jev-mcp-python — Design Architecture

jev-mcp-python — Design Architecture An architecture diagram generated by Archify. MCP Client · host agent · Architecture component MCP Client host agent JevMCPServer + Toolset · one registry (ADR-0013) · one-way judgment layers (ADR-0002) JevMCPServer + Toolset one registry (ADR-0013) arguments · compiled parsers · one-way judgment layers (ADR-0002) arguments compiled parsers limits · frozen caps (ADR-0014) · one-way judgment layers (ADR-0002) limits frozen caps (ADR-0014) Ten JevTools · 10 declarative JevTools · one-way judgment layers (ADR-0002) Ten JevTools 10 declarative JevTools Runtime · lazy provider · pool · one-way judgment layers (ADR-0002) Runtime lazy provider · pool Providers ×4 · envelope-only ×4 · one-way judgment layers (ADR-0002) Providers ×4 envelope-only ×4 Settings → Redactor · env-only · derived secrets · Architecture component Settings → Redactor env-only · derived secrets extract · candidates · executor port · one-way judgment layers (ADR-0002) extract candidates · executor port serialize + text · JSON.stringify · UTF-16 · Architecture component serialize + text JSON.stringify · UTF-16 Policy (pure) · pure · incl. extract · one-way judgment layers (ADR-0002) Policy (pure) pure · incl. extract Validation · answers · caps · one-way judgment layers (ADR-0002) Validation answers · caps Parity oracle · 282 fixtures · replay · Architecture component Parity oracle 282 fixtures · replay Telemetry · spans + metrics · in-process · Architecture component Telemetry spans + metrics · in-process Eval harness · evals/agent.py · spend · Architecture component Eval harness evals/agent.py · spend tools/call validate args typed args cap values ask Jev evaluate raw answers judgments actions + reasons result text config · redaction patterns byte-equal (ADR-0001) spans · metrics paid agent runs one-way judgment layers (ADR-0002)

One registry (ADR-0013)

  • • list_tools ≡ call_tool — one Toolset
  • • unknown tool returns owned text

Model judges, policy decides (ADR-0002)

  • • validation rejects; policy is pure (traced in tools/observed)
  • • truncated or unknown confidence ⇒ never auto

Trust boundary (ADR-0008/0017)

  • • env-only config; tool args are model-controlled
  • • secret set derives from the schema; errors redacted

Frozen parity (ADR-0001/0006/0016)

  • • 282 fixtures replay byte-equal; divergences ADR-tagged
  • • extract: one deadline incl. queue; stdlib re workers