📊vCon MCP Adapters

Convert AI agent framework traces into vCons that carry an MCP session attachment, from the command line or a Python SDK.

Repo: vcon-dev/vcon-mcp-adapters (default branch claude/vcon-mcp-adapters-M1Oie) · Status: pre-release, 0.1.0 in pyproject.toml

vcon-mcp-adapters turns traces from AI agent frameworks into vCons. It is not an OpenTelemetry tracer and does not instrument the vCon MCP server. It reads a trace after the fact, normalizes it into an MCPSession object (turns, tool calls, tool results, usage, artifacts), and attaches that object to a vCon as attachments[0] with purpose: "mcp_session".

Supported inputs

• Anthropic Messages API responses

• OpenAI Responses API calls and OpenAI Agents SDK sessions

• Claude Code session JSONL files

• Exports from Helicone, Langfuse and LangSmith, as files or fetched live from their APIs

Install

pip install vcon-mcp-adapters
pip install "vcon-mcp-adapters[anthropic]"   # or [openai], [agents]

The CHANGELOG lists the Helicone, Claude Code, Langfuse and LangSmith adapters under 0.2.0 to 0.2.2, all marked Unreleased. Check the repo before relying on them.

Convert a trace

trace-to-vcon anthropic response.json --out session.vcon.json \
  --user-name "Alice" --assistant-name "Claude" --model claude-opus-4-7

trace-to-vcon claude-code ~/.claude/projects/<encoded-cwd>/<session>.jsonl \
  --user-name "Alice" --out cc.vcon.json

trace-to-vcon helicone helicone-export.json --user-name "Alice" --out-dir ./out/
trace-to-vcon fetch langsmith --project my-app --out-dir ./out/

trace-to-vcon validate session.vcon.json

Live fetches read HELICONE_API_KEY, the Langfuse key variables, or LANGSMITH_API_KEY from the environment. Export files produce one vCon per record or trace.

Python SDK

from vcon_mcp_adapters import to_vcon
from vcon_mcp_adapters.adapters.anthropic import from_trace
from vcon_mcp_adapters.parties import user_party, ai_agent_party

session = from_trace(open("messages_response.json").read())
vcon = to_vcon(session, parties=[
    user_party(name="Alice", email="[e-mail]"),
    ai_agent_party(provider="anthropic", model="claude-opus-4-7"),
])

Lawful basis

The adapters emit vCons with syntax 0.4.0 and no lawful_basis attachment. Add one before storing or sharing the output if the conversation involves personal data. See Lawful Basis.

See also

• vCon MCP Server overview

• vCon Anthropic Chats, a narrower converter for Claude Code and claude.ai history