diff --git a/docs/frameworks/OPEN_SSE_ARCHITECTURE.md b/docs/frameworks/OPEN_SSE_ARCHITECTURE.md
index 83ebf35a95..0f265d53bd 100644
--- a/docs/frameworks/OPEN_SSE_ARCHITECTURE.md
+++ b/docs/frameworks/OPEN_SSE_ARCHITECTURE.md
@@ -368,7 +368,7 @@ const result = await executor.execute({
 });
 ````
 
-The factory is generated from `config/providerRegistry.ts` which lists all 338 providers and their executor class.
+Resolution goes through the `ExecutorRegistry` (`executors/registry.ts`): every specialized executor is declared in the built-in table of `executors/index.ts` and registered via `registerExecutor(alias, instance)` at module load; `getExecutor()` consults the registry and falls back to a memoized `DefaultExecutor` for any provider without a specialized entry. The full alias → executor mapping is characterized by the golden test `tests/unit/executor-map-golden.test.ts`.
 
 ---
 
diff --git a/open-sse/executors/index.ts b/open-sse/executors/index.ts
index a780e1c8b5..3fc2bdf9b3 100644
--- a/open-sse/executors/index.ts
+++ b/open-sse/executors/index.ts
@@ -1,4 +1,9 @@
 import { SEARCH_PROVIDERS } from "../config/searchRegistry.ts";
+import {
+  registerExecutor,
+  getRegisteredExecutor,
+  hasRegisteredExecutor,
+} from "./registry.ts";
 import { AntigravityExecutor } from "./antigravity.ts";
 import { GithubExecutor } from "./github.ts";
 import { GheCopilotExecutor } from "./ghe-copilot.ts";
@@ -78,6 +83,12 @@ import { XaiExecutor } from "./xai.ts";
 import { PromptQlExecutor } from "./promptql.ts";
 import { ConolWebExecutor } from "./conol-web.ts";
 
+// R0.3 — declarative built-in table. The object literal stays as the single
+// place built-ins are declared (compile-time duplicate-key safety; the
+// check:known-symbols gate parses this literal from source), but lookup goes
+// through the ExecutorRegistry (./registry.ts): every entry is registered at
+// module load below, and getExecutor()/hasSpecializedExecutor() consult the
+// registry — the literal is never read at request time.
 const executors = {
   antigravity: new AntigravityExecutor(),
   agy: new AntigravityExecutor(),
@@ -221,6 +232,13 @@ const executors = {
   cnl: new ConolWebExecutor(), // Alias
 };
 
+// Bootstrap: register every built-in in the ExecutorRegistry. registerExecutor
+// throws on duplicates, so an alias collision fails at module load, exactly as
+// loudly as a duplicate object key would have failed at lint time.
+for (const [alias, executor] of Object.entries(executors)) {
+  registerExecutor(alias, executor);
+}
+
 const defaultCache = new Map();
 
 // #6699 — providers that exist ONLY as Cloud Agent task-API entries
@@ -246,7 +264,8 @@ const CHAT_UNSUPPORTED_CLOUD_AGENT_PROVIDERS = new Set(["jules"]);
 const CHAT_UNSUPPORTED_SEARCH_PROVIDERS = new Set(Object.keys(SEARCH_PROVIDERS));
 
 export function getExecutor(provider) {
-  if (executors[provider]) return executors[provider];
+  const registered = getRegisteredExecutor(provider);
+  if (registered) return registered;
   if (CHAT_UNSUPPORTED_CLOUD_AGENT_PROVIDERS.has(provider)) {
     const err = new Error(
       `Provider "${provider}" is a cloud-agent provider and does not support direct chat completions; use the Cloud Agents task API instead.`
@@ -266,9 +285,11 @@ export function getExecutor(provider) {
 }
 
 export function hasSpecializedExecutor(provider) {
-  return !!executors[provider];
+  return hasRegisteredExecutor(provider);
 }
 
+export { registerExecutor, listExecutorAliases } from "./registry.ts";
+
 export { BaseExecutor } from "./base.ts";
 export { AntigravityExecutor } from "./antigravity.ts";
 export { GithubExecutor } from "./github.ts";
diff --git a/open-sse/executors/registry.ts b/open-sse/executors/registry.ts
new file mode 100644
index 0000000000..4d6a002ecd
--- /dev/null
+++ b/open-sse/executors/registry.ts
@@ -0,0 +1,38 @@
+import type { BaseExecutor } from "./base.ts";
+
+// R0.3 — ExecutorRegistry: runtime registry for provider executors, mirroring
+// open-sse/translator/registry.ts. Built-ins register at module load from
+// executors/index.ts; getExecutor() resolves through this map instead of a
+// hard-coded object literal. This is the seam the v4 plan (M1.6
+// host.registerProvider) extends — today the surface is internal-only.
+//
+// The alias → executor mapping is characterized by
+// tests/unit/executor-map-golden.test.ts (tests/snapshots/executors/): any
+// change to keys, classes or instance sharing shows up as a golden diff.
+
+const registry = new Map<string, BaseExecutor>();
+
+/**
+ * Register an executor under an alias. Aliases are unique: registering the
+ * same alias twice throws, preserving the guarantee the old object literal
+ * gave at compile time (duplicate keys were impossible).
+ */
+export function registerExecutor(alias: string, executor: BaseExecutor): void {
+  if (registry.has(alias)) {
+    throw new Error(`executor alias already registered: "${alias}"`);
+  }
+  registry.set(alias, executor);
+}
+
+export function getRegisteredExecutor(alias: string): BaseExecutor | undefined {
+  return registry.get(alias);
+}
+
+export function hasRegisteredExecutor(alias: string): boolean {
+  return registry.has(alias);
+}
+
+/** All registered aliases, in registration order. */
+export function listExecutorAliases(): string[] {
+  return [...registry.keys()];
+}
diff --git a/tests/snapshots/executors/dispatch-rules.json b/tests/snapshots/executors/dispatch-rules.json
new file mode 100644
index 0000000000..b9ce949a99
--- /dev/null
+++ b/tests/snapshots/executors/dispatch-rules.json
@@ -0,0 +1,91 @@
+{
+  "cloudAgentGuard": {
+    "jules": {
+      "message": "Provider \"jules\" is a cloud-agent provider and does not support direct chat completions; use the Cloud Agents task API instead.",
+      "status": 400,
+      "throws": true
+    }
+  },
+  "fallback": {
+    "className": "DefaultExecutor",
+    "configSource": "openai",
+    "provider": "golden-test-unknown-provider"
+  },
+  "searchGuard": {
+    "brave-search": {
+      "message": "Provider \"brave-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "duckduckgo-free": {
+      "message": "Provider \"duckduckgo-free\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "exa-search": {
+      "message": "Provider \"exa-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "firecrawl": {
+      "message": "Provider \"firecrawl\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "google-pse-search": {
+      "message": "Provider \"google-pse-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "jina-search": {
+      "message": "Provider \"jina-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "linkup-search": {
+      "message": "Provider \"linkup-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "ollama-search": {
+      "message": "Provider \"ollama-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "perplexity-search": {
+      "message": "Provider \"perplexity-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "searchapi-search": {
+      "message": "Provider \"searchapi-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "searxng-search": {
+      "message": "Provider \"searxng-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "serper-search": {
+      "message": "Provider \"serper-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "tavily-search": {
+      "message": "Provider \"tavily-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "youcom-search": {
+      "message": "Provider \"youcom-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    },
+    "zai-search": {
+      "message": "Provider \"zai-search\" is a search provider and does not support chat completions; use the /v1/search endpoint instead.",
+      "status": 400,
+      "throws": true
+    }
+  }
+}
diff --git a/tests/snapshots/executors/executor-map.json b/tests/snapshots/executors/executor-map.json
new file mode 100644
index 0000000000..d0ce4024b5
--- /dev/null
+++ b/tests/snapshots/executors/executor-map.json
@@ -0,0 +1,691 @@
+{
+  "entries": {
+    "9router": {
+      "className": "NineRouterExecutor",
+      "configSource": "<custom-config>",
+      "provider": "9router"
+    },
+    "adapta-web": {
+      "className": "AdaptaWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "adapta-web"
+    },
+    "adobe-firefly": {
+      "className": "AdobeFireflyExecutor",
+      "configSource": "<custom-config>",
+      "provider": "adobe-firefly"
+    },
+    "adp-web": {
+      "className": "AdaptaWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "adapta-web"
+    },
+    "agy": {
+      "className": "AntigravityExecutor",
+      "configSource": "antigravity",
+      "provider": "antigravity"
+    },
+    "amazon-q": {
+      "className": "KiroExecutor",
+      "configSource": "kiro",
+      "provider": "amazon-q"
+    },
+    "antigravity": {
+      "className": "AntigravityExecutor",
+      "configSource": "antigravity",
+      "provider": "antigravity"
+    },
+    "auggie": {
+      "className": "AuggieExecutor",
+      "configSource": "<custom-config>",
+      "provider": "auggie"
+    },
+    "azure-ai": {
+      "className": "AzureAiExecutor",
+      "configSource": "openai",
+      "provider": "azure-ai"
+    },
+    "azure-openai": {
+      "className": "AzureOpenAIExecutor",
+      "configSource": "openai",
+      "provider": "azure-openai"
+    },
+    "bb-web": {
+      "className": "BlackboxWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "blackbox-web"
+    },
+    "bedrock": {
+      "className": "BedrockExecutor",
+      "configSource": "bedrock",
+      "provider": "bedrock"
+    },
+    "blackbox-web": {
+      "className": "BlackboxWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "blackbox-web"
+    },
+    "cbcn": {
+      "className": "CodeBuddyCnExecutor",
+      "configSource": "codebuddy-cn",
+      "provider": "codebuddy-cn"
+    },
+    "cf": {
+      "className": "CloudflareAIExecutor",
+      "configSource": "cloudflare-ai",
+      "provider": "cloudflare-ai"
+    },
+    "cfp": {
+      "className": "CloudflarePlaygroundExecutor",
+      "configSource": "<custom-config>",
+      "provider": "cloudflare-playground"
+    },
+    "cgpt-codex": {
+      "className": "ChatGptWebCodexExecutor",
+      "configSource": "<custom-config>",
+      "provider": "chatgpt-web-codex"
+    },
+    "cgpt-web": {
+      "className": "ChatGptWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "chatgpt-web"
+    },
+    "chatgpt-web": {
+      "className": "ChatGptWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "chatgpt-web"
+    },
+    "chatgpt-web-codex": {
+      "className": "ChatGptWebCodexExecutor",
+      "configSource": "<custom-config>",
+      "provider": "chatgpt-web-codex"
+    },
+    "cheaperinference": {
+      "className": "CheaperInferenceExecutor",
+      "configSource": "cheaperinference",
+      "provider": "cheaperinference"
+    },
+    "chipotle": {
+      "className": "ChipotleExecutor",
+      "configSource": "<custom-config>",
+      "provider": "chipotle"
+    },
+    "cinf": {
+      "className": "CheaperInferenceExecutor",
+      "configSource": "cheaperinference",
+      "provider": "cheaperinference"
+    },
+    "claude-web": {
+      "className": "ClaudeWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "claude-web"
+    },
+    "cliproxyapi": {
+      "className": "CliproxyapiExecutor",
+      "configSource": "<custom-config>",
+      "provider": "cliproxyapi"
+    },
+    "cloudflare-ai": {
+      "className": "CloudflareAIExecutor",
+      "configSource": "cloudflare-ai",
+      "provider": "cloudflare-ai"
+    },
+    "cloudflare-playground": {
+      "className": "CloudflarePlaygroundExecutor",
+      "configSource": "<custom-config>",
+      "provider": "cloudflare-playground"
+    },
+    "cmd": {
+      "className": "CommandCodeExecutor",
+      "configSource": "<custom-config>",
+      "provider": "command-code"
+    },
+    "cnl": {
+      "className": "ConolWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "conol-web"
+    },
+    "codebuddy-cn": {
+      "className": "CodeBuddyCnExecutor",
+      "configSource": "codebuddy-cn",
+      "provider": "codebuddy-cn"
+    },
+    "codex": {
+      "className": "CodexExecutor",
+      "configSource": "codex",
+      "provider": "codex"
+    },
+    "command-code": {
+      "className": "CommandCodeExecutor",
+      "configSource": "<custom-config>",
+      "provider": "command-code"
+    },
+    "conol-web": {
+      "className": "ConolWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "conol-web"
+    },
+    "copilot": {
+      "className": "CopilotWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "copilot-web"
+    },
+    "copilot-m365-web": {
+      "className": "CopilotM365WebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "copilot-m365-web"
+    },
+    "copilot-web": {
+      "className": "CopilotWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "copilot-web"
+    },
+    "cpa": {
+      "className": "CliproxyapiExecutor",
+      "configSource": "<custom-config>",
+      "provider": "cliproxyapi"
+    },
+    "cu": {
+      "className": "CursorExecutor",
+      "configSource": "cursor",
+      "provider": "cursor"
+    },
+    "cursor": {
+      "className": "CursorExecutor",
+      "configSource": "cursor",
+      "provider": "cursor"
+    },
+    "cw-web": {
+      "className": "ClaudeWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "claude-web"
+    },
+    "dario": {
+      "className": "DarioExecutor",
+      "configSource": "<custom-config>",
+      "provider": "dario"
+    },
+    "db": {
+      "className": "DoubaoWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "doubao-web"
+    },
+    "ddgw": {
+      "className": "DuckDuckGoWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "duckduckgo-web"
+    },
+    "deepseek-web": {
+      "className": "DeepSeekWebWithAutoRefreshExecutor",
+      "configSource": "<custom-config>",
+      "provider": "deepseek-web"
+    },
+    "devin": {
+      "className": "DevinCliExecutor",
+      "configSource": "<custom-config>",
+      "provider": "devin-cli"
+    },
+    "devin-cli": {
+      "className": "DevinCliExecutor",
+      "configSource": "<custom-config>",
+      "provider": "devin-cli"
+    },
+    "devin-cli-agentic": {
+      "className": "DevinCliAgenticExecutor",
+      "configSource": "<custom-config>",
+      "provider": "devin-cli-agentic"
+    },
+    "devin-desktop": {
+      "className": "DevinDesktopExecutor",
+      "configSource": "devin-desktop",
+      "provider": "devin-desktop"
+    },
+    "doubao-web": {
+      "className": "DoubaoWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "doubao-web"
+    },
+    "dr": {
+      "className": "DarioExecutor",
+      "configSource": "<custom-config>",
+      "provider": "dario"
+    },
+    "ds-web": {
+      "className": "DeepSeekWebWithAutoRefreshExecutor",
+      "configSource": "<custom-config>",
+      "provider": "deepseek-web"
+    },
+    "duckduckgo-web": {
+      "className": "DuckDuckGoWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "duckduckgo-web"
+    },
+    "felo": {
+      "className": "FeloWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "felo-web"
+    },
+    "felo-web": {
+      "className": "FeloWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "felo-web"
+    },
+    "firefly": {
+      "className": "AdobeFireflyExecutor",
+      "configSource": "<custom-config>",
+      "provider": "adobe-firefly"
+    },
+    "gc": {
+      "className": "GrokCliExecutor",
+      "configSource": "grok-cli",
+      "provider": "grok-cli"
+    },
+    "gembiz": {
+      "className": "GeminiBusinessExecutor",
+      "configSource": "<custom-config>",
+      "provider": "gemini-business"
+    },
+    "gemini-business": {
+      "className": "GeminiBusinessExecutor",
+      "configSource": "<custom-config>",
+      "provider": "gemini-business"
+    },
+    "gemini-web": {
+      "className": "GeminiWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "gemini-web"
+    },
+    "ghe-copilot": {
+      "className": "GheCopilotExecutor",
+      "configSource": "<custom-config>",
+      "provider": "ghe-copilot"
+    },
+    "github": {
+      "className": "GithubExecutor",
+      "configSource": "github",
+      "provider": "github"
+    },
+    "gitlab": {
+      "className": "GitlabExecutor",
+      "configSource": "<custom-config>",
+      "provider": "gitlab"
+    },
+    "gitlab-duo": {
+      "className": "GitlabExecutor",
+      "configSource": "<custom-config>",
+      "provider": "gitlab-duo"
+    },
+    "glm": {
+      "className": "GlmExecutor",
+      "configSource": "glm",
+      "provider": "glm"
+    },
+    "glm-cn": {
+      "className": "GlmExecutor",
+      "configSource": "glm-cn",
+      "provider": "glm-cn"
+    },
+    "glmt": {
+      "className": "GlmExecutor",
+      "configSource": "glmt",
+      "provider": "glmt"
+    },
+    "grok-cli": {
+      "className": "GrokCliExecutor",
+      "configSource": "grok-cli",
+      "provider": "grok-cli"
+    },
+    "grok-web": {
+      "className": "GrokWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "grok-web"
+    },
+    "gweb": {
+      "className": "GeminiWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "gemini-web"
+    },
+    "ha": {
+      "className": "HyperAgentExecutor",
+      "configSource": "<custom-config>",
+      "provider": "hyperagent"
+    },
+    "hailuo-web": {
+      "className": "HailuoWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "hailuo-web"
+    },
+    "hc": {
+      "className": "HuggingChatExecutor",
+      "configSource": "<custom-config>",
+      "provider": "huggingchat"
+    },
+    "huggingchat": {
+      "className": "HuggingChatExecutor",
+      "configSource": "<custom-config>",
+      "provider": "huggingchat"
+    },
+    "hyperagent": {
+      "className": "HyperAgentExecutor",
+      "configSource": "<custom-config>",
+      "provider": "hyperagent"
+    },
+    "in-ai": {
+      "className": "InnerAiExecutor",
+      "configSource": "<custom-config>",
+      "provider": "inner-ai"
+    },
+    "inner-ai": {
+      "className": "InnerAiExecutor",
+      "configSource": "<custom-config>",
+      "provider": "inner-ai"
+    },
+    "kimi": {
+      "className": "MoonshotExecutor",
+      "configSource": "kimi",
+      "provider": "kimi"
+    },
+    "kimi-coding": {
+      "className": "KimiExecutor",
+      "configSource": "kimi-coding",
+      "provider": "kimi-coding"
+    },
+    "kimi-coding-apikey": {
+      "className": "KimiExecutor",
+      "configSource": "kimi-coding-apikey",
+      "provider": "kimi-coding-apikey"
+    },
+    "kimi-web": {
+      "className": "KimiWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "kimi-web"
+    },
+    "kiro": {
+      "className": "KiroExecutor",
+      "configSource": "kiro",
+      "provider": "kiro"
+    },
+    "lma": {
+      "className": "LMArenaExecutor",
+      "configSource": "<custom-config>",
+      "provider": "lmarena"
+    },
+    "lmarena": {
+      "className": "LMArenaExecutor",
+      "configSource": "<custom-config>",
+      "provider": "lmarena"
+    },
+    "microsoft-designer-web": {
+      "className": "MicrosoftDesignerWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "microsoft-designer-web"
+    },
+    "moonshot": {
+      "className": "MoonshotExecutor",
+      "configSource": "moonshot",
+      "provider": "moonshot"
+    },
+    "ms-web": {
+      "className": "MuseSparkWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "muse-spark-web"
+    },
+    "msdesigner": {
+      "className": "MicrosoftDesignerWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "microsoft-designer-web"
+    },
+    "muse-spark-web": {
+      "className": "MuseSparkWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "muse-spark-web"
+    },
+    "nlpcloud": {
+      "className": "NlpCloudExecutor",
+      "configSource": "nlpcloud",
+      "provider": "nlpcloud"
+    },
+    "notion-web": {
+      "className": "NotionWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "notion-web"
+    },
+    "nr": {
+      "className": "NineRouterExecutor",
+      "configSource": "<custom-config>",
+      "provider": "9router"
+    },
+    "nw": {
+      "className": "NotionWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "notion-web"
+    },
+    "opencode": {
+      "className": "OpencodeExecutor",
+      "configSource": "opencode-zen",
+      "provider": "opencode-zen"
+    },
+    "opencode-go": {
+      "className": "OpencodeExecutor",
+      "configSource": "opencode-go",
+      "provider": "opencode-go"
+    },
+    "opencode-zen": {
+      "className": "OpencodeExecutor",
+      "configSource": "opencode-zen",
+      "provider": "opencode-zen"
+    },
+    "pepper": {
+      "className": "ChipotleExecutor",
+      "configSource": "<custom-config>",
+      "provider": "chipotle"
+    },
+    "perplexity-web": {
+      "className": "PerplexityWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "perplexity-web"
+    },
+    "poe-web": {
+      "className": "PoeWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "poe-web"
+    },
+    "pol": {
+      "className": "PollinationsExecutor",
+      "configSource": "pollinations",
+      "provider": "pollinations"
+    },
+    "pollinations": {
+      "className": "PollinationsExecutor",
+      "configSource": "pollinations",
+      "provider": "pollinations"
+    },
+    "pplx-web": {
+      "className": "PerplexityWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "perplexity-web"
+    },
+    "pql": {
+      "className": "PromptQlExecutor",
+      "configSource": "<custom-config>",
+      "provider": "promptql"
+    },
+    "promptql": {
+      "className": "PromptQlExecutor",
+      "configSource": "<custom-config>",
+      "provider": "promptql"
+    },
+    "qoder": {
+      "className": "QoderExecutor",
+      "configSource": "qoder",
+      "provider": "qoder"
+    },
+    "qw": {
+      "className": "QwenWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "qwen-web"
+    },
+    "qwen-web": {
+      "className": "QwenWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "qwen-web"
+    },
+    "raycast": {
+      "className": "RaycastExecutor",
+      "configSource": "raycast",
+      "provider": "raycast"
+    },
+    "rc": {
+      "className": "RaycastExecutor",
+      "configSource": "raycast",
+      "provider": "raycast"
+    },
+    "t3-web": {
+      "className": "T3ChatWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "t3-web"
+    },
+    "t3chat": {
+      "className": "T3ChatWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "t3-web"
+    },
+    "tasw": {
+      "className": "TencentAIStudioWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "tencent-aistudio-web"
+    },
+    "tcw": {
+      "className": "TinyCmsExecutor",
+      "configSource": "<custom-config>",
+      "provider": "tinycms-web"
+    },
+    "tencent-aistudio-web": {
+      "className": "TencentAIStudioWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "tencent-aistudio-web"
+    },
+    "theoldllm": {
+      "className": "TheOldLlmExecutor",
+      "configSource": "<custom-config>",
+      "provider": "theoldllm"
+    },
+    "tinycms-web": {
+      "className": "TinyCmsExecutor",
+      "configSource": "<custom-config>",
+      "provider": "tinycms-web"
+    },
+    "tllm": {
+      "className": "TheOldLlmExecutor",
+      "configSource": "<custom-config>",
+      "provider": "theoldllm"
+    },
+    "trae": {
+      "className": "TraeExecutor",
+      "configSource": "trae",
+      "provider": "trae"
+    },
+    "v0": {
+      "className": "V0VercelWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "v0-vercel-web"
+    },
+    "v0-vercel-web": {
+      "className": "V0VercelWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "v0-vercel-web"
+    },
+    "ven": {
+      "className": "VeniceWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "venice-web"
+    },
+    "venice-web": {
+      "className": "VeniceWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "venice-web"
+    },
+    "veo-free": {
+      "className": "VeoAIFreeWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "veoaifree-web"
+    },
+    "veoaifree-web": {
+      "className": "VeoAIFreeWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "veoaifree-web"
+    },
+    "vertex": {
+      "className": "VertexExecutor",
+      "configSource": "vertex",
+      "provider": "vertex"
+    },
+    "vertex-partner": {
+      "className": "VertexExecutor",
+      "configSource": "vertex",
+      "provider": "vertex"
+    },
+    "xai": {
+      "className": "XaiExecutor",
+      "configSource": "xai",
+      "provider": "xai"
+    },
+    "xai-oauth": {
+      "className": "XaiExecutor",
+      "configSource": "xai-oauth",
+      "provider": "xai-oauth"
+    },
+    "xao": {
+      "className": "XaiExecutor",
+      "configSource": "xai-oauth",
+      "provider": "xai-oauth"
+    },
+    "ybw": {
+      "className": "YuanbaoWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "yuanbao-web"
+    },
+    "yuanbao-web": {
+      "className": "YuanbaoWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "yuanbao-web"
+    },
+    "zai-web": {
+      "className": "ZaiWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "zai-web"
+    },
+    "zc": {
+      "className": "ZcodeExecutor",
+      "configSource": "<custom-config>",
+      "provider": "zcode"
+    },
+    "zcode": {
+      "className": "ZcodeExecutor",
+      "configSource": "<custom-config>",
+      "provider": "zcode"
+    },
+    "zed-hosted": {
+      "className": "ZedHostedExecutor",
+      "configSource": "zed-hosted",
+      "provider": "zed-hosted"
+    },
+    "zenmux-free": {
+      "className": "ZenmuxFreeExecutor",
+      "configSource": "<custom-config>",
+      "provider": "zenmux-free"
+    },
+    "zmf": {
+      "className": "ZenmuxFreeExecutor",
+      "configSource": "<custom-config>",
+      "provider": "zenmux-free"
+    },
+    "zw": {
+      "className": "ZaiWebExecutor",
+      "configSource": "<custom-config>",
+      "provider": "zai-web"
+    }
+  },
+  "keyCount": 137,
+  "sharedInstances": []
+}
diff --git a/tests/unit/executor-map-golden.test.ts b/tests/unit/executor-map-golden.test.ts
new file mode 100644
index 0000000000..ea83e56756
--- /dev/null
+++ b/tests/unit/executor-map-golden.test.ts
@@ -0,0 +1,134 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+// R0.3 GOLDEN LOCK (characterization BEFORE the ExecutorRegistry refactor):
+// freeze the full provider-id → executor mapping of open-sse/executors/index.ts —
+// every specialized key with its executor class, effective provider identity and
+// which PROVIDERS config entry backs it — plus the getExecutor() dispatch rules
+// (specialized hit, DefaultExecutor fallback + cache, cloud-agent guard #6699,
+// search-provider guard #10274). The registry refactor must keep this snapshot
+// byte-identical: any drift in keys, classes, provider identity or guard behavior
+// is a golden diff, not a silent routing change.
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-executor-golden-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+// Dynamic imports AFTER DATA_DIR is set so db/core.ts picks up the temp path.
+const { getExecutor, hasSpecializedExecutor, DefaultExecutor } = await import(
+  "../../open-sse/executors/index.ts"
+);
+const { PROVIDERS } = await import("../../open-sse/config/constants.ts");
+const { SEARCH_PROVIDERS } = await import("../../open-sse/config/searchRegistry.ts");
+const { goldenSnapshot } = await import("../helpers/goldenSnapshot.ts");
+
+test.after(() => {
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+// The specialized keys are not exported; enumerate them through the public
+// surface by probing every plausible id source AND the literal keys read from
+// the module source. Reading the source keeps the golden honest: a key added
+// to (or removed from) the hard-coded map cannot hide from the snapshot.
+function readSpecializedKeys(): string[] {
+  const src = fs.readFileSync(
+    path.resolve(path.dirname(new URL(import.meta.url).pathname), "../../open-sse/executors/index.ts"),
+    "utf8"
+  );
+  const mapMatch = src.match(/const executors = \{([\s\S]*?)\n\};/);
+  assert.ok(mapMatch, "executors map literal not found in open-sse/executors/index.ts");
+  const keys: string[] = [];
+  for (const line of mapMatch[1].split("\n")) {
+    const m = line.match(/^\s*(?:"([^"]+)"|([A-Za-z0-9_$-]+)):\s*new /);
+    if (m) keys.push(m[1] ?? m[2]);
+  }
+  return keys;
+}
+
+// Map a ProviderConfig object back to its PROVIDERS key by identity, so the
+// snapshot records WHICH config backs each executor without freezing the whole
+// (huge, frequently-edited) config content.
+const providerConfigKeyByRef = new Map<object, string>();
+for (const [key, cfg] of Object.entries(PROVIDERS)) {
+  if (cfg && typeof cfg === "object" && !providerConfigKeyByRef.has(cfg)) {
+    providerConfigKeyByRef.set(cfg, key);
+  }
+}
+
+function describeExecutor(instance: unknown): {
+  className: string;
+  provider: string | null;
+  configSource: string | null;
+} {
+  const inst = instance as { constructor: { name: string }; provider?: string; config?: object };
+  const cfg = inst.config;
+  return {
+    className: inst.constructor.name,
+    provider: typeof inst.provider === "string" ? inst.provider : null,
+    configSource:
+      cfg == null ? null : (providerConfigKeyByRef.get(cfg) ?? "<custom-config>"),
+  };
+}
+
+const specializedKeys = readSpecializedKeys();
+
+test("golden: specialized executor map — key → class + provider identity + config source", () => {
+  assert.ok(specializedKeys.length >= 100, `suspiciously few keys: ${specializedKeys.length}`);
+
+  const entries: Record<
+    string,
+    { className: string; provider: string | null; configSource: string | null }
+  > = {};
+  const byInstance = new Map<unknown, string[]>();
+
+  for (const key of [...specializedKeys].sort()) {
+    assert.equal(hasSpecializedExecutor(key), true, `hasSpecializedExecutor(${key})`);
+    const instance = getExecutor(key);
+    entries[key] = describeExecutor(instance);
+    const group = byInstance.get(instance) ?? [];
+    group.push(key);
+    byInstance.set(instance, group);
+  }
+
+  // Keys sharing the SAME instance share per-instance state (session pools,
+  // rotation cooldowns); today every map entry is its own `new X()`. Freeze that.
+  const sharedInstances = [...byInstance.values()]
+    .filter((keys) => keys.length > 1)
+    .map((keys) => keys.sort())
+    .sort((a, b) => a[0].localeCompare(b[0]));
+
+  goldenSnapshot("executors/executor-map", {
+    keyCount: specializedKeys.length,
+    entries,
+    sharedInstances,
+  });
+});
+
+test("golden: getExecutor dispatch rules — fallback, cache and 400-guards", () => {
+  // 1. Unknown provider → DefaultExecutor for that provider, memoized.
+  const unknown = "golden-test-unknown-provider";
+  assert.equal(hasSpecializedExecutor(unknown), false);
+  const fallback = getExecutor(unknown);
+  assert.ok(fallback instanceof DefaultExecutor, "fallback must be DefaultExecutor");
+  assert.equal(getExecutor(unknown), fallback, "DefaultExecutor fallback must be cached");
+
+  // 2. Cloud-agent guard (#6699) and search guard (#10274) → status-400 throw.
+  const guardOutcome = (provider: string) => {
+    try {
+      getExecutor(provider);
+      return { throws: false as const };
+    } catch (err) {
+      const e = err as Error & { status?: number };
+      return { throws: true as const, status: e.status ?? null, message: e.message };
+    }
+  };
+
+  const searchProviders = Object.keys(SEARCH_PROVIDERS).sort();
+  goldenSnapshot("executors/dispatch-rules", {
+    fallback: describeExecutor(fallback),
+    cloudAgentGuard: { jules: guardOutcome("jules") },
+    searchGuard: Object.fromEntries(searchProviders.map((p) => [p, guardOutcome(p)])),
+  });
+});
diff --git a/tests/unit/executor-registry.test.ts b/tests/unit/executor-registry.test.ts
new file mode 100644
index 0000000000..c05128681b
--- /dev/null
+++ b/tests/unit/executor-registry.test.ts
@@ -0,0 +1,57 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+// R0.3 — unit tests for the ExecutorRegistry seam itself (registration
+// semantics + wiring of the built-ins). Behavior parity of the full map is
+// covered separately by tests/unit/executor-map-golden.test.ts.
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-executor-registry-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const { registerExecutor, getRegisteredExecutor, hasRegisteredExecutor, listExecutorAliases } =
+  await import("../../open-sse/executors/registry.ts");
+const { getExecutor, hasSpecializedExecutor, BaseExecutor, DefaultExecutor } = await import(
+  "../../open-sse/executors/index.ts"
+);
+
+test.after(() => {
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+test("built-ins are registered at module load and resolve through the registry", () => {
+  const aliases = listExecutorAliases();
+  assert.ok(aliases.length >= 100, `expected the built-in table, got ${aliases.length} aliases`);
+  for (const alias of ["antigravity", "kiro", "glm", "9router", "conol-web"]) {
+    assert.ok(hasRegisteredExecutor(alias), `missing built-in: ${alias}`);
+    assert.equal(getExecutor(alias), getRegisteredExecutor(alias));
+    assert.ok(getExecutor(alias) instanceof BaseExecutor);
+  }
+});
+
+test("registerExecutor throws on duplicate alias", () => {
+  assert.throws(() => registerExecutor("kiro", getRegisteredExecutor("kiro")!), {
+    message: /already registered: "kiro"/,
+  });
+});
+
+test("registering a new alias makes it resolvable via getExecutor and hasSpecializedExecutor", () => {
+  const alias = "registry-test-provider";
+  assert.equal(hasSpecializedExecutor(alias), false);
+  const instance = new DefaultExecutor(alias);
+  registerExecutor(alias, instance);
+  assert.equal(hasSpecializedExecutor(alias), true);
+  assert.equal(getExecutor(alias), instance);
+});
+
+test("registry lookup is exact — Object.prototype names are not executors", () => {
+  // The old object-literal lookup (`executors[provider]`) leaked prototype
+  // members: getExecutor("constructor") returned Object's constructor. The Map
+  // registry must treat these as unknown providers (DefaultExecutor fallback).
+  for (const name of ["constructor", "toString", "hasOwnProperty", "__proto__"]) {
+    assert.equal(hasSpecializedExecutor(name), false, name);
+    assert.ok(getExecutor(name) instanceof DefaultExecutor, name);
+  }
+});