Add get_values tool to MCP server, register 13 tools

- Implement `get_values` tool for retrieving current values from cache or InfluxDB
- Add `get_values` to MCP server, updating tool count to 13
- Introduce supporting methods in I3xRag for value retrieval
- Update tests to cover `get_values` functionality and tool registration

Author: AlexGodbehere

acs-i3x/bin/api.ts

@@ -1,3 +1,7 @@
+/*
+ * Copyright (c) University of Sheffield AMRC 2026.
+ */
+
 import { ServiceClient, UUIDs } from "@amrc-factoryplus/service-client";
 import { WebAPI } from "@amrc-factoryplus/service-api";
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
@@ -70,7 +74,7 @@ logger.debug({ nodes: i3xRag.nodeCount(), edges: i3xRag.edgeCount() }, "RAG engi
 // MCP server
 const mcpServer = new McpServer({ name: "acs-i3x-rag", version: "1.0.0" });
 registerRagTools(mcpServer, i3xRag);
-logger.info("MCP server registered with 12 RAG tools");
+logger.info("MCP server registered with 13 RAG tools");
 
 // Start HTTP server via WebAPI
 // In dev mode, make all paths public (no Kerberos keytab needed)

acs-i3x/src/mcp/tools.ts

@@ -1,3 +1,7 @@
+/*
+ * Copyright (c) University of Sheffield AMRC 2026.
+ */
+
 /*
  * MCP tool registrations for I3xRag.
  *
@@ -149,4 +153,14 @@ export function registerRagTools(server: McpServer, rag: I3xRag): void {
             return jsonResult(history);
         },
     );
+
+    server.tool(
+        "get_values",
+        "Get current values for one or more elements, trying cache first then InfluxDB.",
+        { element_ids: z.array(z.string()) },
+        async ({ element_ids }) => {
+            const values = await rag.getValues(element_ids);
+            return jsonResult(values);
+        },
+    );
 }

acs-i3x/src/rag/i3x-rag.ts

@@ -1,3 +1,7 @@
+/*
+ * Copyright (c) University of Sheffield AMRC 2026.
+ */
+
 /*
  * I3xRag — graph + search index for RAG-style queries over the i3X object tree.
  *
@@ -44,6 +48,8 @@ export interface HistoryLike {
         startTime: string,
         endTime: string,
     ): Promise<I3xVqt[]>;
+    getCurrentValue(elementId: string): Promise<{ elementId: string; isComposition: boolean; value: unknown; quality: string; timestamp: string } | null>;
+    getCompositionValue(elementId: string, maxDepth?: number): Promise<{ elementId: string; isComposition: boolean; value: unknown; quality: string; timestamp: string } | null>;
 }
 
 /* ------------------------------------------------------------------ */
@@ -106,6 +112,15 @@ export interface ValueFilterResult {
     timestamp: string;
 }
 
+export interface CurrentValueResult {
+    elementId: string;
+    displayName: string;
+    value: unknown;
+    quality: string;
+    timestamp: string;
+    source: "cache" | "influxdb";
+}
+
 /* ------------------------------------------------------------------ */
 /*  I3xRag                                                            */
 /* ------------------------------------------------------------------ */
@@ -356,6 +371,79 @@ export class I3xRag {
         return this.history.queryHistory(elementId, startTime, endTime);
     }
 
+    /** Get current values for multiple elements, trying cache first then InfluxDB. */
+    async getValues(elementIds: string[]): Promise<CurrentValueResult[]> {
+        const results: CurrentValueResult[] = [];
+
+        for (const elementId of elementIds) {
+            const attrs = this.graph.getNodeAttributes(elementId);
+            if (!attrs) {
+                results.push({
+                    elementId,
+                    displayName: "Unknown",
+                    value: undefined,
+                    quality: "Unknown",
+                    timestamp: "",
+                    source: "cache",
+                });
+                continue;
+            }
+
+            // Try cache first
+            const cached = this.valueCache.getValue(elementId);
+            if (cached) {
+                results.push({
+                    elementId,
+                    displayName: attrs.displayName,
+                    value: cached.value,
+                    quality: cached.quality,
+                    timestamp: cached.timestamp,
+                    source: "cache",
+                });
+                continue;
+            }
+
+            // Fall back to InfluxDB
+            try {
+                const obj = this.objectTree.getObject(elementId);
+                const influxValue = obj?.isComposition
+                    ? await this.history.getCompositionValue(elementId)
+                    : await this.history.getCurrentValue(elementId);
+
+                if (influxValue) {
+                    results.push({
+                        elementId,
+                        displayName: attrs.displayName,
+                        value: influxValue.value,
+                        quality: influxValue.quality,
+                        timestamp: influxValue.timestamp,
+                        source: "influxdb",
+                    });
+                } else {
+                    results.push({
+                        elementId,
+                        displayName: attrs.displayName,
+                        value: undefined,
+                        quality: "Unknown",
+                        timestamp: "",
+                        source: "influxdb",
+                    });
+                }
+            } catch (err) {
+                results.push({
+                    elementId,
+                    displayName: attrs.displayName,
+                    value: undefined,
+                    quality: "Error",
+                    timestamp: "",
+                    source: "influxdb",
+                });
+            }
+        }
+
+        return results;
+    }
+
     /* -- internals ------------------------------------------------- */
 
     private buildCompositionNode(

acs-i3x/test/mcp/tools.test.ts

@@ -1,3 +1,7 @@
+/*
+ * Copyright (c) University of Sheffield AMRC 2026.
+ */
+
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
 import { InMemoryTransport } from "@modelcontextprotocol/sdk/inMemory.js";
 import { Client } from "@modelcontextprotocol/sdk/client/index.js";
@@ -44,13 +48,14 @@ describe("MCP tool registrations", () => {
         client = harness.client;
     });
 
-    it("lists all 12 tools", async () => {
+    it("lists all 13 tools", async () => {
         const { tools } = await client.listTools();
         const names = tools.map(t => t.name).sort();
         expect(names).toEqual([
             "composition_tree",
             "find_path",
             "get_history",
+            "get_values",
             "neighborhood",
             "relationship_map",
             "search",
@@ -109,6 +114,18 @@ describe("MCP tool registrations", () => {
         expect(data[0].elementId).toBe("joint1-angle");
     });
 
+    it("get_values retrieves current values from cache for multiple elements", async () => {
+        const result = await client.callTool({ name: "get_values", arguments: { element_ids: ["x-pos", "y-pos", "joint1-angle"] } });
+        const data = parseResult(result);
+        expect(Array.isArray(data)).toBe(true);
+        expect(data.length).toBe(3);
+        const xPos = data.find((v: any) => v.elementId === "x-pos");
+        expect(xPos).toBeDefined();
+        expect(xPos.value).toBe(123.4);
+        expect(xPos.quality).toBe("Good");
+        expect(xPos.source).toBe("cache");
+    });
+
     it("search with missing required query param returns error", async () => {
         const result = await client.callTool({ name: "search", arguments: {} });
         expect(result.isError).toBe(true);