astrid_plugins/wasm/
tool.rs

1//! WASM plugin tool — wraps a single tool exported by a WASM guest.
2
3use std::sync::{Arc, Mutex};
4
5use async_trait::async_trait;
6use serde_json::Value;
7
8use astrid_core::plugin_abi::{ToolInput, ToolOutput};
9
10use crate::context::PluginToolContext;
11use crate::error::{PluginError, PluginResult};
12use crate::tool::PluginTool;
13
14/// A tool backed by a WASM plugin's `execute-tool` export.
15///
16/// Multiple `WasmPluginTool` instances share the same `Arc<Mutex<extism::Plugin>>`
17/// since WASM execution is inherently single-threaded.
18pub struct WasmPluginTool {
19    /// Tool name (unique within the plugin).
20    name: String,
21    /// Human-readable description.
22    description: String,
23    /// JSON schema for input parameters.
24    input_schema: Value,
25    /// Shared Extism plugin instance (all tools share this).
26    plugin: Arc<Mutex<extism::Plugin>>,
27}
28
29impl WasmPluginTool {
30    /// Create a new WASM plugin tool.
31    pub(crate) fn new(
32        name: String,
33        description: String,
34        input_schema: Value,
35        plugin: Arc<Mutex<extism::Plugin>>,
36    ) -> Self {
37        Self {
38            name,
39            description,
40            input_schema,
41            plugin,
42        }
43    }
44}
45
46#[async_trait]
47impl PluginTool for WasmPluginTool {
48    fn name(&self) -> &str {
49        &self.name
50    }
51
52    fn description(&self) -> &str {
53        &self.description
54    }
55
56    fn input_schema(&self) -> Value {
57        self.input_schema.clone()
58    }
59
60    async fn execute(&self, args: Value, _ctx: &PluginToolContext) -> PluginResult<String> {
61        let tool_input = ToolInput {
62            name: self.name.clone(),
63            arguments: serde_json::to_string(&args).map_err(|e| {
64                PluginError::ExecutionFailed(format!("failed to serialize args: {e}"))
65            })?,
66        };
67
68        let input_json = serde_json::to_string(&tool_input).map_err(|e| {
69            PluginError::ExecutionFailed(format!("failed to serialize ToolInput: {e}"))
70        })?;
71
72        // block_in_place allows blocking in an async context with the multi-threaded runtime.
73        let result = tokio::task::block_in_place(|| {
74            let mut plugin = self
75                .plugin
76                .lock()
77                .map_err(|e| PluginError::WasmError(format!("plugin lock poisoned: {e}")))?;
78            plugin
79                .call::<&str, String>("execute-tool", &input_json)
80                .map_err(|e| PluginError::WasmError(format!("execute-tool call failed: {e}")))
81        })?;
82
83        // Parse the output
84        let output: ToolOutput = serde_json::from_str(&result).map_err(|e| {
85            PluginError::ExecutionFailed(format!("failed to parse ToolOutput: {e}"))
86        })?;
87
88        if output.is_error {
89            Err(PluginError::ExecutionFailed(output.content))
90        } else {
91            Ok(output.content)
92        }
93    }
94}
95
96impl std::fmt::Debug for WasmPluginTool {
97    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
98        f.debug_struct("WasmPluginTool")
99            .field("name", &self.name)
100            .field("description", &self.description)
101            .finish_non_exhaustive()
102    }
103}
104
105// Note: WasmPluginTool unit tests requiring a real Extism Plugin are deferred
106// to integration tests with WASM fixtures. The struct itself is tested through
107// WasmPlugin lifecycle tests.
astrid_plugins/wasm/tool.rs

astrid_plugins/wasm/
tool.rs
