diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index e91d38b6acc..fd0f5b64c1e 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -25,7 +25,7 @@ on:
         required: false
         type: string
       release_notes:
-        description: "Reviewed V2 release notes for the Discord announcement (optional)"
+        description: "Reviewed V2 release notes for CHANGELOG.md and the Discord announcement (optional)"
         required: false
         type: string
 
@@ -647,6 +647,7 @@ jobs:
         env:
           OPENCODE_VERSION: ${{ needs.version.outputs.version }}
           OPENCODE_RELEASE: ${{ needs.version.outputs.release }}
+          OPENCODE_RELEASE_NOTES: ${{ (github.ref_name == 'v2' && inputs.release_notes) || '' }}
           AUR_KEY: ${{ secrets.AUR_KEY }}
           GITHUB_TOKEN: ${{ steps.committer.outputs.token }}
           GH_REPO: ${{ needs.version.outputs.repo }}
diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 00000000000..4aad13af4f3
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,3 @@
+# Changelog
+
+Release notes for OpenCode V2, newest first.
diff --git a/script/publish.ts b/script/publish.ts
index 006c699566b..096134a594c 100755
--- a/script/publish.ts
+++ b/script/publish.ts
@@ -27,6 +27,20 @@ async function prepareReleaseFiles() {
   await $`bun install`
 }
 
+async function writeChangelog() {
+  const notes = process.env["OPENCODE_RELEASE_NOTES"]?.trim()
+  if (!notes) return
+  const file = Bun.file("CHANGELOG.md")
+  const text = await file.text()
+  const lines = text.split("\n")
+  if (lines.some((line) => line === `## ${tag}` || line.startsWith(`## ${tag} `))) return
+  const index = lines.findIndex((line) => line.startsWith("## "))
+  const head = (index === -1 ? lines : lines.slice(0, index)).join("\n").trimEnd()
+  const rest = index === -1 ? "" : lines.slice(index).join("\n")
+  const entry = `## ${tag} — ${new Date().toISOString().slice(0, 10)}\n\n${notes}\n`
+  await file.write(`${head}\n\n${entry}${rest ? `\n${rest}` : ""}`)
+}
+
 if (Script.release && !Script.preview) {
   await $`git fetch origin --tags`
   await $`git switch --detach`
@@ -90,6 +104,7 @@ if (Script.release && !Script.preview) {
   await $`git fetch origin`
   await $`git checkout -B v2 origin/v2`
   await prepareReleaseFiles()
+  await writeChangelog()
   if ((await $`git diff --quiet`.nothrow()).exitCode !== 0) {
     // The release already published this code; a push-triggered dev publish of a version bump is wasted work.
     await $`git commit -am ${`sync release versions for ${tag} [skip ci]`}`