content-length"));
-  if (Number.isFinite(length) && length > MAX_FETCH_BYTES) return null;
-  if (!resp.body) return null;
-
-  const reader = resp.body.getReader();
-  const decoder = new TextDecoder();
-  let size = 0;
-  let text = "";
-  try {
-    while (true) {
-      if (signal?.aborted) return null;
-      const { done, value } = await reader.read();
-      if (done) break;
-      size += value.byteLength;
-      if (size > MAX_FETCH_BYTES) {
-        await reader.cancel();
-        return null;
-      }
-      text += decoder.decode(value, { stream: true });
-    }
-    text += decoder.decode();
-    return text;
-  } finally {
-    reader.releaseLock();
-  }
-}
-
+/** Fetch a changed file's raw content at `headSha` through the shared bounded-text helper (#4759) — with the
+ *  analysis context's caching/metering when supplied, mirroring `duplication-delta.ts`'s own `fetchFileAtHead`.
+ *  Returns null on any non-OK / oversized / network outcome so the caller fails safe. */
 async function fetchFileAtHeadSha(
   owner: string,
   repo: string,
@@ -78,19 +57,25 @@ async function fetchFileAtHeadSha(
   headSha: string,
   token: string,
   fetchFn: typeof fetch,
-  signal: AbortSignal | undefined,
+  options: ScanOptions,
 ): Promise<string | null> {
-  try {
-    const encoded = path.split("/").map(encodeURIComponent).join("/");
-    const resp = await fetchFn(
-      `${GITHUB_API}/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/contents/${encoded}?ref=${encodeURIComponent(headSha)}`,
-      { headers: githubHeaders(token, { raw: true }), signal },
-    );
-    if (!resp.ok) return null;
-    return await readBoundedText(resp, signal);
-  } catch {
-    return null;
-  }
+  const encoded = path.split("/").map(encodeURIComponent).join("/");
+  const url = `${GITHUB_API}/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/contents/${encoded}?ref=${encodeURIComponent(headSha)}`;
+  const fetchOptions = {
+    endpointCategory: "github-contents",
+    headers: githubHeaders(token, { raw: true }),
+    signal: options.signal,
+    fetchImpl: fetchFn,
+    diagnostics: options.diagnostics,
+    phase: "complexityDelta",
+    subcall: "github-contents",
+    maxBytes: MAX_FETCH_BYTES,
+    maxCallsPerCategory: MAX_FILES,
+  };
+  const response = options.analysis
+    ? await options.analysis.fetchText(url, fetchOptions)
+    : await boundedFetchText(url, fetchOptions);
+  return response.ok ? response.data : null;
 }
 
 /** Full-file-scan the reconstructed OLD content and the NEW (head) content of one file with
@@ -155,7 +140,7 @@ export async function scanComplexityDelta(
       headSha,
       githubToken,
       fetchFn,
-      options.signal,
+      options,
     );
     if (!headContent) continue;
     if (options.signal?.aborted) break; // an abort during the fetch should suppress this file's findings too
diff --git a/review-enrichment/src/analyzers/doc-comment-drift.ts b/review-enrichment/src/analyzers/doc-comment-drift.ts
index f8225f8d53..59cc937075 100644
--- a/review-enrichment/src/analyzers/doc-comment-drift.ts
+++ b/review-enrichment/src/analyzers/doc-comment-drift.ts
@@ -5,9 +5,13 @@
 // non-parameter signature edit (return type, name, modifier, parameter type) over PRE-EXISTING stale docs a
 // non-finding. Deliberately conservative: only NAMED `function` declarations whose parameters are confidently
 // enumerable (any destructuring / non-identifier param → skip the function). Reports symbol + stale params + line.
-import type { EnrichRequest, DocCommentDriftFinding } from "../types.js";
+import type { AnalyzerDiagnostics, EnrichRequest, DocCommentDriftFinding } from "../types.js";
+import type { AnalysisContext } from "../analysis-context.js";
+import { boundedFetchText } from "../external-fetch.js";
+import { githubHeaders } from "../github-headers.js";
 import { reconstructOldContent } from "./reconstruct-old-content.js";
 
+const GITHUB_API = "https://api.github.com";
 const MAX_FILES = 20;
 const MAX_FINDINGS = 50;
 const MAX_SIGNATURE_LINES = 40;
@@ -22,34 +26,39 @@ const FUNC_DECL_RE = /^\s*(?:export\s+)?(?:default\s+)?(?:async\s+)?function\s*\
 
 interface ScanOptions {
   signal?: AbortSignal;
+  analysis?: Pick<AnalysisContext, "fetchText">;
+  diagnostics?: AnalyzerDiagnostics;
 }
 
-async function readBoundedText(resp: Response, signal?: AbortSignal): Promise<string | null> {
-  const length = Number(resp.headers.get("content-length"));
-  if (Number.isFinite(length) && length > MAX_FETCH_BYTES) return null;
-  if (!resp.body) return null;
-
-  const reader = resp.body.getReader();
-  const decoder = new TextDecoder();
-  let size = 0;
-  let text = "";
-  try {
-    while (true) {
-      if (signal?.aborted) return null;
-      const { done, value } = await reader.read();
-      if (done) break;
-      size += value.byteLength;
-      if (size > MAX_FETCH_BYTES) {
-        await reader.cancel();
-        return null;
-      }
-      text += decoder.decode(value, { stream: true });
-    }
-    text += decoder.decode();
-    return text;
-  } finally {
-    reader.releaseLock();
-  }
+/** Fetch a changed file's raw content at `headSha` through the shared bounded-text helper (#4759) — with the
+ *  analysis context's caching/metering when supplied, mirroring `duplication-delta.ts`'s own `fetchFileAtHead`.
+ *  Returns null on any non-OK / oversized / network outcome so the caller fails safe. */
+async function fetchFileAtHead(
+  owner: string,
+  repo: string,
+  path: string,
+  headSha: string,
+  token: string,
+  fetchFn: typeof fetch,
+  options: ScanOptions,
+): Promise<string | null> {
+  const encoded = path.split("/").map(encodeURIComponent).join("/");
+  const url = `${GITHUB_API}/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/contents/${encoded}?ref=${encodeURIComponent(headSha)}`;
+  const fetchOptions = {
+    endpointCategory: "github-contents",
+    headers: githubHeaders(token, { raw: true }),
+    signal: options.signal,
+    fetchImpl: fetchFn,
+    diagnostics: options.diagnostics,
+    phase: "docCommentDrift",
+    subcall: "github-contents",
+    maxBytes: MAX_FETCH_BYTES,
+    maxCallsPerCategory: MAX_FILES,
+  };
+  const response = options.analysis
+    ? await options.analysis.fetchText(url, fetchOptions)
+    : await boundedFetchText(url, fetchOptions);
+  return response.ok ? response.data : null;
 }
 
 /** Map every named `function NAME` declaration in `content` to its enumerable parameter-name set. A function whose
@@ -312,11 +321,6 @@ export async function scanDocCommentDrift(
   const repo = parts[1];
   if (parts.length !== 2 || !owner || !repo || !SLUG_RE.test(owner) || !SLUG_RE.test(repo)) return [];
 
-  const headers: Record<string, string> = {
-    Authorization: `Bearer ${githubToken}`,
-    Accept: "application/vnd.github.raw",
-    "X-GitHub-Api-Version": "2022-11-28",
-  };
   const sources = files
     .filter((file) => file.patch && SOURCE_RE.test(file.path) && !SKIP_RE.test(file.path))
     .slice(0, MAX_FILES);
@@ -325,17 +329,7 @@ export async function scanDocCommentDrift(
   for (const file of sources) {
     if (options.signal?.aborted) break;
 
-    let content: string | null = null;
-    try {
-      const path = file.path.split("/").map(encodeURIComponent).join("/");
-      const resp = await fetchFn(
-        `https://api.github.com/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/contents/${path}?ref=${encodeURIComponent(headSha)}`,
-        { headers, signal: options.signal },
-      );
-      if (resp.ok) content = await readBoundedText(resp, options.signal);
-    } catch {
-      content = null;
-    }
+    const content = await fetchFileAtHead(owner, repo, file.path, headSha, githubToken, fetchFn, options);
     if (!content) continue;
     if (options.signal?.aborted) break; // an abort during the fetch should suppress this file's findings too
 
diff --git a/review-enrichment/src/analyzers/exhaustiveness-drift.ts b/review-enrichment/src/analyzers/exhaustiveness-drift.ts
index 2bf64252eb..26800ed311 100644
--- a/review-enrichment/src/analyzers/exhaustiveness-drift.ts
+++ b/review-enrichment/src/analyzers/exhaustiveness-drift.ts
@@ -3,7 +3,9 @@
 // files and other changed consumer files at headSha (injected fetch), reverse-applies the patch to recover the
 // pre-PR member set, and only reports high-confidence misses (explicit enum/union cases, no default branch). Bounded
 // file-fetch caps; fail-safe on missing token/headSha, bad slug, or fetch errors.
-import type { EnrichRequest, ExhaustivenessFinding } from "../types.js";
+import type { AnalyzerDiagnostics, EnrichRequest, ExhaustivenessFinding } from "../types.js";
+import type { AnalysisContext } from "../analysis-context.js";
+import { boundedFetchText } from "../external-fetch.js";
 import { githubHeaders } from "../github-headers.js";
 import { reconstructOldContent } from "./reconstruct-old-content.js";
 import { isDiffFileHeaderLine } from "./diff-lines.js";
@@ -28,6 +30,8 @@ const DEFAULT_CASE_RE = /^\s*default\s*:/;
 
 interface ScanOptions {
   signal?: AbortSignal;
+  analysis?: Pick<AnalysisContext, "fetchText">;
+  diagnostics?: AnalyzerDiagnostics;
 }
 
 interface AddedMemberCandidate {
@@ -46,33 +50,9 @@ function isScannablePath(path: string): boolean {
   return SOURCE_RE.test(path) && !SKIP_RE.test(path) && !isTestPath(path);
 }
 
-async function readBoundedText(resp: Response, signal?: AbortSignal): Promise<string | null> {
-  const length = Number(resp.headers.get("content-length"));
-  if (Number.isFinite(length) && length > MAX_FETCH_BYTES) return null;
-  if (!resp.body) return null;
-  const reader = resp.body.getReader();
-  const decoder = new TextDecoder();
-  let size = 0;
-  let text = "";
-  try {
-    while (true) {
-      if (signal?.aborted) return null;
-      const { done, value } = await reader.read();
-      if (done) break;
-      size += value.byteLength;
-      if (size > MAX_FETCH_BYTES) {
-        await reader.cancel();
-        return null;
-      }
-      text += decoder.decode(value, { stream: true });
-    }
-    text += decoder.decode();
-    return text;
-  } finally {
-    reader.releaseLock();
-  }
-}
-
+/** Fetch a changed file's raw content at `headSha` through the shared bounded-text helper (#4759) — with the
+ *  analysis context's caching/metering when supplied, mirroring `duplication-delta.ts`'s own `fetchFileAtHead`.
+ *  Returns null on any non-OK / oversized / network outcome so the caller fails safe. */
 async function fetchFileAtHead(
   owner: string,
   repo: string,
@@ -80,19 +60,25 @@ async function fetchFileAtHead(
   headSha: string,
   token: string,
   fetchFn: typeof fetch,
-  signal: AbortSignal | undefined,
+  options: ScanOptions,
 ): Promise<string | null> {
-  try {
-    const encoded = path.split("/").map(encodeURIComponent).join("/");
-    const resp = await fetchFn(
-      `${GITHUB_API}/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/contents/${encoded}?ref=${encodeURIComponent(headSha)}`,
-      { headers: githubHeaders(token, { raw: true }), signal },
-    );
-    if (!resp.ok) return null;
-    return await readBoundedText(resp, signal);
-  } catch {
-    return null;
-  }
+  const encoded = path.split("/").map(encodeURIComponent).join("/");
+  const url = `${GITHUB_API}/repos/${encodeURIComponent(owner)}/${encodeURIComponent(repo)}/contents/${encoded}?ref=${encodeURIComponent(headSha)}`;
+  const fetchOptions = {
+    endpointCategory: "github-contents",
+    headers: githubHeaders(token, { raw: true }),
+    signal: options.signal,
+    fetchImpl: fetchFn,
+    diagnostics: options.diagnostics,
+    phase: "exhaustiveness",
+    subcall: "github-contents",
+    maxBytes: MAX_FETCH_BYTES,
+    maxCallsPerCategory: MAX_FETCHES,
+  };
+  const response = options.analysis
+    ? await options.analysis.fetchText(url, fetchOptions)
+    : await boundedFetchText(url, fetchOptions);
+  return response.ok ? response.data : null;
 }
 
 /** Walk a unified diff and collect newly added enum/union members with their declaring type name and new-file line. */
@@ -296,7 +282,7 @@ export async function scanExhaustivenessDrift(
       return null;
     }
     fetches += 1;
-    const content = await fetchFileAtHead(owner, repo, path, headSha, githubToken, fetchFn, options.signal);
+    const content = await fetchFileAtHead(owner, repo, path, headSha, githubToken, fetchFn, options);
     contentCache.set(path, content);
     return content;
   };
diff --git a/review-enrichment/test/complexity-delta.test.ts b/review-enrichment/test/complexity-delta.test.ts
index f195ba52b3..b80b8b011f 100644
--- a/review-enrichment/test/complexity-delta.test.ts
+++ b/review-enrichment/test/complexity-delta.test.ts
@@ -204,7 +204,10 @@ test("scanComplexityDelta: stops on an already-aborted signal", async () => {
 
 test("scanComplexityDelta: an abort that becomes true before the body read begins yields no findings for that file", async () => {
   // The signal is still false when the per-file loop's pre-fetch check runs, but flips true INSIDE the fetch
-  // itself -- readBoundedText's own first internal check (not the outer one) must catch this.
+  // itself, before the Response is even returned. The shared boundedFetchText helper (#4759) has no signal-polling
+  // of its own inside its read loop -- it just reads whatever Response the mocked fetchImpl hands back, which
+  // succeeds here regardless of the signal's state -- so it's the loop's OWN post-fetch check that must catch the
+  // now-true signal and discard this file's content.
   const abortController = new AbortController();
   const out = await scanComplexityDelta(
     baseReq([{ path: "src/a.ts", patch: CALC_PATCH }]),
@@ -218,9 +221,10 @@ test("scanComplexityDelta: an abort that becomes true before the body read begin
 });
 
 test("scanComplexityDelta: an abort that fires only after a file's content is fully read stops further files", async () => {
-  // The signal flips true DURING the body read's final chunk (after readBoundedText's last internal check already
-  // passed), so readBoundedText itself returns the content successfully -- the OUTER post-fetch check must still
-  // catch it and stop before a second file is ever fetched.
+  // The signal flips true DURING the body read's final chunk. The shared boundedFetchText helper (#4759) has no
+  // signal-polling of its own inside its read loop, so it finishes reading this (mocked, in-memory) stream and
+  // returns the content successfully -- the loop's OWN post-fetch check must still catch it and stop before a
+  // second file is ever fetched.
   const abortController = new AbortController();
   let fetchCalls = 0;
   const out = await scanComplexityDelta(
@@ -297,6 +301,36 @@ test("scanComplexityDelta: respects the findings cap across files and stops fetc
   assert.equal(fetchCalls, 1); // the cap was hit mid-file-1, so file 2 is never fetched
 });
 
+test("scanComplexityDelta: uses the analysis-context fetchText when supplied, instead of the bare fetch path", async () => {
+  // #4759: the file-content fetch now goes through the shared boundedFetchText helper, which prefers
+  // options.analysis.fetchText (mirrors duplication-delta.ts's own fetchFileAtHead) when an AnalysisContext is
+  // supplied — the raw fetchFn passed as the second positional arg must never be invoked in that case.
+  let analysisCalls = 0;
+  const analysis = {
+    fetchText: async (_url, _opts) => {
+      analysisCalls += 1;
+      return {
+        ok: true,
+        status: 200,
+        data: HEAD_CONTENT,
+        bytes: HEAD_CONTENT.length,
+        elapsedMs: 0,
+        endpointCategory: "github-contents",
+      };
+    },
+  };
+  const findings = await scanComplexityDelta(
+    baseReq([{ path: "src/calc.ts", patch: CALC_PATCH }]),
+    async () => {
+      throw new Error("bare fetch should not be used when analysis.fetchText is supplied");
+    },
+    { analysis },
+  );
+  assert.equal(analysisCalls, 1);
+  assert.equal(findings.length, 1);
+  assert.deepEqual(findings[0], { file: "src/calc.ts", line: 1, name: "calc", before: 5, after: 2, delta: -3 });
+});
+
 test("renderBrief emits a public-safe complexity-delta block", () => {
   const { promptSection } = renderBrief({
     complexityDelta: [{ file: "src/calc.ts", line: 1, name: "calc", before: 5, after: 2, delta: -3 }],
diff --git a/review-enrichment/test/doc-comment-drift.test.ts b/review-enrichment/test/doc-comment-drift.test.ts
index 05800d3c7c..384cd9fc86 100644
--- a/review-enrichment/test/doc-comment-drift.test.ts
+++ b/review-enrichment/test/doc-comment-drift.test.ts
@@ -341,6 +341,29 @@ test("scanDocCommentDrift: stops on an already-aborted signal", async () => {
   assert.deepEqual(out, []);
 });
 
+test("scanDocCommentDrift: uses the analysis-context fetchText when supplied, instead of the bare fetch path", async () => {
+  // #4759: the file-content fetch now goes through the shared boundedFetchText helper, which prefers
+  // options.analysis.fetchText (mirrors duplication-delta.ts's own fetchFileAtHead) when an AnalysisContext is
+  // supplied — the raw fetchFn passed as the second positional arg must never be invoked in that case.
+  let analysisCalls = 0;
+  const analysis = {
+    fetchText: async (_url, _opts) => {
+      analysisCalls += 1;
+      return { ok: true, status: 200, data: DRIFTED, bytes: DRIFTED.length, elapsedMs: 0, endpointCategory: "github-contents" };
+    },
+  };
+  const findings = await scanDocCommentDrift(
+    baseReq([{ path: "src/a.ts", patch: DRIFT_PATCH }]),
+    async () => {
+      throw new Error("bare fetch should not be used when analysis.fetchText is supplied");
+    },
+    { analysis },
+  );
+  assert.equal(analysisCalls, 1);
+  assert.equal(findings.length, 1);
+  assert.deepEqual(findings[0].staleParams, ["oldName"]);
+});
+
 test("renderBrief emits a public-safe doc-comment-drift block", () => {
   const { promptSection } = renderBrief({
     docCommentDrift: [{ file: "src/a.ts", line: 4, symbol: "doThing", staleParams: ["oldName"] }],
diff --git a/review-enrichment/test/exhaustiveness-drift.test.ts b/review-enrichment/test/exhaustiveness-drift.test.ts
index a3b1884ee6..afdb0a9980 100644
--- a/review-enrichment/test/exhaustiveness-drift.test.ts
+++ b/review-enrichment/test/exhaustiveness-drift.test.ts
@@ -152,6 +152,37 @@ test("scanExhaustivenessDrift: enforces the maxFetches cap", async () => {
   assert.equal(fetches, 10);
 });
 
+test("scanExhaustivenessDrift: uses the analysis-context fetchText when supplied, instead of the bare fetch path", async () => {
+  // #4759: the file-content fetch now goes through the shared boundedFetchText helper, which prefers
+  // options.analysis.fetchText (mirrors duplication-delta.ts's own fetchFileAtHead) when an AnalysisContext is
+  // supplied — the raw fetchFn passed as the second positional arg must never be invoked in that case.
+  let analysisCalls = 0;
+  const analysis = {
+    fetchText: async (_url, _opts) => {
+      analysisCalls += 1;
+      return {
+        ok: true,
+        status: 200,
+        data: HEAD_UNCOVERED,
+        bytes: HEAD_UNCOVERED.length,
+        elapsedMs: 0,
+        endpointCategory: "github-contents",
+      };
+    },
+  };
+  const findings = await scanExhaustivenessDrift(
+    req([{ path: "src/status.ts", status: "modified", patch: PATCH_ADD_ARCHIVED }]),
+    async () => {
+      throw new Error("bare fetch should not be used when analysis.fetchText is supplied");
+    },
+    { analysis },
+  );
+  assert.equal(analysisCalls, 1);
+  assert.deepEqual(findings, [
+    { file: "src/status.ts", line: 4, unionName: "Status", addedMember: "Archived" },
+  ]);
+});
+
 test("scanExhaustivenessDrift: returns no findings without a GitHub token", async () => {
   const findings = await scanExhaustivenessDrift(
     req([{ path: "src/status.ts", status: "modified", patch: PATCH_ADD_ARCHIVED }], {