fix: harden workflow console runtime

.serena/project.yml

@@ -31,6 +31,7 @@ project_name: "lda-workflow-as-struct"
 # Note that when using the JetBrains backend, language servers are not used and this list is correspondingly ignored.
 languages:
   - python
+  - typescript
 
 # the encoding used by text files in the project
 # For a list of possible encodings, see https://docs.python.org/3.11/library/codecs.html#standard-encodings

web/apps/console/src/app/App.test.tsx

@@ -0,0 +1,117 @@
+import { cleanup, render, screen, waitFor } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { App } from "./App.js";
+import { callOperation, connectToServer } from "../connection/api.js";
+import type { ConnectResponse, RpcResponse } from "../connection/contracts.js";
+
+vi.mock("../connection/api.js", () => ({
+  connectToServer: vi.fn(),
+  callOperation: vi.fn(),
+}));
+
+const mockedConnectToServer = vi.mocked(connectToServer);
+const mockedCallOperation = vi.mocked(callOperation);
+
+const successfulConnection = (target: string): ConnectResponse => ({
+  ok: true,
+  connection: {
+    status: "connected",
+    target,
+    serverStatus: "ok",
+    storeRoot: "/tmp/store",
+    durationMs: 11,
+  },
+  exchange: { request: {}, response: {} },
+  equivalentCli: "uv run wf status",
+});
+
+const successfulSources = (id: string): RpcResponse => ({
+  ok: true,
+  operation: "workflow.sources.list",
+  label: "List sources",
+  interpreted: {
+    sources: [
+      {
+        id,
+        kind: "python",
+        enabled: true,
+        description: null,
+        counts: {
+          tools: 1,
+          nodeSpecs: 1,
+          reducers: 0,
+          prompts: 0,
+          resources: 0,
+        },
+      },
+    ],
+    total: 1,
+    nextCursor: null,
+  },
+  exchange: { request: {}, response: {} },
+  equivalentCli: "uv run wf source list",
+  durationMs: 7,
+});
+
+const deferred = <T,>() => {
+  let resolve!: (value: T) => void;
+  let reject!: (reason?: unknown) => void;
+  const promise = new Promise<T>((res, rej) => {
+    resolve = res;
+    reject = rej;
+  });
+  return { promise, resolve, reject };
+};
+
+beforeEach(() => {
+  mockedConnectToServer.mockReset();
+  mockedCallOperation.mockReset();
+  sessionStorage.clear();
+});
+
+afterEach(() => {
+  cleanup();
+});
+
+describe("App", () => {
+  it("shows source inventory errors from rejected source refreshes", async () => {
+    mockedConnectToServer.mockResolvedValue(
+      successfulConnection("http://127.0.0.1:8765/rpc"),
+    );
+    mockedCallOperation.mockRejectedValue(new Error("source refresh failed"));
+
+    render(<App />);
+    await userEvent.click(screen.getByRole("button", { name: "Connect" }));
+
+    expect(await screen.findByTestId("sources-error")).toHaveTextContent(
+      "source refresh failed",
+    );
+  });
+
+  it("ignores stale source inventory responses after reconnect", async () => {
+    const firstSources = deferred<RpcResponse>();
+    const secondSources = deferred<RpcResponse>();
+    mockedConnectToServer
+      .mockResolvedValueOnce(successfulConnection("http://first.example/rpc"))
+      .mockResolvedValueOnce(successfulConnection("http://second.example/rpc"));
+    mockedCallOperation
+      .mockReturnValueOnce(firstSources.promise)
+      .mockReturnValueOnce(secondSources.promise);
+
+    render(<App />);
+    await userEvent.click(screen.getByRole("button", { name: "Connect" }));
+    await screen.findByTestId("sources-loading");
+
+    await userEvent.click(screen.getByRole("button", { name: "Reconnect" }));
+    secondSources.resolve(successfulSources("local.second"));
+    firstSources.resolve(successfulSources("local.first"));
+
+    expect(await screen.findByTestId("source-id-local.second")).toHaveTextContent(
+      "local.second",
+    );
+    await waitFor(() => {
+      expect(screen.queryByTestId("source-id-local.first")).toBeNull();
+    });
+  });
+});

web/apps/console/src/app/App.tsx

@@ -1,4 +1,4 @@
-import { useReducer, useEffect, useCallback } from "react";
+import { useReducer, useEffect, useCallback, useRef } from "react";
 import {
   connectionReducer,
   initialState,
@@ -41,42 +41,55 @@ const parseSources = (
 
 export const App = () => {
   const [state, dispatch] = useReducer(connectionReducer, null, initialState);
+  const connectGeneration = useRef(0);
+  const sourcesGeneration = useRef(0);
 
   const loadSources = useCallback(
     async (target: string) => {
-      const result = await callOperation(
-        "workflow.sources.list",
-        target,
-        { limit: 50 },
-      );
-      if (result.ok) {
-        const sources = parseSources(result.interpreted);
-        dispatch({
-          type: "sources_loaded",
-          sources,
-          evidence: {
-            id: `sources-${Date.now()}`,
-            operation: "workflow.sources.list",
-            label: "Source inventory",
-            equivalentCli: result.equivalentCli,
-            request: result.exchange.request,
-            response: result.exchange.response,
-            durationMs: result.durationMs,
-          },
-        });
-      } else {
+      const generation = ++sourcesGeneration.current;
+      dispatch({ type: "sources_loading" });
+      try {
+        const result = await callOperation(
+          "workflow.sources.list",
+          target,
+          { limit: 50 },
+        );
+        if (sourcesGeneration.current !== generation) return;
+        if (result.ok) {
+          const sources = parseSources(result.interpreted);
+          dispatch({
+            type: "sources_loaded",
+            sources,
+            evidence: {
+              id: `sources-${Date.now()}`,
+              operation: "workflow.sources.list",
+              label: "Source inventory",
+              equivalentCli: result.equivalentCli,
+              request: result.exchange.request,
+              response: result.exchange.response,
+              durationMs: result.durationMs,
+            },
+          });
+        } else {
+          dispatch({
+            type: "sources_error",
+            message: result.error.message,
+            evidence: {
+              id: `sources-${Date.now()}`,
+              operation: "workflow.sources.list",
+              label: "Source inventory",
+              equivalentCli: "uv run wf source list --limit 50",
+              request: result.exchange.request,
+              response: result.exchange.response,
+              durationMs: 0,
+            },
+          });
+        }
+      } catch (e: unknown) {
+        if (sourcesGeneration.current !== generation) return;
         dispatch({
           type: "sources_error",
-          message: result.error.message,
-          evidence: {
-            id: `sources-${Date.now()}`,
-            operation: "workflow.sources.list",
-            label: "Source inventory",
-            equivalentCli: "uv run wf source list --limit 50",
-            request: result.exchange.request,
-            response: result.exchange.response,
-            durationMs: 0,
-          },
+          message: e instanceof Error ? e.message : "unknown error",
         });
       }
     },
@@ -90,9 +103,12 @@ export const App = () => {
   }, [state.phase, state.connectedTarget, loadSources]);
 
   const onSubmit = (target: string) => {
+    const generation = ++connectGeneration.current;
+    sourcesGeneration.current++;
     dispatch({ type: "submit", target });
     void connectToServer(target).then(
       (response) => {
+        if (connectGeneration.current !== generation) return;
         if (response.ok) {
           dispatch({ type: "success", data: response });
           dispatch({
@@ -116,9 +132,10 @@ export const App = () => {
         }
       },
       (e: unknown) => {
+        if (connectGeneration.current !== generation) return;
         dispatch({
           type: "failure",
-          code: "rpc_protocol_error",
+          code: errorCodeFromThrown(e),
           message: e instanceof Error ? e.message : "unknown error",
         });
       },
@@ -141,3 +158,10 @@ export const App = () => {
     </div>
   );
 };
+
+const errorCodeFromThrown = (error: unknown): string => {
+  if (!(error instanceof Error)) return "rpc_protocol_error";
+  return error.message.toLowerCase().includes("malformed")
+    ? "malformed_response"
+    : "rpc_protocol_error";
+};

web/apps/console/src/app/state.test.ts

@@ -2,6 +2,8 @@ import { describe, it, expect, beforeEach } from "vitest";
 import {
   connectionReducer,
   initialState,
+  type EvidenceRecord,
+  type SourceRecord,
   type ConnectionState,
   type ConnectionAction,
   STORAGE_KEY,
@@ -21,6 +23,30 @@ const makeSuccess = (target = "http://127.0.0.1:8765/rpc") =>
     equivalentCli: "uv run wf status",
   }) as const;
 
+const evidence: EvidenceRecord = {
+  id: "e1",
+  operation: "workflow.sources.list",
+  label: "Source inventory",
+  equivalentCli: "uv run wf source list",
+  request: {},
+  response: {},
+  durationMs: 12,
+};
+
+const sources: ReadonlyArray<SourceRecord> = [
+  {
+    id: "local.demo",
+    kind: "python",
+    enabled: true,
+    description: null,
+    toolCount: 1,
+    nodeSpecCount: 1,
+    reducerCount: 0,
+    promptCount: 0,
+    resourceCount: 0,
+  },
+];
+
 beforeEach(() => {
   try {
     sessionStorage.clear();
@@ -182,6 +208,39 @@ describe("failure", () => {
     expect(next.connectedTarget).toBe("http://old:8000/rpc");
     expect(next.phase).toBe("unreachable");
   });
+
+  it("maps malformed responses to the dedicated phase", () => {
+    const next = connectionReducer(initialState(), {
+      type: "failure",
+      code: "malformed_response",
+      message: "malformed response from server",
+    });
+    expect(next.phase).toBe("malformed_response");
+  });
+
+  it("distinguishes the console backend from the workflow server", () => {
+    const next = connectionReducer(initialState(), {
+      type: "failure",
+      code: "console_backend_unreachable",
+      message: "Console backend unavailable at 127.0.0.1:8787",
+    });
+    expect(next.phase).toBe("console_backend_unreachable");
+  });
+
+  it("maps decode and size failures to rpc_error", () => {
+    for (const code of [
+      "upstream_timeout",
+      "rpc_decode_error",
+      "response_too_large",
+    ]) {
+      const next = connectionReducer(initialState(), {
+        type: "failure",
+        code,
+        message: code,
+      });
+      expect(next.phase).toBe("rpc_error");
+    }
+  });
 });
 
 describe("reconnect replaces target only on success", () => {
@@ -218,3 +277,53 @@ describe("draft_changed", () => {
     expect(next.phase).toBe("not_configured");
   });
 });
+
+describe("source inventory", () => {
+  it("sets loading state for source refreshes", () => {
+    const state: ConnectionState = {
+      ...initialState(),
+      sourceError: "old error",
+    };
+    const next = connectionReducer(state, { type: "sources_loading" });
+    expect(next.sourcesLoading).toBe(true);
+    expect(next.sourceError).toBeNull();
+  });
+
+  it("records loaded sources and evidence", () => {
+    const state = connectionReducer(initialState(), {
+      type: "sources_loading",
+    });
+    const next = connectionReducer(state, {
+      type: "sources_loaded",
+      sources,
+      evidence,
+    });
+    expect(next.sources).toBe(sources);
+    expect(next.sourcesLoading).toBe(false);
+    expect(next.sourceError).toBeNull();
+    expect(next.evidence).toEqual([evidence]);
+  });
+
+  it("records source errors and optional evidence", () => {
+    const state = connectionReducer(initialState(), {
+      type: "sources_loading",
+    });
+    const next = connectionReducer(state, {
+      type: "sources_error",
+      message: "source list failed",
+      evidence,
+    });
+    expect(next.sourcesLoading).toBe(false);
+    expect(next.sourceError).toBe("source list failed");
+    expect(next.evidence).toEqual([evidence]);
+  });
+
+  it("appends protocol evidence records", () => {
+    const state = initialState();
+    const next = connectionReducer(state, {
+      type: "evidence_recorded",
+      record: evidence,
+    });
+    expect(next.evidence).toEqual([evidence]);
+  });
+});

web/apps/console/src/app/state.ts

@@ -5,6 +5,7 @@ export type ConnectionPhase =
   | "connecting"
   | "connected"
   | "invalid_target"
+  | "console_backend_unreachable"
   | "unreachable"
   | "rpc_error"
   | "malformed_response";
@@ -183,10 +184,14 @@ const mapCodeToPhase = (code: string): ConnectionPhase => {
   switch (code) {
     case "invalid_target":
       return "invalid_target";
+    case "console_backend_unreachable":
+      return "console_backend_unreachable";
     case "upstream_unreachable":
     case "rpc_remote_error":
     case "rpc_protocol_error":
       return "unreachable";
+    case "malformed_response":
+      return "malformed_response";
     case "upstream_timeout":
     case "rpc_decode_error":
     case "response_too_large":

web/apps/console/src/components/ConnectionHeader.tsx

@@ -11,6 +11,8 @@ const phaseLabel = (phase: string): string => {
       return "Connected";
     case "invalid_target":
       return "Invalid target";
+    case "console_backend_unreachable":
+      return "Console backend unavailable";
     case "unreachable":
       return "Server unreachable";
     case "rpc_error":

web/apps/console/src/connection/api.test.ts

@@ -64,6 +64,25 @@ describe("connectToServer", () => {
       expect(result.error.code).toBe("invalid_target");
     }
   });
+
+  it("accepts future server error codes without rejecting the response", async () => {
+    mockFetch.mockReturnValue(
+      jsonResponse(
+        {
+          ok: false,
+          error: { code: "new_server_code", message: "future failure" },
+          exchange: { request: null, response: null },
+        },
+        502,
+      ),
+    );
+
+    const result = await connectToServer("http://127.0.0.1:8000/rpc");
+    expect(result.ok).toBe(false);
+    if (!result.ok) {
+      expect(result.error.code).toBe("new_server_code");
+    }
+  });
 });
 
 describe("callOperation", () => {
@@ -135,7 +154,7 @@ describe("error handling", () => {
 
     await expect(
       connectToServer("http://127.0.0.1:8000/rpc"),
-    ).rejects.toThrow("empty response");
+    ).rejects.toThrow("console backend returned an empty response (HTTP 200)");
   });
 
   it("throws for structurally malformed JSON response", async () => {
@@ -143,7 +162,7 @@ describe("error handling", () => {
 
     await expect(
       connectToServer("http://127.0.0.1:8000/rpc"),
-    ).rejects.toThrow("malformed response");
+    ).rejects.toThrow("malformed response from server:");
   });
 
   it("throws on network failure", async () => {

web/apps/console/src/connection/api.ts

@@ -13,7 +13,9 @@ const fetchJson = async <T>(
   const res = await fetch(url, init);
   const text = await res.text();
   if (!text) {
-    throw new Error("empty response from server");
+    throw new Error(
+      `console backend returned an empty response (HTTP ${res.status})`,
+    );
   }
   let data: unknown;
   try {

web/apps/console/src/connection/contracts.ts

@@ -1,6 +1,6 @@
 import * as v from "valibot";
 
-const BrowserErrorCodeSchema = v.union([
+const KnownBrowserErrorCodeSchema = v.union([
   v.literal("invalid_target"),
   v.literal("unknown_operation"),
   v.literal("upstream_unreachable"),
@@ -10,6 +10,7 @@ const BrowserErrorCodeSchema = v.union([
   v.literal("rpc_decode_error"),
   v.literal("response_too_large"),
 ]);
+const BrowserErrorCodeSchema = v.union([KnownBrowserErrorCodeSchema, v.string()]);
 
 const ExchangeSchema = v.object({
   request: v.nullish(v.unknown(), null),
@@ -67,8 +68,9 @@ export type OperationName = v.InferOutput<typeof OperationNameSchema>;
 const parseDto = <T>(schema: v.GenericSchema<unknown, T>, data: unknown): T => {
   try {
     return v.parse(schema, data);
-  } catch {
-    throw new Error("malformed response from server");
+  } catch (error) {
+    const details = error instanceof Error ? `: ${error.message}` : "";
+    throw new Error(`malformed response from server${details}`);
   }
 };
 

web/apps/console/vite.config.ts

@@ -1,12 +1,38 @@
 import react from "@vitejs/plugin-react";
 import { defineConfig } from "vitest/config";
 
+const backendPort = process.env.WEB_PORT ?? "8787";
+
 export default defineConfig({
   plugins: [react()],
   server: {
     proxy: {
       // Server must listen on this port (set via WEB_PORT env or default 8787)
-      "/api": "http://127.0.0.1:8787",
+      "/api": {
+        target: `http://127.0.0.1:${backendPort}`,
+        configure: (proxy) => {
+          proxy.on("error", (error, _request, response) => {
+            if (response.headersSent) return;
+            const detail =
+              error instanceof Error ? ` (${error.message})` : "";
+            response.writeHead(502, {
+              "content-type": "application/json",
+            });
+            response.end(
+              JSON.stringify({
+                ok: false,
+                error: {
+                  code: "console_backend_unreachable",
+                  message:
+                    `Console backend unavailable at 127.0.0.1:${backendPort}. ` +
+                    `Restart pnpm --dir web dev.${detail}`,
+                },
+                exchange: { request: null, response: null },
+              }),
+            );
+          });
+        },
+      },
     },
   },
   test: {

web/apps/server/package.json

@@ -4,7 +4,7 @@
   "type": "module",
   "scripts": {
     "predev": "pnpm --filter @lda/workflow-rpc build",
-    "dev": "tsx watch src/index.ts",
+    "dev": "tsx src/index.ts",
     "prebuild": "pnpm --filter @lda/workflow-rpc build",
     "build": "tsc -p tsconfig.json",
     "start": "node dist/index.js",

web/apps/server/src/app.test.ts

@@ -11,7 +11,7 @@ const makeExchange = (
   operation: "workflow.health",
   target: "http://127.0.0.1:8765/rpc",
   label: "Health check",
-  interpreted: { status: "ok", store_root: "/tmp/store" },
+  interpreted: { status: "ok", storeRoot: "/tmp/store" },
   exchange: { request: {}, response: { status: "ok" } },
   equivalentCli: "uv run wf status",
   durationMs: 12,
@@ -55,6 +55,7 @@ describe("POST /api/connect", () => {
     expect(body.connection.status).toBe("connected");
     expect(body.connection.target).toBe("http://127.0.0.1:8765/rpc");
     expect(body.connection.serverStatus).toBe("ok");
+    expect(body.connection.storeRoot).toBe("/tmp/store");
     expect(okRunner).toHaveBeenCalledWith(
       "workflow.health",
       "http://127.0.0.1:8000/rpc",
@@ -73,6 +74,21 @@ describe("POST /api/connect", () => {
     expect(body.ok).toBe(false);
     expect(body.error.code).toBe("invalid_target");
   });
+
+  it("returns a decode error when health interpretation is malformed", async () => {
+    const malformedApp = createApp({
+      runOperation: async () => makeExchange({ interpreted: { status: "ok" } }),
+    });
+    const res = await malformedApp.request("/api/connect", {
+      method: "POST",
+      headers: { "content-type": "application/json" },
+      body: JSON.stringify({ target: "http://127.0.0.1:8000/rpc" }),
+    });
+    expect(res.status).toBe(502);
+    const body = await res.json();
+    expect(body.ok).toBe(false);
+    expect(body.error.code).toBe("rpc_decode_error");
+  });
 });
 
 describe("POST /api/rpc", () => {

web/apps/server/src/app.ts

@@ -1,7 +1,12 @@
 import { Hono } from "hono";
 import { bodyLimit } from "hono/body-limit";
 import type { ContentfulStatusCode } from "hono/utils/http-status";
-import type { OperationExchange, OperationName } from "@lda/workflow-rpc";
+import {
+  listOperations,
+  type OperationExchange,
+  type OperationName,
+  type WorkflowHealthInterpreted,
+} from "@lda/workflow-rpc";
 import { addStaticRoutes, validateConsoleRoot } from "./static.js";
 
 export type RunOperation = (
@@ -20,10 +25,22 @@ type BrowserErrorCode =
   | "rpc_decode_error"
   | "response_too_large";
 
-const VALID_OPERATIONS: ReadonlySet<string> = new Set([
-  "workflow.health",
-  "workflow.sources.list",
-]);
+const VALID_OPERATIONS: ReadonlySet<string> = new Set(
+  listOperations().map((operation) => operation.method),
+);
+
+const isOperationName = (value: string): value is OperationName =>
+  VALID_OPERATIONS.has(value);
+
+const isHealthInterpreted = (
+  value: unknown,
+): value is WorkflowHealthInterpreted =>
+  typeof value === "object" &&
+  value !== null &&
+  "status" in value &&
+  value.status === "ok" &&
+  "storeRoot" in value &&
+  typeof value.storeRoot === "string";
 
 const mapErrorToStatus = (
   tag: string,
@@ -92,17 +109,26 @@ export function createApp(dependencies: {
         body.target,
         {},
       );
+      if (!isHealthInterpreted(exchange.interpreted)) {
+        return c.json(
+          {
+            ok: false,
+            error: {
+              code: "rpc_decode_error",
+              message: "workflow.health returned an unexpected shape",
+            },
+            exchange: exchange.exchange,
+          },
+          502,
+        );
+      }
       return c.json({
         ok: true,
         connection: {
           status: "connected",
           target: exchange.target,
           serverStatus: "ok",
-          storeRoot: (
-            exchange.interpreted as { storeRoot?: string; store_root?: string }
-          ).storeRoot ?? (
-            exchange.interpreted as { storeRoot?: string; store_root?: string }
-          ).store_root ?? "",
+          storeRoot: exchange.interpreted.storeRoot,
           durationMs: exchange.durationMs,
         },
         exchange: exchange.exchange,
@@ -145,7 +171,7 @@ export function createApp(dependencies: {
     if (
       !body.operation ||
       typeof body.operation !== "string" ||
-      !VALID_OPERATIONS.has(body.operation)
+      !isOperationName(body.operation)
     ) {
       return c.json(
         {
@@ -173,7 +199,7 @@ export function createApp(dependencies: {
 
     try {
       const exchange = await runOperation(
-        body.operation as OperationName,
+        body.operation,
         body.target,
         body.params ?? {},
       );

web/apps/server/src/index.ts

@@ -1,5 +1,7 @@
-import { Effect, Layer } from "effect";
+import { Effect } from "effect";
 import { serve } from "@hono/node-server";
+import * as fs from "node:fs";
+import * as path from "node:path";
 import { fileURLToPath } from "node:url";
 import {
   WorkflowRpc,
@@ -19,6 +21,13 @@ const hostname = process.env.WEB_HOST ?? "127.0.0.1";
 
 const liveLayer = makeWorkflowRpcLayer();
 const consoleRoot = fileURLToPath(new URL("../../console/dist", import.meta.url));
+const consoleIndex = path.join(consoleRoot, "index.html");
+const staticConsoleRoot = fs.existsSync(consoleIndex) ? consoleRoot : undefined;
+if (!staticConsoleRoot) {
+  // In dev, Vite serves the console and proxies /api to this server. A missing
+  // dist directory should not prevent the API proxy from starting.
+  console.warn(`console dist not found; serving API only: ${consoleRoot}`);
+}
 
 const runOperation: RunOperation = async (
   operation: OperationName,
@@ -30,12 +39,31 @@ const runOperation: RunOperation = async (
     return yield* execute(operation, target, params);
   }).pipe(Effect.provide(liveLayer), Effect.runPromise);
 
-const app = createApp({ runOperation, consoleRoot });
+let app: ReturnType<typeof createApp>;
+try {
+  app = createApp({
+    runOperation,
+    ...(staticConsoleRoot ? { consoleRoot: staticConsoleRoot } : {}),
+  });
+} catch (error) {
+  const message = error instanceof Error ? error.message : String(error);
+  console.error(`Failed to start workflow console server: ${message}`);
+  process.exit(1);
+}
 
-serve({
+const server = serve({
   fetch: app.fetch,
   hostname,
   port,
 });
 
 console.log(`workflow console server listening on http://${hostname}:${port}`);
+
+const shutdown = (signal: NodeJS.Signals) => {
+  console.log(`received ${signal}, stopping workflow console server`);
+  server.close(() => process.exit(0));
+  setTimeout(() => process.exit(1), 5_000).unref();
+};
+
+process.once("SIGINT", shutdown);
+process.once("SIGTERM", shutdown);

web/package.json

@@ -1,8 +1,10 @@
 {
   "name": "@lda/web",
   "private": true,
-  "packageManager": "pnpm@11.3.0",
-  "engines": { "node": ">=22" },
+  "packageManager": "pnpm@11.9.0",
+  "engines": {
+    "node": ">=22"
+  },
   "scripts": {
     "dev": "concurrently --kill-others-on-fail --names server,console --prefix-colors blue,green \"pnpm --filter @lda/web-server dev\" \"pnpm --filter @lda/console dev\"",
     "test": "pnpm -r --if-present test",

web/packages/rpc/src/evidence.ts

@@ -1,5 +1,10 @@
 import { Context, Effect, Layer, Ref, Stream } from "effect";
-import { HttpClient, HttpClientRequest, HttpClientResponse } from "@effect/platform";
+import {
+  HttpBody,
+  HttpClient,
+  HttpClientRequest,
+  HttpClientResponse,
+} from "@effect/platform";
 import {
   RpcProtocolError,
   UpstreamResponseTooLargeError,
@@ -48,6 +53,44 @@ const readRequestBody = (
   return null;
 };
 
+const bodyText = (body: HttpBody.HttpBody): string | null => {
+  if (body._tag === "Uint8Array") {
+    return new TextDecoder().decode(body.body);
+  }
+  if (body._tag === "Raw" && typeof body.body === "string") {
+    return body.body;
+  }
+  return null;
+};
+
+const sanitizeJsonRpcRequest = (
+  request: HttpClientRequest.HttpClientRequest,
+): HttpClientRequest.HttpClientRequest => {
+  const text = bodyText(request.body);
+  if (text === null) return request;
+
+  let body: unknown;
+  try {
+    body = JSON.parse(text);
+  } catch {
+    return request;
+  }
+  if (!isRecord(body) || Array.isArray(body) || body.jsonrpc !== "2.0") {
+    return request;
+  }
+
+  const sanitized = {
+    jsonrpc: "2.0",
+    method: body.method,
+    params: "params" in body ? body.params : undefined,
+    id: "id" in body ? body.id : undefined,
+  };
+
+  return HttpClientRequest.modify(request, {
+    body: HttpBody.text(JSON.stringify(sanitized), "application/json"),
+  });
+};
+
 const readBoundedText = (
   response: HttpClientResponse.HttpClientResponse,
   maxResponseBytes: number,
@@ -135,6 +178,7 @@ export const withEvidenceCapture = <E, R>(
   maxResponseBytes: number,
 ): HttpClient.HttpClient.With<E, R> =>
   client.pipe(
+    HttpClient.mapRequest(sanitizeJsonRpcRequest),
     HttpClient.tapRequest((request) =>
       Ref.set(ref, {
         request: {
@@ -177,11 +221,17 @@ export const withEvidenceCapture = <E, R>(
         // RpcClient's HTTP protocol expects Effect-RPC response messages, while
         // the Python wf server returns standard JSON-RPC objects. Preserve the
         // raw object for evidence and translate only the reconstructed body.
+        const headers = new Headers(response.headers);
+        // The body is rewritten for Effect-RPC, so upstream body metadata no
+        // longer describes the reconstructed Response.
+        headers.delete("content-length");
+        headers.delete("content-encoding");
+        headers.delete("transfer-encoding");
         return HttpClientResponse.fromWeb(
           request,
           new Response(downstreamRpcBodyText(responseBody, bodyText), {
             status: response.status,
-            headers: new Headers(response.headers),
+            headers,
           }),
         );
       }),

web/packages/rpc/src/index.ts

@@ -20,7 +20,11 @@ export {
   getOperationMeta,
   listOperations,
 } from "./method-registry.js";
-export type { OperationMeta } from "./method-registry.js";
+export type {
+  OperationMeta,
+  WorkflowHealthInterpreted,
+  WorkflowSourcesListInterpreted,
+} from "./method-registry.js";
 
 export {
   EvidenceRef,

web/packages/rpc/src/method-registry.ts

@@ -14,66 +14,87 @@ export type OperationMeta = {
   readonly interpret: (result: unknown) => unknown;
 };
 
-const registry: ReadonlyMap<string, OperationMeta> = new Map([
-  [
-    "workflow.health",
-    {
-      method: "workflow.health",
-      label: "Health check",
-      explanation: "Check if the workflow server is running",
-      idempotency: "read",
-      equivalentCli: () => "uv run wf status",
-      interpret: (result) => {
-        const decoded = Schema.decodeUnknownSync(WorkflowHealthResultSchema)(result);
-        return { status: decoded.status, storeRoot: decoded.store_root };
-      },
+export type WorkflowHealthInterpreted = {
+  readonly status: "ok";
+  readonly storeRoot: string;
+};
+
+export type WorkflowSourcesListInterpreted = {
+  readonly sources: ReadonlyArray<{
+    readonly id: string;
+    readonly kind: string;
+    readonly enabled: boolean;
+    readonly description: string | null;
+    readonly counts: {
+      readonly tools: number;
+      readonly nodeSpecs: number;
+      readonly reducers: number;
+      readonly prompts: number;
+      readonly resources: number;
+    };
+  }>;
+  readonly nextCursor: string | null;
+  readonly total: number;
+};
+
+const operationEntries: ReadonlyArray<OperationMeta> = [
+  {
+    method: "workflow.health",
+    label: "Health check",
+    explanation: "Check if the workflow server is running",
+    idempotency: "read",
+    equivalentCli: () => "uv run wf status",
+    interpret: (result): WorkflowHealthInterpreted => {
+      const decoded = Schema.decodeUnknownSync(WorkflowHealthResultSchema)(result);
+      return { status: decoded.status, storeRoot: decoded.store_root };
     },
-  ],
-  [
-    "workflow.sources.list",
-    {
-      method: "workflow.sources.list",
-      label: "List sources",
-      explanation: "List registered data sources with pagination",
-      idempotency: "read",
-      equivalentCli: (params) => {
-        const p = Schema.decodeUnknownSync(WorkflowSourcesListPayloadSchema)(
-          params,
-          { onExcessProperty: "error" },
-        );
-        const parts = ["uv run wf source list"];
-        if (p.limit != null) parts.push(`--limit ${p.limit}`);
-        if (p.cursor != null) parts.push(`--cursor ${p.cursor}`);
-        return parts.join(" ");
-      },
-      interpret: (result) => {
-        const decoded = Schema.decodeUnknownSync(
-          WorkflowSourcesListResultSchema,
-        )(result);
-        return {
-          sources: decoded.sources.map((source) => ({
-            id: source.id,
-            kind: source.kind,
-            enabled: source.enabled,
-            description: source.description,
-            counts: {
-              tools: source.tool_count,
-              nodeSpecs: source.node_spec_count,
-              reducers: source.reducer_count,
-              prompts: source.prompt_count,
-              resources: source.resource_count,
-            },
-          })),
-          nextCursor: decoded.next_cursor,
-          total: decoded.total,
-        };
-      },
+  },
+  {
+    method: "workflow.sources.list",
+    label: "List sources",
+    explanation: "List registered data sources with pagination",
+    idempotency: "read",
+    equivalentCli: (params) => {
+      const p = Schema.decodeUnknownSync(WorkflowSourcesListPayloadSchema)(
+        params,
+        { onExcessProperty: "error" },
+      );
+      const parts = ["uv run wf source list"];
+      if (p.limit != null) parts.push(`--limit ${p.limit}`);
+      if (p.cursor != null) parts.push(`--cursor ${p.cursor}`);
+      return parts.join(" ");
     },
-  ],
-]);
+    interpret: (result): WorkflowSourcesListInterpreted => {
+      const decoded = Schema.decodeUnknownSync(
+        WorkflowSourcesListResultSchema,
+      )(result);
+      return {
+        sources: decoded.sources.map((source) => ({
+          id: source.id,
+          kind: source.kind,
+          enabled: source.enabled,
+          description: source.description,
+          counts: {
+            tools: source.tool_count,
+            nodeSpecs: source.node_spec_count,
+            reducers: source.reducer_count,
+            prompts: source.prompt_count,
+            resources: source.resource_count,
+          },
+        })),
+        nextCursor: decoded.next_cursor,
+        total: decoded.total,
+      };
+    },
+  },
+];
+
+const registry: ReadonlyMap<string, OperationMeta> = new Map(
+  operationEntries.map((entry) => [entry.method, entry]),
+);
 
 export const getOperationMeta = (method: string): OperationMeta | undefined =>
   registry.get(method);
 
 export const listOperations = (): ReadonlyArray<OperationMeta> =>
-  Array.from(registry.values());
+  operationEntries;

web/packages/rpc/src/rpcs.ts

@@ -1,16 +1,21 @@
 import { Rpc, RpcGroup } from "@effect/rpc";
 import { Schema } from "effect";
 
+const NonNegativeIntegerSchema = Schema.Number.pipe(
+  Schema.int(),
+  Schema.between(0, Number.MAX_SAFE_INTEGER),
+);
+
 export const SourceSummarySchema = Schema.Struct({
   id: Schema.String,
   kind: Schema.String,
   enabled: Schema.Boolean,
   description: Schema.NullOr(Schema.String),
-  tool_count: Schema.Number,
-  node_spec_count: Schema.Number,
-  reducer_count: Schema.Number,
-  prompt_count: Schema.Number,
-  resource_count: Schema.Number,
+  tool_count: NonNegativeIntegerSchema,
+  node_spec_count: NonNegativeIntegerSchema,
+  reducer_count: NonNegativeIntegerSchema,
+  prompt_count: NonNegativeIntegerSchema,
+  resource_count: NonNegativeIntegerSchema,
 });
 
 export const WorkflowHealthPayloadSchema = Schema.Struct({});
@@ -34,7 +39,7 @@ export const WorkflowSourcesListPayloadSchema = Schema.Struct({
 export const WorkflowSourcesListResultSchema = Schema.Struct({
   sources: Schema.Array(SourceSummarySchema),
   next_cursor: Schema.NullOr(Schema.String),
-  total: Schema.Number,
+  total: NonNegativeIntegerSchema,
 });
 
 export const WorkflowSourcesList = Rpc.make("workflow.sources.list", {

web/packages/rpc/src/service.test.ts

@@ -1,6 +1,7 @@
 import { Effect, Either } from "effect";
 import { describe, expect, it } from "vitest";
 import {
+  RpcDecodeError,
   RpcProtocolError,
   RpcRemoteError,
   UpstreamConnectionError,
@@ -138,6 +139,68 @@ describe("WorkflowRpc", () => {
     });
   });
 
+  it("maps malformed successful results to decode errors with evidence", async () => {
+    const fetch: typeof globalThis.fetch = async (input, init) => {
+      const request = await requestBody(input, init);
+      return jsonResponse({
+        jsonrpc: "2.0",
+        id: request.id,
+        result: { status: "wrong", store_root: "C:/store" },
+      });
+    };
+
+    const result = await runEither({ fetch });
+
+    expect(Either.isLeft(result)).toBe(true);
+    if (Either.isRight(result)) return;
+    expect(result.left).toBeInstanceOf(RpcDecodeError);
+    expect((result.left as RpcDecodeError).exchange?.response).toMatchObject({
+      result: { status: "wrong", store_root: "C:/store" },
+    });
+  });
+
+  it("rejects invalid source count shapes as decode errors", async () => {
+    const fetch: typeof globalThis.fetch = async (input, init) => {
+      const request = await requestBody(input, init);
+      return jsonResponse({
+        jsonrpc: "2.0",
+        id: request.id,
+        result: {
+          sources: [
+            {
+              id: "local.demo",
+              kind: "python",
+              enabled: true,
+              description: null,
+              tool_count: -1,
+              node_spec_count: 0,
+              reducer_count: 0,
+              prompt_count: 0,
+              resource_count: 0,
+            },
+          ],
+          next_cursor: null,
+          total: 1,
+        },
+      });
+    };
+
+    const result = await Effect.gen(function* () {
+      const rpc = yield* WorkflowRpc;
+      return yield* rpc
+        .execute(
+          "workflow.sources.list",
+          "http://127.0.0.1:8765/rpc",
+          {},
+        )
+        .pipe(Effect.either);
+    }).pipe(Effect.provide(makeWorkflowRpcLayer({ fetch })), Effect.runPromise);
+
+    expect(Either.isLeft(result)).toBe(true);
+    if (Either.isRight(result)) return;
+    expect(result.left).toBeInstanceOf(RpcDecodeError);
+  });
+
   it("fails with a bounded timeout", async () => {
     const fetch: typeof globalThis.fetch = () => new Promise<Response>(() => {});
 

web/packages/rpc/src/service.ts

@@ -154,7 +154,13 @@ const mapCauseToError = (
   }
 
   const description = String(Cause.squash(cause));
-  if (description.toLowerCase().includes("parse") || description.includes("Schema")) {
+  const lowerDescription = description.toLowerCase();
+  if (
+    lowerDescription.includes("parse") ||
+    lowerDescription.includes("schema") ||
+    lowerDescription.includes("decode") ||
+    lowerDescription.includes("expected")
+  ) {
     return new RpcDecodeError({
       message: "workflow RPC result did not match the expected schema",
       exchange,
@@ -176,6 +182,27 @@ const decodeParams = <A, I>(
     ),
   );
 
+const decodeOperationMetadata = (
+  metadata: NonNullable<ReturnType<typeof getOperationMeta>>,
+  result: unknown,
+  params: unknown,
+  evidence: EvidenceRecord | null,
+): Effect.Effect<
+  { readonly interpreted: unknown; readonly equivalentCli: string },
+  RpcDecodeError
+> =>
+  Effect.try({
+    try: () => ({
+      interpreted: metadata.interpret(result),
+      equivalentCli: metadata.equivalentCli(params),
+    }),
+    catch: () =>
+      new RpcDecodeError({
+        message: "workflow RPC result did not match the expected schema",
+        exchange: toExchange(evidence),
+      }),
+  });
+
 const executeImpl =
   (options: WorkflowRpcOptions) =>
   (
@@ -261,14 +288,20 @@ const executeImpl =
           new UnknownOperationError({ message: `unknown operation: ${operation}` }),
         );
       }
+      const decodedMetadata = yield* decodeOperationMetadata(
+        metadata,
+        result,
+        params,
+        evidence,
+      );
       const finishedAt = yield* Clock.currentTimeMillis;
       return {
         operation,
         target: normalizedTarget,
         label: metadata.label,
-        interpreted: metadata.interpret(result),
+        interpreted: decodedMetadata.interpreted,
         exchange: toExchange(evidence),
-        equivalentCli: metadata.equivalentCli(params),
+        equivalentCli: decodedMetadata.equivalentCli,
         durationMs: finishedAt - startedAt,
       };
     });

web/packages/rpc/tsconfig.json

@@ -10,5 +10,6 @@
     "rootDir": "src",
     "outDir": "dist"
   },
-  "include": ["src"]
+  "include": ["src"],
+  "exclude": ["src/**/*.test.ts"]
 }