diff --git a/packages/cli/.npmignore b/packages/cli/.npmignore
index 6337d94..bddc101 100644
--- a/packages/cli/.npmignore
+++ b/packages/cli/.npmignore
@@ -1,6 +1,11 @@
 src/
 tests/
 coverage/
+*.config.ts
+*.config.js
+.prettierrc
+.prettierignore
+tsconfig.json
 .prettierrc
 .prettierignore
 .eslintrc*
diff --git a/packages/cli/.prettierrc b/packages/cli/.prettierrc
index 1d9d0f6..2942f4b 100644
--- a/packages/cli/.prettierrc
+++ b/packages/cli/.prettierrc
@@ -1,5 +1,9 @@
 {
   "semi": true,
+  "singleQuote": false,
+  "printWidth": 100,
+  "trailingComma": "all",
+  "tabWidth": 2
   "singleQuote": true,
   "trailingComma": "all",
   "printWidth": 100,
diff --git a/packages/cli/CHANGELOG.md b/packages/cli/CHANGELOG.md
index ea9d18b..38239fb 100644
--- a/packages/cli/CHANGELOG.md
+++ b/packages/cli/CHANGELOG.md
@@ -1,3 +1,10 @@
+# @stellar-explain/cli
+
+## 0.1.0
+
+### Initial release
+
+- CLI for querying and explaining Stellar transactions via the Stellar Explain API
 # @stellar-explain/cli Changelog
 
 All notable changes to this package will be documented here.
diff --git a/packages/cli/src/build-watch.ts b/packages/cli/src/build-watch.ts
new file mode 100644
index 0000000..42e78c3
--- /dev/null
+++ b/packages/cli/src/build-watch.ts
@@ -0,0 +1,48 @@
+/**
+ * Spawns the TypeScript compiler in watch mode for CLI development.
+ * Issue #333 — Add a build:watch script for CLI development.
+ */
+
+import { spawn, ChildProcess } from "child_process";
+import path from "path";
+
+interface WatchOptions {
+  cwd?: string;
+  silent?: boolean;
+}
+
+export function startWatcher(opts: WatchOptions = {}): ChildProcess {
+  const cwd = opts.cwd ?? path.resolve(__dirname, "..");
+  const tsc = process.platform === "win32" ? "tsc.cmd" : "tsc";
+
+  const child = spawn(tsc, ["--watch", "--preserveWatchOutput"], {
+    cwd,
+    stdio: opts.silent ? "ignore" : "inherit",
+    shell: false,
+  });
+
+  child.on("error", (err) => {
+    console.error("Failed to start tsc watcher:", err.message);
+    process.exit(1);
+  });
+
+  child.on("exit", (code) => {
+    if (code !== null && code !== 0) {
+      console.error(`tsc exited with code ${code}`);
+    }
+  });
+
+  return child;
+}
+
+export function stopWatcher(child: ChildProcess): void {
+  if (!child.killed) child.kill("SIGTERM");
+}
+
+if (require.main === module) {
+  const watcher = startWatcher();
+  process.on("SIGINT", () => {
+    stopWatcher(watcher);
+    process.exit(0);
+  });
+}
diff --git a/packages/cli/src/changeset-helper.ts b/packages/cli/src/changeset-helper.ts
new file mode 100644
index 0000000..3ed0f07
--- /dev/null
+++ b/packages/cli/src/changeset-helper.ts
@@ -0,0 +1,49 @@
+/**
+ * Reads and validates the Changesets config for the CLI package.
+ * Issue #335 — Add Changesets for CLI version management.
+ */
+
+import fs from "fs";
+import path from "path";
+
+interface ChangesetConfig {
+  $schema: string;
+  changelog: string;
+  commit: boolean;
+  access: "public" | "restricted";
+  baseBranch: string;
+  updateInternalDependencies: "patch" | "minor";
+  ignore: string[];
+}
+
+export function loadChangesetConfig(root: string): ChangesetConfig | null {
+  const configPath = path.join(root, ".changeset", "config.json");
+  if (!fs.existsSync(configPath)) return null;
+  try {
+    return JSON.parse(fs.readFileSync(configPath, "utf-8")) as ChangesetConfig;
+  } catch {
+    return null;
+  }
+}
+
+export function validateChangesetConfig(config: ChangesetConfig): string[] {
+  const errors: string[] = [];
+  if (config.access !== "public") errors.push(`access should be "public"`);
+  if (config.baseBranch !== "main") errors.push(`baseBranch should be "main"`);
+  if (config.commit !== false) errors.push(`commit should be false`);
+  return errors;
+}
+
+export function checkChangesetSetup(root: string): void {
+  const config = loadChangesetConfig(root);
+  if (!config) {
+    console.error("Missing .changeset/config.json");
+    process.exit(1);
+  }
+  const errors = validateChangesetConfig(config);
+  if (errors.length > 0) {
+    console.error("Changeset config issues:\n" + errors.join("\n"));
+    process.exit(1);
+  }
+  console.log("Changeset config OK");
+}
diff --git a/packages/cli/src/npmignore-check.ts b/packages/cli/src/npmignore-check.ts
new file mode 100644
index 0000000..16b3f9a
--- /dev/null
+++ b/packages/cli/src/npmignore-check.ts
@@ -0,0 +1,46 @@
+/**
+ * Verifies .npmignore excludes dev-only paths from the published package.
+ * Issue #334 — Add .npmignore to keep published package lean.
+ */
+
+import fs from "fs";
+import path from "path";
+
+const REQUIRED_EXCLUSIONS = [
+  "src/",
+  "tests/",
+  "coverage/",
+  "*.config.ts",
+  "*.config.js",
+  ".prettierrc",
+  ".prettierignore",
+  "tsconfig.json",
+];
+
+export function loadNpmIgnore(root: string): string[] {
+  const filePath = path.join(root, ".npmignore");
+  if (!fs.existsSync(filePath)) return [];
+  return fs
+    .readFileSync(filePath, "utf-8")
+    .split("\n")
+    .map((l) => l.trim())
+    .filter(Boolean);
+}
+
+export function findMissingExclusions(entries: string[]): string[] {
+  return REQUIRED_EXCLUSIONS.filter((req) => !entries.includes(req));
+}
+
+export function checkNpmIgnore(root: string): void {
+  const entries = loadNpmIgnore(root);
+  if (entries.length === 0) {
+    console.error(".npmignore is missing or empty");
+    process.exit(1);
+  }
+  const missing = findMissingExclusions(entries);
+  if (missing.length > 0) {
+    console.error("Missing exclusions in .npmignore:\n" + missing.join("\n"));
+    process.exit(1);
+  }
+  console.log(".npmignore OK — all required exclusions present");
+}
diff --git a/packages/cli/src/prettier-config.ts b/packages/cli/src/prettier-config.ts
index 5f024ce..afe7738 100644
--- a/packages/cli/src/prettier-config.ts
+++ b/packages/cli/src/prettier-config.ts
@@ -1,9 +1,37 @@
+/**
+ * Validates that the Prettier config exists and matches expected rules.
+ * Issue #332 — Add Prettier config to the CLI package.
+ */
+
+import fs from "fs";
+import path from "path";
 import * as fs from 'fs';
 import * as path from 'path';
 
 interface PrettierConfig {
   semi: boolean;
   singleQuote: boolean;
+  printWidth: number;
+  trailingComma: string;
+  tabWidth: number;
+}
+
+const EXPECTED: PrettierConfig = {
+  semi: true,
+  singleQuote: false,
+  printWidth: 100,
+  trailingComma: "all",
+  tabWidth: 2,
+};
+
+export function loadPrettierConfig(root: string): PrettierConfig | null {
+  const configPath = path.join(root, ".prettierrc");
+  if (!fs.existsSync(configPath)) return null;
+  try {
+    return JSON.parse(fs.readFileSync(configPath, "utf-8")) as PrettierConfig;
+  } catch {
+    return null;
+  }
   trailingComma: string;
   printWidth: number;
   tabWidth: number;
@@ -30,6 +58,11 @@ export function loadPrettierConfig(packageDir: string): PrettierConfig {
 
 export function validatePrettierConfig(config: PrettierConfig): string[] {
   const errors: string[] = [];
+  for (const [key, expected] of Object.entries(EXPECTED)) {
+    const actual = config[key as keyof PrettierConfig];
+    if (actual !== expected) {
+      errors.push(`"${key}": expected ${JSON.stringify(expected)}, got ${JSON.stringify(actual)}`);
+    }
   if (config.printWidth < 40 || config.printWidth > 200) {
     errors.push(`printWidth ${config.printWidth} is out of range [40, 200]`);
   }
@@ -42,6 +75,18 @@ export function validatePrettierConfig(config: PrettierConfig): string[] {
   return errors;
 }
 
+export function checkPrettierSetup(root: string): void {
+  const config = loadPrettierConfig(root);
+  if (!config) {
+    console.error("Missing .prettierrc in", root);
+    process.exit(1);
+  }
+  const errors = validatePrettierConfig(config);
+  if (errors.length > 0) {
+    console.error("Prettier config mismatch:\n" + errors.join("\n"));
+    process.exit(1);
+  }
+  console.log("Prettier config OK");
 export function describePrettierConfig(config: PrettierConfig): string {
   const parts = [
     `printWidth=${config.printWidth}`,