diff --git a/client/src/components/settings/GitIdentitySettings.tsx b/client/src/components/settings/GitIdentitySettings.tsx
index bd605afb..90381c48 100644
--- a/client/src/components/settings/GitIdentitySettings.tsx
+++ b/client/src/components/settings/GitIdentitySettings.tsx
@@ -7,7 +7,9 @@
  * keys a clone (Add workspace → Clone) and the pushes from that clone use —
  * an ED25519 and/or an RSA one (AWS CodeCommit takes only RSA) — make one, copy its public half to add to GitHub/GitLab, replace or delete
  * it, and whether git typed in the account's own terminal uses it too (a
- * switch over `core.sshCommand` in its `~/.gitconfig`, issue #82) — and, for
+ * switch over `core.sshCommand` in its `~/.gitconfig`, issue #82), the SSH
+ * login name per host (AWS CodeCommit's SSH key ID, a `url.<…>.insteadOf` in
+ * that same file, so a plain `ssh://git-codecommit…` URL works) — and, for
  * a user with their own Linux account (S3), their own HTTPS
  * logins. The host account's HTTPS logins are the shared Git credentials
  * table above it, so this lists them only for a member. The private key and
@@ -15,7 +17,7 @@
  * seen by a non-admin is read-only.
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
-import { useCallback, useEffect, useState } from "react";
+import { useCallback, useEffect, useState, type ReactNode } from "react";
 import { useTranslation } from "react-i18next";
 import { Copy, KeyRound, Plus, RefreshCw, Trash2 } from "lucide-react";
 import { api, type GitIdentity } from "../../lib/api";
@@ -30,6 +32,140 @@ const INPUT =
 const BTN =
   "inline-flex items-center gap-1.5 rounded border border-border-light px-2.5 py-1 text-xs text-fg-secondary hover:bg-surface-3 disabled:cursor-not-allowed disabled:opacity-40";
 
+const CODECOMMIT_RE = /^git-codecommit\.([a-z0-9-]+)\.amazonaws\.com$/;
+// The regions AWS CodeCommit runs in.
+const AWS_REGIONS = [
+  "ap-southeast-1",
+  "ap-southeast-2",
+  "ap-southeast-3",
+  "ap-northeast-1",
+  "ap-northeast-2",
+  "ap-northeast-3",
+  "ap-south-1",
+  "ap-east-1",
+  "us-east-1",
+  "us-east-2",
+  "us-west-1",
+  "us-west-2",
+  "ca-central-1",
+  "eu-west-1",
+  "eu-west-2",
+  "eu-west-3",
+  "eu-central-1",
+  "eu-north-1",
+  "eu-south-1",
+  "sa-east-1",
+  "me-south-1",
+  "af-south-1",
+  "il-central-1",
+];
+
+function Step({ n, children }: { n: number; children: ReactNode }) {
+  return (
+    <div className="flex gap-2 text-[11px] text-fg-secondary">
+      <span className="flex h-4 w-4 shrink-0 items-center justify-center rounded-full bg-surface-3 text-[10px] text-fg-primary">
+        {n}
+      </span>
+      <div className="min-w-0 flex-1">{children}</div>
+    </div>
+  );
+}
+
+function Code({ children }: { children: ReactNode }) {
+  return (
+    <code className="mt-1 block break-all rounded bg-surface-2 px-1.5 py-1 font-mono text-[10px] text-fg-primary">
+      {children}
+    </code>
+  );
+}
+
+type Key = NonNullable<GitIdentity["sshKeys"]>[number];
+
+/**
+ * One kind of git host and the key it takes: no key → a Generate button;
+ * a key → step 1 (copy its public half) followed by the host's own steps.
+ */
+function KeyCard({
+  title,
+  sub,
+  type,
+  k,
+  id,
+  busy,
+  onGenerate,
+  onRemove,
+  children,
+}: {
+  title: string;
+  sub: string;
+  type: "ed25519" | "rsa";
+  k: Key | undefined;
+  id: GitIdentity;
+  busy: boolean;
+  onGenerate: (type: "ed25519" | "rsa") => Promise<void>;
+  onRemove: (type: "ed25519" | "rsa") => Promise<void>;
+  children: ReactNode;
+}) {
+  const { t } = useTranslation("settings");
+  return (
+    <section aria-label={title} className="space-y-2 rounded border border-border p-2.5">
+      <div className="flex flex-wrap items-center gap-2">
+        <div className="min-w-0 flex-1">
+          <div className="text-xs font-medium text-fg-primary">{title}</div>
+          <div className="text-[10px] text-fg-muted">{sub}</div>
+        </div>
+        {id.writable && (
+          <button
+            type="button"
+            className={BTN}
+            disabled={busy}
+            onClick={() => void onGenerate(type)}
+          >
+            {k ? <RefreshCw className="h-3.5 w-3.5" /> : <Plus className="h-3.5 w-3.5" />}
+            {k ? t("gitIdentity.replace") : t("gitIdentity.generate")}
+          </button>
+        )}
+        {k && id.writable && (
+          <button
+            type="button"
+            className={`${BTN} hover:text-status-danger`}
+            disabled={busy}
+            onClick={() => void onRemove(type)}
+          >
+            <Trash2 className="h-3.5 w-3.5" />
+            {t("gitIdentity.remove")}
+          </button>
+        )}
+      </div>
+      {k ? (
+        <>
+          <Step n={1}>
+            <div className="flex flex-wrap items-center gap-2">
+              <span className="flex-1">{t("gitIdentity.stepCopy")}</span>
+              <button type="button" className={BTN} onClick={() => void copyText(k.publicKey)}>
+                <Copy className="h-3.5 w-3.5" />
+                {t("gitIdentity.copy")}
+              </button>
+            </div>
+            <textarea
+              readOnly
+              aria-label={`${t("gitIdentity.publicKey")} ${type === "rsa" ? "RSA" : "ED25519"}`}
+              value={k.publicKey}
+              rows={type === "rsa" ? 3 : 2}
+              onFocus={(e) => e.currentTarget.select()}
+              className={`${INPUT} mt-1 resize-none break-all font-mono text-[10px]`}
+            />
+            <div className="truncate font-mono text-[10px] text-fg-muted">{k.fingerprint}</div>
+          </Step>
+          {children}
+        </>
+      ) : (
+        <p className="text-[11px] text-fg-muted">{t("gitIdentity.noKey")}</p>
+      )}
+    </section>
+  );
+}
+
 export function GitIdentitySettings() {
   const { t } = useTranslation("settings");
   const [id, setId] = useState<GitIdentity | null>(null);
@@ -71,21 +207,21 @@ export function GitIdentitySettings() {
   // An account may hold one of each; an older server answers `ssh` only.
   const keys = id ? (id.sshKeys ?? (id.ssh ? [id.ssh] : [])) : [];
   const terminal = id?.sshTerminal ?? id?.ssh?.terminal ?? null;
-  const [keyType, setKeyType] = useState<"ed25519" | "rsa">("ed25519");
-  const typeTaken = keys.some((k) => (k.type ?? "ed25519") === keyType);
-  const generate = async () => {
+  const keyOf = (type: "ed25519" | "rsa") => keys.find((k) => (k.type ?? "ed25519") === type);
+  const generate = async (type: "ed25519" | "rsa") => {
+    const taken = !!keyOf(type);
     if (
-      typeTaken &&
+      taken &&
       !(await confirmDialog({
         title: t("gitIdentity.replaceConfirm"),
         confirmLabel: t("gitIdentity.replace"),
       }))
     )
       return;
-    await run(() => api.gitIdentity.generateKey(typeTaken, keyType), t("gitIdentity.keyMade"));
+    await run(() => api.gitIdentity.generateKey(taken, type), t("gitIdentity.keyMade"));
   };
 
-  const removeKey = async (type?: "ed25519" | "rsa") => {
+  const removeKey = async (type: "ed25519" | "rsa") => {
     if (
       !(await confirmDialog({
         title: t("gitIdentity.removeKeyConfirm"),
@@ -113,6 +249,44 @@ export function GitIdentitySettings() {
     if (ok) setForm(null);
   };
 
+  // The SSH login name per host (`url.<…>.insteadOf`), so a plain
+  // `ssh://host/…` URL logs in. AWS CodeCommit's (user = the IAM SSH key ID,
+  // one host per region) gets its own form under the RSA key; anything else
+  // is the "other hosts" form.
+  const sshUsers = id?.sshUsers ?? [];
+  const awsRows = sshUsers.flatMap((r) => {
+    const m = CODECOMMIT_RE.exec(r.host);
+    return m ? [{ ...r, region: m[1] ?? "" }] : [];
+  });
+  const otherRows = sshUsers.filter((r) => !CODECOMMIT_RE.test(r.host));
+  const [aws, setAws] = useState({ keyId: "", region: "ap-southeast-1" });
+  const saveAws = async () => {
+    let user = aws.keyId.trim();
+    let host = `git-codecommit.${aws.region}.amazonaws.com`;
+    // A pasted `ssh://APKA…@git-codecommit.<region>…/…` URL fills both.
+    const m = /^ssh:\/\/([^@/]+)@([^/]+)/i.exec(user);
+    if (m?.[1] && m[2]) {
+      user = m[1];
+      host = m[2].toLowerCase();
+    }
+    const ok = await run(
+      () => api.gitIdentity.setSshUser({ host, user }),
+      t("gitIdentity.awsSaved", { region: CODECOMMIT_RE.exec(host)?.[1] ?? host })
+    );
+    if (ok) setAws({ ...aws, keyId: "" });
+  };
+  const [other, setOther] = useState({ host: "", user: "" });
+  const saveOther = async () => {
+    let host = other.host.trim();
+    const m = /^ssh:\/\/(?:[^@/]+@)?([^/]+)/i.exec(host);
+    if (m?.[1]) host = m[1];
+    const ok = await run(
+      () => api.gitIdentity.setSshUser({ host, user: other.user.trim() }),
+      t("gitIdentity.otherSaved", { host })
+    );
+    if (ok) setOther({ host: "", user: "" });
+  };
+
   const removeLogin = async (host: string) => {
     if (
       !(await confirmDialog({
@@ -206,89 +380,191 @@ export function GitIdentitySettings() {
         )}
       </form>
 
-      <div className="space-y-2 rounded-lg border border-border p-3">
+      <div className="space-y-3 rounded-lg border border-border p-3">
         <div className="flex items-center gap-2">
           <KeyRound className="h-4 w-4 text-fg-muted" aria-hidden />
           <h3 className="flex-1 text-xs font-semibold text-fg-primary">
             {t("gitIdentity.sshTitle")}
           </h3>
-          {id.writable && (
-            <select
-              aria-label={t("gitIdentity.keyType")}
-              value={keyType}
-              disabled={busy}
-              onChange={(e) => setKeyType(e.target.value === "rsa" ? "rsa" : "ed25519")}
-              className="select !py-1 !text-xs"
-            >
-              <option value="ed25519">{t("gitIdentity.keyEd25519")}</option>
-              <option value="rsa">{t("gitIdentity.keyRsa")}</option>
-            </select>
-          )}
-          {id.writable && (
-            <button type="button" className={BTN} disabled={busy} onClick={() => void generate()}>
-              {typeTaken ? <RefreshCw className="h-3.5 w-3.5" /> : <Plus className="h-3.5 w-3.5" />}
-              {typeTaken ? t("gitIdentity.replace") : t("gitIdentity.generate")}
-            </button>
-          )}
         </div>
-        {keys.length ? (
-          <>
-            {keys.map((k) => (
-              <div key={k.type ?? "ed25519"} className="space-y-1.5">
-                <textarea
-                  readOnly
-                  aria-label={`${t("gitIdentity.publicKey")} ${k.type === "rsa" ? "RSA" : "ED25519"}`}
-                  value={k.publicKey}
-                  rows={k.type === "rsa" ? 4 : 2}
-                  onFocus={(e) => e.currentTarget.select()}
-                  className={`${INPUT} resize-none break-all font-mono text-[11px]`}
-                />
-                <div className="flex flex-wrap items-center gap-2">
-                  <span className="min-w-0 flex-1 truncate font-mono text-[10px] text-fg-muted">
-                    {k.type === "rsa" ? "RSA 4096 · " : "ED25519 · "}
-                    {k.fingerprint}
+        <p className="text-[11px] text-fg-muted">{t("gitIdentity.sshIntro")}</p>
+
+        <KeyCard
+          title={t("gitIdentity.gitHubTitle")}
+          sub={t("gitIdentity.gitHubSub")}
+          type="ed25519"
+          k={keyOf("ed25519")}
+          id={id}
+          busy={busy}
+          onGenerate={generate}
+          onRemove={removeKey}
+        >
+          <Step n={2}>{t("gitIdentity.gitHubStepAdd")}</Step>
+          <Step n={3}>
+            {t("gitIdentity.gitHubStepClone")}
+            <Code>git clone git@github.com:&lt;org&gt;/&lt;repo&gt;.git</Code>
+          </Step>
+        </KeyCard>
+
+        <KeyCard
+          title={t("gitIdentity.awsTitle")}
+          sub={t("gitIdentity.awsSub")}
+          type="rsa"
+          k={keyOf("rsa")}
+          id={id}
+          busy={busy}
+          onGenerate={generate}
+          onRemove={removeKey}
+        >
+          <Step n={2}>{t("gitIdentity.awsStepUpload")}</Step>
+          <Step n={3}>
+            {t("gitIdentity.awsStepKeyId")}
+            {id.sshUsers === undefined ? null : (
+              <>
+                {awsRows.map((r) => (
+                  <div key={r.host} className="mt-1 flex items-center gap-2">
+                    <span className="min-w-0 flex-1 truncate font-mono text-[11px] text-fg-secondary">
+                      {r.region} · {r.user}
+                    </span>
+                    {id.writable && (
+                      <button
+                        type="button"
+                        className={`${BTN} hover:text-status-danger`}
+                        disabled={busy}
+                        aria-label={`${t("gitIdentity.remove")} ${r.host}`}
+                        onClick={() => void run(() => api.gitIdentity.removeSshUser(r.host))}
+                      >
+                        <Trash2 className="h-3.5 w-3.5" />
+                      </button>
+                    )}
+                  </div>
+                ))}
+                {id.writable && (
+                  <form
+                    className="mt-1 grid gap-2 sm:grid-cols-[2fr_1fr_auto]"
+                    onSubmit={(e) => {
+                      e.preventDefault();
+                      void saveAws();
+                    }}
+                  >
+                    <input
+                      aria-label={t("gitIdentity.awsKeyId")}
+                      placeholder="APKA…"
+                      autoComplete="off"
+                      value={aws.keyId}
+                      onChange={(e) => setAws({ ...aws, keyId: e.target.value })}
+                      className={`${INPUT} font-mono`}
+                    />
+                    <select
+                      aria-label={t("gitIdentity.awsRegion")}
+                      value={aws.region}
+                      onChange={(e) => setAws({ ...aws, region: e.target.value })}
+                      className="select !py-1 !text-xs"
+                    >
+                      {AWS_REGIONS.map((r) => (
+                        <option key={r} value={r}>
+                          {r}
+                        </option>
+                      ))}
+                    </select>
+                    <button type="submit" className={BTN} disabled={busy || !aws.keyId.trim()}>
+                      {t("gitIdentity.awsSave")}
+                    </button>
+                  </form>
+                )}
+              </>
+            )}
+          </Step>
+          {awsRows.length > 0 && (
+            <div className="rounded border border-status-success/40 bg-status-success/10 p-2 text-[11px] text-fg-primary">
+              {t("gitIdentity.awsReady")}
+              {awsRows.map((r) => (
+                <Code key={r.host}>git clone ssh://{r.host}/v1/repos/&lt;repo&gt;</Code>
+              ))}
+            </div>
+          )}
+        </KeyCard>
+
+        {terminal && (
+          <div className="flex items-start gap-2 rounded border border-border p-2">
+            <div className="min-w-0 flex-1">
+              <div className="text-[11px] text-fg-primary">{t("gitIdentity.terminal")}</div>
+              <div className="text-[10px] text-fg-muted">
+                {terminal === "foreign"
+                  ? t("gitIdentity.terminalForeign")
+                  : t("gitIdentity.terminalHint")}
+              </div>
+            </div>
+            <Switch
+              label={t("gitIdentity.terminal")}
+              checked={terminal === "on"}
+              disabled={busy || !id.writable || terminal === "foreign"}
+              onChange={(on) => void run(() => api.gitIdentity.setTerminalSsh(on))}
+            />
+          </div>
+        )}
+
+        {id.sshUsers !== undefined && (otherRows.length > 0 || id.writable) && (
+          <details className="rounded border border-border p-2" open={otherRows.length > 0}>
+            <summary className="cursor-pointer text-[11px] text-fg-primary">
+              {t("gitIdentity.otherTitle")}
+            </summary>
+            <div className="mt-1.5 space-y-1.5">
+              <div className="text-[10px] text-fg-muted">{t("gitIdentity.otherHint")}</div>
+              {otherRows.map((r) => (
+                <div key={r.host} className="flex items-center gap-2">
+                  <span className="min-w-0 flex-1 truncate font-mono text-[11px] text-fg-secondary">
+                    {r.user}@{r.host}
                   </span>
-                  <button type="button" className={BTN} onClick={() => void copyText(k.publicKey)}>
-                    <Copy className="h-3.5 w-3.5" />
-                    {t("gitIdentity.copy")}
-                  </button>
                   {id.writable && (
                     <button
                       type="button"
                       className={`${BTN} hover:text-status-danger`}
                       disabled={busy}
-                      onClick={() => void removeKey(k.type)}
+                      aria-label={`${t("gitIdentity.remove")} ${r.host}`}
+                      onClick={() => void run(() => api.gitIdentity.removeSshUser(r.host))}
                     >
                       <Trash2 className="h-3.5 w-3.5" />
-                      {t("gitIdentity.remove")}
                     </button>
                   )}
                 </div>
-              </div>
-            ))}
-            {terminal && (
-              <div className="flex items-start gap-2 rounded border border-border p-2">
-                <div className="min-w-0 flex-1">
-                  <div className="text-[11px] text-fg-primary">{t("gitIdentity.terminal")}</div>
-                  <div className="text-[10px] text-fg-muted">
-                    {terminal === "foreign"
-                      ? t("gitIdentity.terminalForeign")
-                      : t("gitIdentity.terminalHint")}
-                  </div>
-                </div>
-                <Switch
-                  label={t("gitIdentity.terminal")}
-                  checked={terminal === "on"}
-                  disabled={busy || !id.writable || terminal === "foreign"}
-                  onChange={(on) => void run(() => api.gitIdentity.setTerminalSsh(on))}
-                />
-              </div>
-            )}
-            <p className="text-[10px] text-fg-muted">{t("gitIdentity.addKeyHint")}</p>
-          </>
-        ) : (
-          <p className="text-[11px] text-fg-muted">{t("gitIdentity.noKey")}</p>
+              ))}
+              {id.writable && (
+                <form
+                  className="grid gap-2 sm:grid-cols-[2fr_1fr_auto]"
+                  onSubmit={(e) => {
+                    e.preventDefault();
+                    void saveOther();
+                  }}
+                >
+                  <input
+                    aria-label={t("gitIdentity.otherHost")}
+                    placeholder="git.example.com"
+                    value={other.host}
+                    onChange={(e) => setOther({ ...other, host: e.target.value })}
+                    className={`${INPUT} font-mono`}
+                  />
+                  <input
+                    aria-label={t("gitIdentity.otherUser")}
+                    placeholder={t("gitIdentity.otherUser")}
+                    autoComplete="off"
+                    value={other.user}
+                    onChange={(e) => setOther({ ...other, user: e.target.value })}
+                    className={`${INPUT} font-mono`}
+                  />
+                  <button
+                    type="submit"
+                    className={BTN}
+                    disabled={busy || !other.host.trim() || !other.user.trim()}
+                  >
+                    {t("gitIdentity.awsSave")}
+                  </button>
+                </form>
+              )}
+            </div>
+          </details>
         )}
+        <p className="text-[10px] text-fg-muted">{t("gitIdentity.privateNote")}</p>
       </div>
 
       {member && (
diff --git a/client/src/components/settings/__tests__/GitIdentitySettings.test.tsx b/client/src/components/settings/__tests__/GitIdentitySettings.test.tsx
index 8e6ee4e9..625b24ee 100644
--- a/client/src/components/settings/__tests__/GitIdentitySettings.test.tsx
+++ b/client/src/components/settings/__tests__/GitIdentitySettings.test.tsx
@@ -2,11 +2,13 @@
  * @file Tests for Settings → Git → Your git identity: a user with no key
  * makes one, a key shows only its public half and copies it, replacing asks
  * first, and a member (S3) adds an HTTPS login of their own while the host's
- * view leaves HTTPS to the shared Git credentials table.
+ * view leaves HTTPS to the shared Git credentials table, and an SSH user per
+ * host is saved — AWS CodeCommit's key ID inside its own RSA section, any
+ * other host under "Other SSH hosts" — so the sections never mix.
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 import { describe, it, expect, vi, beforeEach } from "vitest";
-import { render, screen, waitFor } from "@testing-library/react";
+import { render, screen, waitFor, within } from "@testing-library/react";
 import userEvent from "@testing-library/user-event";
 import { GitIdentitySettings } from "../GitIdentitySettings";
 import { api, type GitIdentity } from "../../../lib/api";
@@ -20,6 +22,8 @@ vi.mock("../../../lib/api", () => ({
       generateKey: vi.fn(),
       removeKey: vi.fn(),
       setTerminalSsh: vi.fn(),
+      setSshUser: vi.fn(),
+      removeSshUser: vi.fn(),
       saveHttps: vi.fn(),
       saveAuthor: vi.fn(),
       removeHttps: vi.fn(),
@@ -49,7 +53,8 @@ describe("GitIdentitySettings", () => {
     vi.mocked(api.gitIdentity.get).mockResolvedValue(view());
     vi.mocked(api.gitIdentity.generateKey).mockResolvedValue(view({ ssh: KEY }));
     render(<GitIdentitySettings />);
-    await userEvent.click(await screen.findByRole("button", { name: "Generate SSH key" }));
+    const gh = await screen.findByRole("region", { name: /GitHub/ });
+    await userEvent.click(within(gh).getByRole("button", { name: "Generate key" }));
     expect(confirmDialog).not.toHaveBeenCalled();
     expect(api.gitIdentity.generateKey).toHaveBeenCalledWith(false, "ed25519");
     expect(await screen.findByLabelText(/^Public key/)).toHaveValue(KEY.publicKey);
@@ -86,43 +91,84 @@ describe("GitIdentitySettings", () => {
     expect(await screen.findByText("github.com")).toBeInTheDocument();
   });
 
-  it("makes an RSA key when that type is picked (AWS CodeCommit takes only RSA)", async () => {
+  it("makes the RSA key from the AWS CodeCommit section", async () => {
     vi.mocked(api.gitIdentity.get).mockResolvedValue(view());
     vi.mocked(api.gitIdentity.generateKey).mockResolvedValue(
       view({ ssh: { ...KEY, type: "rsa", publicKey: "ssh-rsa AAAAB3 an@agenthub" } })
     );
     render(<GitIdentitySettings />);
-    await userEvent.selectOptions(await screen.findByLabelText("Key type"), "rsa");
-    await userEvent.click(screen.getByRole("button", { name: "Generate SSH key" }));
+    const aws = await screen.findByRole("region", { name: "AWS CodeCommit" });
+    await userEvent.click(within(aws).getByRole("button", { name: "Generate key" }));
     expect(api.gitIdentity.generateKey).toHaveBeenCalledWith(false, "rsa");
-    expect(await screen.findByText(/^RSA 4096 · /)).toBeInTheDocument();
+    expect(await screen.findByLabelText("Public key RSA")).toBeInTheDocument();
   });
 
-  it("adds an RSA key beside the ED25519 one and deletes each on its own", async () => {
+  it("keeps each key in its own section and deletes each on its own", async () => {
     const RSA = {
       type: "rsa" as const,
       publicKey: "ssh-rsa AAAAB3 an@agenthub",
       fingerprint: "SHA256:r",
     };
     const ED = { ...KEY, type: "ed25519" as const };
-    vi.mocked(api.gitIdentity.get).mockResolvedValue(view({ ssh: ED, sshKeys: [ED] }));
-    vi.mocked(api.gitIdentity.generateKey).mockResolvedValue(
+    vi.mocked(api.gitIdentity.get).mockResolvedValue(
       view({ ssh: ED, sshKeys: [ED, RSA], sshTerminal: "on" })
     );
     vi.mocked(api.gitIdentity.removeKey).mockResolvedValue(view({ ssh: ED, sshKeys: [ED] }));
     render(<GitIdentitySettings />);
-    await userEvent.selectOptions(await screen.findByLabelText("Key type"), "rsa");
-    // No RSA key yet: a plain Generate, no replace prompt, the ED25519 key stays.
-    await userEvent.click(screen.getByRole("button", { name: "Generate SSH key" }));
-    expect(confirmDialog).not.toHaveBeenCalled();
-    expect(api.gitIdentity.generateKey).toHaveBeenCalledWith(false, "rsa");
-    expect(await screen.findByLabelText("Public key RSA")).toHaveValue(RSA.publicKey);
-    expect(screen.getByLabelText("Public key ED25519")).toHaveValue(ED.publicKey);
+    const gh = await screen.findByRole("region", { name: /GitHub/ });
+    const aws = screen.getByRole("region", { name: "AWS CodeCommit" });
+    expect(within(gh).getByLabelText("Public key ED25519")).toHaveValue(ED.publicKey);
+    expect(within(aws).getByLabelText("Public key RSA")).toHaveValue(RSA.publicKey);
+    // Each section explains only its own host.
+    expect(within(gh).queryByText(/IAM/)).toBeNull();
+    expect(within(aws).queryByText(/GitHub/)).toBeNull();
     expect(screen.getByRole("switch", { name: /terminal/ })).toBeChecked();
-    await userEvent.click(screen.getAllByRole("button", { name: "Delete" })[1]!);
+    await userEvent.click(within(aws).getByRole("button", { name: "Delete" }));
     await waitFor(() => expect(api.gitIdentity.removeKey).toHaveBeenCalledWith("rsa"));
   });
 
+  it("saves the CodeCommit SSH key ID for a region and shows the plain clone", async () => {
+    const RSA = { type: "rsa" as const, publicKey: "ssh-rsa AAAAB3 x", fingerprint: "SHA256:r" };
+    const H = "git-codecommit.eu-west-1.amazonaws.com";
+    vi.mocked(api.gitIdentity.get).mockResolvedValue(view({ sshKeys: [RSA], sshUsers: [] }));
+    vi.mocked(api.gitIdentity.setSshUser).mockResolvedValue(
+      view({ sshKeys: [RSA], sshUsers: [{ host: H, user: "APKA1" }] })
+    );
+    vi.mocked(api.gitIdentity.removeSshUser).mockResolvedValue(
+      view({ sshKeys: [RSA], sshUsers: [] })
+    );
+    render(<GitIdentitySettings />);
+    const aws = await screen.findByRole("region", { name: "AWS CodeCommit" });
+    await userEvent.type(within(aws).getByLabelText("SSH key ID"), " APKA1 ");
+    await userEvent.selectOptions(within(aws).getByLabelText("Region"), "eu-west-1");
+    await userEvent.click(within(aws).getByRole("button", { name: "Save" }));
+    expect(api.gitIdentity.setSshUser).toHaveBeenCalledWith({ host: H, user: "APKA1" });
+    expect(await within(aws).findByText("eu-west-1 · APKA1")).toBeInTheDocument();
+    expect(within(aws).getByText(`git clone ssh://${H}/v1/repos/<repo>`)).toBeInTheDocument();
+    // A CodeCommit host never shows up again under "other hosts".
+    expect(screen.queryByText(`APKA1@${H}`)).toBeNull();
+    await userEvent.click(within(aws).getByRole("button", { name: `Delete ${H}` }));
+    expect(api.gitIdentity.removeSshUser).toHaveBeenCalledWith(H);
+  });
+
+  it("saves a user for any other SSH host under the advanced section", async () => {
+    vi.mocked(api.gitIdentity.get).mockResolvedValue(view({ ssh: KEY, sshUsers: [] }));
+    vi.mocked(api.gitIdentity.setSshUser).mockResolvedValue(
+      view({ ssh: KEY, sshUsers: [{ host: "git.example.com", user: "deploy" }] })
+    );
+    render(<GitIdentitySettings />);
+    await userEvent.click(await screen.findByText("Other SSH hosts (advanced)"));
+    await userEvent.type(screen.getByLabelText("Host"), "ssh://git.example.com/x");
+    await userEvent.type(screen.getByLabelText("User name"), "deploy");
+    const form = screen.getByLabelText("Host").closest("form")!;
+    await userEvent.click(within(form).getByRole("button", { name: "Save" }));
+    expect(api.gitIdentity.setSshUser).toHaveBeenCalledWith({
+      host: "git.example.com",
+      user: "deploy",
+    });
+    expect(await screen.findByText("deploy@git.example.com")).toBeInTheDocument();
+  });
+
   it("warns while the commit author is unset and saves it", async () => {
     vi.mocked(api.gitIdentity.get).mockResolvedValue(view({ author: { name: null, email: null } }));
     vi.mocked(api.gitIdentity.saveAuthor).mockResolvedValue(view());
diff --git a/client/src/i18n/locales/en/settings.json b/client/src/i18n/locales/en/settings.json
index dd617d6f..f1752d6a 100644
--- a/client/src/i18n/locales/en/settings.json
+++ b/client/src/i18n/locales/en/settings.json
@@ -901,8 +901,8 @@
     "title": "Your git identity",
     "descriptionMember": "Your own SSH key and HTTPS logins, kept in your own home. Add workspace → Clone uses them, and the clone keeps them for its later fetch, pull and push.",
     "descriptionHost": "The SSH key of the account this AgentHub runs as. Add workspace → Clone uses it, and the clone keeps it for its later fetch, pull and push. HTTPS logins for this account are the Git credentials above.",
-    "sshTitle": "SSH key",
-    "generate": "Generate SSH key",
+    "sshTitle": "SSH keys",
+    "generate": "Generate key",
     "replace": "Replace key",
     "replaceConfirm": "Replace the SSH key? Clones that use the old key stop working until the new public key is added to their host.",
     "keyMade": "SSH key ready — add its public key to your git host.",
@@ -910,17 +910,34 @@
     "removeKeyConfirm": "Delete this SSH key? Clones that use it can no longer fetch or push.",
     "publicKey": "Public key",
     "copy": "Copy public key",
-    "addKeyHint": "Add this public key to your account on the git host (GitHub: Settings → SSH and GPG keys; GitLab: Preferences → SSH Keys; AWS: IAM → Security credentials → SSH public keys — RSA only, and clone as ssh://<SSH key ID>@git-codecommit…, not git@). Paste the whole line as one line. The private key never leaves the server.",
-    "noKey": "No SSH key yet. Without one, an SSH clone uses the account's default ~/.ssh keys.",
+    "noKey": "No key yet. Generate one to start.",
     "httpsTitle": "HTTPS logins",
     "noLogins": "No HTTPS login saved. A clone asks for one when a host needs it.",
     "removeLoginConfirm": "Delete the login for {{host}}? Clones from that host will ask for a login again.",
-    "keyType": "Key type",
-    "keyEd25519": "ED25519 (GitHub, GitLab, Gitea)",
-    "keyRsa": "RSA 4096 (AWS CodeCommit, older servers)",
     "terminal": "Use this key for git in the terminal",
     "terminalHint": "A clone, fetch or push you type yourself (in a pane or over SSH) uses this key, then your own ~/.ssh keys. Sets core.sshCommand in your ~/.gitconfig.",
-    "terminalForeign": "Your ~/.gitconfig already sets its own core.sshCommand, so AgentHub leaves it alone. Remove it to use this key in the terminal."
+    "terminalForeign": "Your ~/.gitconfig already sets its own core.sshCommand, so AgentHub leaves it alone. Remove it to use this key in the terminal.",
+    "sshIntro": "Use the section for where your code lives. Each kind of host takes its own key; you need only the ones you use.",
+    "gitHubTitle": "GitHub · GitLab · Gitea · Bitbucket",
+    "gitHubSub": "ED25519 key — the git@… SSH address",
+    "gitHubStepAdd": "Add it to your account on the host: GitHub → Settings → SSH and GPG keys → New SSH key. GitLab: Preferences → SSH Keys. Paste the whole line.",
+    "gitHubStepClone": "Clone with the SSH address the repository page shows:",
+    "awsTitle": "AWS CodeCommit",
+    "awsSub": "RSA 4096 key — AWS accepts only RSA",
+    "stepCopy": "Copy the public key.",
+    "awsStepUpload": "In the AWS console: IAM → Users → your user → Security credentials → SSH public keys for AWS CodeCommit → Upload SSH public key, and paste it.",
+    "awsStepKeyId": "AWS then shows an SSH key ID (it starts with APKA). Paste it here and pick the region of your repositories:",
+    "awsKeyId": "SSH key ID",
+    "awsRegion": "Region",
+    "awsSave": "Save",
+    "awsSaved": "SSH key ID saved for {{region}}",
+    "awsReady": "Ready. Clone with the plain address CodeCommit shows — in a terminal or in Add workspace → Clone:",
+    "otherTitle": "Other SSH hosts (advanced)",
+    "otherHint": "Only for a host that logs you in with a user name other than git. Then a plain ssh://<host>/… address logs in as that user.",
+    "otherHost": "Host",
+    "otherUser": "User name",
+    "otherSaved": "SSH user saved for {{host}}",
+    "privateNote": "Only the public key is ever shown; the private key never leaves the server."
   },
   "gitCreds": {
     "title": "Git credentials",
diff --git a/client/src/i18n/locales/vi/settings.json b/client/src/i18n/locales/vi/settings.json
index 27e91f2e..823b28e6 100644
--- a/client/src/i18n/locales/vi/settings.json
+++ b/client/src/i18n/locales/vi/settings.json
@@ -902,7 +902,7 @@
     "descriptionMember": "SSH key và đăng nhập HTTPS riêng của bạn, lưu trong home của chính bạn. Add workspace → Clone dùng chúng, và bản clone giữ lại cho các lần fetch, pull, push sau.",
     "descriptionHost": "SSH key của tài khoản mà AgentHub đang chạy. Add workspace → Clone dùng key này, và bản clone giữ lại cho các lần fetch, pull, push sau. Đăng nhập HTTPS của tài khoản này là mục Git credentials ở trên.",
     "sshTitle": "SSH key",
-    "generate": "Tạo SSH key",
+    "generate": "Tạo key",
     "replace": "Thay key",
     "replaceConfirm": "Thay SSH key? Các bản clone dùng key cũ sẽ không hoạt động cho tới khi public key mới được thêm vào host.",
     "keyMade": "SSH key đã sẵn sàng — hãy thêm public key vào git host của bạn.",
@@ -910,17 +910,34 @@
     "removeKeyConfirm": "Xoá SSH key này? Các bản clone dùng nó sẽ không fetch/push được nữa.",
     "publicKey": "Public key",
     "copy": "Copy public key",
-    "addKeyHint": "Thêm public key này vào tài khoản trên git host (GitHub: Settings → SSH and GPG keys; GitLab: Preferences → SSH Keys; AWS: IAM → Security credentials → SSH public keys — chỉ nhận RSA, và clone bằng ssh://<SSH key ID>@git-codecommit…, không phải git@). Dán nguyên dòng, trên một dòng. Private key không bao giờ rời khỏi server.",
-    "noKey": "Chưa có SSH key. Khi chưa có, clone qua SSH dùng key mặc định trong ~/.ssh của tài khoản.",
+    "noKey": "Chưa có key. Bấm Tạo key để bắt đầu.",
     "httpsTitle": "Đăng nhập HTTPS",
     "noLogins": "Chưa lưu đăng nhập HTTPS nào. Khi clone, host nào cần sẽ hỏi.",
     "removeLoginConfirm": "Xoá đăng nhập của {{host}}? Clone từ host đó sẽ hỏi đăng nhập lại.",
-    "keyType": "Loại key",
-    "keyEd25519": "ED25519 (GitHub, GitLab, Gitea)",
-    "keyRsa": "RSA 4096 (AWS CodeCommit, server cũ)",
     "terminal": "Dùng key này cho git trong terminal",
     "terminalHint": "Lệnh clone, fetch hay push bạn tự gõ (trong pane hoặc qua SSH) sẽ dùng key này, sau đó tới các key trong ~/.ssh của bạn. Ghi core.sshCommand vào ~/.gitconfig của bạn.",
-    "terminalForeign": "~/.gitconfig của bạn đã tự đặt core.sshCommand nên AgentHub không động vào. Xoá nó đi nếu muốn dùng key này trong terminal."
+    "terminalForeign": "~/.gitconfig của bạn đã tự đặt core.sshCommand nên AgentHub không động vào. Xoá nó đi nếu muốn dùng key này trong terminal.",
+    "sshIntro": "Dùng đúng mục theo nơi chứa code của bạn. Mỗi loại host dùng một key riêng; chỉ cần tạo key cho nơi bạn dùng.",
+    "gitHubTitle": "GitHub · GitLab · Gitea · Bitbucket",
+    "gitHubSub": "Key ED25519 — địa chỉ SSH dạng git@…",
+    "gitHubStepAdd": "Thêm vào tài khoản trên host: GitHub → Settings → SSH and GPG keys → New SSH key. GitLab: Preferences → SSH Keys. Dán nguyên dòng.",
+    "gitHubStepClone": "Clone bằng địa chỉ SSH mà trang repository hiển thị:",
+    "awsTitle": "AWS CodeCommit",
+    "awsSub": "Key RSA 4096 — AWS chỉ nhận RSA",
+    "stepCopy": "Copy public key.",
+    "awsStepUpload": "Trên AWS console: IAM → Users → user của bạn → Security credentials → SSH public keys for AWS CodeCommit → Upload SSH public key, rồi dán vào.",
+    "awsStepKeyId": "AWS sẽ hiện một SSH key ID (bắt đầu bằng APKA). Dán vào đây và chọn region chứa repository:",
+    "awsKeyId": "SSH key ID",
+    "awsRegion": "Region",
+    "awsSave": "Lưu",
+    "awsSaved": "Đã lưu SSH key ID cho {{region}}",
+    "awsReady": "Sẵn sàng. Clone bằng địa chỉ trơn mà CodeCommit hiển thị — trong terminal hoặc Add workspace → Clone:",
+    "otherTitle": "Host SSH khác (nâng cao)",
+    "otherHint": "Chỉ dùng cho host đăng nhập bằng tên user khác git. Sau khi lưu, địa chỉ ssh://<host>/… trơn sẽ đăng nhập bằng user đó.",
+    "otherHost": "Host",
+    "otherUser": "Tên user",
+    "otherSaved": "Đã lưu SSH user cho {{host}}",
+    "privateNote": "Chỉ public key được hiển thị; private key không bao giờ rời khỏi server."
   },
   "gitCreds": {
     "title": "Git credentials",
diff --git a/client/src/lib/api.ts b/client/src/lib/api.ts
index f82efcb3..d8b335c5 100644
--- a/client/src/lib/api.ts
+++ b/client/src/lib/api.ts
@@ -2676,6 +2676,11 @@ export const api = {
     /** PUT /api/me/git/ssh-terminal — use the key for git typed in the account's terminal. */
     setTerminalSsh: (on: boolean) =>
       request<GitIdentity>("/me/git/ssh-terminal", { method: "PUT", body: JSON.stringify({ on }) }),
+    /** PUT /api/me/git/ssh-user — the SSH login name for a host (CodeCommit: the SSH key ID). */
+    setSshUser: (body: { host: string; user: string }) =>
+      request<GitIdentity>("/me/git/ssh-user", { method: "PUT", body: JSON.stringify(body) }),
+    removeSshUser: (host: string) =>
+      request<GitIdentity>(`/me/git/ssh-user/${encodeURIComponent(host)}`, { method: "DELETE" }),
     saveHttps: (body: { host: string; username: string; password: string }) =>
       request<GitIdentity>("/me/git/https", { method: "POST", body: JSON.stringify(body) }),
     removeHttps: (host: string) =>
@@ -4210,6 +4215,8 @@ export interface GitIdentity {
   sshKeys?: { type?: "ed25519" | "rsa"; publicKey: string; fingerprint: string }[];
   /** The terminal switch (shared by both keys); null without a key. */
   sshTerminal?: "on" | "off" | "foreign" | null;
+  /** SSH login name per host (`url.<…>.insteadOf` in `~/.gitconfig`); absent from an older server. */
+  sshUsers?: { host: string; user: string }[];
   /** The account's commit author (`git config --global`); null fields = unset. */
   author: { name: string | null; email: string | null };
   https: {
diff --git a/docs/API.md b/docs/API.md
index aa9d4ec5..258858c7 100644
--- a/docs/API.md
+++ b/docs/API.md
@@ -1046,6 +1046,8 @@ GET    /api/me/git                 { account: "member"|"host", writable, ssh: {
 POST   /api/me/git/ssh-key         Make the SSH key of `type` — Body: { replace?, type?: "ed25519" | "rsa" } (409 EEXISTS when that TYPE exists, without replace; the other type is kept — an account may hold one of each, and every ssh git offers both) → 201, same shape
 DELETE /api/me/git/ssh-key         Delete the key of `?type=ed25519|rsa`, or every key without it (404 ENOTFOUND, 400 EBADKEYTYPE) — also removes our terminal `core.sshCommand`
 PUT    /api/me/git/ssh-terminal    Use the key for git typed in the account's own terminal — Body: { on } — sets/unsets `core.sshCommand` in its `~/.gitconfig` (ours first, then `~/.ssh/id_*`); on by default when a member makes a key; 409 EFOREIGNSSH over one the user wrote, which is never touched
+PUT    /api/me/git/ssh-user        The SSH login name for one host — Body: { host, user } — writes `url."ssh://<user>@<host>/".insteadOf "ssh://<host>/"` to the account's `~/.gitconfig` (replacing ours for that host), so a plain `ssh://<host>/…` URL logs in as `user` (AWS CodeCommit: the IAM SSH key ID `APKA…`); 400 EBADHOST / EBADSSHUSER. Listed as `sshUsers: [{host, user}]` in GET /api/me/git
+DELETE /api/me/git/ssh-user/:host  Drop that rule (404 ENOTFOUND); any other `insteadOf` the user wrote is never touched
 POST   /api/me/git/https           Save an https login — Body: { host, username, password }
 DELETE /api/me/git/https/:host     Delete one (404 ENOTFOUND)
 PUT    /api/me/git/author          Commit author — Body: { name, email } (400 EBADAUTHOR) — `git config --global user.name/email` as the account
diff --git a/docs/SERVER-MODE.md b/docs/SERVER-MODE.md
index 558192b3..0f3928da 100644
--- a/docs/SERVER-MODE.md
+++ b/docs/SERVER-MODE.md
@@ -562,7 +562,7 @@ What runs as the member, and how:
   - In a member's folder, git and `gh` run as `sudo -n -u ah-<name> git …`, so git's own ownership check passes and every file stays the member's.
   - The editor and `.gitignore` saves go through `/opt/agenthub/libexec/write-as`.
   - A file uploaded in the Files tab (`POST /api/lanes/:id/git/upload`) is written the same way, AS the member through `write-as` (content on stdin), and only as a NEW file in an existing folder of the workspace — never over an existing name, never into `.git`, never a home dot folder, at most 25 MB. With **Download** on a file (`GET /api/lanes/:id/git/download`, read like any member file below, up to 512 MB) this is how a member with no SSH or `scp` to the host moves files in and out of their own folder; both work in a folder that is not a git repo.
-  - AgentHub's stored git logins are never handed to a member's git, and a password typed in the git bar goes into the member's OWN store (below) for that one call — through `write-as`'s stdin, never sudo's argv or env — and out again unless "remember" was ticked; a store that cannot be read is never rewritten (`409 ESTOREUNREADABLE`). The member keeps their OWN identity in Settings → Git → **Your git identity** (`/api/me/git`): a commit author (`user.name`/`user.email` in their `~/.gitconfig` — commits fail without one; a new member has none), SSH keys AgentHub makes for them (an ED25519 and/or an RSA one — AWS CodeCommit takes only RSA) and HTTPS logins, both under `~/.config/agenthub/` in their home, written as them by `write-as` (0600). Add workspace → **Clone** (`POST /api/lanes/clone`) clones as them with it and writes it into the clone's own config (`core.sshCommand` / `credential.helper=store --file=…`), so the git bar and their agents' pushes in that repo use it too. A plain `git` they type themselves in a pane reads none of that, so making the key also sets `core.sshCommand` in their `~/.gitconfig` (the key first, then `~/.ssh/id_*`; a switch under the key, issue #82) — unless they already set their own, which is left alone. A login typed in the Clone dialog goes to their store through `write-as`'s stdin, never sudo's argv or env, and is removed again after the clone unless "remember" was ticked.
+  - AgentHub's stored git logins are never handed to a member's git, and a password typed in the git bar goes into the member's OWN store (below) for that one call — through `write-as`'s stdin, never sudo's argv or env — and out again unless "remember" was ticked; a store that cannot be read is never rewritten (`409 ESTOREUNREADABLE`). The member keeps their OWN identity in Settings → Git → **Your git identity** (`/api/me/git`): a commit author (`user.name`/`user.email` in their `~/.gitconfig` — commits fail without one; a new member has none), SSH keys AgentHub makes for them (an ED25519 and/or an RSA one — AWS CodeCommit takes only RSA) and HTTPS logins, both under `~/.config/agenthub/` in their home, written as them by `write-as` (0600). Add workspace → **Clone** (`POST /api/lanes/clone`) clones as them with it and writes it into the clone's own config (`core.sshCommand` / `credential.helper=store --file=…`), so the git bar and their agents' pushes in that repo use it too. A plain `git` they type themselves in a pane reads none of that, so making the key also sets `core.sshCommand` in their `~/.gitconfig` (the key first, then `~/.ssh/id_*`; a switch under the key, issue #82) — unless they already set their own, which is left alone. The SSH keys are shown one section per kind of host, each with only its own steps: **GitHub · GitLab · Gitea · Bitbucket** (ED25519) and **AWS CodeCommit** (RSA: copy → upload in IAM → paste the SSH key ID `APKA…` and pick the region), plus a collapsed **Other SSH hosts (advanced)**. The key ID (or another host's user) is saved as `url."ssh://<user>@<host>/".insteadOf "ssh://<host>/"` in the same `~/.gitconfig`, so the plain `git clone ssh://git-codecommit.<region>.amazonaws.com/v1/repos/<repo>` works in a pane and in Clone. A login typed in the Clone dialog goes to their store through `write-as`'s stdin, never sudo's argv or env, and is removed again after the clone unless "remember" was ticked.
 - **Files a pane reads.** These are written into `~/.agenthub/handoff/` AS the member (`write-as`). The dashboard never writes, changes or deletes anything in a member's home itself: the member could have swapped the name for a link. The files are:
   - the workspace prompt and its context files;
   - the AI Proxy settings: no key, only that pane's own token for the gateway;
diff --git a/server/__tests__/git-clone.test.js b/server/__tests__/git-clone.test.js
index e9b4a805..25c2b3cd 100644
--- a/server/__tests__/git-clone.test.js
+++ b/server/__tests__/git-clone.test.js
@@ -393,6 +393,56 @@ describe("/api/me/git/ssh-terminal (issue #82)", () => {
   });
 });
 
+describe("/api/me/git/ssh-user (CodeCommit SSH key ID)", () => {
+  const getUrl = (url) =>
+    execFileSync("git", ["ls-remote", "--get-url", url], { encoding: "utf8" }).trim();
+  const HOST = "git-codecommit.ap-southeast-1.amazonaws.com";
+
+  it("makes a plain ssh:// URL log in as the saved user, and only for that host", async () => {
+    const r = await request("PUT", "/api/me/git/ssh-user", {
+      host: ` ${HOST.toUpperCase()} `,
+      user: "APKAEXAMPLE1",
+    });
+    assert.equal(r.status, 200);
+    assert.deepEqual(r.body.sshUsers, [{ host: HOST, user: "APKAEXAMPLE1" }]);
+    assert.equal(getUrl(`ssh://${HOST}/v1/repos/x`), `ssh://APKAEXAMPLE1@${HOST}/v1/repos/x`);
+    assert.equal(getUrl("ssh://other.test/x"), "ssh://other.test/x");
+    // A second save replaces, never stacks a second rewrite.
+    const again = await request("PUT", "/api/me/git/ssh-user", {
+      host: HOST,
+      user: "APKAEXAMPLE2",
+    });
+    assert.deepEqual(again.body.sshUsers, [{ host: HOST, user: "APKAEXAMPLE2" }]);
+    assert.equal(getUrl(`ssh://${HOST}/v1/repos/x`), `ssh://APKAEXAMPLE2@${HOST}/v1/repos/x`);
+    const del = await request("DELETE", `/api/me/git/ssh-user/${HOST}`);
+    assert.deepEqual(del.body.sshUsers, []);
+    assert.equal(getUrl(`ssh://${HOST}/v1/repos/x`), `ssh://${HOST}/v1/repos/x`);
+    assert.equal((await request("DELETE", `/api/me/git/ssh-user/${HOST}`)).status, 404);
+  });
+
+  it("refuses a bad host or user, and leaves the user's own insteadOf alone", async () => {
+    const own = "url.ssh://me@mine.test/.insteadOf";
+    execFileSync("git", ["config", "--global", own, "ssh://mine.test/"]);
+    try {
+      assert.equal(
+        (await request("PUT", "/api/me/git/ssh-user", { host: "-oProxy", user: "a" })).body.error
+          .code,
+        "EBADHOST"
+      );
+      const bad = await request("PUT", "/api/me/git/ssh-user", { host: HOST, user: "a@b" });
+      assert.equal(bad.status, 400);
+      assert.equal(bad.body.error.code, "EBADSSHUSER");
+      // Ours lists only our shape; a rule the user wrote for another host is kept.
+      const r = await request("GET", "/api/me/git");
+      assert.deepEqual(r.body.sshUsers, [{ host: "mine.test", user: "me" }]);
+      assert.equal((await request("DELETE", "/api/me/git/ssh-user/other.test")).status, 404);
+      assert.equal(getUrl("ssh://mine.test/x"), "ssh://me@mine.test/x");
+    } finally {
+      execFileSync("git", ["config", "--global", "--unset", own]);
+    }
+  });
+});
+
 describe("git-identity, member account (S3, stubbed)", () => {
   const runAs = require("../lib/run-as");
   const worktree = require("../lib/worktree");
diff --git a/server/lib/git-identity.js b/server/lib/git-identity.js
index 2e81c4f2..3e43b568 100644
--- a/server/lib/git-identity.js
+++ b/server/lib/git-identity.js
@@ -23,7 +23,8 @@
  * A plain `git` typed in a terminal reads none of that, so the account's own
  * `~/.gitconfig` may also carry our `core.sshCommand` (`setTerminalSsh`: on
  * by default for a member, a switch for the host; a user's own is never
- * overwritten).
+ * overwritten), plus a per-host SSH login name (`setSshUser`: AWS CodeCommit
+ * wants the IAM SSH key ID as the user) as a `url.<…>.insteadOf` rule there.
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 
@@ -468,6 +469,79 @@ async function setTerminalSsh(account, on) {
   return terminalSshState(account);
 }
 
+// ── SSH login name per host (`~/.gitconfig` url.<…>.insteadOf) ─────────────
+
+// AWS CodeCommit logs an SSH key in by its IAM key ID (`APKA…`) as the user
+// name, so `ssh://git-codecommit…/v1/repos/x` (no user) is refused. One
+// `url."ssh://<user>@<host>/".insteadOf "ssh://<host>/"` per host makes the
+// plain URL work for every git of the account — a clone typed in a pane, the
+// Clone dialog's and the git bar's — without touching `~/.ssh/config`. The
+// user name is no secret (an ID, not a key), so it may cross sudo's argv.
+const SSH_USER_RE = /^[A-Za-z0-9_][A-Za-z0-9._-]{0,63}$/;
+const insteadOfBase = (host, user) => `ssh://${user}@${host}/`;
+
+/** `[{host, user}]` — only the rules of exactly our shape; any other insteadOf is the user's. */
+async function listSshUsers(account) {
+  const { git } = require("./worktree");
+  const out = await git(homeOf(account), [
+    "config",
+    "--global",
+    "--get-regexp",
+    "^url\\..*\\.insteadof$",
+  ]).then(
+    (r) => r.stdout,
+    () => ""
+  );
+  const rows = [];
+  for (const line of out.split("\n")) {
+    const m = /^url\.ssh:\/\/([^@/\s]+)@([^/\s]+)\/\.insteadof ssh:\/\/([^/\s]+)\/$/.exec(line);
+    if (m && m[2] === m[3] && SSH_USER_RE.test(m[1]) && HOST_RE.test(m[2])) {
+      rows.push({ host: m[2], user: m[1] });
+    }
+  }
+  return rows;
+}
+
+/** Drop our rule for `host` (whatever its user); false when there was none. */
+async function removeSshUser(account, host) {
+  const { git } = require("./worktree");
+  const h = String(host || "").toLowerCase();
+  const rows = (await listSshUsers(account)).filter((r) => r.host === h);
+  for (const r of rows) {
+    await git(homeOf(account), [
+      "config",
+      "--global",
+      "--fixed-value",
+      "--unset-all",
+      `url.${insteadOfBase(r.host, r.user)}.insteadOf`,
+      `ssh://${r.host}/`,
+    ]);
+  }
+  return rows.length > 0;
+}
+
+/** Log in to `host` over SSH as `user` (replaces our earlier rule for that host). */
+async function setSshUser(account, { host, user } = {}) {
+  const h = String(host || "")
+    .trim()
+    .toLowerCase();
+  const u = String(user || "").trim();
+  if (!HOST_RE.test(h)) {
+    throw err("EBADHOST", "a host name like git-codecommit.us-east-1.amazonaws.com");
+  }
+  if (!SSH_USER_RE.test(u)) throw err("EBADSSHUSER", "a user name of letters, digits, . _ -");
+  await removeSshUser(account, h);
+  const { git } = require("./worktree");
+  await git(homeOf(account), [
+    "config",
+    "--global",
+    "--add",
+    `url.${insteadOfBase(h, u)}.insteadOf`,
+    `ssh://${h}/`,
+  ]);
+  return listSshUsers(account);
+}
+
 // ── Network commands in an existing repo (git bar fetch/pull/push) ─────────
 
 /**
@@ -714,6 +788,9 @@ module.exports = {
   terminalSshCommand,
   terminalSshState,
   setTerminalSsh,
+  listSshUsers,
+  setSshUser,
+  removeSshUser,
   listHttps,
   saveHttps,
   removeHttps,
diff --git a/server/routes/git-identity.js b/server/routes/git-identity.js
index 0e0ea824..8c72fe3b 100644
--- a/server/routes/git-identity.js
+++ b/server/routes/git-identity.js
@@ -3,7 +3,8 @@
  * mounted at `/api/me/git`: the SSH keys a clone uses — ed25519 and/or rsa (make, replace, delete —
  * only the PUBLIC key is ever returned) and the HTTPS logins (save, delete —
  * `hasToken` only, never a password), whether the account's own terminal
- * git uses that key (`core.sshCommand`), and the commit author (`user.name` /
+ * git uses that key (`core.sshCommand`), the SSH login name per host
+ * (`url.<…>.insteadOf` — AWS CodeCommit's SSH key ID), and the commit author (`user.name` /
  * `user.email` of the account's global git config — a member's commits fail
  * without one). The account is the signed-in user's
  * own Linux account under S3, else the host's, which only an admin (or local
@@ -29,6 +30,7 @@ const STATUS = {
   ESTOREUNREADABLE: 409,
   EBADKEYTYPE: 400,
   EFOREIGNSSH: 409,
+  EBADSSHUSER: 400,
 };
 
 function fail(res, e) {
@@ -47,6 +49,7 @@ async function view(account) {
     ssh: keys[0] ? { ...keys[0], terminal } : null,
     sshKeys: keys,
     sshTerminal: terminal ?? null,
+    sshUsers: await identity.listSshUsers(account),
     https: identity.listHttps(account),
     author: await identity.getAuthor(account),
   };
@@ -115,6 +118,32 @@ router.put("/ssh-terminal", sameOriginGuard, async (req, res) => {
   }
 });
 
+/**
+ * The SSH user name for one host (`{host, user}`) — e.g. AWS CodeCommit's SSH
+ * key ID, so a plain `ssh://git-codecommit…/` URL logs in. DELETE drops it.
+ */
+router.put("/ssh-user", sameOriginGuard, async (req, res) => {
+  try {
+    const account = accountOf(req, { write: true });
+    await identity.setSshUser(account, req.body || {});
+    res.json(await view(account));
+  } catch (e) {
+    fail(res, e);
+  }
+});
+
+router.delete("/ssh-user/:host", sameOriginGuard, async (req, res) => {
+  try {
+    const account = accountOf(req, { write: true });
+    if (!(await identity.removeSshUser(account, req.params.host))) {
+      return res.status(404).json({ error: { code: "ENOTFOUND", message: "no such SSH user" } });
+    }
+    res.json(await view(account));
+  } catch (e) {
+    fail(res, e);
+  }
+});
+
 router.post("/https", sameOriginGuard, async (req, res) => {
   try {
     const account = accountOf(req, { write: true });