flutter pub add mcp_dart基于插件公开信息、社区数据与项目使用情况整理的选型参考。
mcp_dart 包是 Model Context Protocol (MCP) SDK 的 Dart 实现，可在 Flutter 应用中无缝集成上下文感知的 AI 模型。它通过定义管理模型上下文、提示和响应的标准协议，促进客户端与大语言模型（LLM）之间的结构化通信。专为开发 AI 驱动的应用程序的开发者设计，支持在 Android、iOS、Web、macOS、Windows 和 Linux 上跨平台部署。该包简化了动态上下文数据的处理，提升了提示的准确性，并降低了生成工作流中的延迟。
以下为关联源码仓库的 README 原文快照，最新内容请访问源码仓库。
mcp_dart is a dual-era Dart and Flutter SDK for MCP clients, servers, and AI
hosts. It implements the complete core client/server wire surface of the locked
MCP 2026-07-28 specification, retains the MCP 2025-11-25 feature set, and
negotiates supported earlier initialization-based specifications.
Here, core means the normative wire requirements assigned to client and server roles by the pinned final specification. It excludes optional MCP extensions, host UI behavior, an authorization-server implementation, JSON Schema external-reference resolution, and custom JSON Schema vocabularies.
[!IMPORTANT] This release is
mcp_dart 2.4.2. The separately versioned stable CLI remainsmcp_dart_cli 0.2.1, which requiresmcp_dart ^2.4.2. Current source passes every scored requirement in the official alpha.11 MCP2025-11-25and2026-07-28client and server sets, including all 25 required 2026 authorization scenarios, plus bidirectional published TypeScript SDK 2.0.0 and Python SDK 2.1.1 interoperability.
The project is pursuing MCP SDK Tier 1. Tier 1 is not yet claimed or assigned. The technical baseline is green; the remaining official audit, repository-governance, and SDK Working Group steps are tracked in the roadmap and 48-feature coverage inventory.
The public maintenance contract is documented in the contribution guide, security policy, dependency policy, and versioning policy.
| Package | Minimum Dart SDK |
|---|---|
mcp_dart 2.4.2 |
3.4 |
mcp_dart_cli 0.2.1 |
3.12 |
SDK-only generated projects retain the SDK's Dart 3.4 minimum. CLI projects use Dart 3.12 because the CLI and its toolchain target that release.
Install Dart from dart.dev.
Use the latest stable package for production projects:
dart pub add mcp_dart
Pin the stable 2.4 line explicitly when reproducible dependency resolution is important:
dependencies:
mcp_dart: ^2.4.2
The snippets below use the current stable SDK line. Package versions
remain separate from protocol profiles: McpProtocol.stable names the SDK's
default compatibility policy.
The SDK and CLI are versioned independently. The stable CLI's ^2.4.2
constraint accepts SDK versions from 2.4.2 up to, but not including, 3.0.0.
For direct SDK integration, start with the getting-started guide. The CLI below is optional and provides scaffolding, inspection, and conformance commands.
mcp_dart 2.4.2 bounds incoming stdio and IO stream messages to 10 MiB by
default, with configurable limits for larger messages. See the
transport guide before upgrading integrations that
exchange larger frames.MCP has three roles: a host owns the user experience, a client connects that host to one server, and a server exposes tools, resources, and prompts. A host can manage multiple clients and servers.
| Profile | Protocol behavior |
|---|---|
McpProtocol.stable |
Default dual-era profile: prefer MCP 2026-07-28, then fall back to initialization-based MCP specifications; body-only discovery probes are bounded to 5 seconds |
McpProtocol.legacy |
Initialization-era profile: negotiate the MCP 2025-11-25, MCP 2025-06-18, MCP 2025-03-26, MCP 2024-11-05, or MCP 2024-10-07 specification |
McpProtocol.require2026 |
Require MCP 2026-07-28 and reject legacy initialization |
Use stableProtocolVersion or defaultProtocolVersion for MCP 2026-07-28.
previewProtocolVersion remains as a deprecated alias for applications built
against a 2.3 prerelease.
latestInitializationProtocolVersion remains 2025-11-25 when the default
profile falls back to the legacy lifecycle. For compatibility,
latestProtocolVersion and supportedProtocolVersions retain their mcp_dart
2.2 initialization-era values; use allSupportedProtocolVersions for the
dual-era list.
Select a profile only when you need to constrain negotiation:
final legacyClient = McpClient(
const Implementation(name: 'my-client', version: '1.0.0'),
options: const McpClientOptions(protocol: McpProtocol.legacy),
);
final strict2026Server = McpServer(
const Implementation(name: 'my-server', version: '1.0.0'),
options: const McpServerOptions(protocol: McpProtocol.require2026),
);
See the MCP 2026-07-28 transition guide for fallback rules and APIs specific to MCP 2026-07-28, or run the strict MCP 2026-07-28 example. Applications upgrading from the stable 2.2 line should also follow the 2.2 to 2.3 migration guide.
Install the matching stable CLI:
dart pub global activate mcp_dart_cli 0.2.1
mcp_dart create my_server
cd my_server
mcp_dart inspect
The 0.2.1 CLI creates a project with mcp_dart: ^2.4.2. The inspector
launches the generated stdio server itself. After leaving the interactive
inspector, you can run a single tool directly:
mcp_dart inspect --tool add --json-args '{"a": 1, "b": 2}'
Useful commands:
| Command | Purpose |
|---|---|
create |
Scaffold a Dart MCP server using the SDK channel paired with the CLI |
serve |
Run a generated server over stdio or HTTP |
doctor |
Check project health and connectivity |
inspect |
Interactively use a server's capabilities |
inspect-server |
Produce a structured report for a live server |
inspect-client |
Run a stdio harness that inspects a connecting client |
trace |
Proxy and record a real stdio session |
conformance |
Run the repository's built-in protocol regression fixtures |
See the CLI documentation for command options and scope.
Standalone integration examples may declare newer Dart SDK requirements; check each example README before running it.
StreamableHttpClientTransport supports OAuthClientProvider and optional
authorization-code discovery. Servers can use authenticator or
authenticationHandler and publish protected-resource metadata.
The checked-in OAuth examples store tokens in plaintext files for local learning. Production applications must use platform secure storage or an encrypted credential service. See the OAuth examples and Streamable HTTP authentication.
Do not expose example HTTP servers directly to untrusted networks. Production deployments should use TLS, authenticate requests, and configure the documented Host and Origin protections.
| Target | Stdio | Streamable HTTP | Legacy HTTP+SSE | IO/custom stream |
|---|---|---|---|---|
| Dart VM / desktop server | Yes | Client and server | Client and server | Yes |
| Browser / Flutter Web | No process spawning | Client | Client | Yes |
| Flutter mobile | Only app-managed native helpers | Remote client | Remote client | Yes |
| Flutter desktop | Local helper processes | Client and server | Client and server | Yes |
Legacy HTTP+SSE is deprecated under MCP SEP-2596 and is retained only for explicit compatibility. Use Streamable HTTP for new remote integrations.
See Flutter host and client recipes for lifecycle and secure-storage guidance.
The Dart team maintains dart_mcp in
dart-lang/ai.
Choose it when you prefer the Dart team's APIs. Choose mcp_dart when you need
this SDK's transport, security, compatibility, extension, and inspection
surface. Re-check both packages' current releases before a production decision.