1,258 pages for port.
Titles and paths first, then pages whose text carries it. Each row opens that page as this site last read it.
Versioning Published MCP Servers
Model Context Protocol · in the page
registry/versioning
…ur before general availability. If you encounter any issues, please report them on [GitHub](https://github.com/modelcontextprotocol/registry/issues). MCP servers **MUST** define a version string in `…
SEP-1024: MCP Client Security Requirements for Local Server Installation
Model Context Protocol · in the page
seps/1024-mcp-client-security-requirements-for-local-server-
…itical security vulnerabilities in MCP client implementations that support one-click installation of local MCP servers. The current MCP specification lacks explicit security requirements for client-si…
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
…anism for external (3rd-party) OAuth flows. This was a particularly important motivating factor emerging from discussions in #234 and #284. 3. Payment and Subscription Flows: Financial transactions re…
SEP-1302: Formalize Working Groups and Interest Groups in MCP Governance
Model Context Protocol · in the page
seps/1302-formalize-working-groups-and-interest-groups-in-mc
…WG, or even to start a SEP. However, forming consensus in IG’s to support justifying the creation of a WG is often a good idea. Similarly, citing IG or WG support of a SEP helps the SEP as well. ###…
SEP-1303: Input Validation Errors as Tool Execution Errors
Model Context Protocol · in the page
seps/1303-input-validation-errors-as-tool-execution-errors
…ing section to include: ``` ## Error Handling Tools use two error reporting mechanisms: 1. **Protocol Errors**: Standard JSON-RPC errors for issues like: - Unknown tools - Server errors 2.…
SEP-1319: Decouple Request Payload from RPC Methods Definition
Model Context Protocol · in the page
seps/1319-decouple-request-payload-from-rpc-methods-definiti
…he data payload from the definition of the remote procedure that transports it, leading to a clearer, more modular, and more maintainable specification. ## Motivation The current MCP specification t…
SEP-1330: Elicitation Enum Schema Improvements and Standards Compliance
Model Context Protocol · in the page
seps/1330-elicitation-enum-schema-improvements-and-standards
…avor of JSON Schema-compliant patterns, and introducing additional support for multi-select enum schemas in addition to single choice schemas. The new schemas have been validated against the JSON spec…
SEP-1577: Sampling With Tools
Model Context Protocol · in the page
seps/1577--sampling-with-tools
…on), and reduces the complexity of client implementations (context support becoming explicitly optional). ## Motivation * [Sampling](https://modelcontextprotocol.io/specification/2025-06-18/client/s…
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
…:** * Validate schemas according to declared or default dialect * Support at least JSON Schema 2020-12 ## Rationale ### Why 2020-12? 1. **Ecosystem alignment**: Python SDK (via Pydantic) and Go SD…
SEP-1686: Tasks
Model Context Protocol · in the page
seps/1686-tasks
…on ([SEP-2663](/seps/2663-tasks-extension.md)). This SEP improves support for task-based workflows in the Model Context Protocol (MCP). It introduces both the **task primitive** and the associated **…
SEP-1730: SDKs Tiering System
Model Context Protocol · in the page
seps/1730-sdks-tiering-system
…xt Protocol (MCP) SDKs to establish clear expectations for feature support, maintenance commitments, and quality standards. The system defines three tiers of SDK support with objective, measurable cri…
SEP-1850: PR-Based SEP Workflow
Model Context Protocol · in the page
seps/1850-pr-based-sep-workflow
…number 2. **Open a pull request** containing the draft SEP and any supporting materials 3. **Request a sponsor** from the Maintainers list; tag potential sponsors from [MAINTAINERS.md](https://github.…
SEP-1865: MCP Apps - Interactive User Interfaces for MCP
Model Context Protocol · in the page
seps/1865-mcp-apps-interactive-user-interfaces-for-mcp
…thout formal standardization: * Servers cannot reliably expect UI support via MCP * Each host may implement slightly different behaviors * Security and auditability patterns are inconsistent * Develo…
SEP-2085: Governance Succession and Amendment Procedures
Model Context Protocol · in the page
seps/2085-governance-succession-and-amendment
…ting during interregnum periods ensures major decisions have broad support during transitional periods. ### Amendment Process Design The amendment process balances stability with adaptability: * **…
SEP-2106: Tools `inputSchema` & `outputSchema` Conform to JSON Schema 2020-12
Model Context Protocol · in the page
seps/2106-json-schema-2020-12
…n `inputSchema`, `outputSchema`, and `structuredContent` to better support JSON Schema 2020-12. Specifically: * **`inputSchema`**: Keeps `type: "object"` required (since tool arguments are objects),…
SEP-2127: MCP Server Cards - HTTP Server Discovery
Model Context Protocol · in the page
seps/2127-mcp-server-cards
…covery. This enables clients to automatically discover available transports, protocol versions, and connection guidance before establishing a connection. As an Extensions Track SEP (per [SEP-2133](/s…
SEP-2133: Extensions
Model Context Protocol · in the page
seps/2133-extensions
…textprotocol/oauth-client-credentials` or `com.example/websocket-transport`. The names follow the same rules as the [\_meta keys](https://modelcontextprotocol.io/specification/draft/basic/index.md#met…
SEP-2148: MCP Contributor Ladder
Model Context Protocol · in the page
seps/2148-contributor-ladder
…inees must still secure the required sponsorship. Sponsors confirm support in the nomination issue. ### Decision-Making & Escalation #### Delegation as Default MCP operates on a principle of delega…
SEP-2149: MCP Group Governance and Charter Template
Model Context Protocol · in the page
seps/2149-working-group-charter-template
…onal affiliation with the parties involved—to resolve the issue and report back to the group 4. The designated CM either: (a) provides binding guidance, (b) requests more information, or (c) recommend…
SEP-2207: OIDC-Flavored Refresh Token Guidance
Model Context Protocol · in the page
seps/2207-oidc-refresh-token-guidance
…ken issuance and requests, particularly when Authorization Servers support the `offline_access` scope. The `offline_access` scope originated in OIDC but can be adopted by any OAuth 2.1 Authorization S…
SEP-2260: Require Server requests to be associated with a Client request.
Model Context Protocol · in the page
seps/2260-Require-Server-requests-to-be-associated-with-Client-requests
…dards Track | | **Created** | 2026-02-16 | | **Author(s)** | MCP Transports Working Group | | **Sponsor** | [@CaitieM20](https://github.com/CaitieM20) - Caitie McCaffrey | | **PR** | [#2260](https://g…
SEP-2322: Multi Round-Trip Requests
Model Context Protocol · in the page
seps/2322-MRTR
…CP servers at scale in the common case. It also reduces the HTTP transport's dependence on SSE streams, which cause problems in a lot of environments that cannot support long-lived connections. This…
SEP-2468: Recommend Issuer (iss) Parameter in MCP Auth Responses
Model Context Protocol · in the page
seps/2468-recommend-issuer-claim-for-auth
…validate issuer if provided and a SHOULD for authorization servers supporting MCP scenarios. Future SEPs and releases may change the SHOULD to a MUST. ## Specification ### Issuer Parameter Requireme…
SEP-2484: Require Conformance Tests for Standards Track SEPs to Reach Final Status
Model Context Protocol · in the page
seps/2484-conformance-tests-required-for-final-seps
…iners translate that English into code, and every translation is an opportunity for drift. SEP-1730 (SDK Tiering) already depends on conformance tests (Tier 1 requires 100% pass rate, Tier 2 requires…
SEP-2549: TTL for List Results
Model Context Protocol · in the page
seps/2549-TTL-for-list-results
…pull/2549) | *** ## Abstract This SEP proposes adding fields to support caching result objects returned by `tools/list`, `prompts/list`, `resources/list`, `resources/read`, and `resources/templates…
SEP-2567: Sessionless MCP via Explicit State Handles
Model Context Protocol · in the page
seps/2567-sessionless-mcp
…otocol version is in use and which optional capabilities each side supports — is established once per session and assumed for its duration. [SEP-2575] resolves this by removing `initialize` and carryi…
SEP-2575: Make MCP Stateless
Model Context Protocol · in the page
seps/2575-stateless-mcp
…simpler alternative exists to solve a critical use case. ### Transport Consistency It is critical that these stateless principles are applied consistently across all transports. Keeping the `stdi…
SEP-2577: Deprecate Roots, Sampling, and Logging
Model Context Protocol · in the page
seps/2577-deprecate-roots-sampling-and-logging
…version's release. Each of those subsequent versions will in turn support the features for one year after its own release, assuming the one-year-per-version support policy proposed in a separate SEP.…
SEP-2596: Specification Feature Lifecycle and Deprecation Policy
Model Context Protocol · in the page
seps/2596-spec-feature-lifecycle-and-deprecation
…features, but each case has been handled ad hoc: * The HTTP+SSE transport is described as "deprecated" in the [Streamable HTTP backwards-compatibility guidance][transports-compat], with no stated r…
SEP-2640: Skills Extension
Model Context Protocol · in the page
seps/2640-skills-extension
…https://agentskills.io/specification); this SEP defines only the transport binding. The extension defines three protocol methods. Every server declaring the extension implements `skills/list`, which…
SEP-2663: Tasks Extension
Model Context Protocol · in the page
seps/2663-tasks-extension
…ult or error. Task creation is server-directed: the client signals support by including the extension in its per-request capabilities, and the server decides on a per-request basis whether to material…
SEP-973: Expose additional metadata for Implementations, Resources, Tools and Prompts
Model Context Protocol · in the page
seps/973-expose-additional-metadata-for-implementations-res
…62 into a single, cohesive enhancement. * **Flexible Icon Sizes:** Supports multiple icon sizes (e.g., `48x48`, `96x96`, or `any` for vector formats) to accommodate different client UI needs. * **Opti…
SEP-985: Align OAuth 2.0 Protected Resource Metadata with RFC 9728
Model Context Protocol · in the page
seps/985-align-oauth-20-protected-resource-metadata-with-rf
…C:** Go with SHOULD over MAY for WWW-Authenticate is that it makes supporting other features, such as incremental authorization easier (e.g. you make a request for a tool, but need additional scopes,…
SEP-986: Specify Format for Tool Names
Model Context Protocol · in the page
seps/986-specify-format-for-tool-names
…or hierarchical and namespaced tool names (e.g., using / and .). * Support both human-readable and machine-generated names. * Avoid unnecessary restrictions that could block valid use cases. ## Ratio…
SEP-990: Enable enterprise IdP policy controls during MCP OAuth flows
Model Context Protocol · in the page
seps/990-enable-enterprise-idp-policy-controls-during-mcp-o
…Access Token MRS-->>-C: MCP Response with Data end ``` > [!IMPORTANT] > > **State:** Ready to Review
SEP-991: Enable URL-based Client Registration using OAuth Client ID Metadata Documents
Model Context Protocol · in the page
seps/991-enable-url-based-client-registration-using-oauth-c
…ess policies. ## Motivation The Model Context Protocol currently supports two client registration approaches: 1. **Pre-registration**: Requires either client developers or users to manually registe…
SEP-994: Shared Communication Practices/Guidelines
Model Context Protocol · in the page
seps/994-shared-communication-practicesguidelines
…er-form discussions 3. **GitHub Issues**: For actionable tasks, bug reports, and feature requests Security-sensitive issues follow a separate process defined in SECURITY.md. ### Discord Guidelines…
Specification Enhancement Proposals (SEPs)
Model Context Protocol · in the page
seps/index
…ardization.md) | HTTP Header Standardization for Streamable HTTP Transport | Final | Standards Track | 2026-02-04 | | [SEP-2207](/seps/2207-oidc-refresh-token-guidance.md) | OIDC-Flavored Refresh Toke…
Architecture
Model Context Protocol · in the page
specification/2024-11-05/architecture/index
…* Shared protocol enables interoperability * Modular design supports extensibility 3. **Servers should not be able to read the whole conversation, nor "see into" other servers** * Server…
Overview
Model Context Protocol · in the page
specification/2024-11-05/basic/index
…like logging and argument completion All implementations **MUST** support the base protocol and lifecycle management components. Other components **MAY** be implemented based on the specific needs of…
Lifecycle
Model Context Protocol · in the page
specification/2024-11-05/basic/lifecycle
…by sending an `initialize` request containing: * Protocol version supported * Client capabilities * Client implementation information ```json theme={null} { "jsonrpc": "2.0", "id": 1, "method"…
Cancellation
Model Context Protocol · in the page
specification/2024-11-05/basic/utilities/cancellation
# Cancellation The Model Context Protocol (MCP) supports optional cancellation of in-progress requests through notification messages. Either side can send a cancellation notification to indicate that…
Progress
Model Context Protocol · in the page
specification/2024-11-05/basic/utilities/progress
# Progress The Model Context Protocol (MCP) supports optional progress tracking for long-running operations through notification messages. Either side can send progress notifications to provide updat…
Roots
Model Context Protocol · in the page
specification/2024-11-05/client/roots
…es they have access to. Servers can request the list of roots from supporting clients and receive notifications when that list changes. ## User Interaction Model Roots in MCP are typically exposed t…
Sampling
Model Context Protocol · in the page
specification/2024-11-05/client/sampling
…esponses for review before delivery ## Capabilities Clients that support sampling **MUST** declare the `sampling` capability during [initialization](/specification/2024-11-05/basic/lifecycle.md#init…
Specification
Model Context Protocol · in the page
specification/2024-11-05/index
…ithub.io/language-server-protocol/), which standardizes how to add support for programming languages across a whole ecosystem of development tools. In a similar way, MCP standardizes how to integrate…
Prompts
Model Context Protocol · in the page
specification/2024-11-05/server/prompts
…ny specific user interaction model. ## Capabilities Servers that support prompts **MUST** declare the `prompts` capability during [initialization](/specification/2024-11-05/basic/lifecycle.md#initia…
Resources
Model Context Protocol · in the page
specification/2024-11-05/server/resources
…ny specific user interaction model. ## Capabilities Servers that support resources **MUST** declare the `resources` capability: ```json theme={null} { "capabilities": { "resources": { "…
Tools
Model Context Protocol · in the page
specification/2024-11-05/server/tools
…o ensure a human is in the > loop ## Capabilities Servers that support tools **MUST** declare the `tools` capability: ```json theme={null} { "capabilities": { "tools": { "listChanged"…
Completion
Model Context Protocol · in the page
specification/2024-11-05/server/utilities/completion
…lues. ## User Interaction Model Completion in MCP is designed to support interactive user experiences similar to IDE code completion. For example, applications may show completion suggestions in a…