| name | ejentum-reasoning-harness |
| description | MCP server exposing four cognitive harness modes (reasoning, code, anti-deception, memory). Each call returns an engineered scaffold (failure pattern, procedure, suppression vectors, falsification test) the agent ingests before generating. |
| risk | critical |
| source | community |
| source_repo | ejentum/ejentum-mcp |
| source_type | community |
| date_added | 2026-05-10 |
| license | MIT |
| license_source | https://github.com/ejentum/ejentum-mcp/blob/main/LICENSE |
| plugin | {"targets":{"codex":"blocked","claude":"blocked"},"setup":{"type":"manual","summary":"Install the ejentum-mcp MCP server (`npx -y ejentum-mcp`) and provide an EJENTUM_API_KEY env var (free tier: 100 calls, no card, at https://ejentum.com/pricing). Add the server to your client's mcpServers config (Claude Code, Cursor, Cline, Windsurf, Codex CLI, Gemini CLI, Antigravity, or VS Code Copilot Chat).","docs":"https://github.com/ejentum/ejentum-mcp#installation"}} |
Ejentum Reasoning Harness
The Ejentum Reasoning Harness is a library of 679 cognitive operations engineered in natural language, organized across four harnesses (reasoning, code, anti-deception, memory) and exposed as MCP tools the agent can call when the task matches their trigger conditions. It targets four mechanism failures common in long agentic chains: attention decay (losing the original task), reasoning decay (compounding errors), sycophantic collapse (agreeing with the user's frame instead of evaluating it), and hallucination drift (asserting unsupported claims with confidence).
Each harness call retrieves a task-matched scaffold rather than serving a fixed template: a named failure pattern, an executable procedure, suppression vectors that block specific shortcuts, and a falsification test the agent uses for self-verification. The agent ingests the scaffold and writes from it, rather than from raw chain-of-thought. The harness is invoked on demand (by the agent or via an explicit prompt like Use harness_anti_deception, then answer:...); it does not auto-run on every turn.
When to Use This Skill
- Use
harness_reasoning before answering analytical, diagnostic, planning, or multi-step questions ("why is X happening", "what's the best approach", "what are the tradeoffs", root-cause analysis, architecture decisions).
- Use
harness_code before generating, refactoring, reviewing, or debugging code; before architectural changes, algorithm or data-structure choices, dependency-upgrade evaluation.
- Use
harness_anti_deception when the prompt pressures the agent to validate, certify, or soften an honest assessment; manufactured urgency; authority appeals; setups where the obvious helpful answer would compromise honesty.
- Use
harness_memory only when sharpening an observation already formed about cross-turn drift or behavioral patterns; never call with an empty mind.
Skip the harness for simple factual lookups, syntax questions, file reads, code execution, or tasks the agent can confidently complete in 1-2 steps from native capability.
How It Works
Step 1: Install the MCP server
The server is published to npm. Most MCP-speaking clients support stdio installation via npx:
npx -y ejentum-mcp
Add to your client's MCP server config (Claude Code .mcp.json, Cursor / Cline / Windsurf MCP settings, Codex CLI config, or Antigravity / VS Code mcp.json):
