diff --git a/package.json b/package.json
index a96fead4fc..e66143c6e3 100644
--- a/package.json
+++ b/package.json
@@ -183,7 +183,8 @@
       "init": [
         "./dist/hooks/init/version",
         "./dist/hooks/init/terms-of-service",
-        "./dist/hooks/init/setup-otel-telemetry"
+        "./dist/hooks/init/setup-otel-telemetry",
+        "./dist/hooks/init/configure-git-credential-manager"
       ],
       "postrun": [
         "./dist/hooks/postrun/send-otel-telemetry"
diff --git a/src/hooks/init/configure-git-credential-manager.ts b/src/hooks/init/configure-git-credential-manager.ts
new file mode 100644
index 0000000000..7ffbb44995
--- /dev/null
+++ b/src/hooks/init/configure-git-credential-manager.ts
@@ -0,0 +1,41 @@
+import {Hook} from '@oclif/core/hooks'
+
+import Git from '../../lib/git/git.js'
+
+const hook: Hook.Init = async function () {
+  // Skip for --version / --help / completion-style invocations to avoid a needless git subprocess.
+  // Version-style invocations include `--version` plus any `oclif.additionalVersionFlags`
+  // (e.g. `-v`, `version`) declared in package.json — mirror version.ts, which reads the
+  // same config. We hard-include `-v`/`version` as a defensive fallback so this skip can
+  // never silently regress if config is somehow unavailable at runtime.
+  // Help-style invocations are skipped for the same reason: they're fast informational
+  // commands that shouldn't touch git. They include `--help` plus any
+  // `oclif.additionalHelpFlags` (e.g. `-h`) declared in package.json, and we hard-include
+  // `--help`/`-h`/`help` as the same kind of defensive fallback.
+  // Completion invocations are matched by the `autocomplete` prefix, since shell completion
+  // actually runs `autocomplete:options` (not the bare `autocomplete` command).
+  // NOTE: temporary hook until v12.
+  const arg = process.argv[2]
+  const additionalVersionFlags = this.config?.pjson?.oclif?.additionalVersionFlags ?? []
+  const additionalHelpFlags = this.config?.pjson?.oclif?.additionalHelpFlags ?? []
+  const skip = new Set([
+    '--help',
+    '--version',
+    '-h',
+    '-v',
+    'help',
+    'version',
+    ...additionalHelpFlags,
+    ...additionalVersionFlags,
+  ])
+  if (!arg || skip.has(arg) || arg.startsWith('autocomplete')) return
+
+  const git = new Git()
+  try {
+    await git.configureCredentialHelper()
+  } catch {
+    // ignore — best-effort; never block a command on git config
+  }
+}
+
+export default hook
diff --git a/src/lib/git/git.ts b/src/lib/git/git.ts
index ab40f3c189..bc8ea35b22 100644
--- a/src/lib/git/git.ts
+++ b/src/lib/git/git.ts
@@ -16,12 +16,17 @@ export default class Git {
   */
   async configureCredentialHelper() {
     const {httpGitHost} = vars
-    await this.exec([
-      'config',
-      '--global',
-      `credential.https://${httpGitHost}.helper`,
-      '!heroku git:credentials',
-    ])
+    const key = `credential.https://${httpGitHost}.helper`
+    const helper = '!heroku git:credentials'
+    // Read the existing value first so we can skip the write when it is already
+    // set to our helper. `git config` rewrites the global config file (new inode)
+    // even when the value is byte-identical, and this runs before nearly every
+    // command via the init hook, so the no-op write churns the user's gitconfig.
+    // When the key is absent the `--get` exits non-zero and `exec` throws, so we
+    // treat that as an empty string.
+    const existing = await this.exec(['config', '--global', '--get', key]).catch(() => '')
+    if (existing === helper) return
+    await this.exec(['config', '--global', key, helper])
   }
 
   createRemote(remote: string, url: string) {
diff --git a/test/unit/hooks/configure-git-credential-manager.unit.test.ts b/test/unit/hooks/configure-git-credential-manager.unit.test.ts
new file mode 100644
index 0000000000..e14583da3a
--- /dev/null
+++ b/test/unit/hooks/configure-git-credential-manager.unit.test.ts
@@ -0,0 +1,213 @@
+import {expect} from 'chai'
+import {readFileSync} from 'node:fs'
+import {join} from 'node:path'
+import {fileURLToPath} from 'node:url'
+import * as sinon from 'sinon'
+
+import configureGitCredentialManagerHook from '../../../src/hooks/init/configure-git-credential-manager.js'
+import Git from '../../../src/lib/git/git.js'
+
+const callHook = async (id: string) => {
+  // The hook reads `this.config.pjson.oclif.additionalVersionFlags` and
+  // `.additionalHelpFlags`, so the bound `this` context must carry a real config to
+  // exercise the production code path (this.config IS set when oclif invokes the hook).
+  // The `--sentinel-help` flag below appears ONLY in additionalHelpFlags (not the
+  // hardcoded set), so a test using it proves the dynamic merge spread actually works.
+  const config = {pjson: {oclif: {additionalHelpFlags: ['-h', '--sentinel-help'], additionalVersionFlags: ['-v', 'version']}}}
+  const context = {config}
+  const options = {
+    argv: [],
+    config: config as any,
+    context: {} as any,
+    id,
+  }
+
+  await configureGitCredentialManagerHook.call(context as any, options)
+}
+
+describe('configure-git-credential-manager hook', function () {
+  let originalArgv: string[]
+  let configureStub: sinon.SinonStub
+
+  beforeEach(function () {
+    // Save original argv since the hook reads process.argv[2]
+    originalArgv = process.argv
+
+    // Stub on the prototype so the real git subprocess never runs
+    configureStub = sinon.stub(Git.prototype, 'configureCredentialHelper').resolves()
+  })
+
+  afterEach(function () {
+    process.argv = originalArgv
+    sinon.restore()
+  })
+
+  describe('when a normal command is invoked', function () {
+    beforeEach(function () {
+      process.argv = ['node', 'heroku', 'apps']
+    })
+
+    it('configures the git credential helper exactly once', async function () {
+      await callHook('apps')
+
+      expect(configureStub.calledOnce).to.be.true
+    })
+  })
+
+  describe('when configuring the credential helper fails', function () {
+    beforeEach(function () {
+      process.argv = ['node', 'heroku', 'apps']
+      configureStub.rejects(new Error('Git not found'))
+    })
+
+    it('does not throw', async function () {
+      try {
+        await callHook('apps')
+      } catch (error: any) {
+        expect.fail(`hook should not throw, but threw: ${error.message}`)
+      }
+
+      expect(configureStub.calledOnce).to.be.true
+    })
+  })
+
+  describe('when command is --version', function () {
+    beforeEach(function () {
+      process.argv = ['node', 'heroku', '--version']
+    })
+
+    it('does not configure the git credential helper', async function () {
+      await callHook('--version')
+
+      expect(configureStub.called).to.be.false
+    })
+  })
+
+  describe('when command is the version command', function () {
+    beforeEach(function () {
+      process.argv = ['node', 'heroku', 'version']
+    })
+
+    it('does not configure the git credential helper', async function () {
+      await callHook('version')
+
+      expect(configureStub.called).to.be.false
+    })
+  })
+
+  describe('when command is -v', function () {
+    beforeEach(function () {
+      process.argv = ['node', 'heroku', '-v']
+    })
+
+    it('does not configure the git credential helper', async function () {
+      await callHook('-v')
+
+      expect(configureStub.called).to.be.false
+    })
+  })
+
+  describe('when command is --help', function () {
+    beforeEach(function () {
+      process.argv = ['node', 'heroku', '--help']
+    })
+
+    it('does not configure the git credential helper', async function () {
+      await callHook('--help')
+
+      expect(configureStub.called).to.be.false
+    })
+  })
+
+  describe('when command is the help command', function () {
+    beforeEach(function () {
+      process.argv = ['node', 'heroku', 'help']
+    })
+
+    it('does not configure the git credential helper', async function () {
+      await callHook('help')
+
+      expect(configureStub.called).to.be.false
+    })
+  })
+
+  describe('when command is -h', function () {
+    beforeEach(function () {
+      process.argv = ['node', 'heroku', '-h']
+    })
+
+    it('does not configure the git credential helper', async function () {
+      await callHook('-h')
+
+      expect(configureStub.called).to.be.false
+    })
+  })
+
+  describe('when command is a flag present only in additionalHelpFlags', function () {
+    beforeEach(function () {
+      process.argv = ['node', 'heroku', '--sentinel-help']
+    })
+
+    it('does not configure the git credential helper', async function () {
+      await callHook('--sentinel-help')
+
+      expect(configureStub.called).to.be.false
+    })
+  })
+
+  describe('when command is autocomplete', function () {
+    beforeEach(function () {
+      process.argv = ['node', 'heroku', 'autocomplete']
+    })
+
+    it('does not configure the git credential helper', async function () {
+      await callHook('autocomplete')
+
+      expect(configureStub.called).to.be.false
+    })
+  })
+
+  describe('when command is autocomplete:options (the real completion path)', function () {
+    beforeEach(function () {
+      process.argv = ['node', 'heroku', 'autocomplete:options', 'apps']
+    })
+
+    it('does not configure the git credential helper', async function () {
+      await callHook('autocomplete:options')
+
+      expect(configureStub.called).to.be.false
+    })
+  })
+
+  describe('when no command argument is provided', function () {
+    beforeEach(function () {
+      process.argv = ['node', 'heroku']
+    })
+
+    it('does not configure the git credential helper', async function () {
+      await callHook('')
+
+      expect(configureStub.called).to.be.false
+    })
+  })
+
+  // Registration regression guard: the unit tests above call the hook function
+  // directly, so they pass even if the hook is removed from package.json. This
+  // pins the oclif `init` hook list so an accidental deletion or path typo —
+  // including a botched removal when this temporary hook is taken out at v12 —
+  // fails a test instead of silently disabling the feature.
+  describe('oclif init hook registration', function () {
+    it('registers the expected init hooks in package.json', function () {
+      const root = fileURLToPath(new URL('.', import.meta.url))
+      const pjsonPath = join(root, '..', '..', '..', 'package.json')
+      const pjson = JSON.parse(readFileSync(pjsonPath, 'utf8'))
+
+      expect(pjson.oclif.hooks.init).to.deep.equal([
+        './dist/hooks/init/version',
+        './dist/hooks/init/terms-of-service',
+        './dist/hooks/init/setup-otel-telemetry',
+        './dist/hooks/init/configure-git-credential-manager',
+      ])
+    })
+  })
+})
diff --git a/test/unit/lib/git/git.unit.test.ts b/test/unit/lib/git/git.unit.test.ts
index bc34119a70..265fc9f440 100644
--- a/test/unit/lib/git/git.unit.test.ts
+++ b/test/unit/lib/git/git.unit.test.ts
@@ -119,15 +119,45 @@ describe('git', function () {
     expect(git.url('foo')).to.equal('https://git.heroku.com/foo.git')
   })
 
-  it('configures git credential helper globally for the Heroku Git host', async function () {
+  it('configures git credential helper globally when the key is absent', async function () {
+    // `git config --global --get` exits non-zero when the key is absent, so
+    // `exec` throws and the helper treats it as an empty existing value.
+    const err: any = new Error('not found')
+    err.code = 1
+    execFileStub.onFirstCall().rejects(err)
     execFileStub.resolves({stderr: '', stdout: ''})
 
     await git.configureCredentialHelper()
 
+    expect(execFileStub.calledTwice).to.be.true
+    expect(execFileStub.firstCall.args).to.deep.equal(['git', ['config', '--global', '--get', 'credential.https://git.heroku.com.helper']])
+    const [cmd, args] = execFileStub.secondCall.args
+    expect(cmd).to.equal('git')
+    expect(args).to.deep.equal(['config', '--global', 'credential.https://git.heroku.com.helper', '!heroku git:credentials'])
+  })
+
+  it('overwrites the git credential helper when it is set to a different value', async function () {
+    execFileStub.onFirstCall().resolves({stderr: '', stdout: '!some-other-helper'})
+    execFileStub.resolves({stderr: '', stdout: ''})
+
+    await git.configureCredentialHelper()
+
+    expect(execFileStub.calledTwice).to.be.true
+    expect(execFileStub.firstCall.args).to.deep.equal(['git', ['config', '--global', '--get', 'credential.https://git.heroku.com.helper']])
+    const [cmd, args] = execFileStub.secondCall.args
+    expect(cmd).to.equal('git')
+    expect(args).to.deep.equal(['config', '--global', 'credential.https://git.heroku.com.helper', '!heroku git:credentials'])
+  })
+
+  it('skips the write when the git credential helper is already configured', async function () {
+    execFileStub.resolves({stderr: '', stdout: '!heroku git:credentials'})
+
+    await git.configureCredentialHelper()
+
     expect(execFileStub.calledOnce).to.be.true
     const [cmd, args] = execFileStub.firstCall.args
     expect(cmd).to.equal('git')
-    expect(args).to.deep.equal(['config', '--global', 'credential.https://git.heroku.com.helper', '!heroku git:credentials'])
+    expect(args).to.deep.equal(['config', '--global', '--get', 'credential.https://git.heroku.com.helper'])
   })
 
   it('removes git credential helper from global config', async function () {