{
  "schemaVersion": 1,
  "updatedAt": "2026-10-15",
  "extension": {
    "id": "io.modelcontextprotocol/skills",
    "sourceRevision": "167da6c0d42c247a8f8470228a10ca711e3f6c45",
    "baseProtocol": "2026-07-28 or later",
    "sep": 2640,
    "sepStatus": "Final",
    "finalMergedAt": "2026-09-13",
    "statusSourceRevision": "5ea996028df322ce97d1c906731cf8c05a6e268e"
  },
  "contracts": [
    {
      "harness": "claude-code",
      "variant": "2.1.296-installed-bundle",
      "support": {
        "extensionNegotiation": "unknown",
        "skillsList": "partial",
        "skillsGet": "partial",
        "skillMdResourceRead": "native",
        "supportingFileResourceRead": "native",
        "manifestSha256Verification": "unsupported",
        "manifestByteSizeVerification": "unsupported",
        "modelActivation": "partial"
      },
      "conditions": [
        "tengu_mcp_skills feature gate defaults false; effective rollout not inspected",
        "Server must advertise resources and the extension",
        "Loader reads optional top-level digest, not stable resources manifest",
        "Activation is command-construction source evidence, not an observed model run",
        "Native resource-read labels refer only to generic MCP file access, not skill discovery or activation",
        "skills/get helper exists; loader use and wire behavior remain unverified"
      ],
      "default": true,
      "verifiedAt": "2026-10-14",
      "evidence": [
        "mcp-skills-specification-stable-skills-mdx",
        "claude-2-1-296-mcp-skills-bundle"
      ],
      "references": [
        "https://github.com/modelcontextprotocol/ext-skills/blob/167da6c0d42c247a8f8470228a10ca711e3f6c45/specification/stable/skills.mdx"
      ],
      "unknowns": [
        "Host wire exchange, effective feature rollout and actual model activation were not probed."
      ],
      "details": {
        "sourceRevision": null,
        "wireProbe": "not-run",
        "bundle": {
          "version": "2.1.296",
          "sha256": "c9b5341637becbd423ddffc5b254afb645682a3868cb708bbc6cc0e7bb419937",
          "bytes": 240664432,
          "markers": {
            "gate": 195222586,
            "listRequest": 224261236,
            "getRequest": 224261355,
            "fetcher": 228849353,
            "cacheHit": 228852745,
            "command": 228855679
          },
          "observations": [
            "Feature gate tengu_mcp_skills still defaults false; effective account rollout not read.",
            "Connection paths condition discovery on the feature gate and resources; fetcher requires server extension identity.",
            "List parser retains frontmatter, uri and optional top-level digest; loader does not consume stable per-file resources manifest.",
            "A skills/get request helper is exported; no getMcpSkill call was found in decoded source strings, and the inspected loader calls listMcpSkillPage only. This is helper implementation evidence, not an exercised retrieval path.",
            "Discovery still caps at 100 valid entries and 20 pages, eagerly reading SKILL.md on cache misses.",
            "Fresh reads verify a valid optional top-level SHA-256 digest; cache hits reuse text without rehash in the inspected loader.",
            "No per-file manifest byte-size or digest enforcement and no field-by-field catalog/frontmatter comparison in the inspected loader.",
            "Constructs server-qualified source:mcp skill commands and a resource root; ignores hooks and allowed-tools grants."
          ],
          "requestHelperCallsFound": 0,
          "inspectionBoundary": "Decoded embedded JavaScript for gate, request wrappers, loader/cache and connection call sites; no proprietary source copied into repository."
        },
        "auditBoundary": {
          "auditedOn": "2026-10-14",
          "wireProbe": "not-run",
          "activationProbe": "not-run",
          "defaultMeaning": "Preferred registry variant; does not mean the feature is enabled"
        }
      },
      "method": "source-and-documentation-inspection; no host wire or model probe",
      "clientVersion": "2.1.296"
    },
    {
      "harness": "codex",
      "variant": "0.162.1-source",
      "support": {
        "extensionNegotiation": "unsupported",
        "skillsList": "unknown",
        "skillsGet": "unknown",
        "skillMdResourceRead": "native",
        "supportingFileResourceRead": "native",
        "manifestSha256Verification": "unknown",
        "manifestByteSizeVerification": "unknown",
        "modelActivation": "unknown"
      },
      "conditions": [
        "Known extension allowlist excludes Skills; generic resources API is a separate capability",
        "App Server skills/list is not MCP Skills discovery",
        "Native resource-read labels refer only to generic MCP file access, not skill discovery or activation",
        "OpenAI plugin portal can import an MCP skill snapshot according to documentation; this does not establish live Skills extension support in Codex CLI"
      ],
      "default": true,
      "verifiedAt": "2026-10-14",
      "evidence": [
        "mcp-skills-specification-stable-skills-mdx",
        "mcp-skills-refresh-codex-codex-rs-codex-mcp-src-client-capabilities-rs",
        "mcp-skills-refresh-codex-codex-rs-codex-mcp-src-connection-manager-resources-rs",
        "mcp-skills-refresh-codex-codex-rs-codex-mcp-src-rmcp-client-rs",
        "mcp-skills-refresh-openai-mcp",
        "mcp-skills-refresh-openai-skills"
      ],
      "references": [
        "https://github.com/modelcontextprotocol/ext-skills/blob/167da6c0d42c247a8f8470228a10ca711e3f6c45/specification/stable/skills.mdx",
        "https://raw.githubusercontent.com/openai/codex/092d3acd6bec3e3a14bdc7e7a2810ab628ab759d/codex-rs/codex-mcp/src/client_capabilities.rs",
        "https://raw.githubusercontent.com/openai/codex/092d3acd6bec3e3a14bdc7e7a2810ab628ab759d/codex-rs/codex-mcp/src/connection_manager/resources.rs",
        "https://raw.githubusercontent.com/openai/codex/092d3acd6bec3e3a14bdc7e7a2810ab628ab759d/codex-rs/codex-mcp/src/rmcp_client.rs",
        "https://developers.openai.com/plugins/build/mcp-server.md",
        "https://developers.openai.com/plugins/build/skills.md"
      ],
      "unknowns": [
        "Host wire exchange, effective feature rollout and actual model activation were not probed."
      ],
      "details": {
        "sourceRevision": "092d3acd6bec3e3a14bdc7e7a2810ab628ab759d",
        "wireProbe": "not-run",
        "auditBoundary": {
          "auditedOn": "2026-10-14",
          "wireProbe": "not-run",
          "activationProbe": "not-run",
          "defaultMeaning": "Preferred registry variant; does not mean the feature is enabled"
        },
        "pluginImport": {
          "support": "documented",
          "surface": "OpenAI plugin submission portal Scan Tools",
          "delivery": "submission-time static snapshot",
          "runtimeFetch": false,
          "protocolProfile": "bounded static subset; docs describe it as draft SEP-2640",
          "tested": false,
          "limits": {
            "skills": 5,
            "catalogPages": 10,
            "filesPerSkill": 100,
            "skillMdBytes": 262144,
            "supportingFileBytes": 1048576,
            "skillBytes": 5242880,
            "scanArchiveBytes": 8388608
          },
          "verification": [
            "per-resource digest",
            "catalog/frontmatter equality",
            "safe unique paths",
            "import size limits"
          ],
          "stableManifestSizeVerification": "not documented; enforcing import limits is separate from comparing manifest size"
        }
      },
      "method": "source-and-documentation-inspection; no host wire or model probe",
      "clientVersion": "0.162.1"
    },
    {
      "harness": "cursor-agent",
      "variant": "documentation-snapshot-2026-10-14",
      "support": {
        "extensionNegotiation": "unknown",
        "skillsList": "unknown",
        "skillsGet": "unknown",
        "skillMdResourceRead": "native",
        "supportingFileResourceRead": "native",
        "manifestSha256Verification": "unknown",
        "manifestByteSizeVerification": "unknown",
        "modelActivation": "unknown"
      },
      "conditions": [
        "Documentation does not establish extension stages or a client version",
        "Native resource-read labels refer only to generic MCP file access, not skill discovery or activation"
      ],
      "default": true,
      "verifiedAt": "2026-10-14",
      "evidence": ["mcp-skills-specification-stable-skills-mdx", "mcp-skills-refresh-cursor-mcp"],
      "references": [
        "https://github.com/modelcontextprotocol/ext-skills/blob/167da6c0d42c247a8f8470228a10ca711e3f6c45/specification/stable/skills.mdx",
        "https://cursor.com/docs/mcp"
      ],
      "unknowns": [
        "Host wire exchange, effective feature rollout and actual model activation were not probed."
      ],
      "details": {
        "sourceRevision": null,
        "wireProbe": "not-run",
        "auditBoundary": {
          "auditedOn": "2026-10-14",
          "wireProbe": "not-run",
          "activationProbe": "not-run",
          "defaultMeaning": "Preferred registry variant; does not mean the feature is enabled"
        }
      },
      "method": "source-and-documentation-inspection; no host wire or model probe"
    },
    {
      "harness": "opencode",
      "variant": "1.19.0-source",
      "support": {
        "extensionNegotiation": "unsupported",
        "skillsList": "unknown",
        "skillsGet": "unknown",
        "skillMdResourceRead": "native",
        "supportingFileResourceRead": "native",
        "manifestSha256Verification": "unknown",
        "manifestByteSizeVerification": "unknown",
        "modelActivation": "unknown"
      },
      "conditions": [
        "Reviewed MCP constructor advertises roots only; no Skills extension declaration",
        "Released v1.19.0 source; reviewed constructor advertises roots without the Skills extension",
        "Native resource-read labels refer only to generic MCP file access, not skill discovery or activation"
      ],
      "default": false,
      "verifiedAt": "2026-10-14",
      "evidence": [
        "mcp-skills-specification-stable-skills-mdx",
        "mcp-skills-refresh-opencode-packages-opencode-src-mcp-index-ts"
      ],
      "references": [
        "https://github.com/modelcontextprotocol/ext-skills/blob/167da6c0d42c247a8f8470228a10ca711e3f6c45/specification/stable/skills.mdx",
        "https://raw.githubusercontent.com/anomalyco/opencode/733b2c627e5aec39cb33cc22373bdce33053ef2c/packages/opencode/src/mcp/index.ts"
      ],
      "unknowns": [
        "Host wire exchange, effective feature rollout and actual model activation were not probed."
      ],
      "details": {
        "sourceRevision": "733b2c627e5aec39cb33cc22373bdce33053ef2c",
        "wireProbe": "not-run",
        "auditBoundary": {
          "auditedOn": "2026-10-14",
          "wireProbe": "not-run",
          "activationProbe": "not-run",
          "defaultMeaning": "Preferred registry variant; does not mean the feature is enabled"
        }
      },
      "method": "source-and-documentation-inspection; no host wire or model probe",
      "clientVersion": "1.19.0"
    },
    {
      "harness": "pi",
      "variant": "1.2.0-native-client",
      "support": {
        "extensionNegotiation": "unsupported",
        "skillsList": "unknown",
        "skillsGet": "unknown",
        "skillMdResourceRead": "native",
        "supportingFileResourceRead": "native",
        "manifestSha256Verification": "unknown",
        "manifestByteSizeVerification": "unknown",
        "modelActivation": "unknown"
      },
      "conditions": [
        "Built-in runtime passes roots, not a Skills extension capability",
        "Built-in v1.2.0 accepts base protocols only through 2025-11-25; custom SDK capabilities are outside this contract",
        "Native resource-read labels refer only to generic MCP file access, not skill discovery or activation"
      ],
      "default": true,
      "verifiedAt": "2026-10-14",
      "evidence": [
        "mcp-skills-specification-stable-skills-mdx",
        "mcp-skills-refresh-pi-packages-mcp-src-protocol-types-ts",
        "mcp-skills-refresh-pi-packages-coding-agent-src-extensions-mcp-runtime-ts",
        "mcp-skills-refresh-pi-packages-mcp-src-client-ts"
      ],
      "references": [
        "https://github.com/modelcontextprotocol/ext-skills/blob/167da6c0d42c247a8f8470228a10ca711e3f6c45/specification/stable/skills.mdx",
        "https://raw.githubusercontent.com/earendil-works/pi/06a466935536f8c9bcacb2d5efc0fc021be1bdff/packages/mcp/src/protocol/types.ts",
        "https://raw.githubusercontent.com/earendil-works/pi/06a466935536f8c9bcacb2d5efc0fc021be1bdff/packages/coding-agent/src/extensions/mcp/runtime.ts",
        "https://raw.githubusercontent.com/earendil-works/pi/06a466935536f8c9bcacb2d5efc0fc021be1bdff/packages/mcp/src/client.ts"
      ],
      "unknowns": [
        "Host wire exchange, effective feature rollout and actual model activation were not probed."
      ],
      "details": {
        "sourceRevision": "06a466935536f8c9bcacb2d5efc0fc021be1bdff",
        "wireProbe": "not-run",
        "auditBoundary": {
          "auditedOn": "2026-10-14",
          "wireProbe": "not-run",
          "activationProbe": "not-run",
          "defaultMeaning": "Preferred registry variant; does not mean the feature is enabled"
        }
      },
      "method": "source-and-documentation-inspection; no host wire or model probe",
      "clientVersion": "1.2.0"
    },
    {
      "harness": "opencode",
      "variant": "2.0.29-source",
      "default": true,
      "verifiedAt": "2026-10-15",
      "clientVersion": "2.0.29",
      "method": "source-inspection",
      "sourceRevision": "042d0832f5f3a73eaa039a58a7d565776f6d4290",
      "evidence": ["refresh-opencode-2.0.29-mcp-client"],
      "references": [
        "https://github.com/anomalyco/opencode/blob/042d0832f5f3a73eaa039a58a7d565776f6d4290/packages/core/src/mcp/client.ts#L184-L221"
      ],
      "support": {
        "extensionNegotiation": "unsupported",
        "skillsList": "unknown",
        "skillsGet": "unknown",
        "skillMdResourceRead": "native",
        "supportingFileResourceRead": "native",
        "manifestSha256Verification": "unknown",
        "manifestByteSizeVerification": "unknown",
        "modelActivation": "unknown"
      },
      "conditions": [
        "The reviewed MCP constructor advertises roots and optional elicitation, without the Skills extension.",
        "Native resource reads refer to generic MCP resource access, not Skills extension discovery or activation."
      ],
      "unknowns": ["No host wire exchange or model activation probe was run."],
      "details": {
        "sourceRevision": "042d0832f5f3a73eaa039a58a7d565776f6d4290",
        "wireProbe": "not-run",
        "activationProbe": "not-run"
      }
    }
  ],
  "dimensions": [
    "extensionNegotiation",
    "skillsList",
    "skillsGet",
    "skillMdResourceRead",
    "supportingFileResourceRead",
    "manifestSha256Verification",
    "manifestByteSizeVerification",
    "modelActivation"
  ]
}