> ## Documentation Index > Fetch the complete documentation index at: https://modelcontextprotocol.io/llms.txt > Use this file to discover all available pages before exploring further. # Specification Enhancement Proposals (SEPs) > Index of all MCP Specification Enhancement Proposals Specification Enhancement Proposals (SEPs) are the primary mechanism for proposing major changes to the Model Context Protocol. Each SEP provides a concise technical specification and rationale for proposed features. Each SEP is reachable by number at `/seps/` (for example, [/seps/1850](https://modelcontextprotocol.io/seps/1850.md)). > **[Submit a SEP](https://modelcontextprotocol.io/community/sep-guidelines.md)** > > Learn how to submit your own Specification Enhancement Proposal ## Summary * **Final**: 43 ## All SEPs | SEP | Title | Status | Type | Created | | - | - | - | - | - | | [SEP-2663](https://modelcontextprotocol.io/seps/2663-tasks-extension.md) | Tasks Extension | Final | Extensions Track | 2026-04-27 | | [SEP-2640](https://modelcontextprotocol.io/seps/2640-skills-extension.md) | Skills Extension | Final | Extensions Track | 2026-04-23 | | [SEP-2596](https://modelcontextprotocol.io/seps/2596-spec-feature-lifecycle-and-deprecation.md) | Specification Feature Lifecycle and Deprecation Policy | Final | Process | 2026-04-17 | | [SEP-2577](https://modelcontextprotocol.io/seps/2577-deprecate-roots-sampling-and-logging.md) | Deprecate Roots, Sampling, and Logging | Final | Standards Track | 2026-04-14 | | [SEP-2575](https://modelcontextprotocol.io/seps/2575-stateless-mcp.md) | Make MCP Stateless | Final | Standards Track | 2025-06-18 | | [SEP-2567](https://modelcontextprotocol.io/seps/2567-sessionless-mcp.md) | Sessionless MCP via Explicit State Handles | Final | Standards Track | 2026-03-11 | | [SEP-2549](https://modelcontextprotocol.io/seps/2549-TTL-for-list-results.md) | TTL for List Results | Final | Standards Track | 2026-04-09 | | [SEP-2484](https://modelcontextprotocol.io/seps/2484-conformance-tests-required-for-final-seps.md) | Require Conformance Tests for Standards Track SEPs to Reach Final Status | Final | Process | 2026-03-27 | | [SEP-2468](https://modelcontextprotocol.io/seps/2468-recommend-issuer-claim-for-auth.md) | Recommend Issuer (iss) Parameter in MCP Auth Responses | Final | Standards Track | 2026-03-25 | | [SEP-2322](https://modelcontextprotocol.io/seps/2322-MRTR.md) | Multi Round-Trip Requests | Final | Standards Track | 2026-02-03 | | [SEP-2260](https://modelcontextprotocol.io/seps/2260-Require-Server-requests-to-be-associated-with-Client-requests.md) | Require Server requests to be associated with a Client request. | Final | Standards Track | 2026-02-16 | | [SEP-2243](https://modelcontextprotocol.io/seps/2243-http-standardization.md) | HTTP Header Standardization for Streamable HTTP Transport | Final | Standards Track | 2026-02-04 | | [SEP-2207](https://modelcontextprotocol.io/seps/2207-oidc-refresh-token-guidance.md) | OIDC-Flavored Refresh Token Guidance | Final | Standards Track | 2026-02-04 | | [SEP-2164](https://modelcontextprotocol.io/seps/2164-resource-not-found-error.md) | Standardize Resource Not Found Error Code | Final | Standards Track | 2026-01-28 | | [SEP-2149](https://modelcontextprotocol.io/seps/2149-working-group-charter-template.md) | MCP Group Governance and Charter Template | Final | Process | 2025-01-15 | | [SEP-2148](https://modelcontextprotocol.io/seps/2148-contributor-ladder.md) | MCP Contributor Ladder | Final | Process | 2026-01-15 | | [SEP-2133](https://modelcontextprotocol.io/seps/2133-extensions.md) | Extensions | Final | Standards Track | 2025-01-21 | | [SEP-2127](https://modelcontextprotocol.io/seps/2127-mcp-server-cards.md) | MCP Server Cards - HTTP Server Discovery | Final | Extensions Track | 2026-01-21 | | [SEP-2106](https://modelcontextprotocol.io/seps/2106-json-schema-2020-12.md) | Tools `inputSchema` & `outputSchema` Conform to JSON Schema 2020-12 | Final | Standards Track | 2026-01-06 | | [SEP-2085](https://modelcontextprotocol.io/seps/2085-governance-succession-and-amendment.md) | Governance Succession and Amendment Procedures | Final | Process | 2025-12-05 | | [SEP-1865](https://modelcontextprotocol.io/seps/1865-mcp-apps-interactive-user-interfaces-for-mcp.md) | MCP Apps - Interactive User Interfaces for MCP | Final | Extensions Track | 2025-11-21 | | [SEP-1850](https://modelcontextprotocol.io/seps/1850-pr-based-sep-workflow.md) | PR-Based SEP Workflow | Final | Process | 2025-11-20 | | [SEP-1730](https://modelcontextprotocol.io/seps/1730-sdks-tiering-system.md) | SDKs Tiering System | Final | Standards Track | 2025-10-29 | | [SEP-1699](https://modelcontextprotocol.io/seps/1699-support-sse-polling-via-server-side-disconnect.md) | Support SSE polling via server-side disconnect | Final | Standards Track | 2025-10-22 | | [SEP-1686](https://modelcontextprotocol.io/seps/1686-tasks.md) | Tasks | Final | Standards Track | 2025-10-20 | | [SEP-1613](https://modelcontextprotocol.io/seps/1613-establish-json-schema-2020-12-as-default-dialect-f.md) | Establish JSON Schema 2020-12 as Default Dialect for MCP | Final | Standards Track | 2025-10-06 | | [SEP-1577](https://modelcontextprotocol.io/seps/1577--sampling-with-tools.md) | Sampling With Tools | Final | Standards Track | 2025-09-30 | | [SEP-1330](https://modelcontextprotocol.io/seps/1330-elicitation-enum-schema-improvements-and-standards.md) | Elicitation Enum Schema Improvements and Standards Compliance | Final | Standards Track | 2025-08-11 | | [SEP-1319](https://modelcontextprotocol.io/seps/1319-decouple-request-payload-from-rpc-methods-definiti.md) | Decouple Request Payload from RPC Methods Definition | Final | Standards Track | 2025-08-08 | | [SEP-1303](https://modelcontextprotocol.io/seps/1303-input-validation-errors-as-tool-execution-errors.md) | Input Validation Errors as Tool Execution Errors | Final | Standards Track | 2025-08-05 | | [SEP-1302](https://modelcontextprotocol.io/seps/1302-formalize-working-groups-and-interest-groups-in-mc.md) | Formalize Working Groups and Interest Groups in MCP Governance | Final | Standards Track | 2025-08-05 | | [SEP-1046](https://modelcontextprotocol.io/seps/1046-support-oauth-client-credentials-flow-in-authoriza.md) | Support OAuth client credentials flow in authorization | Final | Standards Track | 2025-07-23 | | [SEP-1036](https://modelcontextprotocol.io/seps/1036-url-mode-elicitation-for-secure-out-of-band-intera.md) | URL Mode Elicitation for secure out-of-band interactions | Final | Standards Track | 2025-07-22 | | [SEP-1034](https://modelcontextprotocol.io/seps/1034--support-default-values-for-all-primitive-types-in.md) | Support default values for all primitive types in elicitation schemas | Final | Standards Track | 2025-07-22 | | [SEP-1024](https://modelcontextprotocol.io/seps/1024-mcp-client-security-requirements-for-local-server-.md) | MCP Client Security Requirements for Local Server Installation | Final | Standards Track | 2025-07-22 | | [SEP-994](https://modelcontextprotocol.io/seps/994-shared-communication-practicesguidelines.md) | Shared Communication Practices/Guidelines | Final | Process | 2025-07-17 | | [SEP-991](https://modelcontextprotocol.io/seps/991-enable-url-based-client-registration-using-oauth-c.md) | Enable URL-based Client Registration using OAuth Client ID Metadata Documents | Final | Standards Track | 2025-07-07 | | [SEP-990](https://modelcontextprotocol.io/seps/990-enable-enterprise-idp-policy-controls-during-mcp-o.md) | Enable enterprise IdP policy controls during MCP OAuth flows | Final | Standards Track | 2025-06-04 | | [SEP-986](https://modelcontextprotocol.io/seps/986-specify-format-for-tool-names.md) | Specify Format for Tool Names | Final | Standards Track | 2025-07-16 | | [SEP-985](https://modelcontextprotocol.io/seps/985-align-oauth-20-protected-resource-metadata-with-rf.md) | Align OAuth 2.0 Protected Resource Metadata with RFC 9728 | Final | Standards Track | 2025-07-16 | | [SEP-973](https://modelcontextprotocol.io/seps/973-expose-additional-metadata-for-implementations-res.md) | Expose additional metadata for Implementations, Resources, Tools and Prompts | Final | Standards Track | 2025-07-15 | | [SEP-932](https://modelcontextprotocol.io/seps/932-model-context-protocol-governance.md) | Model Context Protocol Governance | Final | Process | 2025-07-08 | | [SEP-414](https://modelcontextprotocol.io/seps/414-request-meta.md) | Document OpenTelemetry Trace Context Propagation Conventions | Final | Standards Track | 2025-04-25 | ## SEP Status Definitions | Status | Definition | | - | - | | Draft | SEP proposal with a sponsor, undergoing informal review | | In-Review | SEP proposal ready for formal review by Core Maintainers | | Accepted | SEP accepted, awaiting reference implementation | | Final | SEP finalized with reference implementation complete | | Rejected | SEP rejected by Core Maintainers | | Withdrawn | SEP withdrawn by the author | | Superseded | SEP replaced by a newer SEP | | Dormant | SEP without a sponsor, closed after 6 months |