diff --git a/src/dashboard.tsx b/src/dashboard.tsx
index 243aa8d..d942f9d 100644
--- a/src/dashboard.tsx
+++ b/src/dashboard.tsx
@@ -1085,6 +1085,10 @@ export async function renderDashboard(period: Period = 'week', provider: string
     await waitUntilExit()
   } else {
     const { unmount } = render(<StaticDashboard projects={filteredProjects} period={period} activeProvider={provider} planUsages={planUsages} label={label} dayMode={initialDay != null} />, { patchConsole: false })
+    // Non-interactive one-shot output: ink schedules the frame through a
+    // throttled render, so yield a tick to let it flush to stdout before
+    // unmounting. Unmounting synchronously can race the flush and drop output.
+    await new Promise<void>(resolve => setTimeout(resolve, 0))
     unmount()
   }
 }
diff --git a/src/main.ts b/src/main.ts
index 1fad67b..f92c07f 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -4,6 +4,7 @@ import { installMenubarApp } from './menubar-installer.js'
 import { exportCsv, exportJson, type PeriodExport } from './export.js'
 import { loadPricing, setModelAliases, setLocalModelSavings, setProxyPaths, normalizeProxyPath } from './models.js'
 import { parseAllSessions, filterProjectsByName, filterProjectsByDateRange, clearSessionCache } from './parser.js'
+import { allProviderNames } from './providers/index.js'
 import { convertCost } from './currency.js'
 import { renderStatusBar } from './format.js'
 import { toDateString } from './daily-cache.js'
@@ -122,6 +123,15 @@ function assertFormat(value: string, allowed: readonly string[], command: string
   }
 }
 
+function assertProvider(value: string, command: string): void {
+  const names = allProviderNames()
+  if (value === 'all' || names.includes(value)) return
+  process.stderr.write(
+    `codeburn ${command}: unknown provider "${value}". Valid values: all, ${names.join(', ')}.\n`
+  )
+  process.exit(1)
+}
+
 async function runJsonReport(period: Period, provider: string, project: string[], exclude: string[]): Promise<void> {
   await loadPricing()
   const { range, label } = getDateRange(period)
@@ -421,6 +431,7 @@ program
   .option('--refresh <seconds>', 'Auto-refresh interval in seconds (0 to disable)', parseInteger, 30)
   .action(async (opts) => {
     assertFormat(opts.format, ['tui', 'json'], 'report')
+    assertProvider(opts.provider, 'report')
     let customRange: DateRange | null = null
     let daySelection: ReturnType<typeof parseDayFlag> = null
     try {
@@ -473,6 +484,7 @@ program
   .option('--no-optimize', 'Skip optimize findings (menubar-json only, faster)')
   .action(async (opts) => {
     assertFormat(opts.format, ['terminal', 'menubar-json', 'json'], 'status')
+    assertProvider(opts.provider, 'status')
     if (opts.day && (opts.from || opts.to)) {
       process.stderr.write('error: --day cannot be combined with --from or --to\n')
       process.exit(1)
@@ -553,6 +565,7 @@ program
   .option('--refresh <seconds>', 'Auto-refresh interval in seconds (0 to disable)', parseInteger, 30)
   .action(async (opts) => {
     assertFormat(opts.format, ['tui', 'json'], 'today')
+    assertProvider(opts.provider, 'today')
     if (opts.format === 'json') {
       await runJsonReport('today', opts.provider, opts.project, opts.exclude)
       return
@@ -570,6 +583,7 @@ program
   .option('--refresh <seconds>', 'Auto-refresh interval in seconds (0 to disable)', parseInteger, 30)
   .action(async (opts) => {
     assertFormat(opts.format, ['tui', 'json'], 'month')
+    assertProvider(opts.provider, 'month')
     if (opts.format === 'json') {
       await runJsonReport('month', opts.provider, opts.project, opts.exclude)
       return
@@ -589,6 +603,7 @@ program
   .option('--exclude <name>', 'Exclude projects matching name (repeatable)', collect, [])
   .action(async (opts) => {
     assertFormat(opts.format, ['csv', 'json'], 'export')
+    assertProvider(opts.provider, 'export')
     await loadPricing()
     const pf = opts.provider
     const fp = (p: ProjectSummary[]) => filterProjectsByName(p, opts.project, opts.exclude)
@@ -1036,6 +1051,7 @@ program
   .option('--format <format>', 'Output format: text, json', 'text')
   .action(async (opts) => {
     assertFormat(opts.format, ['text', 'json'], 'optimize')
+    assertProvider(opts.provider, 'optimize')
     await loadPricing()
     const { range, label } = getDateRange(opts.period)
     const projects = await parseAllSessions(range, opts.provider)
@@ -1048,6 +1064,7 @@ program
   .option('-p, --period <period>', 'Analysis period: today, week, 30days, month, all', 'all')
   .option('--provider <provider>', 'Filter by provider (e.g. claude, gemini, cursor, copilot)', 'all')
   .action(async (opts) => {
+    assertProvider(opts.provider, 'compare')
     await loadPricing()
     const { range } = getDateRange(opts.period)
     await renderCompare(range, opts.provider)
@@ -1067,6 +1084,7 @@ program
   .option('--no-totals', 'Suppress the footer totals row')
   .option('--format <format>', 'Output format: table, markdown, json, csv', 'table')
   .action(async (opts) => {
+    assertProvider(opts.provider, 'models')
     const { aggregateModels, renderTable, renderMarkdown, renderJson, renderCsv } = await import('./models-report.js')
     await loadPricing()
 
diff --git a/src/providers/index.ts b/src/providers/index.ts
index 93af972..f52886b 100644
--- a/src/providers/index.ts
+++ b/src/providers/index.ts
@@ -154,6 +154,22 @@ async function loadCrush(): Promise<Provider | null> {
 
 const coreProviders: Provider[] = [claude, cline, codebuff, codex, copilot, devin, droid, gemini, ibmBob, kiloCode, kiro, kimi, mistralVibe, mux, openclaw, pi, omp, qwen, rooCode]
 
+// Lazily loaded providers, listed by name so --provider validation works even
+// when an optional module fails to load. Must stay in sync with getAllProviders.
+const lazyProviderNames = ['antigravity', 'forge', 'goose', 'cursor', 'opencode', 'cursor-agent', 'crush', 'warp', 'vercel-gateway']
+
+// Canonical set of every provider name (core + lazy), used to validate the
+// --provider CLI flag. Computed lazily so importing this module never depends on
+// every provider object being defined at load time (e.g. under test mocks).
+let allProviderNamesCache: string[] | undefined
+export function allProviderNames(): readonly string[] {
+  allProviderNamesCache ??= [
+    ...coreProviders.map(p => p.name),
+    ...lazyProviderNames,
+  ].sort()
+  return allProviderNamesCache
+}
+
 export async function getAllProviders(): Promise<Provider[]> {
   const [ag, forge, gs, cursor, opencode, cursorAgent, crush, warp, vercelGw] = await Promise.all([
     loadAntigravity(), loadForge(), loadGoose(), loadCursor(), loadOpenCode(), loadCursorAgent(), loadCrush(), loadWarp(), loadVercelGateway(),
diff --git a/tests/cli-provider-validation.test.ts b/tests/cli-provider-validation.test.ts
new file mode 100644
index 0000000..4fa9089
--- /dev/null
+++ b/tests/cli-provider-validation.test.ts
@@ -0,0 +1,72 @@
+import { mkdtemp, rm } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { spawnSync } from 'node:child_process'
+
+import { afterEach, describe, expect, it } from 'vitest'
+
+import { allProviderNames, getAllProviders } from '../src/providers/index.js'
+
+let homes: string[] = []
+
+afterEach(async () => {
+  while (homes.length > 0) {
+    const h = homes.pop()
+    if (h) await rm(h, { recursive: true, force: true })
+  }
+})
+
+async function makeHome(): Promise<string> {
+  const home = await mkdtemp(join(tmpdir(), 'codeburn-provider-cli-'))
+  homes.push(home)
+  return home
+}
+
+function runCli(args: string[], home: string) {
+  return spawnSync(process.execPath, ['--import', 'tsx', 'src/cli.ts', ...args], {
+    cwd: process.cwd(),
+    env: { ...process.env, HOME: home, CLAUDE_CONFIG_DIR: join(home, '.claude'), TZ: 'UTC' },
+    encoding: 'utf-8',
+    timeout: 30_000,
+  })
+}
+
+describe('allProviderNames', () => {
+  it('is non-empty, sorted, and excludes the "all" sentinel', () => {
+    const names = allProviderNames()
+    expect(names.length).toBeGreaterThan(0)
+    expect([...names]).toEqual([...names].sort())
+    expect(names).not.toContain('all')
+  })
+
+  it('covers every loadable provider (guards against lazy-list drift)', async () => {
+    const loaded = (await getAllProviders()).map(p => p.name)
+    const names = allProviderNames()
+    for (const name of loaded) {
+      expect(names).toContain(name)
+    }
+  })
+})
+
+describe('codeburn --provider validation', () => {
+  it('rejects an unknown provider with a clear error and exit 1', async () => {
+    const home = await makeHome()
+    const res = runCli(['report', '--provider', 'claud', '-p', 'today'], home)
+    expect(res.status).toBe(1)
+    expect(res.stderr).toContain('unknown provider "claud"')
+    expect(res.stderr).toContain('Valid values: all,')
+  })
+
+  it('accepts a valid provider', async () => {
+    const home = await makeHome()
+    const res = runCli(['status', '--provider', 'claude', '--format', 'json'], home)
+    expect(res.status).toBe(0)
+    expect(res.stderr).not.toContain('unknown provider')
+  })
+
+  it('accepts the "all" sentinel', async () => {
+    const home = await makeHome()
+    const res = runCli(['status', '--provider', 'all', '--format', 'json'], home)
+    expect(res.status).toBe(0)
+  })
+})