1,120 pages for message.
Titles and paths first, then pages whose text carries it. Each row opens that page as this site last read it.
Build with Agent Skills
Model Context Protocol · in the page
docs/2026-07-28/develop/build-with-agent-skills
…s * **Upstream auth** — API keys, OAuth 2.0, or none If your opening message already covers these, the agent skips ahead to the recommendation. ## Deployment paths Based on discovery, the skill rec…
Client Best Practices
Model Context Protocol · in the page
docs/2026-07-28/develop/clients/client-best-practices
…ority of the context window before the model has even read the user's message. ![Comparison of loading all tools upfront versus discovering tools on demand. The upfront approach consumes \~150,000 to…
Connect to remote MCP Servers
Model Context Protocol · in the page
docs/2026-07-28/develop/connect-remote-servers
…&s=53acf21f6807dd5323b70b84b5d98d8a) in the bottom-left corner of the message input area. Then hover over "Connectors", move the cursor over "Add to Example Remote Server", where hovering displays the…
Architecture overview
Model Context Protocol · in the page
docs/2026-07-28/learn/architecture
…s and servers, including transport-specific connection establishment, message framing, and authorization. Conceptually the data layer is the inner layer, while the transport layer is the outer layer.…
Understanding MCP clients
Model Context Protocol · in the page
docs/2026-07-28/learn/client-concepts
…} { method: "elicitation/create", params: { mode: "form", message: "Please confirm your Barcelona vacation booking details:", requestedSchema: { type: "object", properties:…
Understanding MCP servers
Model Context Protocol · in the page
docs/2026-07-28/learn/server-concepts
…nal APIs, modify files, or trigger other logic. | Search flights Send messages Create calendar events | Model | | **Resources** | Passive data sources that provide read-only access to information for…
Debugging
Model Context Protocol · in the page
docs/2026-07-28/tools/debugging
…-28/server/utilities/logging.md) over the protocol (`notifications/message`) is deprecated as of protocol version `2026-07-28`. 3. **Client developer tools**: most MCP clients expose logs and conne…
CLI client
Model Context Protocol · in the page
docs/2026-07-28/tools/inspector/cli
…```json theme={null} { "error": { "code": "auth_required", "message": "Unauthorized", "status": 401, "url": "https://api.example/mcp" } } ``` The envelope carries `code` and `mess…
mcpdo connection client
Model Context Protocol · in the page
docs/2026-07-28/tools/inspector/mcpdo
…og entry mcpdo @my-server tools/list mcpdo @my-server tools/call echo message:=hi mcpdo @my-server resources/read file:///tmp/notes.txt mcpdo connections/list # what's open mcpd…
Protocol eras
Model Context Protocol · in the page
docs/2026-07-28/tools/inspector/protocol-eras
…ted, the negotiated era is shown as a badge on the **Protocol** tab's Messages header and in **Connection Info**. On a modern connection, `server/discover` also supplies `capabilities` (including `ext…
Recipes
Model Context Protocol · in the page
docs/2026-07-28/tools/inspector/recipes
…disconnected`, `connecting`, then `connected` or `error` (`data-error-message` has the detail) | | `[data-testid="connection-status"]` | `data-deeplink` | `parsed`, `rejected`, or `none` (`none` means…
Web client
Model Context Protocol · in the page
docs/2026-07-28/tools/inspector/web
…ompts` capability | List prompts, supply arguments, preview generated messages. | | **Resources** | `resources` capability | Browse, read, and subscribe to resources. | | **Skills** | The server decla…
Understanding Authorization in MCP
Model Context Protocol · in the page
docs/2026-07-28/tutorials/security/authorization
…({ jsonrpc: "2.0", error: { code: -32000, message: "Bad Request: No valid session ID provided", }, id: null, }); return; } await transport.handleRe…
Security Best Practices
Model Context Protocol · in the page
docs/2026-07-28/tutorials/security/security_best_practices
…keys, and other secrets * **Internal network reconnaissance**: Error messages reveal information about internal network topology and services * **Service interaction**: POST requests (e.g., to toke…
Build an MCP client
Model Context Protocol · in the page
docs/draft/develop/build-client
…> str: """Process a query using Claude and available tools""" messages = [ { "role": "user", "content": query } ] tool_list = await client.list…
Build an MCP server
Model Context Protocol · in the page
docs/draft/develop/build-server
…** Never write to stdout. Writing to stdout will corrupt the JSON-RPC messages and break your server. The `print()` function writes to stdout by default, so keep it out of a STDIO server entirely. **…
Build with Agent Skills
Model Context Protocol · in the page
docs/draft/develop/build-with-agent-skills
…s * **Upstream auth** — API keys, OAuth 2.0, or none If your opening message already covers these, the agent skips ahead to the recommendation. ## Deployment paths Based on discovery, the skill rec…
Client Best Practices
Model Context Protocol · in the page
docs/draft/develop/clients/client-best-practices
…ority of the context window before the model has even read the user's message. ![Comparison of loading all tools upfront versus discovering tools on demand. The upfront approach consumes \~150,000 to…
Connect to remote MCP Servers
Model Context Protocol · in the page
docs/draft/develop/connect-remote-servers
…&s=53acf21f6807dd5323b70b84b5d98d8a) in the bottom-left corner of the message input area. Then hover over "Connectors", move the cursor over "Add to Example Remote Server", where hovering displays the…
Architecture overview
Model Context Protocol · in the page
docs/draft/learn/architecture
…s and servers, including transport-specific connection establishment, message framing, and authorization. Conceptually the data layer is the inner layer, while the transport layer is the outer layer.…
Understanding MCP clients
Model Context Protocol · in the page
docs/draft/learn/client-concepts
…} { method: "elicitation/create", params: { mode: "form", message: "Please confirm your Barcelona vacation booking details:", requestedSchema: { type: "object", properties:…
Understanding MCP servers
Model Context Protocol · in the page
docs/draft/learn/server-concepts
…nal APIs, modify files, or trigger other logic. | Search flights Send messages Create calendar events | Model | | **Resources** | Passive data sources that provide read-only access to information for…
Debugging
Model Context Protocol · in the page
docs/draft/tools/debugging
…aft/server/utilities/logging.md) over the protocol (`notifications/message`) is deprecated as of protocol version `2026-07-28`. 3. **Client developer tools**: most MCP clients expose logs and conne…
CLI client
Model Context Protocol · in the page
docs/draft/tools/inspector/cli
…```json theme={null} { "error": { "code": "auth_required", "message": "Unauthorized", "status": 401, "url": "https://api.example/mcp" } } ``` The envelope carries `code` and `mess…
mcpdo connection client
Model Context Protocol · in the page
docs/draft/tools/inspector/mcpdo
…og entry mcpdo @my-server tools/list mcpdo @my-server tools/call echo message:=hi mcpdo @my-server resources/read file:///tmp/notes.txt mcpdo connections/list # what's open mcpd…
Protocol eras
Model Context Protocol · in the page
docs/draft/tools/inspector/protocol-eras
…ted, the negotiated era is shown as a badge on the **Protocol** tab's Messages header and in **Connection Info**. On a modern connection, `server/discover` also supplies `capabilities` (including `ext…
Recipes
Model Context Protocol · in the page
docs/draft/tools/inspector/recipes
…disconnected`, `connecting`, then `connected` or `error` (`data-error-message` has the detail) | | `[data-testid="connection-status"]` | `data-deeplink` | `parsed`, `rejected`, or `none` (`none` means…
Web client
Model Context Protocol · in the page
docs/draft/tools/inspector/web
…ompts` capability | List prompts, supply arguments, preview generated messages. | | **Resources** | `resources` capability | Browse, read, and subscribe to resources. | | **Skills** | The server decla…
Understanding Authorization in MCP
Model Context Protocol · in the page
docs/draft/tutorials/security/authorization
…({ jsonrpc: "2.0", error: { code: -32000, message: "Bad Request: No valid session ID provided", }, id: null, }); return; } await transport.handleRe…
Security Best Practices
Model Context Protocol · in the page
docs/draft/tutorials/security/security_best_practices
…keys, and other secrets * **Internal network reconnaissance**: Error messages reveal information about internal network topology and services * **Service interaction**: POST requests (e.g., to toke…
MCP Apps
Model Context Protocol · in the page
extensions/apps/overview
…h a `ui/` method name prefix. The app can request tool calls, send messages, update the model's context, and receive data from the host. ```mermaid theme={null} sequenceDiagram participant…
Skills
Model Context Protocol · in the page
extensions/skills/overview
…st metadata](/specification/draft/basic/index.md#_meta). ## Protocol Messages ### Listing Skills To discover available skills, clients send a `skills/list` request. This operation supports [paginat…
Tasks
Model Context Protocol · in the page
extensions/tasks/overview
…_required`, `completed`, `failed`, `cancelled`) and optional status messages, giving clients visibility into progress. * **Mid-flight interaction.** When a task needs input (e.g., an elicitation for…
How to Automate Publishing with GitHub Actions
Model Context Protocol · in the page
registry/github-actions
…publish the server to the MCP Registry. ## Troubleshooting | Error Message | Action | | - | - | | "Authentication failed" | Ensure `id-token: write` permission is set for OIDC, or check secrets. |…
Quickstart: Publish an MCP Server to the MCP Registry
Model Context Protocol · in the page
registry/quickstart
….github.my-username/weather" ... }]} ``` ## Troubleshooting | Error Message | Action | | - | - | | "Registry validation failed for package" | Ensure your package includes the required validation inf…
Official MCP Registry Terms of Service
Model Context Protocol · in the page
registry/terms-of-service
…omote or facilitate unlawful online gambling or disruptive commercial messages or advertisements; 6. Use the Registry for any activities where the use or failure of the Registry could lead to death…
SEP-1034: Support default values for all primitive types in elicitation schemas
Model Context Protocol · in the page
seps/1034--support-default-values-for-all-primitive-types-in
…null} const response = await client.request("elicitation/create", { message: "Configure email reply", requestedSchema: { type: "object", properties: { recipients: { type: "st…
SEP-1036: URL Mode Elicitation for secure out-of-band interactions
Model Context Protocol · in the page
seps/1036-url-mode-elicitation-for-secure-out-of-band-intera
…citation/create", "params": { "mode": "form", // New field "message": "Please provide your GitHub username", "requestedSchema": { "type": "object", "properties": { "n…
SEP-1303: Input Validation Errors as Tool Execution Errors
Model Context Protocol · in the page
seps/1303-input-validation-errors-as-tool-execution-errors
…otivation Language models can learn from tool input validation error messages and retry a tools/call with corrected parameters accordingly, but only if they receive the error feedback in their contex…
SEP-1319: Decouple Request Payload from RPC Methods Definition
Model Context Protocol · in the page
seps/1319-decouple-request-payload-from-rpc-methods-definiti
…es/966)), a transport-agnostic definition of its request and response messages. The current structure makes this practically impossible. By refactoring the specification to separate the data model (t…
SEP-1577: Sampling With Tools
Model Context Protocol · in the page
seps/1577--sampling-with-tools
…This SEP introduces `tools` & `toolChoice` params to `sampling/createMessage` and soft-deprecates `includeContext` (fences `thisServer` & `allServers` under a capability). This allows MCP servers to…
SEP-1613: Establish JSON Schema 2020-12 as Default Dialect for MCP
Model Context Protocol · in the page
seps/1613-establish-json-schema-2020-12-as-default-dialect-f
…Schema 2020-12 as the default dialect for embedded schemas within MCP messages (tool `inputSchema`/`outputSchema` and elicitation `requestedSchema` fields). Schemas may explicitly declare alternative…
SEP-1686: Tasks
Model Context Protocol · in the page
seps/1686-tasks
…e calling the tool again. It cannot resume until receiving a new user message. This also complicates expiration times, as it is not possible to predict when the client will retrieve the result when th…
SEP-1730: SDKs Tiering System
Model Context Protocol · in the page
seps/1730-sdks-tiering-system
…est Suite->>SDK: Execute test scenario SDK->>Test Suite: Protocol messages Test Suite->>Validator: Submit trace Validator->>Test Suite: Compliance report Test Suite->>SDK: Pass/Fail re…
SEP-1865: MCP Apps - Interactive User Interfaces for MCP
Model Context Protocol · in the page
seps/1865-mcp-apps-interactive-user-interfaces-for-mcp
…s (timeouts, errors, etc.). **Alternatives considered:** * **Custom message protocol:** Current MCP-UI approach with message types like tool, intent, prompt, etc. These message types can be transl…
SEP-2106: Tools `inputSchema` & `outputSchema` Conform to JSON Schema 2020-12
Model Context Protocol · in the page
seps/2106-json-schema-2020-12
…for MCP, has implemented extensive workarounds: 1. **Explicit error messages** acknowledge the limitation: ```python theme={null} raise ValueError( f"Output schemas must represent obje…
SEP-2127: MCP Server Cards - HTTP Server Discovery
Model Context Protocol · in the page
seps/2127-mcp-server-cards
…connect using configured endpoints. * No changes to core MCP protocol messages or connection flows are required. ### Migration Path 1. **Phase 1** (Optional): Servers can begin exposing server cards…
SEP-2133: Extensions
Model Context Protocol · in the page
seps/2133-extensions
…fields. Extensions may have settings that are sent in client/server messages for fine-grained configuration. This SEP defines *Official Extensions* and *Experimental Extensions*. Experimental exten…
SEP-2164: Standardize Resource Not Found Error Code
Model Context Protocol · in the page
seps/2164-resource-not-found-error
…"jsonrpc": "2.0", "id": 2, "error": { "code": -32602, "message": "Resource not found", "data": { "uri": "file:///nonexistent.txt" } } } ``` The `data` field SHOULD incl…
SEP-2243: HTTP Header Standardization for Streamable HTTP Transport
Model Context Protocol · in the page
seps/2243-http-standardization
…is requirement applies to any network intermediary that processes the message body, as well as the MCP server itself. > **Implementation Note**: When validating integer parameter values, servers SHOU…