From c1c7a85bbecdc4fe8203acd8b32c49e537ca7258 Mon Sep 17 00:00:00 2001 From: Stephen Toub Date: Thu, 9 Apr 2026 09:44:35 -0400 Subject: [PATCH 1/5] Refactor MCP server config types across all SDK languages Introduce an abstract McpServerConfig base class in C# with a private protected constructor and sealed derived types McpStdioServerConfig and McpHttpServerConfig. Shared properties (Tools, Type, Timeout) are deduplicated into the base class. The Type property uses the JsonPolymorphic discriminator pattern consistent with SessionEvent. All Dictionary McpServers properties are now strongly typed as Dictionary. Rename Local/Remote to Stdio/Http across all four SDK languages to match MCP protocol terminology: - C#: McpStdioServerConfig / McpHttpServerConfig - TypeScript: MCPStdioServerConfig / MCPHttpServerConfig - Go: MCPStdioServerConfig / MCPHTTPServerConfig - Python: MCPStdioServerConfig / MCPHttpServerConfig Update documentation examples accordingly. Fixes #245 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --- docs/features/mcp.md | 5 +- docs/troubleshooting/mcp-debugging.md | 26 ++++------ dotnet/src/Client.cs | 4 +- dotnet/src/Types.cs | 66 +++++++++++++------------- dotnet/test/CloneTests.cs | 14 +++--- dotnet/test/McpAndAgentsTests.cs | 33 +++++-------- go/types.go | 10 ++-- nodejs/src/index.ts | 4 +- nodejs/src/types.ts | 6 +-- nodejs/test/e2e/mcp_and_agents.test.ts | 16 +++---- python/copilot/session.py | 6 +-- 11 files changed, 89 insertions(+), 101 deletions(-) diff --git a/docs/features/mcp.md b/docs/features/mcp.md index d16666501..0329293b1 100644 --- a/docs/features/mcp.md +++ b/docs/features/mcp.md @@ -143,11 +143,10 @@ await using var client = new CopilotClient(); await using var session = await client.CreateSessionAsync(new SessionConfig { Model = "gpt-5", - McpServers = new Dictionary + McpServers = new Dictionary { - ["my-local-server"] = new McpLocalServerConfig + ["my-local-server"] = new McpStdioServerConfig { - Type = "local", Command = "node", Args = new List { "./mcp-server.js" }, Tools = new List { "*" }, diff --git a/docs/troubleshooting/mcp-debugging.md b/docs/troubleshooting/mcp-debugging.md index 30e05fd3e..d7b455ecf 100644 --- a/docs/troubleshooting/mcp-debugging.md +++ b/docs/troubleshooting/mcp-debugging.md @@ -250,19 +250,17 @@ public static class McpDotnetConfigExample { public static void Main() { - var servers = new Dictionary + var servers = new Dictionary { - ["my-dotnet-server"] = new McpLocalServerConfig + ["my-dotnet-server"] = new McpStdioServerConfig { - Type = "local", Command = @"C:\Tools\MyServer\MyServer.exe", Args = new List(), Cwd = @"C:\Tools\MyServer", Tools = new List { "*" }, }, - ["my-dotnet-tool"] = new McpLocalServerConfig + ["my-dotnet-tool"] = new McpStdioServerConfig { - Type = "local", Command = "dotnet", Args = new List { @"C:\Tools\MyTool\MyTool.dll" }, Cwd = @"C:\Tools\MyTool", @@ -275,9 +273,8 @@ public static class McpDotnetConfigExample ```csharp // Correct configuration for .NET exe -["my-dotnet-server"] = new McpLocalServerConfig +["my-dotnet-server"] = new McpStdioServerConfig { - Type = "local", Command = @"C:\Tools\MyServer\MyServer.exe", // Full path with .exe Args = new List(), Cwd = @"C:\Tools\MyServer", // Set working directory @@ -285,9 +282,8 @@ public static class McpDotnetConfigExample } // For dotnet tool (DLL) -["my-dotnet-tool"] = new McpLocalServerConfig +["my-dotnet-tool"] = new McpStdioServerConfig { - Type = "local", Command = "dotnet", Args = new List { @"C:\Tools\MyTool\MyTool.dll" }, Cwd = @"C:\Tools\MyTool", @@ -305,11 +301,10 @@ public static class McpNpxConfigExample { public static void Main() { - var servers = new Dictionary + var servers = new Dictionary { - ["filesystem"] = new McpLocalServerConfig + ["filesystem"] = new McpStdioServerConfig { - Type = "local", Command = "cmd", Args = new List { "/c", "npx", "-y", "@modelcontextprotocol/server-filesystem", "C:\\allowed\\path" }, Tools = new List { "*" }, @@ -321,9 +316,8 @@ public static class McpNpxConfigExample ```csharp // Windows needs cmd /c for npx -["filesystem"] = new McpLocalServerConfig +["filesystem"] = new McpStdioServerConfig { - Type = "local", Command = "cmd", Args = new List { "/c", "npx", "-y", "@modelcontextprotocol/server-filesystem", "C:\\allowed\\path" }, Tools = new List { "*" }, @@ -357,9 +351,9 @@ xattr -d com.apple.quarantine /path/to/mcp-server ```typescript -import { MCPLocalServerConfig } from "@github/copilot-sdk"; +import { MCPStdioServerConfig } from "@github/copilot-sdk"; -const mcpServers: Record = { +const mcpServers: Record = { "my-server": { command: "/opt/homebrew/bin/node", args: ["/path/to/server.js"], diff --git a/dotnet/src/Client.cs b/dotnet/src/Client.cs index aad44e4eb..4c228e112 100644 --- a/dotnet/src/Client.cs +++ b/dotnet/src/Client.cs @@ -1637,7 +1637,7 @@ internal record CreateSessionRequest( bool? Hooks, string? WorkingDirectory, bool? Streaming, - Dictionary? McpServers, + Dictionary? McpServers, string? EnvValueMode, List? CustomAgents, string? Agent, @@ -1692,7 +1692,7 @@ internal record ResumeSessionRequest( bool? EnableConfigDiscovery, bool? DisableResume, bool? Streaming, - Dictionary? McpServers, + Dictionary? McpServers, string? EnvValueMode, List? CustomAgents, string? Agent, diff --git a/dotnet/src/Types.cs b/dotnet/src/Types.cs index d8262e140..3e6ecf2c7 100644 --- a/dotnet/src/Types.cs +++ b/dotnet/src/Types.cs @@ -1413,10 +1413,17 @@ public class AzureOptions // ============================================================================ /// -/// Configuration for a local/stdio MCP server. +/// Abstract base class for MCP server configurations. /// -public class McpLocalServerConfig +[JsonPolymorphic( + TypeDiscriminatorPropertyName = "type", + IgnoreUnrecognizedTypeDiscriminators = true)] +[JsonDerivedType(typeof(McpStdioServerConfig), "stdio")] +[JsonDerivedType(typeof(McpHttpServerConfig), "http")] +public abstract class McpServerConfig { + private protected McpServerConfig() { } + /// /// List of tools to include from this server. Empty list means none. Use "*" for all. /// @@ -1424,16 +1431,26 @@ public class McpLocalServerConfig public List Tools { get; set; } = []; /// - /// Server type. Defaults to "local". + /// The server type discriminator. /// - [JsonPropertyName("type")] - public string? Type { get; set; } + [JsonIgnore] + public virtual string Type => "unknown"; /// /// Optional timeout in milliseconds for tool calls to this server. /// [JsonPropertyName("timeout")] public int? Timeout { get; set; } +} + +/// +/// Configuration for a local/stdio MCP server. +/// +public sealed class McpStdioServerConfig : McpServerConfig +{ + /// + [JsonIgnore] + public override string Type => "stdio"; /// /// Command to run the MCP server. @@ -1463,25 +1480,11 @@ public class McpLocalServerConfig /// /// Configuration for a remote MCP server (HTTP or SSE). /// -public class McpRemoteServerConfig +public sealed class McpHttpServerConfig : McpServerConfig { - /// - /// List of tools to include from this server. Empty list means none. Use "*" for all. - /// - [JsonPropertyName("tools")] - public List Tools { get; set; } = []; - - /// - /// Server type. Must be "http" or "sse". - /// - [JsonPropertyName("type")] - public string Type { get; set; } = "http"; - - /// - /// Optional timeout in milliseconds for tool calls to this server. - /// - [JsonPropertyName("timeout")] - public int? Timeout { get; set; } + /// + [JsonIgnore] + public override string Type => "http"; /// /// URL of the remote server. @@ -1539,7 +1542,7 @@ public class CustomAgentConfig /// MCP servers specific to this agent. /// [JsonPropertyName("mcpServers")] - public Dictionary? McpServers { get; set; } + public Dictionary? McpServers { get; set; } /// /// Whether the agent should be available for model inference. @@ -1608,7 +1611,7 @@ protected SessionConfig(SessionConfig? other) Hooks = other.Hooks; InfiniteSessions = other.InfiniteSessions; McpServers = other.McpServers is not null - ? new Dictionary(other.McpServers, other.McpServers.Comparer) + ? new Dictionary(other.McpServers, other.McpServers.Comparer) : null; Model = other.Model; ModelCapabilities = other.ModelCapabilities; @@ -1740,9 +1743,9 @@ protected SessionConfig(SessionConfig? other) /// /// MCP server configurations for the session. - /// Keys are server names, values are server configurations (McpLocalServerConfig or McpRemoteServerConfig). + /// Keys are server names, values are server configurations ( or ). /// - public Dictionary? McpServers { get; set; } + public Dictionary? McpServers { get; set; } /// /// Custom agent configurations for the session. @@ -1836,7 +1839,7 @@ protected ResumeSessionConfig(ResumeSessionConfig? other) Hooks = other.Hooks; InfiniteSessions = other.InfiniteSessions; McpServers = other.McpServers is not null - ? new Dictionary(other.McpServers, other.McpServers.Comparer) + ? new Dictionary(other.McpServers, other.McpServers.Comparer) : null; Model = other.Model; ModelCapabilities = other.ModelCapabilities; @@ -1972,9 +1975,9 @@ protected ResumeSessionConfig(ResumeSessionConfig? other) /// /// MCP server configurations for the session. - /// Keys are server names, values are server configurations (McpLocalServerConfig or McpRemoteServerConfig). + /// Keys are server names, values are server configurations ( or ). /// - public Dictionary? McpServers { get; set; } + public Dictionary? McpServers { get; set; } /// /// Custom agent configurations for the session. @@ -2519,8 +2522,7 @@ public class SystemMessageTransformRpcResponse [JsonSerializable(typeof(GetForegroundSessionResponse))] [JsonSerializable(typeof(GetModelsResponse))] [JsonSerializable(typeof(GetStatusResponse))] -[JsonSerializable(typeof(McpLocalServerConfig))] -[JsonSerializable(typeof(McpRemoteServerConfig))] +[JsonSerializable(typeof(McpServerConfig))] [JsonSerializable(typeof(MessageOptions))] [JsonSerializable(typeof(ModelBilling))] [JsonSerializable(typeof(ModelCapabilities))] diff --git a/dotnet/test/CloneTests.cs b/dotnet/test/CloneTests.cs index a0051ffbc..dcde71f99 100644 --- a/dotnet/test/CloneTests.cs +++ b/dotnet/test/CloneTests.cs @@ -86,7 +86,7 @@ public void SessionConfig_Clone_CopiesAllProperties() ExcludedTools = ["tool3"], WorkingDirectory = "/workspace", Streaming = true, - McpServers = new Dictionary { ["server1"] = new object() }, + McpServers = new Dictionary { ["server1"] = new McpStdioServerConfig { Command = "echo" } }, CustomAgents = [new CustomAgentConfig { Name = "agent1" }], Agent = "agent1", SkillDirectories = ["/skills"], @@ -118,7 +118,7 @@ public void SessionConfig_Clone_CollectionsAreIndependent() { AvailableTools = ["tool1"], ExcludedTools = ["tool2"], - McpServers = new Dictionary { ["s1"] = new object() }, + McpServers = new Dictionary { ["s1"] = new McpStdioServerConfig { Command = "echo" } }, CustomAgents = [new CustomAgentConfig { Name = "a1" }], SkillDirectories = ["/skills"], DisabledSkills = ["skill1"], @@ -129,7 +129,7 @@ public void SessionConfig_Clone_CollectionsAreIndependent() // Mutate clone collections clone.AvailableTools!.Add("tool99"); clone.ExcludedTools!.Add("tool99"); - clone.McpServers!["s2"] = new object(); + clone.McpServers!["s2"] = new McpStdioServerConfig { Command = "echo" }; clone.CustomAgents!.Add(new CustomAgentConfig { Name = "a2" }); clone.SkillDirectories!.Add("/more"); clone.DisabledSkills!.Add("skill99"); @@ -146,7 +146,7 @@ public void SessionConfig_Clone_CollectionsAreIndependent() [Fact] public void SessionConfig_Clone_PreservesMcpServersComparer() { - var servers = new Dictionary(StringComparer.OrdinalIgnoreCase) { ["server"] = new object() }; + var servers = new Dictionary(StringComparer.OrdinalIgnoreCase) { ["server"] = new McpStdioServerConfig { Command = "echo" } }; var original = new SessionConfig { McpServers = servers }; var clone = original.Clone(); @@ -161,7 +161,7 @@ public void ResumeSessionConfig_Clone_CollectionsAreIndependent() { AvailableTools = ["tool1"], ExcludedTools = ["tool2"], - McpServers = new Dictionary { ["s1"] = new object() }, + McpServers = new Dictionary { ["s1"] = new McpStdioServerConfig { Command = "echo" } }, CustomAgents = [new CustomAgentConfig { Name = "a1" }], SkillDirectories = ["/skills"], DisabledSkills = ["skill1"], @@ -172,7 +172,7 @@ public void ResumeSessionConfig_Clone_CollectionsAreIndependent() // Mutate clone collections clone.AvailableTools!.Add("tool99"); clone.ExcludedTools!.Add("tool99"); - clone.McpServers!["s2"] = new object(); + clone.McpServers!["s2"] = new McpStdioServerConfig { Command = "echo" }; clone.CustomAgents!.Add(new CustomAgentConfig { Name = "a2" }); clone.SkillDirectories!.Add("/more"); clone.DisabledSkills!.Add("skill99"); @@ -189,7 +189,7 @@ public void ResumeSessionConfig_Clone_CollectionsAreIndependent() [Fact] public void ResumeSessionConfig_Clone_PreservesMcpServersComparer() { - var servers = new Dictionary(StringComparer.OrdinalIgnoreCase) { ["server"] = new object() }; + var servers = new Dictionary(StringComparer.OrdinalIgnoreCase) { ["server"] = new McpStdioServerConfig { Command = "echo" } }; var original = new ResumeSessionConfig { McpServers = servers }; var clone = original.Clone(); diff --git a/dotnet/test/McpAndAgentsTests.cs b/dotnet/test/McpAndAgentsTests.cs index 1d35ffda4..782b01123 100644 --- a/dotnet/test/McpAndAgentsTests.cs +++ b/dotnet/test/McpAndAgentsTests.cs @@ -13,11 +13,10 @@ public class McpAndAgentsTests(E2ETestFixture fixture, ITestOutputHelper output) [Fact] public async Task Should_Accept_MCP_Server_Configuration_On_Session_Create() { - var mcpServers = new Dictionary + var mcpServers = new Dictionary { - ["test-server"] = new McpLocalServerConfig + ["test-server"] = new McpStdioServerConfig { - Type = "local", Command = "echo", Args = ["hello"], Tools = ["*"] @@ -50,11 +49,10 @@ public async Task Should_Accept_MCP_Server_Configuration_On_Session_Resume() await session1.SendAndWaitAsync(new MessageOptions { Prompt = "What is 1+1?" }); // Resume with MCP servers - var mcpServers = new Dictionary + var mcpServers = new Dictionary { - ["test-server"] = new McpLocalServerConfig + ["test-server"] = new McpStdioServerConfig { - Type = "local", Command = "echo", Args = ["hello"], Tools = ["*"] @@ -78,18 +76,16 @@ public async Task Should_Accept_MCP_Server_Configuration_On_Session_Resume() [Fact] public async Task Should_Handle_Multiple_MCP_Servers() { - var mcpServers = new Dictionary + var mcpServers = new Dictionary { - ["server1"] = new McpLocalServerConfig + ["server1"] = new McpStdioServerConfig { - Type = "local", Command = "echo", Args = ["server1"], Tools = ["*"] }, - ["server2"] = new McpLocalServerConfig + ["server2"] = new McpStdioServerConfig { - Type = "local", Command = "echo", Args = ["server2"], Tools = ["*"] @@ -207,11 +203,10 @@ public async Task Should_Handle_Custom_Agent_With_MCP_Servers() DisplayName = "MCP Agent", Description = "An agent with its own MCP servers", Prompt = "You are an agent with MCP servers.", - McpServers = new Dictionary + McpServers = new Dictionary { - ["agent-server"] = new McpLocalServerConfig + ["agent-server"] = new McpStdioServerConfig { - Type = "local", Command = "echo", Args = ["agent-mcp"], Tools = ["*"] @@ -264,11 +259,10 @@ public async Task Should_Handle_Multiple_Custom_Agents() public async Task Should_Pass_Literal_Env_Values_To_Mcp_Server_Subprocess() { var testHarnessDir = FindTestHarnessDir(); - var mcpServers = new Dictionary + var mcpServers = new Dictionary { - ["env-echo"] = new McpLocalServerConfig + ["env-echo"] = new McpStdioServerConfig { - Type = "local", Command = "node", Args = [Path.Combine(testHarnessDir, "test-mcp-server.mjs")], Env = new Dictionary { ["TEST_SECRET"] = "hunter2" }, @@ -299,11 +293,10 @@ public async Task Should_Pass_Literal_Env_Values_To_Mcp_Server_Subprocess() [Fact] public async Task Should_Accept_Both_MCP_Servers_And_Custom_Agents() { - var mcpServers = new Dictionary + var mcpServers = new Dictionary { - ["shared-server"] = new McpLocalServerConfig + ["shared-server"] = new McpStdioServerConfig { - Type = "local", Command = "echo", Args = ["shared"], Tools = ["*"] diff --git a/go/types.go b/go/types.go index c26f075e3..4c4809467 100644 --- a/go/types.go +++ b/go/types.go @@ -382,8 +382,8 @@ type SessionHooks struct { OnErrorOccurred ErrorOccurredHandler } -// MCPLocalServerConfig configures a local/stdio MCP server -type MCPLocalServerConfig struct { +// MCPStdioServerConfig configures a local/stdio MCP server +type MCPStdioServerConfig struct { Tools []string `json:"tools"` Type string `json:"type,omitempty"` // "local" or "stdio" Timeout int `json:"timeout,omitempty"` @@ -393,8 +393,8 @@ type MCPLocalServerConfig struct { Cwd string `json:"cwd,omitempty"` } -// MCPRemoteServerConfig configures a remote MCP server (HTTP or SSE) -type MCPRemoteServerConfig struct { +// MCPHTTPServerConfig configures a remote MCP server (HTTP or SSE) +type MCPHTTPServerConfig struct { Tools []string `json:"tools"` Type string `json:"type"` // "http" or "sse" Timeout int `json:"timeout,omitempty"` @@ -402,7 +402,7 @@ type MCPRemoteServerConfig struct { Headers map[string]string `json:"headers,omitempty"` } -// MCPServerConfig can be either MCPLocalServerConfig or MCPRemoteServerConfig +// MCPServerConfig can be either MCPStdioServerConfig or MCPHTTPServerConfig // Use a map[string]any for flexibility, or create separate configs type MCPServerConfig map[string]any diff --git a/nodejs/src/index.ts b/nodejs/src/index.ts index 3fab122db..b8be99a89 100644 --- a/nodejs/src/index.ts +++ b/nodejs/src/index.ts @@ -30,8 +30,8 @@ export type { GetStatusResponse, InfiniteSessionConfig, InputOptions, - MCPLocalServerConfig, - MCPRemoteServerConfig, + MCPStdioServerConfig, + MCPHttpServerConfig, MCPServerConfig, MessageOptions, ModelBilling, diff --git a/nodejs/src/types.ts b/nodejs/src/types.ts index c2d095234..93fbe11a2 100644 --- a/nodejs/src/types.ts +++ b/nodejs/src/types.ts @@ -937,7 +937,7 @@ interface MCPServerConfigBase { /** * Configuration for a local/stdio MCP server. */ -export interface MCPLocalServerConfig extends MCPServerConfigBase { +export interface MCPStdioServerConfig extends MCPServerConfigBase { type?: "local" | "stdio"; command: string; args: string[]; @@ -951,7 +951,7 @@ export interface MCPLocalServerConfig extends MCPServerConfigBase { /** * Configuration for a remote MCP server (HTTP or SSE). */ -export interface MCPRemoteServerConfig extends MCPServerConfigBase { +export interface MCPHttpServerConfig extends MCPServerConfigBase { type: "http" | "sse"; /** * URL of the remote server. @@ -966,7 +966,7 @@ export interface MCPRemoteServerConfig extends MCPServerConfigBase { /** * Union type for MCP server configurations. */ -export type MCPServerConfig = MCPLocalServerConfig | MCPRemoteServerConfig; +export type MCPServerConfig = MCPStdioServerConfig | MCPHttpServerConfig; // ============================================================================ // Custom Agent Configuration Types diff --git a/nodejs/test/e2e/mcp_and_agents.test.ts b/nodejs/test/e2e/mcp_and_agents.test.ts index 28ebf28b5..59e6d498b 100644 --- a/nodejs/test/e2e/mcp_and_agents.test.ts +++ b/nodejs/test/e2e/mcp_and_agents.test.ts @@ -5,7 +5,7 @@ import { dirname, resolve } from "path"; import { fileURLToPath } from "url"; import { describe, expect, it } from "vitest"; -import type { CustomAgentConfig, MCPLocalServerConfig, MCPServerConfig } from "../../src/index.js"; +import type { CustomAgentConfig, MCPStdioServerConfig, MCPServerConfig } from "../../src/index.js"; import { approveAll } from "../../src/index.js"; import { createSdkTestContext } from "./harness/sdkTestContext.js"; @@ -24,7 +24,7 @@ describe("MCP Servers and Custom Agents", async () => { command: "echo", args: ["hello"], tools: ["*"], - } as MCPLocalServerConfig, + } as MCPStdioServerConfig, }; const session = await client.createSession({ @@ -56,7 +56,7 @@ describe("MCP Servers and Custom Agents", async () => { command: "echo", args: ["hello"], tools: ["*"], - } as MCPLocalServerConfig, + } as MCPStdioServerConfig, }; const session2 = await client.resumeSession(sessionId, { @@ -81,13 +81,13 @@ describe("MCP Servers and Custom Agents", async () => { command: "echo", args: ["server1"], tools: ["*"], - } as MCPLocalServerConfig, + } as MCPStdioServerConfig, server2: { type: "local", command: "echo", args: ["server2"], tools: ["*"], - } as MCPLocalServerConfig, + } as MCPStdioServerConfig, }; const session = await client.createSession({ @@ -107,7 +107,7 @@ describe("MCP Servers and Custom Agents", async () => { args: [TEST_MCP_SERVER], tools: ["*"], env: { TEST_SECRET: "hunter2" }, - } as MCPLocalServerConfig, + } as MCPStdioServerConfig, }; const session = await client.createSession({ @@ -219,7 +219,7 @@ describe("MCP Servers and Custom Agents", async () => { command: "echo", args: ["agent-mcp"], tools: ["*"], - } as MCPLocalServerConfig, + } as MCPStdioServerConfig, }, }, ]; @@ -268,7 +268,7 @@ describe("MCP Servers and Custom Agents", async () => { command: "echo", args: ["shared"], tools: ["*"], - } as MCPLocalServerConfig, + } as MCPStdioServerConfig, }; const customAgents: CustomAgentConfig[] = [ diff --git a/python/copilot/session.py b/python/copilot/session.py index b3f62789d..f57915a96 100644 --- a/python/copilot/session.py +++ b/python/copilot/session.py @@ -725,7 +725,7 @@ class SessionHooks(TypedDict, total=False): # ============================================================================ -class MCPLocalServerConfig(TypedDict, total=False): +class MCPStdioServerConfig(TypedDict, total=False): """Configuration for a local/stdio MCP server.""" tools: list[str] # List of tools to include. [] means none. "*" means all. @@ -737,7 +737,7 @@ class MCPLocalServerConfig(TypedDict, total=False): cwd: NotRequired[str] # Working directory -class MCPRemoteServerConfig(TypedDict, total=False): +class MCPHttpServerConfig(TypedDict, total=False): """Configuration for a remote MCP server (HTTP or SSE).""" tools: list[str] # List of tools to include. [] means none. "*" means all. @@ -747,7 +747,7 @@ class MCPRemoteServerConfig(TypedDict, total=False): headers: NotRequired[dict[str, str]] # HTTP headers -MCPServerConfig = MCPLocalServerConfig | MCPRemoteServerConfig +MCPServerConfig = MCPStdioServerConfig | MCPHttpServerConfig # ============================================================================ # Custom Agent Configuration Types From 138e91265931e3210033bea6a6b34d9ae217798b Mon Sep 17 00:00:00 2001 From: Stephen Toub Date: Thu, 9 Apr 2026 10:03:22 -0400 Subject: [PATCH 2/5] Use idiomatic HTTP casing in Python and TypeScript type names Rename MCPHttpServerConfig to MCPHTTPServerConfig in Python (matching stdlib convention: HTTPServer, HTTPError) and TypeScript (matching the all-caps treatment of MCP already in use). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --- nodejs/src/index.ts | 2 +- nodejs/src/types.ts | 4 ++-- python/copilot/session.py | 4 ++-- 3 files changed, 5 insertions(+), 5 deletions(-) diff --git a/nodejs/src/index.ts b/nodejs/src/index.ts index b8be99a89..1ca8432c9 100644 --- a/nodejs/src/index.ts +++ b/nodejs/src/index.ts @@ -31,7 +31,7 @@ export type { InfiniteSessionConfig, InputOptions, MCPStdioServerConfig, - MCPHttpServerConfig, + MCPHTTPServerConfig, MCPServerConfig, MessageOptions, ModelBilling, diff --git a/nodejs/src/types.ts b/nodejs/src/types.ts index 93fbe11a2..153c1ca32 100644 --- a/nodejs/src/types.ts +++ b/nodejs/src/types.ts @@ -951,7 +951,7 @@ export interface MCPStdioServerConfig extends MCPServerConfigBase { /** * Configuration for a remote MCP server (HTTP or SSE). */ -export interface MCPHttpServerConfig extends MCPServerConfigBase { +export interface MCPHTTPServerConfig extends MCPServerConfigBase { type: "http" | "sse"; /** * URL of the remote server. @@ -966,7 +966,7 @@ export interface MCPHttpServerConfig extends MCPServerConfigBase { /** * Union type for MCP server configurations. */ -export type MCPServerConfig = MCPStdioServerConfig | MCPHttpServerConfig; +export type MCPServerConfig = MCPStdioServerConfig | MCPHTTPServerConfig; // ============================================================================ // Custom Agent Configuration Types diff --git a/python/copilot/session.py b/python/copilot/session.py index f57915a96..45e8826b7 100644 --- a/python/copilot/session.py +++ b/python/copilot/session.py @@ -737,7 +737,7 @@ class MCPStdioServerConfig(TypedDict, total=False): cwd: NotRequired[str] # Working directory -class MCPHttpServerConfig(TypedDict, total=False): +class MCPHTTPServerConfig(TypedDict, total=False): """Configuration for a remote MCP server (HTTP or SSE).""" tools: list[str] # List of tools to include. [] means none. "*" means all. @@ -747,7 +747,7 @@ class MCPHttpServerConfig(TypedDict, total=False): headers: NotRequired[dict[str, str]] # HTTP headers -MCPServerConfig = MCPStdioServerConfig | MCPHttpServerConfig +MCPServerConfig = MCPStdioServerConfig | MCPHTTPServerConfig # ============================================================================ # Custom Agent Configuration Types From f769503b2474e77e99821bb064cf41eb13bda167 Mon Sep 17 00:00:00 2001 From: Stephen Toub Date: Thu, 9 Apr 2026 10:20:36 -0400 Subject: [PATCH 3/5] Update mcp-servers C# scenario to use strongly-typed McpServerConfig API Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --- test/scenarios/tools/mcp-servers/csharp/Program.cs | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/test/scenarios/tools/mcp-servers/csharp/Program.cs b/test/scenarios/tools/mcp-servers/csharp/Program.cs index 2ee25aacd..e3c1ed428 100644 --- a/test/scenarios/tools/mcp-servers/csharp/Program.cs +++ b/test/scenarios/tools/mcp-servers/csharp/Program.cs @@ -10,16 +10,16 @@ try { - var mcpServers = new Dictionary(); + var mcpServers = new Dictionary(); var mcpServerCmd = Environment.GetEnvironmentVariable("MCP_SERVER_CMD"); if (!string.IsNullOrEmpty(mcpServerCmd)) { var mcpArgs = Environment.GetEnvironmentVariable("MCP_SERVER_ARGS"); - mcpServers["example"] = new Dictionary + mcpServers["example"] = new McpStdioServerConfig { - { "type", "stdio" }, - { "command", mcpServerCmd }, - { "args", string.IsNullOrEmpty(mcpArgs) ? Array.Empty() : mcpArgs.Split(' ') }, + Command = mcpServerCmd, + Args = string.IsNullOrEmpty(mcpArgs) ? [] : [.. mcpArgs.Split(' ')], + Tools = ["*"], }; } From 56cee2fc5bb0e818362ab40141fc0005e018af60 Mon Sep 17 00:00:00 2001 From: Stephen Toub Date: Thu, 9 Apr 2026 10:38:44 -0400 Subject: [PATCH 4/5] Make Go MCPServerConfig type-safe with interface + marker method Change MCPServerConfig from map[string]any to an interface with a private marker method, matching the type-safety approach used for C#. MCPStdioServerConfig and MCPHTTPServerConfig implement the interface and use MarshalJSON to auto-inject the type discriminator. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --- docs/features/mcp.md | 10 ++- go/internal/e2e/mcp_and_agents_test.go | 67 +++++++++------------ go/types.go | 42 ++++++++++--- test/scenarios/tools/mcp-servers/go/main.go | 8 +-- 4 files changed, 73 insertions(+), 54 deletions(-) diff --git a/docs/features/mcp.md b/docs/features/mcp.md index 0329293b1..d8af04533 100644 --- a/docs/features/mcp.md +++ b/docs/features/mcp.md @@ -113,15 +113,13 @@ func main() { } defer client.Stop() - // MCPServerConfig is map[string]any for flexibility session, err := client.CreateSession(ctx, &copilot.SessionConfig{ Model: "gpt-5", MCPServers: map[string]copilot.MCPServerConfig{ - "my-local-server": { - "type": "local", - "command": "node", - "args": []string{"./mcp-server.js"}, - "tools": []string{"*"}, + "my-local-server": copilot.MCPStdioServerConfig{ + Command: "node", + Args: []string{"./mcp-server.js"}, + Tools: []string{"*"}, }, }, }) diff --git a/go/internal/e2e/mcp_and_agents_test.go b/go/internal/e2e/mcp_and_agents_test.go index 7b7d4d037..e05f44585 100644 --- a/go/internal/e2e/mcp_and_agents_test.go +++ b/go/internal/e2e/mcp_and_agents_test.go @@ -18,11 +18,10 @@ func TestMCPServers(t *testing.T) { ctx.ConfigureForTest(t) mcpServers := map[string]copilot.MCPServerConfig{ - "test-server": { - "type": "local", - "command": "echo", - "args": []string{"hello"}, - "tools": []string{"*"}, + "test-server": copilot.MCPStdioServerConfig{ + Command: "echo", + Args: []string{"hello"}, + Tools: []string{"*"}, }, } @@ -75,11 +74,10 @@ func TestMCPServers(t *testing.T) { // Resume with MCP servers mcpServers := map[string]copilot.MCPServerConfig{ - "test-server": { - "type": "local", - "command": "echo", - "args": []string{"hello"}, - "tools": []string{"*"}, + "test-server": copilot.MCPStdioServerConfig{ + Command: "echo", + Args: []string{"hello"}, + Tools: []string{"*"}, }, } @@ -117,13 +115,12 @@ func TestMCPServers(t *testing.T) { mcpServerDir := filepath.Dir(mcpServerPath) mcpServers := map[string]copilot.MCPServerConfig{ - "env-echo": { - "type": "local", - "command": "node", - "args": []string{mcpServerPath}, - "tools": []string{"*"}, - "env": map[string]string{"TEST_SECRET": "hunter2"}, - "cwd": mcpServerDir, + "env-echo": copilot.MCPStdioServerConfig{ + Command: "node", + Args: []string{mcpServerPath}, + Tools: []string{"*"}, + Env: map[string]string{"TEST_SECRET": "hunter2"}, + Cwd: mcpServerDir, }, } @@ -157,17 +154,15 @@ func TestMCPServers(t *testing.T) { ctx.ConfigureForTest(t) mcpServers := map[string]copilot.MCPServerConfig{ - "server1": { - "type": "local", - "command": "echo", - "args": []string{"server1"}, - "tools": []string{"*"}, + "server1": copilot.MCPStdioServerConfig{ + Command: "echo", + Args: []string{"server1"}, + Tools: []string{"*"}, }, - "server2": { - "type": "local", - "command": "echo", - "args": []string{"server2"}, - "tools": []string{"*"}, + "server2": copilot.MCPStdioServerConfig{ + Command: "echo", + Args: []string{"server2"}, + Tools: []string{"*"}, }, } @@ -327,11 +322,10 @@ func TestCustomAgents(t *testing.T) { Description: "An agent with its own MCP servers", Prompt: "You are an agent with MCP servers.", MCPServers: map[string]copilot.MCPServerConfig{ - "agent-server": { - "type": "local", - "command": "echo", - "args": []string{"agent-mcp"}, - "tools": []string{"*"}, + "agent-server": copilot.MCPStdioServerConfig{ + Command: "echo", + Args: []string{"agent-mcp"}, + Tools: []string{"*"}, }, }, }, @@ -399,11 +393,10 @@ func TestCombinedConfiguration(t *testing.T) { ctx.ConfigureForTest(t) mcpServers := map[string]copilot.MCPServerConfig{ - "shared-server": { - "type": "local", - "command": "echo", - "args": []string{"shared"}, - "tools": []string{"*"}, + "shared-server": copilot.MCPStdioServerConfig{ + Command: "echo", + Args: []string{"shared"}, + Tools: []string{"*"}, }, } diff --git a/go/types.go b/go/types.go index 4c4809467..568bcc1b9 100644 --- a/go/types.go +++ b/go/types.go @@ -382,10 +382,15 @@ type SessionHooks struct { OnErrorOccurred ErrorOccurredHandler } -// MCPStdioServerConfig configures a local/stdio MCP server +// MCPServerConfig is implemented by MCP server configuration types. +// Only MCPStdioServerConfig and MCPHTTPServerConfig implement this interface. +type MCPServerConfig interface { + mcpServerConfig() +} + +// MCPStdioServerConfig configures a local/stdio MCP server. type MCPStdioServerConfig struct { Tools []string `json:"tools"` - Type string `json:"type,omitempty"` // "local" or "stdio" Timeout int `json:"timeout,omitempty"` Command string `json:"command"` Args []string `json:"args"` @@ -393,18 +398,41 @@ type MCPStdioServerConfig struct { Cwd string `json:"cwd,omitempty"` } -// MCPHTTPServerConfig configures a remote MCP server (HTTP or SSE) +func (MCPStdioServerConfig) mcpServerConfig() {} + +// MarshalJSON implements json.Marshaler, injecting the "type" discriminator. +func (c MCPStdioServerConfig) MarshalJSON() ([]byte, error) { + type alias MCPStdioServerConfig + return json.Marshal(struct { + Type string `json:"type"` + alias + }{ + Type: "stdio", + alias: alias(c), + }) +} + +// MCPHTTPServerConfig configures a remote MCP server (HTTP or SSE). type MCPHTTPServerConfig struct { Tools []string `json:"tools"` - Type string `json:"type"` // "http" or "sse" Timeout int `json:"timeout,omitempty"` URL string `json:"url"` Headers map[string]string `json:"headers,omitempty"` } -// MCPServerConfig can be either MCPStdioServerConfig or MCPHTTPServerConfig -// Use a map[string]any for flexibility, or create separate configs -type MCPServerConfig map[string]any +func (MCPHTTPServerConfig) mcpServerConfig() {} + +// MarshalJSON implements json.Marshaler, injecting the "type" discriminator. +func (c MCPHTTPServerConfig) MarshalJSON() ([]byte, error) { + type alias MCPHTTPServerConfig + return json.Marshal(struct { + Type string `json:"type"` + alias + }{ + Type: "http", + alias: alias(c), + }) +} // CustomAgentConfig configures a custom agent type CustomAgentConfig struct { diff --git a/test/scenarios/tools/mcp-servers/go/main.go b/test/scenarios/tools/mcp-servers/go/main.go index d2ae5ab86..72cbdc067 100644 --- a/test/scenarios/tools/mcp-servers/go/main.go +++ b/test/scenarios/tools/mcp-servers/go/main.go @@ -30,10 +30,10 @@ func main() { if argsStr := os.Getenv("MCP_SERVER_ARGS"); argsStr != "" { args = strings.Split(argsStr, " ") } - mcpServers["example"] = copilot.MCPServerConfig{ - "type": "stdio", - "command": cmd, - "args": args, + mcpServers["example"] = copilot.MCPStdioServerConfig{ + Command: cmd, + Args: args, + Tools: []string{"*"}, } } From b8ef5b0ae9ea7415293b9c2c433df6f88cf90c53 Mon Sep 17 00:00:00 2001 From: Stephen Toub Date: Thu, 9 Apr 2026 10:51:27 -0400 Subject: [PATCH 5/5] Fix consistency gaps: update JSDoc and drop stale type field in Python tests - Update MCPServerConfigBase JSDoc to reference stdio/http instead of local/remote - Remove explicit type: local from Python E2E tests (omitted type defaults to stdio, matching Go/C# pattern) Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --- nodejs/src/types.ts | 4 ++-- python/e2e/test_mcp_and_agents.py | 4 ---- 2 files changed, 2 insertions(+), 6 deletions(-) diff --git a/nodejs/src/types.ts b/nodejs/src/types.ts index 153c1ca32..2e9b6ba47 100644 --- a/nodejs/src/types.ts +++ b/nodejs/src/types.ts @@ -924,8 +924,8 @@ interface MCPServerConfigBase { */ tools: string[]; /** - * Indicates "remote" or "local" server type. - * If not specified, defaults to "local". + * Indicates the server type: "stdio" for local/subprocess servers, "http"/"sse" for remote servers. + * If not specified, defaults to "stdio". */ type?: string; /** diff --git a/python/e2e/test_mcp_and_agents.py b/python/e2e/test_mcp_and_agents.py index c6a590d6c..f93ba432d 100644 --- a/python/e2e/test_mcp_and_agents.py +++ b/python/e2e/test_mcp_and_agents.py @@ -25,7 +25,6 @@ async def test_should_accept_mcp_server_configuration_on_session_create( """Test that MCP server configuration is accepted on session create""" mcp_servers: dict[str, MCPServerConfig] = { "test-server": { - "type": "local", "command": "echo", "args": ["hello"], "tools": ["*"], @@ -59,7 +58,6 @@ async def test_should_accept_mcp_server_configuration_on_session_resume( # Resume with MCP servers mcp_servers: dict[str, MCPServerConfig] = { "test-server": { - "type": "local", "command": "echo", "args": ["hello"], "tools": ["*"], @@ -86,7 +84,6 @@ async def test_should_pass_literal_env_values_to_mcp_server_subprocess( """Test that env values are passed as literals to MCP server subprocess""" mcp_servers: dict[str, MCPServerConfig] = { "env-echo": { - "type": "local", "command": "node", "args": [TEST_MCP_SERVER], "tools": ["*"], @@ -180,7 +177,6 @@ async def test_should_accept_both_mcp_servers_and_custom_agents(self, ctx: E2ETe """Test that both MCP servers and custom agents can be configured together""" mcp_servers: dict[str, MCPServerConfig] = { "shared-server": { - "type": "local", "command": "echo", "args": ["shared"], "tools": ["*"],