diff --git a/docs/contributing/api-patterns.md b/docs/contributing/api-patterns.md
index ecbb46607..58e592be4 100644
--- a/docs/contributing/api-patterns.md
+++ b/docs/contributing/api-patterns.md
@@ -63,6 +63,11 @@ await api.issues.update({
 });
 ```
 
+### Resolved Issue IDs
+
+Use `String(issue.id)` for API requests after resolving an issue. Short IDs can
+fail to resolve for legacy mixed-case project slugs; keep them for display.
+
 ### Multi-Region Support
 
 Sentry uses region-specific URLs:
diff --git a/packages/mcp-core/src/tools/catalog/get-issue-details.numeric-id.test.ts b/packages/mcp-core/src/tools/catalog/get-issue-details.numeric-id.test.ts
new file mode 100644
index 000000000..506553756
--- /dev/null
+++ b/packages/mcp-core/src/tools/catalog/get-issue-details.numeric-id.test.ts
@@ -0,0 +1,95 @@
+import {
+  autofixStateFixture,
+  eventsFixture,
+  issueFixture,
+  mswServer,
+} from "@sentry/mcp-server-mocks";
+import { http, HttpResponse } from "msw";
+import { describe, expect, it } from "vitest";
+import getIssueDetails from "./get-issue-details";
+import getSentryResource from "./get-sentry-resource";
+
+const organizationSlug = "sentry-mcp-evals";
+const issueId = String(issueFixture.id);
+const eventId = eventsFixture.id;
+const issueUrl = `https://${organizationSlug}.sentry.io/issues/${issueId}/`;
+const context = {
+  constraints: { organizationSlug: undefined },
+  accessToken: "access-token",
+  userId: "1",
+};
+
+describe("issue details with an unresolvable short ID", () => {
+  it.each([
+    {
+      name: "numeric issue ID",
+      call: () =>
+        getIssueDetails.handler(
+          { organizationSlug, issueId, regionUrl: null },
+          context,
+        ),
+    },
+    {
+      name: "issue URL",
+      call: () =>
+        getIssueDetails.handler({ issueUrl, regionUrl: null }, context),
+    },
+    {
+      name: "numeric issue ID and explicit event ID",
+      call: () =>
+        getIssueDetails.handler(
+          { organizationSlug, issueId, eventId, regionUrl: null },
+          context,
+        ),
+    },
+    {
+      name: "event ID resolved through issue search",
+      call: () =>
+        getIssueDetails.handler(
+          { organizationSlug, eventId, regionUrl: null },
+          context,
+        ),
+    },
+    {
+      name: "resource issue URL",
+      call: () => getSentryResource.handler({ url: issueUrl }, context),
+    },
+    {
+      name: "resource event URL",
+      call: () =>
+        getSentryResource.handler(
+          { url: `${issueUrl}events/${eventId}/` },
+          context,
+        ),
+    },
+  ])("loads $name and enrichment by numeric ID", async ({ call }) => {
+    const base = `https://sentry.io/api/0/organizations/${organizationSlug}`;
+    mswServer.use(
+      http.get(`${base}/issues/`, () => HttpResponse.json([issueFixture])),
+      http.get(`${base}/issues/${issueFixture.shortId}/*`, () =>
+        HttpResponse.json({ detail: "Not found" }, { status: 404 }),
+      ),
+      http.get(`${base}/issues/${issueId}/autofix/`, () =>
+        HttpResponse.json(autofixStateFixture),
+      ),
+      http.get(`${base}/issues/${issueId}/external-issues/`, () =>
+        HttpResponse.json([
+          {
+            id: "123",
+            issueId,
+            serviceType: "github",
+            displayName: "example/app#123",
+            webUrl: "https://github.com/example/app/issues/123",
+          },
+        ]),
+      ),
+    );
+
+    const result = await call();
+
+    expect(result).toContain(`Issue ${issueFixture.shortId}`);
+    expect(result).toContain(eventsFixture.id);
+    expect(result).toContain("## Seer Analysis");
+    expect(result).toContain("**example/app#123** (github)");
+  });
+});
diff --git a/packages/mcp-core/src/tools/catalog/get-issue-details.test.ts b/packages/mcp-core/src/tools/catalog/get-issue-details.test.ts
index 8715c80ed..abbb465dd 100644
--- a/packages/mcp-core/src/tools/catalog/get-issue-details.test.ts
+++ b/packages/mcp-core/src/tools/catalog/get-issue-details.test.ts
@@ -370,7 +370,7 @@ describe("get_issue_details", () => {
       }
       mswServer.use(
         http.get(
-          `${base}/events/latest/`,
+          `https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/${issue ? issue().id : "6507376925"}/events/latest/`,
           () =>
             HttpResponse.json({
               ...event(),
@@ -411,7 +411,7 @@ describe("get_issue_details", () => {
         { once: true },
       ),
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/PERF-N1-001/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/7890123456/events/latest/",
         () =>
           HttpResponse.json({
             ...createPerformanceEvent(),
@@ -448,7 +448,7 @@ describe("get_issue_details", () => {
   it("keeps the replay note when error events use formatted.content", async () => {
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () =>
           HttpResponse.json({
             ...createDefaultEvent(),
@@ -485,7 +485,7 @@ describe("get_issue_details", () => {
   it("embeds the shared formatter's analysis in the Seer section when present", async () => {
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/autofix/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/autofix/",
         () =>
           HttpResponse.json({
             autofix: { run_id: 7, status: "completed", blocks: [] },
@@ -536,7 +536,7 @@ describe("get_issue_details", () => {
     async ({ status, expected }) => {
       mswServer.use(
         http.get(
-          "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/autofix/",
+          "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/autofix/",
           () =>
             HttpResponse.json({
               autofix: { run_id: 7, status, blocks: [] },
@@ -580,7 +580,7 @@ describe("get_issue_details", () => {
 
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () => HttpResponse.json(event),
         { once: true },
       ),
@@ -712,7 +712,7 @@ describe("get_issue_details", () => {
 
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () => HttpResponse.json(event),
         { once: true },
       ),
@@ -752,7 +752,7 @@ describe("get_issue_details", () => {
 
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () => HttpResponse.json(event),
         { once: true },
       ),
@@ -816,7 +816,7 @@ describe("get_issue_details", () => {
         { once: true },
       ),
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/TEAM-ISSUE-001/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/123456789/events/latest/",
         () => HttpResponse.json(createDefaultEvent()),
         { once: true },
       ),
@@ -840,7 +840,7 @@ describe("get_issue_details", () => {
   it("lists threads and stacktrace lookup guidance only for multi-thread events", async () => {
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () =>
           HttpResponse.json(
             createDefaultEvent({
@@ -936,7 +936,7 @@ describe("get_issue_details", () => {
   it("omits thread list and stacktrace lookup guidance for single-thread events", async () => {
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () =>
           HttpResponse.json(
             createDefaultEvent({
@@ -1005,7 +1005,7 @@ describe("get_issue_details", () => {
 
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () => HttpResponse.json(event),
         { once: true },
       ),
@@ -1175,7 +1175,7 @@ describe("get_issue_details", () => {
         { once: true },
       ),
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/PERF-N1-001/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/7890123456/events/latest/",
         () => {
           // Create event with specific evidence data for this test
           const event = createPerformanceEvent();
@@ -1265,7 +1265,7 @@ describe("get_issue_details", () => {
         { once: true },
       ),
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/PERF-N1-001/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/7890123456/events/latest/",
         () => {
           // Create event with specific evidence data for this test
           const event = createPerformanceEvent();
@@ -1556,7 +1556,7 @@ describe("get_issue_details", () => {
     let autofixRequested = false;
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/autofix/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/autofix/",
         () => {
           autofixRequested = true;
           return HttpResponse.json({ autofix: null });
@@ -1586,7 +1586,7 @@ describe("get_issue_details", () => {
     let autofixRequested = false;
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/autofix/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/autofix/",
         () => {
           autofixRequested = true;
           return HttpResponse.json({ autofix: null });
@@ -1641,7 +1641,7 @@ describe("get_issue_details", () => {
     // Use mswServer.use to prepend a handler - MSW uses LIFO order
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/autofix/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/autofix/",
         () => HttpResponse.json(inProgressFixture),
         { once: true }, // Ensure this handler is only used once for this test
       ),
@@ -1684,7 +1684,7 @@ describe("get_issue_details", () => {
 
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/autofix/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/autofix/",
         () => HttpResponse.json(failedFixture),
         { once: true },
       ),
@@ -1739,7 +1739,7 @@ describe("get_issue_details", () => {
 
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/autofix/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/autofix/",
         () => HttpResponse.json(needsInfoFixture),
         { once: true },
       ),
@@ -1778,7 +1778,7 @@ describe("get_issue_details", () => {
 
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/DEFAULT-001/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/123456/events/latest/",
         () => HttpResponse.json(defaultEvent),
       ),
       http.get(
@@ -1842,7 +1842,7 @@ describe("get_issue_details", () => {
 
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/BLOG-CSP-4XC/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/4256774711/events/latest/",
         () => HttpResponse.json(cspEvent),
       ),
       http.get(
@@ -1924,7 +1924,7 @@ describe("get_issue_details", () => {
           }),
       ),
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/MALFORMED-TAGS-001/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/123456/events/latest/",
         () => HttpResponse.json(eventWithMalformedTags),
       ),
     );
@@ -2014,7 +2014,7 @@ describe("get_issue_details", () => {
         },
       ),
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CONTEXT-001/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/123456/events/latest/",
         () => {
           return HttpResponse.json(eventWithContext);
         },
@@ -2070,7 +2070,7 @@ describe("get_issue_details", () => {
         { once: true },
       ),
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/MCP-SERVER-EQE/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6898891101/events/latest/",
         () => HttpResponse.json(regressedEventFixture),
         { once: true },
       ),
@@ -2152,7 +2152,7 @@ describe("get_issue_details", () => {
 
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/external-issues/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/external-issues/",
         () => HttpResponse.json(mockExternalIssues),
         { once: true },
       ),
@@ -2216,7 +2216,7 @@ describe("get_issue_details", () => {
     mswServer.use(
       // More specific pattern for events (must come first to match before the issue pattern)
       http.get(
-        "https://sentry.io/api/0/organizations/*/issues/FUTURE-TYPE-001/events/latest/",
+        "https://sentry.io/api/0/organizations/*/issues/7777777777/events/latest/",
         () => {
           return HttpResponse.json(unsupportedEventFixture);
         },
@@ -2342,7 +2342,7 @@ describe("structuredContent", () => {
   function mockLatestEventWithFormatted(formatted: unknown) {
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () => HttpResponse.json({ ...createDefaultEvent(), formatted }),
       ),
     );
@@ -2411,7 +2411,7 @@ describe("structuredContent", () => {
     // rendered for transactions, so a transaction must not take the structured path
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () =>
           HttpResponse.json({
             ...createDefaultEvent(),
@@ -2431,7 +2431,7 @@ describe("structuredContent", () => {
     // an issue whose only replay is attached would otherwise report no replays at all
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () =>
           HttpResponse.json({
             ...createDefaultEvent(),
@@ -2472,7 +2472,7 @@ describe("structuredContent", () => {
     // upstream schemas are passthrough, so anything not mapped must not appear
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () =>
           HttpResponse.json({
             ...createDefaultEvent(),
@@ -2480,7 +2480,7 @@ describe("structuredContent", () => {
           }),
       ),
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/external-issues/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/external-issues/",
         () =>
           HttpResponse.json([
             {
@@ -2508,7 +2508,7 @@ describe("structuredContent", () => {
     // renders and the payload drops is a regression for every MCP user
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () =>
           HttpResponse.json({
             ...createDefaultEvent(),
@@ -2566,7 +2566,7 @@ describe("structuredContent", () => {
           }),
       ),
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/7890123456/events/latest/",
         () =>
           HttpResponse.json({
             ...createDefaultEvent(),
@@ -2604,7 +2604,7 @@ describe("structuredContent", () => {
           }),
       ),
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/7890123456/events/latest/",
         () =>
           HttpResponse.json({
             ...createDefaultEvent(),
@@ -2629,7 +2629,7 @@ describe("structuredContent", () => {
     );
     mswServer.use(
       http.get(
-        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/events/latest/",
+        "https://sentry.io/api/0/organizations/sentry-mcp-evals/issues/6507376925/events/latest/",
         () =>
           HttpResponse.json({
             ...createDefaultEvent(),
diff --git a/packages/mcp-core/src/tools/catalog/get-issue-details.ts b/packages/mcp-core/src/tools/catalog/get-issue-details.ts
index 8eb9178b7..6d2f910c1 100644
--- a/packages/mcp-core/src/tools/catalog/get-issue-details.ts
+++ b/packages/mcp-core/src/tools/catalog/get-issue-details.ts
@@ -406,7 +406,7 @@ export default defineTool({
         apiService
           .getEventForIssue({
             organizationSlug: orgSlug,
-            issueId: issue.shortId,
+            issueId: String(issue.id),
             eventId,
           })
           // Optionally enhance 404 errors with parameter context
@@ -414,7 +414,7 @@ export default defineTool({
             if (error instanceof ApiNotFoundError) {
               throw enhanceNotFoundError(error, {
                 organizationSlug: orgSlug,
-                issueId: issue.shortId,
+                issueId: String(issue.id),
                 eventId,
               });
             }
@@ -524,7 +524,7 @@ export default defineTool({
       apiService
         .getLatestEventForIssue({
           organizationSlug: orgSlug,
-          issueId: issue.shortId,
+          issueId: String(issue.id),
         })
         .then(async (event) => ({
           event,
@@ -648,7 +648,7 @@ async function fetchIssueEnrichmentData({
       seerEnabled,
     }),
     apiService
-      .getIssueExternalLinks({ organizationSlug, issueId: issue.shortId })
+      .getIssueExternalLinks({ organizationSlug, issueId })
       .catch(() => undefined),
     apiService
       .listReplayIdsForIssue({
@@ -691,7 +691,7 @@ async function maybeFetchAutofixState({
   }
 
   return apiService
-    .getAutofixState({ organizationSlug, issueId: issue.shortId })
+    .getAutofixState({ organizationSlug, issueId: String(issue.id) })
     .catch(() => undefined);
 }
 
diff --git a/packages/mcp-server-mocks/src/index.ts b/packages/mcp-server-mocks/src/index.ts
index b0629e08a..2c505f596 100644
--- a/packages/mcp-server-mocks/src/index.ts
+++ b/packages/mcp-server-mocks/src/index.ts
@@ -1334,6 +1334,11 @@ export const restHandlers = buildHandlers([
     path: "/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-41/autofix/",
     fetch: () => HttpResponse.json({ autofix: null }),
   },
+  {
+    method: "get",
+    path: "/api/0/organizations/sentry-mcp-evals/issues/:issueId(\\d+)/autofix/",
+    fetch: () => HttpResponse.json({ autofix: null }),
+  },
   {
     method: "post",
     path: "/api/0/organizations/sentry-mcp-evals/issues/CLOUDFLARE-MCP-42/autofix/",