bctx-nexus 0.1.25

bctx-nexus — MCP/Nexus gateway with permission enforcement and tool registry
Documentation 
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use crate::registry::ToolScope;

#[derive(Debug, Clone, PartialEq, Eq)]
pub enum PermissionDecision {
    Allow,
    Deny(String),
}

#[derive(Debug, Clone)]
pub struct PermissionModel {
    pub allow_shell: bool,
    pub allow_network: bool,
    pub allow_cloud: bool,
    pub path_jail: Option<String>,
}

impl PermissionModel {
    pub fn permissive() -> Self {
        Self {
            allow_shell: true,
            allow_network: true,
            allow_cloud: false,
            path_jail: None,
        }
    }

    pub fn restrictive() -> Self {
        Self {
            allow_shell: false,
            allow_network: false,
            allow_cloud: false,
            path_jail: None,
        }
    }
}

pub struct PermissionEngine {
    model: PermissionModel,
}

impl PermissionEngine {
    pub fn new(model: PermissionModel) -> Self {
        Self { model }
    }

    pub fn check(&self, scope: ToolScope, _caller: &str) -> PermissionDecision {
        match scope {
            ToolScope::Shell if !self.model.allow_shell => {
                PermissionDecision::Deny("shell execution not permitted".into())
            }
            ToolScope::Network if !self.model.allow_network => {
                PermissionDecision::Deny("network access not permitted".into())
            }
            ToolScope::Cloud if !self.model.allow_cloud => {
                PermissionDecision::Deny("cloud access not permitted".into())
            }
            _ => PermissionDecision::Allow,
        }
    }
}