The Capability Surface Matrix states which public surfaces should exist for each client level. The matrix helps site owners check whether lower-capability agents can safely discover a no-op path before richer integrations begin.
| Client | Static HTML | llms.txt | Sitemap | JSON | GET-Action | POST | OpenAPI | MCP | A2A | Memory | 证据 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| L0 URL-only | Yes | Yes | Yes | 客户端配置必需 | No | No | No | No | No | No | 客户端配置必需 |
| L1 URL synthesizer | Yes | Yes | Yes | Yes | 客户端配置必需 | No | No | No | No | No | 客户端配置必需 |
| L2 schema-capable | Yes | Yes | Yes | Yes | 客户端配置必需 | Yes | Yes | 客户端配置必需 | 客户端配置必需 | No | Yes |
| L3 tool agent | Yes | Yes | Yes | Yes | Human review | Yes | Yes | 客户端配置必需 | 客户端配置必需 | Human review | Yes |
| L4 workflow agent | Yes | Yes | Yes | Yes | Human review | Yes | Yes | 客户端配置必需 | 客户端配置必需 | Human review | Yes |
| L5 multi-agent | Yes | Yes | Yes | Yes | Human review | Yes | Yes | 客户端配置必需 | Yes | Human review | Yes |
| L6 audited system | Yes | Yes | Yes | Yes | Human review | Yes | Yes | 客户端配置必需 | Yes | Human review | Yes |
Machine-readable matrix
The public JSON companions are /spec/capability-surface-matrix.json and /spec/agent-executability-matrix.json. They keep support cells and executable route-record requirements separate so validators can compare sites without interpreting prose.