rustapi_mcp/
config.rs

1//! Configuration for the MCP server / integration.
2
3use std::collections::HashSet;
4
5/// Configuration for the native MCP server.
6///
7/// This is the primary way users control what gets exposed as tools,
8/// authentication for MCP clients, transport behavior, etc.
9#[derive(Debug, Clone)]
10pub struct McpConfig {
11    /// Human-friendly name of this MCP server (shown to agents).
12    pub name: String,
13    /// Version string.
14    pub version: String,
15    /// Optional description.
16    pub description: Option<String>,
17
18    /// Whether tool discovery and calling is enabled.
19    pub tools_enabled: bool,
20
21    /// Explicitly allowed tags. Only routes that have at least one of these tags
22    /// (via OpenAPI `tags` or future route metadata) will be exposed as tools.
23    ///
24    /// Empty set + no other allow rules = nothing is exposed (safe default).
25    pub allowed_tags: HashSet<String>,
26
27    /// Explicit path prefixes that are allowed to become tools.
28    /// Example: `["/api/public", "/agent"]`
29    pub allowed_path_prefixes: Vec<String>,
30
31    /// Admin / MCP client token.
32    ///
33    /// When set, MCP clients must present this (via header or query param,
34    /// transport dependent) to use discovery or invocation.
35    pub admin_token: Option<String>,
36
37    /// Whether to include detailed error information in tool responses.
38    /// In production you usually want this `false` (similar to RUSTAPI_ENV=production).
39    pub expose_detailed_errors: bool,
40
41    /// Maximum number of tools to advertise in one `tools/list` response.
42    /// Helps protect against very large route sets.
43    pub max_tools: usize,
44
45    /// How `tools/call` should be executed.
46    /// Proxy (default) always goes over HTTP (correct and works for external targets).
47    /// InProcess / Auto are for when an in-process RustApi instance is available.
48    pub invocation_mode: InvocationMode,
49}
50
51/// Controls whether tool invocation goes through the normal HTTP path or
52/// a direct in-memory call (when available).
53#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
54pub enum InvocationMode {
55    /// Always proxy via the configured `http_base` (safest, works everywhere).
56    #[default]
57    Proxy,
58    /// Use direct in-process invocation when a RustApi runtime is attached.
59    InProcess,
60    /// Choose automatically (InProcess if runtime available, else Proxy).
61    Auto,
62}
63
64impl Default for McpConfig {
65    fn default() -> Self {
66        Self {
67            name: "rustapi-mcp".to_string(),
68            version: "0.0.0".to_string(),
69            description: None,
70            tools_enabled: true,
71            allowed_tags: HashSet::new(),
72            allowed_path_prefixes: vec![],
73            admin_token: None,
74            expose_detailed_errors: false,
75            max_tools: 256,
76            invocation_mode: InvocationMode::Proxy,
77        }
78    }
79}
80
81impl McpConfig {
82    /// Create a new config with reasonable defaults.
83    pub fn new() -> Self {
84        Self::default()
85    }
86
87    /// Set the name advertised to MCP clients.
88    pub fn name(mut self, name: impl Into<String>) -> Self {
89        self.name = name.into();
90        self
91    }
92
93    /// Set the version advertised to MCP clients.
94    pub fn version(mut self, version: impl Into<String>) -> Self {
95        self.version = version.into();
96        self
97    }
98
99    /// Set a human description.
100    pub fn description(mut self, desc: impl Into<String>) -> Self {
101        self.description = Some(desc.into());
102        self
103    }
104
105    /// Enable or disable the tools capability entirely.
106    pub fn enable_tools(mut self, enabled: bool) -> Self {
107        self.tools_enabled = enabled;
108        self
109    }
110
111    /// Allow tools only for routes that carry at least one of the given tags.
112    ///
113    /// This is the recommended way to safely expose a curated surface to agents.
114    pub fn allowed_tags<I, S>(mut self, tags: I) -> Self
115    where
116        I: IntoIterator<Item = S>,
117        S: Into<String>,
118    {
119        self.allowed_tags = tags.into_iter().map(Into::into).collect();
120        self
121    }
122
123    /// Add a path prefix that is allowed to be exposed as tools.
124    pub fn allow_path_prefix(mut self, prefix: impl Into<String>) -> Self {
125        self.allowed_path_prefixes.push(prefix.into());
126        self
127    }
128
129    /// Require this token for MCP clients (discovery + calls).
130    pub fn admin_token(mut self, token: impl Into<String>) -> Self {
131        self.admin_token = Some(token.into());
132        self
133    }
134
135    /// Control whether tool responses include full internal error details.
136    pub fn expose_detailed_errors(mut self, expose: bool) -> Self {
137        self.expose_detailed_errors = expose;
138        self
139    }
140
141    /// Set the maximum number of tools to list.
142    pub fn max_tools(mut self, max: usize) -> Self {
143        self.max_tools = max;
144        self
145    }
146
147    /// Choose invocation strategy for tool calls.
148    pub fn invocation_mode(mut self, mode: InvocationMode) -> Self {
149        self.invocation_mode = mode;
150        self
151    }
152}
rustapi_mcp/config.rs

rustapi_mcp/
config.rs
