// End-to-end coverage for the cloud MCP server.//// The `McpSessionDO` in mcp-session.ts wires several things that previously// had zero integration coverage:// - `createScopedExecutor` against a real drizzle adapter (the 2026-04-16// prod outage was a schema spread bug here; see services/db.schema.test.ts)// - `createExecutionEngine` with an in-process code executor// - `createExecutorMcpServer` for the MCP request surface// - Real `@modelcontextprotocol/sdk` Client → server round-trips//// This test replicates the DO's init path (minus the WorkerTransport and// Durable Object routing, which are thin CF plumbing) and drives it with a// real MCP Client over in-memory transports. If any of the wiring drifts —// schema, plugin list, engine contract, MCP handshake — these tests fail// before prod does. import { describe, expect, it } from "@effect/vitest";import { Effect } from "effect";import { Client } from "@modelcontextprotocol/sdk/client/index.js";import { InMemoryTransport } from "@modelcontextprotocol/sdk/inMemory.js";import { ElicitRequestSchema } from "@modelcontextprotocol/sdk/types.js";import type { ClientCapabilities } from "@modelcontextprotocol/sdk/types.js"; import { createExecutorMcpServer } from "@executor/host-mcp";import { createExecutionEngine } from "@executor/execution";import { makeQuickJsExecutor } from "@executor/runtime-quickjs";import { ElicitationResponse, FormElicitation, Scope, ScopeId, collectSchemas, createExecutor, definePlugin,} from "@executor/sdk";import { makePostgresAdapter, makePostgresBlobStore,} from "@executor/storage-postgres";import { openApiPlugin } from "@executor/plugin-openapi";import { mcpPlugin } from "@executor/plugin-mcp";import { graphqlPlugin } from "@executor/plugin-graphql";import { workosVaultPlugin } from "@executor/plugin-workos-vault"; import { DbService } from "./services/db";import { makeFakeVaultClient } from "./services/__test-harness__/api-harness"; // ---------------------------------------------------------------------------// Test-only plugin: exposes one in-memory tool that elicits once. Lets the// eliciting test drive the real engine + sandbox rather than a stub engine.// --------------------------------------------------------------------------- const EMPTY_INPUT_SCHEMA = { type: "object", properties: {}, additionalProperties: false,} as const; const elicitingTestPlugin = definePlugin(() => ({ id: "eliciting-test" as const, storage: () => ({}), staticSources: () => [ { id: "e2e", kind: "in-memory", name: "E2E Test", tools: [ { name: "needsApproval", description: "Tool that asks the caller to approve before returning.", inputSchema: EMPTY_INPUT_SCHEMA, handler: ({ elicit }: { elicit: (r: FormElicitation) => Effect.Effect<typeof ElicitationResponse.Type, unknown> }) => Effect.gen(function* () { const response = yield* elicit( new FormElicitation({ message: "Approve?", requestedSchema: { type: "object", properties: { approved: { type: "boolean" } }, }, }), ); return { action: response.action, content: response.content ?? null }; }).pipe(Effect.orDie), }, ], }, ],})); // ---------------------------------------------------------------------------// Session harness — mirrors McpSessionDO.init() minus the WorkerTransport// --------------------------------------------------------------------------- const ELICITATION_CAPS: ClientCapabilities = { elicitation: { form: {}, url: {} },}; type BuildOptions = { readonly withElicitingPlugin?: boolean }; const buildScopedExecutor = ( scopeId: string, scopeName: string, options: BuildOptions = {},) => Effect.gen(function* () { const { db } = yield* DbService; const basePlugins = [ openApiPlugin(), mcpPlugin({ dangerouslyAllowStdioMCP: false }), graphqlPlugin(), workosVaultPlugin({ client: makeFakeVaultClient() }), ] as const; const plugins = options.withElicitingPlugin ? ([...basePlugins, elicitingTestPlugin()] as const) : basePlugins; const schema = collectSchemas(plugins); const adapter = makePostgresAdapter({ db, schema }); const blobs = makePostgresBlobStore({ db }); const scope = new Scope({ id: ScopeId.make(scopeId), name: scopeName, createdAt: new Date(), }); return yield* createExecutor({ scopes: [scope], adapter, blobs, plugins }); }); // Builds a scope, wires a real execution engine + MCP server, and yields// them connected to an in-memory MCP client. Shaped as an acquireRelease so// the transport teardown is guaranteed when the test scope closes.const openSession = ( orgId: string, options: BuildOptions & { readonly caps?: ClientCapabilities } = {},) => Effect.acquireRelease( Effect.gen(function* () { const executor = yield* buildScopedExecutor(orgId, `Org ${orgId}`, options); const engine = createExecutionEngine({ executor, codeExecutor: makeQuickJsExecutor() }); const mcpServer = yield* createExecutorMcpServer({ engine }); const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair(); const client = new Client( { name: "cloud-e2e-test", version: "1.0.0" }, { capabilities: options.caps ?? ELICITATION_CAPS }, ); yield* Effect.promise(() => mcpServer.connect(serverTransport)); yield* Effect.promise(() => client.connect(clientTransport)); return { client, clientTransport, serverTransport }; }), ({ clientTransport, serverTransport }) => Effect.promise(async () => { await clientTransport.close().catch(() => undefined); await serverTransport.close().catch(() => undefined); }), ).pipe(Effect.map(({ client }) => ({ client }))); const nextOrgId = (() => { let seq = 0; return () => `org_mcp_e2e_${++seq}_${crypto.randomUUID().slice(0, 8)}`;})(); // ---------------------------------------------------------------------------// Tests// --------------------------------------------------------------------------- describe("cloud MCP session end-to-end", () => { it.effect("initializes and exposes the execute tool to the MCP client", () => Effect.gen(function* () { const { client } = yield* openSession(nextOrgId()); const tools = yield* Effect.promise(() => client.listTools()); const names = tools.tools.map((t) => t.name); expect(names).toContain("execute"); }).pipe(Effect.provide(DbService.Live), Effect.scoped), ); it.effect("runs user code via the execute tool end-to-end", () => Effect.gen(function* () { const { client } = yield* openSession(nextOrgId()); const result = yield* Effect.promise(() => client.callTool({ name: "execute", arguments: { code: "return 1 + 2" } }), ); expect(result.isError).toBeFalsy(); const text = (result.content as Array<{ type: string; text: string }>)[0]!.text; expect(text).toContain("3"); }).pipe(Effect.provide(DbService.Live), Effect.scoped), ); // Isolates the drizzle adapter path so a schema spread drift surfaces as // a raw "unknown model" error. The prod outage on 2026-04-16 would have // thrown at `executor.sources.list()` when the MCP session's drizzle // instance lost the executor-schema tables. it.effect("exercises the drizzle adapter directly via executor.sources.list", () => Effect.gen(function* () { const executor = yield* buildScopedExecutor(nextOrgId(), "drizzle-probe"); const sources = yield* executor.sources.list(); expect(Array.isArray(sources)).toBe(true); }).pipe(Effect.provide(DbService.Live), Effect.scoped), ); it.effect("bridges a form elicitation from engine to client and back", () => Effect.gen(function* () { const { client } = yield* openSession(nextOrgId(), { withElicitingPlugin: true }); client.setRequestHandler(ElicitRequestSchema, async () => ({ action: "accept" as const, content: { approved: true }, })); const result = yield* Effect.promise(() => client.callTool({ name: "execute", arguments: { code: "return await tools.e2e.needsApproval({});" }, }), ); expect(result.isError).toBeFalsy(); const text = (result.content as Array<{ type: string; text: string }>)[0]!.text; expect(text).toContain("accept"); expect(text).toContain("approved"); }).pipe(Effect.provide(DbService.Live), Effect.scoped), );});
// End-to-end coverage for the cloud MCP server.
//
// The `McpSessionDO` in mcp-session.ts wires several things that previously
// had zero integration coverage:
// - `createScopedExecutor` against a real drizzle adapter (the 2026-04-16
// prod outage was a schema spread bug here; see services/db.schema.test.ts)
// - `createExecutionEngine` with an in-process code executor
// - `createExecutorMcpServer` for the MCP request surface
// - Real `@modelcontextprotocol/sdk` Client → server round-trips
//
// This test replicates the DO's init path (minus the WorkerTransport and
// Durable Object routing, which are thin CF plumbing) and drives it with a
// real MCP Client over in-memory transports. If any of the wiring drifts —
// schema, plugin list, engine contract, MCP handshake — these tests fail
// before prod does.
import { describe, expect, it } from "@effect/vitest";
import { Effect } from "effect";
import { Client } from "@modelcontextprotocol/sdk/client/index.js";
import { InMemoryTransport } from "@modelcontextprotocol/sdk/inMemory.js";
import { ElicitRequestSchema } from "@modelcontextprotocol/sdk/types.js";
import type { ClientCapabilities } from "@modelcontextprotocol/sdk/types.js";
import { createExecutorMcpServer } from "@executor/host-mcp";
import { createExecutionEngine } from "@executor/execution";
import { makeQuickJsExecutor } from "@executor/runtime-quickjs";
import {
ElicitationResponse,
FormElicitation,
Scope,
ScopeId,
collectSchemas,
createExecutor,
definePlugin,
} from "@executor/sdk";
import {
makePostgresAdapter,
makePostgresBlobStore,
} from "@executor/storage-postgres";
import { openApiPlugin } from "@executor/plugin-openapi";
import { mcpPlugin } from "@executor/plugin-mcp";
import { graphqlPlugin } from "@executor/plugin-graphql";
import { workosVaultPlugin } from "@executor/plugin-workos-vault";
import { DbService } from "./services/db";
import { makeFakeVaultClient } from "./services/__test-harness__/api-harness";
// ---------------------------------------------------------------------------
// Test-only plugin: exposes one in-memory tool that elicits once. Lets the
// eliciting test drive the real engine + sandbox rather than a stub engine.
// ---------------------------------------------------------------------------
const EMPTY_INPUT_SCHEMA = {
type: "object",
properties: {},
additionalProperties: false,
} as const;
const elicitingTestPlugin = definePlugin(() => ({
id: "eliciting-test" as const,
storage: () => ({}),
staticSources: () => [
{
id: "e2e",
kind: "in-memory",
name: "E2E Test",
tools: [
{
name: "needsApproval",
description: "Tool that asks the caller to approve before returning.",
inputSchema: EMPTY_INPUT_SCHEMA,
handler: ({ elicit }: { elicit: (r: FormElicitation) => Effect.Effect<typeof ElicitationResponse.Type, unknown> }) =>
Effect.gen(function* () {
const response = yield* elicit(
new FormElicitation({
message: "Approve?",
requestedSchema: {
type: "object",
properties: { approved: { type: "boolean" } },
},
}),
);
return { action: response.action, content: response.content ?? null };
}).pipe(Effect.orDie),
},
],
},
],
}));
// ---------------------------------------------------------------------------
// Session harness — mirrors McpSessionDO.init() minus the WorkerTransport
// ---------------------------------------------------------------------------
const ELICITATION_CAPS: ClientCapabilities = {
elicitation: { form: {}, url: {} },
};
type BuildOptions = { readonly withElicitingPlugin?: boolean };
const buildScopedExecutor = (
scopeId: string,
scopeName: string,
options: BuildOptions = {},
) =>
Effect.gen(function* () {
const { db } = yield* DbService;
const basePlugins = [
openApiPlugin(),
mcpPlugin({ dangerouslyAllowStdioMCP: false }),
graphqlPlugin(),
workosVaultPlugin({ client: makeFakeVaultClient() }),
] as const;
const plugins = options.withElicitingPlugin
? ([...basePlugins, elicitingTestPlugin()] as const)
: basePlugins;
const schema = collectSchemas(plugins);
const adapter = makePostgresAdapter({ db, schema });
const blobs = makePostgresBlobStore({ db });
const scope = new Scope({
id: ScopeId.make(scopeId),
name: scopeName,
createdAt: new Date(),
});
return yield* createExecutor({ scopes: [scope], adapter, blobs, plugins });
});
// Builds a scope, wires a real execution engine + MCP server, and yields
// them connected to an in-memory MCP client. Shaped as an acquireRelease so
// the transport teardown is guaranteed when the test scope closes.
const openSession = (
orgId: string,
options: BuildOptions & { readonly caps?: ClientCapabilities } = {},
) =>
Effect.acquireRelease(
Effect.gen(function* () {
const executor = yield* buildScopedExecutor(orgId, `Org ${orgId}`, options);
const engine = createExecutionEngine({ executor, codeExecutor: makeQuickJsExecutor() });
const mcpServer = yield* createExecutorMcpServer({ engine });
const [clientTransport, serverTransport] = InMemoryTransport.createLinkedPair();
const client = new Client(
{ name: "cloud-e2e-test", version: "1.0.0" },
{ capabilities: options.caps ?? ELICITATION_CAPS },
);
yield* Effect.promise(() => mcpServer.connect(serverTransport));
yield* Effect.promise(() => client.connect(clientTransport));
return { client, clientTransport, serverTransport };
}),
({ clientTransport, serverTransport }) =>
Effect.promise(async () => {
await clientTransport.close().catch(() => undefined);
await serverTransport.close().catch(() => undefined);
}),
).pipe(Effect.map(({ client }) => ({ client })));
const nextOrgId = (() => {
let seq = 0;
return () => `org_mcp_e2e_${++seq}_${crypto.randomUUID().slice(0, 8)}`;
})();
// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------
describe("cloud MCP session end-to-end", () => {
it.effect("initializes and exposes the execute tool to the MCP client", () =>
Effect.gen(function* () {
const { client } = yield* openSession(nextOrgId());
const tools = yield* Effect.promise(() => client.listTools());
const names = tools.tools.map((t) => t.name);
expect(names).toContain("execute");
}).pipe(Effect.provide(DbService.Live), Effect.scoped),
);
it.effect("runs user code via the execute tool end-to-end", () =>
Effect.gen(function* () {
const { client } = yield* openSession(nextOrgId());
const result = yield* Effect.promise(() =>
client.callTool({ name: "execute", arguments: { code: "return 1 + 2" } }),
);
expect(result.isError).toBeFalsy();
const text = (result.content as Array<{ type: string; text: string }>)[0]!.text;
expect(text).toContain("3");
}).pipe(Effect.provide(DbService.Live), Effect.scoped),
);
// Isolates the drizzle adapter path so a schema spread drift surfaces as
// a raw "unknown model" error. The prod outage on 2026-04-16 would have
// thrown at `executor.sources.list()` when the MCP session's drizzle
// instance lost the executor-schema tables.
it.effect("exercises the drizzle adapter directly via executor.sources.list", () =>
Effect.gen(function* () {
const executor = yield* buildScopedExecutor(nextOrgId(), "drizzle-probe");
const sources = yield* executor.sources.list();
expect(Array.isArray(sources)).toBe(true);
}).pipe(Effect.provide(DbService.Live), Effect.scoped),
);
it.effect("bridges a form elicitation from engine to client and back", () =>
Effect.gen(function* () {
const { client } = yield* openSession(nextOrgId(), { withElicitingPlugin: true });
client.setRequestHandler(ElicitRequestSchema, async () => ({
action: "accept" as const,
content: { approved: true },
}));
const result = yield* Effect.promise(() =>
client.callTool({
name: "execute",
arguments: { code: "return await tools.e2e.needsApproval({});" },
}),
);
expect(result.isError).toBeFalsy();
const text = (result.content as Array<{ type: string; text: string }>)[0]!.text;
expect(text).toContain("accept");
expect(text).toContain("approved");
}).pipe(Effect.provide(DbService.Live), Effect.scoped),
);
});