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feat(mcp): append server instructions to context (#32490)

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Co-authored-by: Aiden Cline <aidenpcline@gmail.com>
This commit is contained in:
4rcadia
2026-06-24 12:54:19 -04:00
committed by GitHub
parent 2e909334c1
commit e8e83afbce
8 changed files with 269 additions and 36 deletions
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packages/opencode/test/session/prompt.test.ts
+82 -28
View File
@@ -56,6 +56,7 @@ import { reply, TestLLMServer } from "../lib/llm-server"
import { RuntimeFlags } from "@/effect/runtime-flags"
import { ProviderV2 } from "@opencode-ai/core/provider"
import { ModelV2 } from "@opencode-ai/core/model"
import { LocationServiceMap } from "@opencode-ai/core/location-layer"
const summary = Layer.succeed(
SessionSummary.Service,
@@ -108,29 +109,32 @@ function errorTool(parts: SessionV1.Part[]) {
return part?.state.status === "error" ? (part as ErrorToolPart) : undefined
}
const mcp = Layer.succeed(
MCP.Service,
MCP.Service.of({
status: () => Effect.succeed({}),
clients: () => Effect.succeed({}),
tools: () => Effect.succeed({}),
prompts: () => Effect.succeed({}),
resources: () => Effect.succeed({}),
resourceTemplates: () => Effect.succeed({}),
add: () => Effect.succeed({ status: { status: "disabled" as const } }),
connect: () => Effect.void,
disconnect: () => Effect.void,
getPrompt: () => Effect.succeed(undefined),
readResource: () => Effect.succeed(undefined),
startAuth: () => Effect.die("unexpected MCP auth in prompt-effect tests"),
authenticate: () => Effect.die("unexpected MCP auth in prompt-effect tests"),
finishAuth: () => Effect.die("unexpected MCP auth in prompt-effect tests"),
removeAuth: () => Effect.void,
supportsOAuth: () => Effect.succeed(false),
hasStoredTokens: () => Effect.succeed(false),
getAuthStatus: () => Effect.succeed("not_authenticated" as const),
}),
)
function makeMcp(instructions: MCP.ServerInstructions[] = []) {
return Layer.succeed(
MCP.Service,
MCP.Service.of({
status: () => Effect.succeed({}),
clients: () => Effect.succeed({}),
instructions: () => Effect.succeed(instructions),
tools: () => Effect.succeed({}),
prompts: () => Effect.succeed({}),
resources: () => Effect.succeed({}),
resourceTemplates: () => Effect.succeed({}),
add: () => Effect.succeed({ status: { status: "disabled" as const } }),
connect: () => Effect.void,
disconnect: () => Effect.void,
getPrompt: () => Effect.succeed(undefined),
readResource: () => Effect.succeed(undefined),
startAuth: () => Effect.die("unexpected MCP auth in prompt-effect tests"),
authenticate: () => Effect.die("unexpected MCP auth in prompt-effect tests"),
finishAuth: () => Effect.die("unexpected MCP auth in prompt-effect tests"),
removeAuth: () => Effect.void,
supportsOAuth: () => Effect.succeed(false),
hasStoredTokens: () => Effect.succeed(false),
getAuthStatus: () => Effect.succeed("not_authenticated" as const),
}),
)
}
const lsp = Layer.succeed(
LSP.Service,
@@ -164,7 +168,10 @@ const blockingProcessor = Layer.succeed(
}),
)
function makePrompt(input?: { processor?: "blocking" }) {
function makePrompt(input?: {
mcpInstructions?: MCP.ServerInstructions[]
processor?: "blocking"
}) {
const deps = Layer.mergeAll(
Session.defaultLayer,
Snapshot.defaultLayer,
@@ -177,7 +184,7 @@ function makePrompt(input?: { processor?: "blocking" }) {
Config.defaultLayer,
ProviderSvc.defaultLayer,
lsp,
mcp,
makeMcp(input?.mcpInstructions),
FSUtil.defaultLayer,
BackgroundJob.defaultLayer,
status,
@@ -223,24 +230,47 @@ function makePrompt(input?: { processor?: "blocking" }) {
Layer.provideMerge(registry),
Layer.provideMerge(trunc),
Layer.provide(Instruction.defaultLayer),
Layer.provide(SystemPrompt.defaultLayer),
Layer.provide(
SystemPrompt.layer.pipe(
Layer.provide(Skill.defaultLayer),
Layer.provide(LocationServiceMap.layer),
Layer.provide(deps),
),
),
Layer.provide(RuntimeFlags.layer({ experimentalEventSystem: true })),
Layer.provideMerge(deps),
Layer.provide(summary),
)
}
function makeHttp(input?: { processor?: "blocking" }) {
function makeHttp(input?: {
mcpInstructions?: MCP.ServerInstructions[]
processor?: "blocking"
}) {
return Layer.mergeAll(TestLLMServer.layer, makePrompt(input))
}
function makeHttpNoLLMServer(input?: { processor?: "blocking" }) {
function makeHttpNoLLMServer(input?: {
mcpInstructions?: MCP.ServerInstructions[]
processor?: "blocking"
}) {
return makePrompt(input)
}
const it = testEffect(makeHttp())
const noLLMServer = testEffect(makeHttpNoLLMServer())
const raceNoLLMServer = testEffect(makeHttpNoLLMServer({ processor: "blocking" }))
const withMcpInstructions = testEffect(
makeHttp({
mcpInstructions: [
{
name: "guide-server",
instructions: "Use lookup before mutate.",
tools: ["guide-server_lookup"],
},
],
}),
)
const unix = process.platform !== "win32" ? it.instance : it.instance.skip
const unixNoLLMServer = process.platform !== "win32" ? noLLMServer.instance : noLLMServer.instance.skip
@@ -507,6 +537,30 @@ it.instance("loop calls LLM and returns assistant message", () =>
}),
)
withMcpInstructions.instance("loop includes MCP instructions in model system context", () =>
Effect.gen(function* () {
const { llm } = yield* useServerConfig(providerCfg)
const prompt = yield* SessionPrompt.Service
const sessions = yield* Session.Service
const chat = yield* sessions.create({
title: "Pinned",
permission: [{ permission: "*", pattern: "*", action: "allow" }],
})
yield* llm.hang
yield* user(chat.id, "hello")
const fiber = yield* prompt.loop({ sessionID: chat.id }).pipe(Effect.forkChild)
yield* awaitWithTimeout(llm.wait(1), "timed out waiting for MCP instruction request", "10 seconds")
const hits = yield* llm.hits
const body = JSON.stringify(hits[0]?.body)
expect(body).toContain('<server name=\\"guide-server\\">')
expect(body).toContain("Use lookup before mutate.")
yield* Fiber.interrupt(fiber)
}),
15_000,
)
it.instance("loop surfaces content-filter finishes as session errors", () =>
Effect.gen(function* () {
const { llm } = yield* useServerConfig(providerCfg)
packages/opencode/test/session/snapshot-tool-race.test.ts
+1
View File
@@ -37,6 +37,7 @@ const mcp = Layer.succeed(
MCP.Service.of({
status: () => Effect.succeed({}),
clients: () => Effect.succeed({}),
instructions: () => Effect.succeed([]),
tools: () => Effect.succeed({}),
prompts: () => Effect.succeed({}),
resources: () => Effect.succeed({}),
packages/opencode/test/session/system.test.ts
+55
View File
@@ -5,6 +5,7 @@ import { NamedError } from "@opencode-ai/core/util/error"
import { Skill } from "../../src/skill"
import { Permission } from "../../src/permission"
import { SystemPrompt } from "../../src/session/system"
import { MCP } from "../../src/mcp"
import { LocationServiceMap } from "@opencode-ai/core/location-layer"
import { testEffect } from "../lib/effect"
@@ -44,6 +45,23 @@ const build: Agent.Info = {
const it = testEffect(
SystemPrompt.layer.pipe(
Layer.provide(LocationServiceMap.layer),
Layer.provide(
Layer.mock(MCP.Service, {
instructions: () =>
Effect.succeed([
{
name: "guide-server",
instructions: "Use lookup before mutate.",
tools: [],
},
{
name: "tool-server",
instructions: "Prefer search before update.",
tools: ["tool-server_search", "tool-server_update"],
},
]),
}),
),
Layer.provide(
Layer.succeed(
Skill.Service,
@@ -83,4 +101,41 @@ describe("session.system", () => {
expect(output).not.toContain("manual-skill")
}),
)
it.effect("MCP output includes connected server instructions", () =>
Effect.gen(function* () {
const prompt = yield* SystemPrompt.Service
const output = yield* prompt.mcp(build)
expect(output).toBe(
[
"<mcp_instructions>",
' <server name="guide-server">',
" Use lookup before mutate.",
" </server>",
' <server name="tool-server">',
" Prefer search before update.",
" </server>",
"</mcp_instructions>",
].join("\n"),
)
}),
)
it.effect("MCP output omits servers when all advertised tools are denied", () =>
Effect.gen(function* () {
const prompt = yield* SystemPrompt.Service
const output = yield* prompt.mcp(build, Permission.fromConfig({ "tool-server_*": "deny" }))
expect(output).toBe(
[
"<mcp_instructions>",
' <server name="guide-server">',
" Use lookup before mutate.",
" </server>",
"</mcp_instructions>",
].join("\n"),
)
}),
)
})