diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 26a5da1..7008c6e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -33,6 +33,9 @@ jobs:
       - name: Check schema
         run: pnpm check:schema
 
+      - name: Check changesets
+        run: pnpm check:changesets
+
       - name: Unit tests
         run: pnpm test
 
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 98aa551..5986173 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -45,6 +45,9 @@ jobs:
       - name: Install dependencies
         run: pnpm install --frozen-lockfile
 
+      - name: Check changesets
+        run: pnpm check:changesets
+
       - name: Get release info
         id: release-info
         run: |
diff --git a/.husky/pre-commit b/.husky/pre-commit
index d7b967c..c1838ab 100644
--- a/.husky/pre-commit
+++ b/.husky/pre-commit
@@ -1,3 +1,4 @@
 pnpm install --frozen-lockfile --silent
 pnpm typecheck
 pnpm lint
+pnpm check:changesets
diff --git a/AGENTS.md b/AGENTS.md
index 65cadd2..dad152f 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -26,6 +26,7 @@ During UI tests that require processes to be running, either give the user a pro
 - `pnpm format` — Biome check with write
 - `pnpm gen:schema` — regenerate `schema.json` from `extensions/processes/config/types.ts`
 - `pnpm check:schema` — verify `schema.json` is up to date
+- `pnpm check:changesets` — validate `.changeset/*.md` frontmatter, package names, and bump types
 - `pnpm test` — Unit tests
 - `pnpm test:e2e` — End-to-end tests
 - `pnpm changeset` — Add a changeset
diff --git a/package.json b/package.json
index 727b326..98bc868 100644
--- a/package.json
+++ b/package.json
@@ -77,6 +77,7 @@
     "format": "biome check --write",
     "gen:schema": "ts-json-schema-generator --path extensions/processes/config/types.ts --type ProcessConfig --no-type-check -o schema.json",
     "check:schema": "ts-json-schema-generator --path extensions/processes/config/types.ts --type ProcessConfig --no-type-check -o /tmp/pi-processes-schema-check.json && diff -q schema.json /tmp/pi-processes-schema-check.json",
+    "check:changesets": "node scripts/check-changesets.ts",
     "check:lockfile": "pnpm install --frozen-lockfile --ignore-scripts",
     "prepare": "[ -d .git ] && husky || true",
     "changeset": "changeset",
diff --git a/scripts/check-changesets.ts b/scripts/check-changesets.ts
new file mode 100644
index 0000000..a065c25
--- /dev/null
+++ b/scripts/check-changesets.ts
@@ -0,0 +1,80 @@
+#!/usr/bin/env node
+// Validates .changeset/*.md files: frontmatter shape, package names, bump types.
+import { readdirSync, readFileSync } from "node:fs";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const root = join(dirname(fileURLToPath(import.meta.url)), "..");
+const changesetDir = join(root, ".changeset");
+const validBumps = new Set(["major", "minor", "patch"]);
+
+const pkg = JSON.parse(readFileSync(join(root, "package.json"), "utf8")) as {
+  name: string;
+};
+const pkgName = pkg.name;
+const knownPackages = new Set([pkgName]);
+
+const files = readdirSync(changesetDir)
+  .filter((f) => f.endsWith(".md") && f !== "README.md")
+  .sort();
+
+const errors: string[] = [];
+
+for (const file of files) {
+  const path = join(".changeset", file);
+  const content = readFileSync(join(changesetDir, file), "utf8");
+  const match = content.match(/^---\r?\n([\s\S]*?)\r?\n---\r?\n([\s\S]*)$/);
+
+  if (!match) {
+    errors.push(`${path}: missing or malformed frontmatter block`);
+    continue;
+  }
+
+  const [, frontmatter, body] = match;
+  const lines = frontmatter.split(/\r?\n/).filter((line) => line.trim() !== "");
+
+  if (lines.length === 0) {
+    errors.push(`${path}: frontmatter lists no packages`);
+  }
+
+  for (const line of lines) {
+    const entry = line.match(
+      /^\s*(?:"([^"]+)"|'([^']+)'|([^:]+?))\s*:\s*(.+?)\s*$/,
+    );
+    if (!entry) {
+      errors.push(`${path}: cannot parse frontmatter line: ${line.trim()}`);
+      continue;
+    }
+
+    const name = entry[1] ?? entry[2] ?? entry[3];
+    const bump = entry[4].replace(/^["']|["']$/g, "");
+
+    if (!knownPackages.has(name)) {
+      errors.push(
+        `${path}: unknown package "${name}" (expected one of: ${[...knownPackages].join(", ")})`,
+      );
+    }
+    if (!validBumps.has(bump)) {
+      errors.push(
+        `${path}: invalid bump "${bump}" for "${name}" (expected major, minor or patch)`,
+      );
+    }
+  }
+
+  if (body.trim() === "") {
+    errors.push(`${path}: empty changeset description`);
+  }
+}
+
+if (errors.length > 0) {
+  console.error("Invalid changesets:\n");
+  for (const error of errors) {
+    console.error(`  ${error}`);
+  }
+  console.error("");
+  process.exit(1);
+}
+
+console.log(
+  `Checked ${files.length} changeset${files.length === 1 ? "" : "s"}.`,
+);
diff --git a/tsconfig.json b/tsconfig.json
index fa13cbc..03befb5 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -10,7 +10,7 @@
     "resolveJsonModule": true,
     "noEmit": true
   },
-  "include": ["src/**/*", "extensions/**/*", "tests/**/*"],
+  "include": ["src/**/*", "extensions/**/*", "scripts/**/*", "tests/**/*"],
   // tests/evals has its own tsconfig: it depends on the gitignored vendored
   // pi-evals harness, so `pnpm typecheck` must stay green without a sync.
   "exclude": ["node_modules", "tests/evals"]