diff --git a/src/cliproxy/config/generator.ts b/src/cliproxy/config/generator.ts
index 87523ddb..8e9ded86 100644
--- a/src/cliproxy/config/generator.ts
+++ b/src/cliproxy/config/generator.ts
@@ -17,6 +17,17 @@ import { CLIPROXY_DEFAULT_PORT } from './port-manager';
 import { loadOrCreateUnifiedConfig } from '../../config/config-loader-facade';
 import { getActiveDockerLegacyApiKeys } from '../../docker/docker-key-rotation';
 import { isValidCliproxyRetryValue } from '../../config/schemas/cliproxy';
+import type { CLIProxyOAuthModelAliasConfig } from '../../config/schemas/cliproxy';
+import {
+  mergeOAuthModelAliases,
+  parseOAuthModelAliasSection,
+  serializeOAuthModelAliasBody,
+} from './oauth-model-alias-config';
+import {
+  mergePayloadConfig,
+  parsePayloadSection,
+  serializePayloadSection,
+} from './payload-rule-config';
 
 /** Internal API key for CCS-managed requests */
 export const CCS_INTERNAL_API_KEY = 'ccs-internal-managed';
@@ -46,8 +57,9 @@ export const CCS_CONTROL_PANEL_SECRET = 'ccs';
  * v18: Persist routing.session-affinity and routing.session-affinity-ttl from CCS unified config
  * v19: Persist backend-aware management panel repository from CCS unified config
  * v20: Pool-gated cooling/routing/retry-cap block; disable-cooling flips to false for pool users
+ * v21: Persist user-defined OAuth aliases and scoped payload override rules
  */
-export const CLIPROXY_CONFIG_VERSION = 20;
+export const CLIPROXY_CONFIG_VERSION = 21;
 
 export const ORIGINAL_MANAGEMENT_PANEL_REPOSITORY =
   'https://github.com/router-for-me/Cli-Proxy-API-Management-Center';
@@ -296,7 +308,7 @@ function addAliasEntry(
   if (getDeniedModelIdReasonForProvider(normalized.name, 'agy')) return;
   if (getDeniedModelIdReasonForProvider(normalized.alias, 'agy')) return;
 
-  const key = `${normalized.name}\u0000${normalized.alias}`;
+  const key = normalized.alias;
   const existingIndex = indexByKey.get(key);
   if (existingIndex !== undefined) {
     if (normalized.fork) entries[existingIndex].fork = true;
@@ -307,6 +319,33 @@ function addAliasEntry(
   entries.push(normalized);
 }
 
+function upsertConfiguredAliasEntry(
+  entries: OAuthModelAliasEntry[],
+  indexByKey: Map<string, number>,
+  entry: OAuthModelAliasEntry
+): void {
+  const normalized: OAuthModelAliasEntry = {
+    name: sanitizeYamlScalar(entry.name),
+    alias: normalizeAntigravityAlias(entry.alias),
+    fork: entry.fork || undefined,
+  };
+  if (!normalized.name || !normalized.alias) return;
+  if (getDeniedModelIdReasonForProvider(normalized.name, 'agy')) return;
+  if (getDeniedModelIdReasonForProvider(normalized.alias, 'agy')) return;
+
+  const existingIndex = entries.findIndex((candidate) => candidate.alias === normalized.alias);
+  if (existingIndex === -1) {
+    addAliasEntry(entries, indexByKey, normalized);
+    return;
+  }
+
+  entries[existingIndex] = normalized;
+  indexByKey.clear();
+  entries.forEach((candidate, index) => {
+    indexByKey.set(candidate.alias, index);
+  });
+}
+
 function buildAntigravityAliasKey(entry: Pick<OAuthModelAliasEntry, 'name' | 'alias'>): string {
   return `${sanitizeYamlScalar(entry.name)}\u0000${normalizeAntigravityAlias(entry.alias)}`;
 }
@@ -622,9 +661,13 @@ function writeLegacyGeminiAliasCleanupBackup(configPath: string, existingContent
  * Generate oauth-model-alias YAML section.
  * Merges default Antigravity aliases with any user-added custom aliases.
  */
-function generateOAuthModelAliasSection(existingAliases?: string): string {
+function generateOAuthModelAliasSection(
+  existingAliases?: string,
+  configuredAliases?: CLIProxyOAuthModelAliasConfig
+): string {
   const aliasEntries: OAuthModelAliasEntry[] = [];
   const aliasIndexByKey = new Map<string, number>();
+  const normalizedConfiguredAliases = mergeOAuthModelAliases({}, configuredAliases);
 
   // Start with default aliases.
   for (const alias of DEFAULT_ANTIGRAVITY_ALIASES) {
@@ -639,6 +682,11 @@ function generateOAuthModelAliasSection(existingAliases?: string): string {
     }
   }
 
+  // CCS-owned structured aliases replace the same client alias in place.
+  for (const alias of normalizedConfiguredAliases.antigravity ?? []) {
+    upsertConfiguredAliasEntry(aliasEntries, aliasIndexByKey, alias);
+  }
+
   // Expand lightweight compatibility aliases (dot/hyphen + customtools toggle).
   for (const alias of getCompatibilityAliases(aliasEntries)) {
     addAliasEntry(aliasEntries, aliasIndexByKey, alias);
@@ -652,7 +700,15 @@ function generateOAuthModelAliasSection(existingAliases?: string): string {
     })
     .join('\n');
 
-  return `oauth-model-alias:\n  antigravity:\n${entries}`;
+  const existingAliasConfig = parseOAuthModelAliasSection(existingAliases ?? '');
+  const mergedAliasConfig = mergeOAuthModelAliases(
+    existingAliasConfig,
+    normalizedConfiguredAliases
+  );
+  delete mergedAliasConfig.antigravity;
+  const otherProviders = serializeOAuthModelAliasBody(mergedAliasConfig);
+
+  return `oauth-model-alias:\n  antigravity:\n${entries}${otherProviders ? `\n${otherProviders}` : ''}`;
 }
 
 /**
@@ -663,11 +719,13 @@ function generateOAuthModelAliasSection(existingAliases?: string): string {
  * @param port - Server port (default: 8317)
  * @param userApiKeys - User-added API keys to preserve (default: [])
  * @param existingAliases - Existing oauth-model-alias content to merge with defaults
+ * @param existingPayload - Existing payload content to merge with structured CCS rules
  */
 function generateUnifiedConfigContent(
   port: number = CLIPROXY_DEFAULT_PORT,
   userApiKeys: string[] = [],
-  existingAliases?: string
+  existingAliases?: string,
+  existingPayload?: string
 ): string {
   const authDir = getAuthDir(); // Base auth dir - CLIProxyAPI scans subdirectories
   // Convert Windows backslashes to forward slashes for YAML compatibility
@@ -682,6 +740,10 @@ function generateUnifiedConfigContent(
   const requestRetry = getRequestRetry();
   const maxRetryInterval = getMaxRetryInterval();
   const managementPanelRepository = getManagementPanelRepository();
+  const userRoutingConfig = loadOrCreateUnifiedConfig().cliproxy;
+  const payloadSection = serializePayloadSection(
+    mergePayloadConfig(parsePayloadSection(existingPayload ?? ''), userRoutingConfig.payload)
+  );
 
   // Get effective auth tokens (respects user customization)
   const effectiveApiKey = getEffectiveApiKey();
@@ -795,7 +857,8 @@ ${apiKeysYaml}
 
 # OAuth tokens directory (auto-discovered by CLIProxyAPI)
 auth-dir: "${authDirNormalized}"
-${generateOAuthModelAliasSection(existingAliases)}
+${generateOAuthModelAliasSection(existingAliases, userRoutingConfig.oauth_model_alias)}
+${payloadSection ? `${payloadSection}\n` : ''}
 `;
 
   return config;
@@ -917,6 +980,7 @@ export function regenerateConfig(
   let effectivePort = port;
   let userApiKeys: string[] = [];
   let existingAliases = '';
+  let existingPayload = '';
   const preservedSections: PreservedYamlSection[] = [];
 
   if (fs.existsSync(configPath)) {
@@ -945,15 +1009,21 @@ export function regenerateConfig(
 
       // Preserve user customizations while pruning legacy generated Gemini preview noise.
       const existingConfigVersion = getConfigVersionFromContent(content);
-      const preservedAliases = extractPreservedAntigravityAliases(
-        extractYamlSection(content, 'oauth-model-alias'),
-        {
-          enableLegacyGeminiStaleCleanup:
-            existingConfigVersion === null ||
-            existingConfigVersion < LEGACY_GEMINI_STALE_ALIAS_MIGRATION_VERSION,
-        }
-      );
-      existingAliases = preservedAliases.yaml;
+      const existingAliasBody = extractYamlSection(content, 'oauth-model-alias');
+      const preservedAliases = extractPreservedAntigravityAliases(existingAliasBody, {
+        enableLegacyGeminiStaleCleanup:
+          existingConfigVersion === null ||
+          existingConfigVersion < LEGACY_GEMINI_STALE_ALIAS_MIGRATION_VERSION,
+      });
+      const preservedAliasConfig = parseOAuthModelAliasSection(existingAliasBody);
+      const preservedAntigravityConfig = parseOAuthModelAliasSection(preservedAliases.yaml);
+      if (preservedAntigravityConfig.antigravity) {
+        preservedAliasConfig.antigravity = preservedAntigravityConfig.antigravity;
+      } else {
+        delete preservedAliasConfig.antigravity;
+      }
+      existingAliases = serializeOAuthModelAliasBody(preservedAliasConfig);
+      existingPayload = extractYamlSection(content, 'payload');
       if (preservedAliases.prunedLegacyAliasCount > 0) {
         writeLegacyGeminiAliasCleanupBackup(configPath, content);
       }
@@ -969,7 +1039,12 @@ export function regenerateConfig(
   fs.mkdirSync(authDir, { recursive: true, mode: 0o700 });
 
   // Generate fresh config with preserved user API keys and aliases
-  let configContent = generateUnifiedConfigContent(effectivePort, userApiKeys, existingAliases);
+  let configContent = generateUnifiedConfigContent(
+    effectivePort,
+    userApiKeys,
+    existingAliases,
+    existingPayload
+  );
 
   // Re-append managed top-level sections that are not part of the generated defaults.
   for (const section of preservedSections) {
diff --git a/src/cliproxy/config/oauth-model-alias-config.ts b/src/cliproxy/config/oauth-model-alias-config.ts
new file mode 100644
index 00000000..3a1c31d7
--- /dev/null
+++ b/src/cliproxy/config/oauth-model-alias-config.ts
@@ -0,0 +1,130 @@
+/** Parse, merge, and serialize user-owned CLIProxy OAuth model aliases. */
+
+import * as yaml from 'js-yaml';
+import type {
+  CLIProxyOAuthModelAliasConfig,
+  CLIProxyOAuthModelAliasEntry,
+} from '../../config/schemas/cliproxy';
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null && !Array.isArray(value);
+}
+
+function normalizeAliasEntry(value: unknown): CLIProxyOAuthModelAliasEntry | null {
+  if (!isRecord(value) || typeof value.name !== 'string' || typeof value.alias !== 'string') {
+    return null;
+  }
+
+  const name = value.name.trim();
+  const alias = value.alias.trim();
+  if (!name || !alias) {
+    return null;
+  }
+
+  return {
+    name,
+    alias,
+    ...(value.fork === true ? { fork: true } : {}),
+  };
+}
+
+function aliasKey(entry: CLIProxyOAuthModelAliasEntry): string {
+  return entry.alias;
+}
+
+export function parseOAuthModelAliasSection(body: string): CLIProxyOAuthModelAliasConfig {
+  if (!body.trim()) {
+    return {};
+  }
+
+  try {
+    const parsed = yaml.load(`oauth-model-alias:\n${body}`);
+    if (!isRecord(parsed) || !isRecord(parsed['oauth-model-alias'])) {
+      return {};
+    }
+
+    const result = Object.create(null) as CLIProxyOAuthModelAliasConfig;
+    for (const [provider, entries] of Object.entries(parsed['oauth-model-alias'])) {
+      if (!provider.trim() || !Array.isArray(entries)) {
+        continue;
+      }
+
+      const normalized = entries
+        .map(normalizeAliasEntry)
+        .filter((entry): entry is CLIProxyOAuthModelAliasEntry => entry !== null);
+      if (normalized.length > 0) {
+        result[provider] = normalized;
+      }
+    }
+    return result;
+  } catch {
+    return {};
+  }
+}
+
+export function mergeOAuthModelAliases(
+  existing: CLIProxyOAuthModelAliasConfig,
+  configured?: CLIProxyOAuthModelAliasConfig
+): CLIProxyOAuthModelAliasConfig {
+  const merged = Object.create(null) as CLIProxyOAuthModelAliasConfig;
+
+  for (const [sourceIndex, source] of [existing, configured].entries()) {
+    if (!isRecord(source)) {
+      continue;
+    }
+    const replaceMatching = sourceIndex === 1;
+    for (const [provider, rawEntries] of Object.entries(source)) {
+      if (!provider.trim() || !Array.isArray(rawEntries)) {
+        continue;
+      }
+
+      const entries = merged[provider] ?? [];
+      const indexByKey = new Map(entries.map((entry, index) => [aliasKey(entry), index]));
+      for (const rawEntry of rawEntries) {
+        const entry = normalizeAliasEntry(rawEntry);
+        if (!entry) {
+          continue;
+        }
+
+        const key = aliasKey(entry);
+        const existingIndex = indexByKey.get(key);
+        if (existingIndex !== undefined) {
+          if (replaceMatching) {
+            entries[existingIndex] = entry;
+          } else if (entry.fork) {
+            entries[existingIndex] = { ...entries[existingIndex], fork: true };
+          }
+          continue;
+        }
+
+        indexByKey.set(key, entries.length);
+        entries.push(entry);
+      }
+
+      if (entries.length > 0) {
+        merged[provider] = entries;
+      }
+    }
+  }
+
+  return merged;
+}
+
+export function serializeOAuthModelAliasBody(config: CLIProxyOAuthModelAliasConfig): string {
+  if (Object.keys(config).length === 0) {
+    return '';
+  }
+
+  return yaml
+    .dump(config, {
+      indent: 2,
+      lineWidth: -1,
+      noRefs: true,
+      noCompatMode: true,
+      quotingType: '"',
+    })
+    .trimEnd()
+    .split('\n')
+    .map((line) => `  ${line}`)
+    .join('\n');
+}
diff --git a/src/cliproxy/config/payload-rule-config.ts b/src/cliproxy/config/payload-rule-config.ts
new file mode 100644
index 00000000..b46a8a14
--- /dev/null
+++ b/src/cliproxy/config/payload-rule-config.ts
@@ -0,0 +1,141 @@
+/** Parse, merge, and serialize user-owned CLIProxy payload rules. */
+
+import * as yaml from 'js-yaml';
+import type {
+  CLIProxyPayloadConfig,
+  CLIProxyPayloadModelSelector,
+  CLIProxyPayloadOverrideRule,
+} from '../../config/schemas/cliproxy';
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null && !Array.isArray(value);
+}
+
+function isValidModelSelector(value: unknown): value is CLIProxyPayloadModelSelector {
+  if (!isRecord(value) || typeof value.name !== 'string') {
+    return false;
+  }
+
+  return value.name.trim().length > 0;
+}
+
+function cloneOverrideRule(value: unknown): CLIProxyPayloadOverrideRule | null {
+  if (!isRecord(value) || !Array.isArray(value.models) || !isRecord(value.params)) {
+    return null;
+  }
+
+  if (value.models.length === 0 || !value.models.every(isValidModelSelector)) {
+    return null;
+  }
+
+  return structuredClone(value) as CLIProxyPayloadOverrideRule;
+}
+
+function canonicalizeForKey(value: unknown): unknown {
+  if (Array.isArray(value)) {
+    return value.map(canonicalizeForKey);
+  }
+  if (!isRecord(value)) {
+    return value;
+  }
+
+  return Object.fromEntries(
+    Object.keys(value)
+      .sort()
+      .map((key) => [key, canonicalizeForKey(value[key])])
+  );
+}
+
+function predicateKey(rule: CLIProxyPayloadOverrideRule): string {
+  const predicate = Object.fromEntries(Object.entries(rule).filter(([key]) => key !== 'params'));
+  return JSON.stringify(canonicalizeForKey(predicate));
+}
+
+export function parsePayloadSection(body: string): CLIProxyPayloadConfig | undefined {
+  if (!body.trim()) {
+    return undefined;
+  }
+
+  try {
+    const parsed = yaml.load(`payload:\n${body}`);
+    if (!isRecord(parsed) || !isRecord(parsed.payload)) {
+      return undefined;
+    }
+    return parsed.payload as CLIProxyPayloadConfig;
+  } catch {
+    return undefined;
+  }
+}
+
+export function mergePayloadConfig(
+  existing?: CLIProxyPayloadConfig,
+  configured?: CLIProxyPayloadConfig
+): CLIProxyPayloadConfig | undefined {
+  const existingConfig = isRecord(existing) ? (existing as CLIProxyPayloadConfig) : undefined;
+  const configuredConfig = isRecord(configured) ? (configured as CLIProxyPayloadConfig) : undefined;
+  if (!existingConfig && !configuredConfig) {
+    return undefined;
+  }
+
+  const merged: CLIProxyPayloadConfig = {
+    ...(existingConfig ?? {}),
+    ...(configuredConfig ?? {}),
+  };
+  const rules: CLIProxyPayloadOverrideRule[] = [];
+  const indexByPredicate = new Map<string, number>();
+
+  const addRules = (rawRules: unknown, replaceMatching: boolean) => {
+    if (!Array.isArray(rawRules)) {
+      return;
+    }
+
+    for (const rawRule of rawRules) {
+      const rule = cloneOverrideRule(rawRule);
+      if (!rule) {
+        continue;
+      }
+
+      const key = predicateKey(rule);
+      const existingIndex = indexByPredicate.get(key);
+      if (existingIndex !== undefined) {
+        if (replaceMatching) {
+          rules[existingIndex] = rule;
+        }
+        continue;
+      }
+
+      indexByPredicate.set(key, rules.length);
+      rules.push(rule);
+    }
+  };
+
+  addRules(existingConfig?.override, false);
+  addRules(configuredConfig?.override, true);
+
+  if (rules.length > 0) {
+    merged.override = rules;
+  } else {
+    delete merged.override;
+  }
+
+  return Object.keys(merged).length > 0 ? merged : undefined;
+}
+
+export function serializePayloadSection(config?: CLIProxyPayloadConfig): string {
+  if (!config || Object.keys(config).length === 0) {
+    return '';
+  }
+
+  return yaml
+    .dump(
+      { payload: config },
+      {
+        indent: 2,
+        lineWidth: -1,
+        noRefs: true,
+        noCompatMode: true,
+        quotingType: '"',
+      }
+    )
+    .trimEnd();
+}
diff --git a/src/cliproxy/types/config-types.ts b/src/cliproxy/types/config-types.ts
index bf873439..b67e02d2 100644
--- a/src/cliproxy/types/config-types.ts
+++ b/src/cliproxy/types/config-types.ts
@@ -3,6 +3,10 @@
  */
 
 import type { CompositeTierConfig } from '../../config/unified-config-types';
+import type {
+  CLIProxyOAuthModelAliasConfig,
+  CLIProxyPayloadConfig,
+} from '../../config/schemas/cliproxy';
 import type { CliproxyRoutingStrategy } from './provider-types';
 
 /** CLIProxy config.yaml structure (minimal) */
@@ -11,6 +15,8 @@ export interface CLIProxyConfig {
   'api-keys': string[];
   'auth-dir': string;
   debug: boolean;
+  'oauth-model-alias'?: CLIProxyOAuthModelAliasConfig;
+  payload?: CLIProxyPayloadConfig;
   routing?: {
     strategy?: CliproxyRoutingStrategy;
     'session-affinity'?: boolean;
diff --git a/src/config/schemas/cliproxy.ts b/src/config/schemas/cliproxy.ts
index 92da2cb9..d3d1f6c7 100644
--- a/src/config/schemas/cliproxy.ts
+++ b/src/config/schemas/cliproxy.ts
@@ -135,6 +135,50 @@ export interface CLIProxyRetryConfig {
   max_retry_interval?: number;
 }
 
+/** One OAuth model alias exposed by CLIProxy to compatible clients. */
+export interface CLIProxyOAuthModelAliasEntry {
+  /** Upstream model ID used after alias resolution. */
+  name: string;
+  /** Client-visible model ID accepted by CLIProxy. */
+  alias: string;
+  /** Keep both the upstream name and alias visible when supported upstream. */
+  fork?: boolean;
+}
+
+/** Provider/protocol keyed OAuth model aliases (for example `codex`). */
+export type CLIProxyOAuthModelAliasConfig = Record<string, CLIProxyOAuthModelAliasEntry[]>;
+
+/** Model selector for a CLIProxy payload rule. */
+export interface CLIProxyPayloadModelSelector {
+  /** Client-visible model ID to match before OAuth alias resolution. */
+  name: string;
+  /** Optional protocol boundary, such as `codex`. */
+  protocol?: string;
+  /** Additional CLIProxy selector constraints retained across regeneration. */
+  [constraint: string]: unknown;
+}
+
+/** A scoped CLIProxy payload override rule. */
+export interface CLIProxyPayloadOverrideRule {
+  /** All client model/protocol selectors covered by this rule. */
+  models: CLIProxyPayloadModelSelector[];
+  /** Upstream request parameters added when a selector matches. */
+  params: Record<string, unknown>;
+  /** Additional CLIProxy match constraints retained across regeneration. */
+  [constraint: string]: unknown;
+}
+
+/**
+ * User-owned CLIProxy payload configuration.
+ *
+ * Unknown supported payload subsections are retained so CCS regeneration does
+ * not erase options introduced by newer CLIProxy releases.
+ */
+export interface CLIProxyPayloadConfig {
+  override?: CLIProxyPayloadOverrideRule[];
+  [section: string]: unknown;
+}
+
 /** Lower bound (inclusive) accepted for CLIProxy retry config fields. */
 export const CLIPROXY_RETRY_MIN_VALUE = 0;
 
@@ -217,4 +261,8 @@ export interface CLIProxyConfig {
   pool_routing?: CLIProxyPoolRoutingConfig;
   /** Request-retry behavior for transient upstream errors (opt-in, default: disabled) */
   retry?: CLIProxyRetryConfig;
+  /** User-defined OAuth model aliases emitted into managed CLIProxy config. */
+  oauth_model_alias?: CLIProxyOAuthModelAliasConfig;
+  /** Scoped payload rules emitted into managed CLIProxy config. */
+  payload?: CLIProxyPayloadConfig;
 }
diff --git a/src/config/schemas/index.ts b/src/config/schemas/index.ts
index 43a437b5..6bbcede2 100644
--- a/src/config/schemas/index.ts
+++ b/src/config/schemas/index.ts
@@ -29,6 +29,13 @@ export type {
   CLIProxyLoggingConfig,
   CLIProxySafetyConfig,
   CLIProxyRoutingConfig,
+  CLIProxyRetryConfig,
+  CLIProxyPoolRoutingConfig,
+  CLIProxyOAuthModelAliasEntry,
+  CLIProxyOAuthModelAliasConfig,
+  CLIProxyPayloadModelSelector,
+  CLIProxyPayloadOverrideRule,
+  CLIProxyPayloadConfig,
   CLIProxyConfig,
 } from './cliproxy';
 
diff --git a/src/config/schemas/version.ts b/src/config/schemas/version.ts
index 98979314..9f060cd9 100644
--- a/src/config/schemas/version.ts
+++ b/src/config/schemas/version.ts
@@ -19,5 +19,6 @@
  * Version 11 = Discord Channels runtime auto-enable preferences
  * Version 12 = Official Channels multi-provider support (Telegram, Discord, iMessage)
  * Version 13 = Browser automation defaults to safe manual/off exposure
+ * Version 14 = User-defined CLIProxy OAuth aliases and scoped payload rules
  */
-export const UNIFIED_CONFIG_VERSION = 13;
+export const UNIFIED_CONFIG_VERSION = 14;