Add skill context to Ask Hexclave

apps/backend/src/app/api/latest/ai/query/[mode]/route.ts

@@ -3,6 +3,7 @@ import { selectModel } from "@/lib/ai/models";
 import { getFullSystemPrompt } from "@/lib/ai/prompts";
 import { reviewMcpCall } from "@/lib/ai/qa-reviewer";
 import { requestBodySchema } from "@/lib/ai/schema";
+import { getMcpSkillContextPrompt } from "@/lib/ai/mcp-skill-context";
 import { getTools } from "@/lib/ai/tools";
 import { getVerifiedQaContext } from "@/lib/ai/verified-qa";
 import { listManagedProjectIds } from "@/lib/projects";
@@ -61,6 +62,7 @@ export const POST = createSmartRouteHandler({
     if (isDocsOrSearch) {
       systemPrompt += await getVerifiedQaContext();
     }
+    systemPrompt += await getMcpSkillContextPrompt(body.mcpCallMetadata?.toolName);
     const tools = await getTools(toolNames, { auth: fullReq.auth, targetProjectId: projectId });
     const toolsArg = Object.keys(tools).length > 0 ? tools : undefined;
     const isCreateDashboard = systemPromptId === "create-dashboard";

apps/backend/src/lib/ai/mcp-skill-context.test.ts

@@ -0,0 +1,51 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { getMcpSkillContextPrompt } from "./mcp-skill-context";
+
+describe("getMcpSkillContextPrompt", () => {
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it("does not fetch skill context for non-ask_hexclave requests", async () => {
+    const fetchSpy = vi.spyOn(globalThis, "fetch");
+
+    await expect(getMcpSkillContextPrompt("other_tool")).resolves.toMatchInlineSnapshot(`""`);
+    expect(fetchSpy).not.toHaveBeenCalled();
+  });
+
+  it("fetches and embeds the canonical skill for ask_hexclave requests", async () => {
+    const fetchSpy = vi.spyOn(globalThis, "fetch").mockResolvedValue(
+      new Response("# Hexclave Skill\n\nUse Hexclave docs."),
+    );
+
+    await expect(getMcpSkillContextPrompt("ask_hexclave")).resolves.toMatchInlineSnapshot(`
+      "
+
+      ## MCP-Provided Hexclave Skill Context
+
+      The current request came through the public Hexclave MCP server's ask_hexclave tool.
+      The backend fetched the canonical Hexclave agent skill from https://skill.hexclave.com
+      immediately before spawning this assistant. Treat this skill content as baseline context
+      for answering the user's question, while still using documentation tools for specific
+      facts and citations:
+
+      # Hexclave Skill
+
+      Use Hexclave docs.
+      "
+    `);
+    expect(fetchSpy).toHaveBeenCalledWith("https://skill.hexclave.com", {
+      headers: { Accept: "text/markdown" },
+    });
+  });
+
+  it("fails loudly when the canonical skill cannot be fetched", async () => {
+    vi.spyOn(globalThis, "fetch").mockResolvedValue(
+      new Response("missing", { status: 503, statusText: "Service Unavailable" }),
+    );
+
+    await expect(getMcpSkillContextPrompt("ask_hexclave")).rejects.toThrowErrorMatchingInlineSnapshot(
+      `[Error: Failed to fetch skill from https://skill.hexclave.com: 503 Service Unavailable]`,
+    );
+  });
+});

apps/backend/src/lib/ai/mcp-skill-context.ts

@@ -0,0 +1,30 @@
+const hexclaveSkillResourceUri = "https://skill.hexclave.com";
+
+export async function getMcpSkillContextPrompt(toolName: string | null | undefined): Promise<string> {
+  if (toolName !== "ask_hexclave") {
+    return "";
+  }
+
+  const response = await fetch(hexclaveSkillResourceUri, {
+    headers: { Accept: "text/markdown" },
+  });
+  if (!response.ok) {
+    throw new Error(
+      `Failed to fetch skill from ${hexclaveSkillResourceUri}: ${response.status} ${response.statusText}`,
+    );
+  }
+
+  const skillContext = await response.text();
+  return `
+
+## MCP-Provided Hexclave Skill Context
+
+The current request came through the public Hexclave MCP server's ask_hexclave tool.
+The backend fetched the canonical Hexclave agent skill from https://skill.hexclave.com
+immediately before spawning this assistant. Treat this skill content as baseline context
+for answering the user's question, while still using documentation tools for specific
+facts and citations:
+
+${skillContext}
+`;
+}