EVE + LangChain

Compatibility: Experimental integration — structurally implemented but not included in the supported release-candidate adapter matrix.

The LangChain adapter routes tool calls made through LangChain's tool interface into EVE's governance composition root so CoreGuard makes a deterministic ALLOW / BLOCK / MODIFY decision before a tool executes. The adapter is structurally implemented, but LangChain was not installed during release-candidate validation, so it was not validated against a pinned live version and is marked UNTESTED / experimental. Only the generic adapter is SUPPORTED.

How governance works here

Each tool invocation is submitted to EVE before it runs. No LLM is in the decision path.

from eve_coreguard import CoreGuardClient

client = CoreGuardClient(api_key="eve_sk_...")

result = client.evaluate(
    request_id="req-9d31",
    tenant_id="tenant_demo",
    proposed_action={"type": "search_orders", "query": "status:refunded", "limit": 50},
    model_output={"decision": "call_tool", "confidence": 0.9},
    context={"principal_id": "chain_support", "session_id": "sess_9d31"},
    policy_set="tool_calls_v1",
)
# result.decision.status: ALLOWED -> execute; BLOCKED -> skip the tool; MODIFIED -> use result.decision.action.

eve-coreguard (0.2.7) is published on PyPI. Entry point: the CoreGuardClient class.

Hardened alternative

This adapter is wrapper-enforced: a chain (or code) that invokes the underlying tool directly, bypassing the wrapped tool, is not intercepted. For a boundary a direct call cannot route around:

• Put tools behind a restricted server-side tool registry so the chain reaches them only through the governed path.
• Proxy tool execution through a sidecar so governance runs out-of-process.
• Apply network enforcement so tool endpoints are only reachable via the governed path.
• For MCP tools, route through the MCP gateway, which binds the approved request to the executed request (see mcp.md).

Readiness

• This adapter: experimental (UNTESTED against a pinned live LangChain version; wrapper-enforced).
• Generic Python adapter: SUPPORTED.
• EVE SDK core: RELEASE CANDIDATE WITH EXCLUSIONS.

Limitations

• Not validated against a pinned live framework version.
• Wrapper-enforced: bypassable by a direct underlying-tool call. Hard enforcement requires a gateway/sidecar or restricted server-side tool registry.
• Hosted mode requires a reachable endpoint; embedded governance is the EVE service.
• Evidence verification proves authenticity and integrity, not decision correctness; independent verification needs the ECDSA P-384 public key.