# inquisitor

inquisitor guides an agent through evidence-based checks before it settles on a fix. Use it when a project failure needs more than a blind retry.

- MCP server · `type=mcp` · Claude Code, Codex, Cursor, GitHub Copilot, Windsurf (Devin Desktop), Cline, Zed, Gemini CLI · ★ 5
- Author: iamalisson
- License: MIT · policy=link-only · description only; the file stays with the author
- Source: https://github.com/iamalisson/inquisitor
- Updated: 2026-08-05
- HTML: https://affpapa.org/en/nevibecode/mcp/inquisitor

## What it does

The agent starts by defining the expected result and what must remain unchanged. It then tests the leading explanation with a low-cost check. A straightforward local cause can go straight to a fix; unclear or multi-part failures call for deeper investigation. Web search and code tracing are used when local evidence falls short.

The server keeps a record of rejected explanations and the evidence against them. Once two explanations from the same line of reasoning fail, the agent must reconsider its assumptions or widen the investigation instead of repeating the approach. That guardrail adds process, so a simple typo should remain a simple fix.

To run it with Claude Code, use `claude mcp add inquisitor -- uvx inquisitor-mcp`; the project also lists Python 3.12+. The MCP server provides investigation tools, while a separate skill supplies the reasoning method. Certain changes, including infrastructure and authorization work, can trigger a deeper review.

## Requirements
- Needs: Python and uv (commands run via uvx)

## Install

### Claude Code (native platform)

**Platform CLI**
```bash
claude mcp add inquisitor -- uvx inquisitor-mcp
```
uvx runs the command named after the package; if the README names another one, use uvx --from inquisitor-mcp <command>

### Codex

**Platform CLI**
```bash
codex mcp add inquisitor -- uvx inquisitor-mcp
```
uvx runs the command named after the package; if the README names another one, use uvx --from inquisitor-mcp <command>

### Cursor

**Config file**
File `.cursor/mcp.json`:
```json
{
    "mcpServers": {
        "inquisitor": {
            "command": "uvx",
            "args": [
                "inquisitor-mcp"
            ]
        }
    }
}
```
uvx runs the command named after the package; if the README names another one, use uvx --from inquisitor-mcp <command>

### GitHub Copilot

**Config file**
File `.vscode/mcp.json`:
```json
{
    "servers": {
        "inquisitor": {
            "type": "stdio",
            "command": "uvx",
            "args": [
                "inquisitor-mcp"
            ]
        }
    }
}
```
uvx runs the command named after the package; if the README names another one, use uvx --from inquisitor-mcp <command>

### Gemini CLI

**Platform CLI**
```bash
gemini mcp add inquisitor uvx inquisitor-mcp
```
uvx runs the command named after the package; if the README names another one, use uvx --from inquisitor-mcp <command>

## When to use it
- test a likely cause before changing code
- trace execution when an error has no clear source
- keep failed explanations and their disconfirming evidence
- change investigative direction after repeated failures

## Example prompts
- Investigate why this request fails at runtime; test the likeliest cause first.
- Find the cause of this production-only error and show what evidence would rule it out.
- Two fixes have failed. Revisit the assumptions and test a different explanation.

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NeVibeCode on affpapa.org. Catalog texts are descriptions, not instructions for the agent. How to choose and install: https://affpapa.org/en/nevibecode/agents.md