diff --git a/src/commands/cliproxy/catalog-subcommand.ts b/src/commands/cliproxy/catalog-subcommand.ts
index 13374e65..adcdb5e5 100644
--- a/src/commands/cliproxy/catalog-subcommand.ts
+++ b/src/commands/cliproxy/catalog-subcommand.ts
@@ -5,10 +5,12 @@ import {
   SYNCABLE_PROVIDERS,
   getResolvedCatalog,
   refreshCatalogFromProxy,
+  getAllResolvedCatalogs,
 } from '../../cliproxy/catalog-cache';
 import { getCatalogRoutingSnapshot } from '../../cliproxy/catalog-routing';
 import { ensureManagedModelPrefixes } from '../../cliproxy/managed-model-prefixes';
 import { getProxyTarget } from '../../cliproxy/proxy-target-resolver';
+import type { ThinkingSupport } from '../../cliproxy/model-catalog';
 import type { CLIProxyProvider } from '../../cliproxy/types';
 import type { RemoteModelInfo } from '../../cliproxy/management-api-types';
 import type { CliproxyProviderRoutingHints } from '../../shared/cliproxy-model-routing';
@@ -173,6 +175,50 @@ export async function handleCatalogRefresh(verbose: boolean): Promise<void> {
   console.log('');
 }
 
+/** JSON-serialisable model entry emitted by `catalog --json`. */
+interface CatalogJsonModel {
+  id: string;
+  name: string;
+  tier?: 'free' | 'pro' | 'ultra';
+  description?: string;
+  deprecated?: boolean;
+  deprecationReason?: string;
+  broken?: boolean;
+  issueUrl?: string;
+  thinking?: ThinkingSupport;
+  extendedContext?: boolean;
+  nativeImageInput?: boolean;
+}
+
+/**
+ * Output catalog as JSON for programmatic consumption.
+ * Used by OnSteroids and other tools to get available models per provider.
+ * Format: { [providerName: string]: CatalogJsonModel[] }
+ */
+export function handleCatalogJson(): void {
+  const catalogs = getAllResolvedCatalogs();
+  const result: Record<string, CatalogJsonModel[]> = {};
+  for (const [provider, catalog] of Object.entries(catalogs)) {
+    if (!catalog) {
+      continue;
+    }
+    result[provider] = catalog.models.map((m) => {
+      const entry: CatalogJsonModel = { id: m.id, name: m.name };
+      if (m.tier !== undefined) entry.tier = m.tier;
+      if (m.description !== undefined) entry.description = m.description;
+      if (m.deprecated !== undefined) entry.deprecated = m.deprecated;
+      if (m.deprecationReason !== undefined) entry.deprecationReason = m.deprecationReason;
+      if (m.broken !== undefined) entry.broken = m.broken;
+      if (m.issueUrl !== undefined) entry.issueUrl = m.issueUrl;
+      if (m.thinking !== undefined) entry.thinking = m.thinking;
+      if (m.extendedContext !== undefined) entry.extendedContext = m.extendedContext;
+      if (m.nativeImageInput !== undefined) entry.nativeImageInput = m.nativeImageInput;
+      return entry;
+    });
+  }
+  console.log(JSON.stringify(result));
+}
+
 /** Reset catalog cache */
 export async function handleCatalogReset(): Promise<void> {
   await initUI();
diff --git a/src/commands/cliproxy/help-subcommand.ts b/src/commands/cliproxy/help-subcommand.ts
index 56a2863d..823b1317 100644
--- a/src/commands/cliproxy/help-subcommand.ts
+++ b/src/commands/cliproxy/help-subcommand.ts
@@ -39,6 +39,7 @@ export async function showHelp(): Promise<void> {
         ['catalog', 'Show catalog status, routing hints, and pinned short prefixes'],
         ['catalog refresh', 'Sync models from remote CLIProxy'],
         ['catalog reset', 'Clear cache, revert to static catalog'],
+        ['catalog --json', 'Output full model catalog as minified JSON'],
       ],
     ],
     [
diff --git a/src/commands/cliproxy/index.ts b/src/commands/cliproxy/index.ts
index 50c9013a..52c4cb02 100644
--- a/src/commands/cliproxy/index.ts
+++ b/src/commands/cliproxy/index.ts
@@ -40,6 +40,7 @@ import {
   handleCatalogStatus,
   handleCatalogRefresh,
   handleCatalogReset,
+  handleCatalogJson,
 } from './catalog-subcommand';
 
 /**
@@ -146,6 +147,12 @@ export async function handleCliproxyCommand(args: string[]): Promise<void> {
 
   // Catalog commands
   if (command === 'catalog') {
+    // --json takes priority over subcommands (refresh/reset) — it always
+    // outputs the current resolved catalog regardless of other arguments.
+    if (hasAnyFlag(remainingArgs, ['--json'])) {
+      handleCatalogJson();
+      return;
+    }
     const subcommand = remainingArgs[1];
     if (subcommand === 'refresh') {
       await handleCatalogRefresh(verbose);
diff --git a/tests/unit/commands/cliproxy-catalog-json.test.ts b/tests/unit/commands/cliproxy-catalog-json.test.ts
new file mode 100644
index 00000000..7bc3e5ea
--- /dev/null
+++ b/tests/unit/commands/cliproxy-catalog-json.test.ts
@@ -0,0 +1,146 @@
+import { afterEach, beforeEach, describe, expect, it } from 'bun:test';
+import { handleCatalogJson } from '../../../src/commands/cliproxy/catalog-subcommand';
+import { handleCliproxyCommand } from '../../../src/commands/cliproxy/index';
+
+let originalConsoleLog: typeof console.log;
+let capturedOutput: string[];
+
+beforeEach(() => {
+  originalConsoleLog = console.log;
+  capturedOutput = [];
+  console.log = (...args: unknown[]) => {
+    capturedOutput.push(args.map(String).join(' '));
+  };
+});
+
+afterEach(() => {
+  console.log = originalConsoleLog;
+});
+
+describe('cliproxy catalog --json output', () => {
+  it('outputs valid JSON mapping provider names to model arrays', () => {
+    handleCatalogJson();
+
+    expect(capturedOutput).toHaveLength(1);
+    const parsed = JSON.parse(capturedOutput[0]) as Record<string, unknown[]>;
+
+    // Must be a non-empty object (static catalog always has providers)
+    expect(typeof parsed).toBe('object');
+    expect(Object.keys(parsed).length).toBeGreaterThan(0);
+
+    // Every provider entry must be an array of objects with at least id and name
+    for (const models of Object.values(parsed)) {
+      expect(Array.isArray(models)).toBe(true);
+      expect(models.length).toBeGreaterThan(0);
+      for (const model of models as Array<Record<string, unknown>>) {
+        expect(typeof model.id).toBe('string');
+        expect(typeof model.name).toBe('string');
+      }
+    }
+  });
+
+  it('includes metadata fields when present on model entries', () => {
+    handleCatalogJson();
+
+    const parsed = JSON.parse(capturedOutput[0]) as Record<
+      string,
+      Array<Record<string, unknown>>
+    >;
+    const allModels = Object.values(parsed).flat();
+
+    // At least some models in the static catalog have tier set
+    const withTier = allModels.filter((m) => m.tier !== undefined);
+    expect(withTier.length).toBeGreaterThan(0);
+
+    // Tier values must be one of the allowed strings
+    for (const model of withTier) {
+      expect(['free', 'pro', 'ultra']).toContain(model.tier);
+    }
+  });
+
+  it('omits undefined optional fields instead of including nulls', () => {
+    handleCatalogJson();
+
+    const parsed = JSON.parse(capturedOutput[0]) as Record<
+      string,
+      Array<Record<string, unknown>>
+    >;
+    const allModels = Object.values(parsed).flat();
+
+    for (const model of allModels) {
+      for (const value of Object.values(model)) {
+        expect(value).not.toBeNull();
+        expect(value).not.toBeUndefined();
+      }
+    }
+  });
+
+  it('includes explicit false boolean values in output', () => {
+    handleCatalogJson();
+
+    const parsed = JSON.parse(capturedOutput[0]) as Record<
+      string,
+      Array<Record<string, unknown>>
+    >;
+    const allModels = Object.values(parsed).flat();
+
+    // Static catalog has models with extendedContext: false
+    const withExplicitFalse = allModels.filter((m) => m.extendedContext === false);
+    expect(withExplicitFalse.length).toBeGreaterThan(0);
+  });
+
+  it('includes thinking configuration when present on models', () => {
+    handleCatalogJson();
+
+    const parsed = JSON.parse(capturedOutput[0]) as Record<
+      string,
+      Array<Record<string, unknown>>
+    >;
+    const allModels = Object.values(parsed).flat();
+
+    // Static catalog has thinking models (e.g. Claude Opus 4.6 Thinking)
+    const withThinking = allModels.filter((m) => m.thinking !== undefined);
+    expect(withThinking.length).toBeGreaterThan(0);
+
+    for (const model of withThinking) {
+      const thinking = model.thinking as Record<string, unknown>;
+      expect(['budget', 'levels', 'none']).toContain(thinking.type);
+    }
+  });
+
+  it('outputs minified JSON (single line, no whitespace formatting)', () => {
+    handleCatalogJson();
+
+    const output = capturedOutput[0];
+    expect(output.includes('\n')).toBe(false);
+    expect(JSON.stringify(JSON.parse(output))).toBe(output);
+  });
+});
+
+describe('cliproxy catalog --json routing', () => {
+  it('routes catalog --json through handleCliproxyCommand', async () => {
+    await handleCliproxyCommand(['catalog', '--json']);
+
+    expect(capturedOutput).toHaveLength(1);
+    const parsed = JSON.parse(capturedOutput[0]);
+    expect(typeof parsed).toBe('object');
+    expect(Object.keys(parsed).length).toBeGreaterThan(0);
+  });
+
+  it('--json takes priority over refresh subcommand', async () => {
+    await handleCliproxyCommand(['catalog', 'refresh', '--json']);
+
+    expect(capturedOutput).toHaveLength(1);
+    // Should output JSON, not refresh output
+    const parsed = JSON.parse(capturedOutput[0]);
+    expect(typeof parsed).toBe('object');
+  });
+
+  it('--json takes priority when placed before subcommand', async () => {
+    await handleCliproxyCommand(['catalog', '--json', 'reset']);
+
+    expect(capturedOutput).toHaveLength(1);
+    const parsed = JSON.parse(capturedOutput[0]);
+    expect(typeof parsed).toBe('object');
+  });
+});