---
title: "Capabilities observed in traffic"
description: "Generated from data/observed/hf-mcp-clients.json: evalstate/mcp-clients at c30d6f28, report generated 2026-11-09, window 2026-09-10 to 2026-11-08. 12 clients, 4 with a registry entry."
canonical: https://canimcp.io/observed
last-updated: 2026-11-11
---

# Capabilities observed in traffic

Generated from `data/observed/hf-mcp-clients.json`: `evalstate/mcp-clients` at [`c30d6f28`](https://huggingface.co/datasets/evalstate/mcp-clients/blob/c30d6f2859b699fe9f36e674e4722bfd2d8a1258/reports/dashboard-v1.json), report generated 2026-11-09, window 2026-09-10 to 2026-11-08. 12 clients, 4 with a registry entry.

A flag is set when more than 50% of a client's `2026-07-28` tool calls in the window declare the capability, or when a backfill has it. The initialize-era backfill (2026-06-07 to 2026-07-26) can set elicitation, elicitation_url, mcp_apps for a client even though it lies outside the window. Where a backfill could have set a flag the At column is `?`, because the report does not say which path did. `skills` is set by a successful `skills/list` call, so an unset skills flag is not recorded as unsupported. A client with no `2026-07-28` traffic in the window gets no record for an unset flag.

| Client | Wire names | Tool calls by revision, 30d | elicitation | elicitation.url | apps | tasks |
|---|---|---|---|---|---|---|
| Claude Code | `claude-code` | `2026-07-28` 99.2%, `2025-11-25` 0.8%, `2025-06-18` <0.1%, `2025-03-26` <0.1% | ● ? | ● | ○ | ○ |
| Claude.ai | `Anthropic/ClaudeAI` | `2026-07-28` 99.7%, `2025-11-25` 0.3% | ○ | ○ | ● ? | ○ |
| [Codex CLI](/clients/openai-codex.md) | `codex-mcp-client` | `2026-07-28` <0.1%, `2025-06-18` 100% | ● ? | ● ? | ● | ○ |
| Codex Desktop | `openai-mcp (Codex)` | `2026-07-28` 96.5%, `2025-11-25` 3.5% | ● | ● | ● ? | ○ |
| OpenAI ChatGPT | `openai-mcp` | `2026-07-28` 46.2%, `2025-11-25` 53.8% | ○ | ○ | ● ? | ○ |
| Hugging Face ChatUI | `chat-ui-mcp` | `2026-07-28` 100% | ● | ● | ○ | ○ |
| [OpenCode](/clients/opencode.md) | `opencode` | `2026-07-28` <0.1%, `2025-11-25` 99.9%, `2025-03-26` <0.1%, `2024-11-05` <0.1% | ● | ● | ○ | ○ |
| Cursor | `Cursor`, `Cursor MCP Availability`, `cursor-agent`, `cursor-check`, `cursor-diag`, `cursor-hf-check`, `cursor-mcp-sync-check`, `cursor-public-preflight`, `cursor-test`, `cursor-vscode` | `2025-11-25` 99.9%, `2025-06-18` <0.1%, `2025-03-26` <0.1%, `2024-11-05` <0.1% | ● ? |  | ● ? |  |
| Visual Studio Code | `Visual Studio Code`, `Visual Studio Code - Insiders` | `2025-11-25` 100% | ● ? | ● ? | ● ? |  |
| Llama UI | `llama-ui-mcp` | `2025-11-25` 100% | ○ | ○ | ○ | ○ |
| [fast-agent](/clients/fast-agent.md) | `fast-agent-mcp` | `2026-07-28` 100% | ● ? | ● ? | ○ | ○ |
| [Antigravity](/clients/antigravity.md) | `Antigravity`, `Antigravity-Client`, `antigravity`, `antigravity-client` | `2026-07-28` 97.3%, `2025-11-25` 2.1%, `2025-03-26` <0.1%, `2024-11-05` 0.6% | ● ? | ● ? | ○ | ○ |

`●` set, observed at `2026-07-28` · `● ?` set, revision unknown · `○` not set · blank: no record.

## Policy

The source's policy block, verbatim.

```json
{
  "capability_backfill_path": "reports/dashboard-capability-backfill-v1.json",
  "capability_proportion_threshold": 0.5,
  "elicitation_historical_source": "initialize.capabilities.elicitation",
  "elicitation_request_source": "clientCapabilities.elicitation",
  "elicitation_url_historical_source": "initialize.capabilities.elicitation.url",
  "elicitation_url_request_source": "clientCapabilities.elicitation.url",
  "everything_else_historical_qualification": "legacy tool calls in immutable initialize backfill window",
  "everything_else_minimum_tool_calls": 1000,
  "everything_else_request_qualification": "valid-protocol tool calls in report window",
  "historical_capability_limit": [
    "elicitation",
    "elicitation_url",
    "mcp_apps"
  ],
  "mcp_apps_historical_source": "initialize.capabilities.extensions.io.modelcontextprotocol/ui",
  "mcp_apps_request_source": "clientCapabilities.extensions.io.modelcontextprotocol/ui",
  "mcp_remote_policy": "excluded",
  "modern_protocol_version": "2026-07-28",
  "skills_observation_source": "successful client-originated skills/list transport metrics",
  "valid_protocol_versions": [
    "2024-11-05",
    "2025-03-26",
    "2025-06-18",
    "2025-11-25",
    "2026-07-28"
  ]
}
```

---

Generated from `data/observed/*.json` by `scripts/build-cards.js`. Rerun `npm run ingest:observed` and `npm run build:cards`, do not edit this file.