systemprompt-api 0.61.0

//! Per-tool audit for external MCP servers served over the HTTP gateway.
//!
//! A client-mediated `tools/call` to an external provider has no backend
//! process to record it, so the gateway taps the forwarded request/response,
//! writes one `mcp_tool_executions` row under the calling user, and hands the
//! result to the artifact ingest. The execution id is minted before the
//! response leaves, and stamped into its `_meta`, so the client's own later
//! report of the same result carries the exact server key. `record` composes
//! the tap over the upstream body; the tap owns an [`McpAudit`] and finalizes
//! it (once) on stream EOF or drop.
//!
//! The newest unclaimed intent for the tool in the calling session is claimed
//! to pair the execution, mirroring [`systemprompt_mcp::McpToolExecutor`]. A
//! claim makes the pairing inferred, never exact; failing to claim leaves the
//! execution unpaired rather than failing the call, which has already returned
//! to the client.
//!
//! Copyright (c) systemprompt.io — Business Source License 1.1.
//! See <https://systemprompt.io> for licensing details.

pub mod jsonrpc;
pub mod tap;

use std::sync::Arc;

use chrono::{DateTime, Utc};
use serde_json::Value;
use systemprompt_identifiers::McpExecutionId;
use systemprompt_mcp::models::{ExecutionStatus, ToolExecutionRequest, ToolExecutionResult};
use systemprompt_mcp::repository::ToolUsageRepository;
use systemprompt_mcp::{
    ArtifactIngest, INTENT_CLAIM_WINDOW_SECONDS, IngestRequest, from_wire_value,
};
use systemprompt_models::RequestContext;
use systemprompt_models::mcp::{Correlation, ExecutionSource};

pub(crate) use jsonrpc::parse_tool_call;
pub(crate) use tap::record;

use jsonrpc::{ToolCallInvocation, ToolCallOutcome};

#[derive(Debug)]
pub struct McpAudit {
    repo: Arc<ToolUsageRepository>,
    ingest: Option<Arc<ArtifactIngest>>,
    context: RequestContext,
    server_name: String,
    invocation: ToolCallInvocation,
    started_at: DateTime<Utc>,
    mcp_execution_id: McpExecutionId,
}

impl McpAudit {
    pub fn new(
        repo: Arc<ToolUsageRepository>,
        ingest: Option<Arc<ArtifactIngest>>,
        context: RequestContext,
        server_name: String,
        invocation: ToolCallInvocation,
    ) -> Self {
        Self {
            repo,
            ingest,
            context,
            server_name,
            invocation,
            started_at: Utc::now(),
            mcp_execution_id: McpExecutionId::new(uuid::Uuid::new_v4().to_string()),
        }
    }

    const fn request_id(&self) -> &Value {
        &self.invocation.id
    }

    pub const fn mcp_execution_id(&self) -> &McpExecutionId {
        &self.mcp_execution_id
    }

    fn finalize(self, outcome: Option<ToolCallOutcome>) {
        let (output, error_message, result) = match outcome {
            Some(o) => (o.output, o.error_message, o.result),
            None => (
                None,
                Some("external MCP tool call produced no parseable result".to_owned()),
                None,
            ),
        };

        let request = ToolExecutionRequest {
            tool_name: self.invocation.tool_name,
            server_name: self.server_name.clone(),
            input: self.invocation.arguments,
            started_at: self.started_at,
            context: self.context,
            request_method: Some("mcp".to_owned()),
            request_source: Some(self.server_name),
            ai_tool_call_id: None,
            source: ExecutionSource::Proxy,
        };
        let result_row = ToolExecutionResult {
            status: ExecutionStatus::from_error(error_message.is_some()).to_string(),
            error_message,
            output,
            output_schema: None,
            started_at: self.started_at,
            completed_at: Some(Utc::now()),
        };

        let repo = self.repo;
        let ingest = self.ingest;
        let mcp_execution_id = self.mcp_execution_id;
        tokio::spawn(async move {
            let mut request = request;
            request.ai_tool_call_id = request.context.ai_tool_call_id().cloned();
            // Why: no client sends `x-ai-tool-call-id`, so an external-server
            // execution arrives with nothing to join it to the inference turn
            // that asked for it. The in-process executor claims the newest
            // unclaimed intent for the tool in this session; without the same
            // claim here, every proxied call stayed unpaired — and eight of
            // nine configured servers are external.
            let correlation = if request.ai_tool_call_id.is_some() {
                Correlation::Exact
            } else {
                claim_intent(&repo, &mut request, &mcp_execution_id).await
            };
            if let Err(e) = repo
                .log_execution_sync_with_id(&mcp_execution_id, &request, &result_row, correlation)
                .await
            {
                tracing::warn!(
                    tool = %request.tool_name,
                    server = %request.server_name,
                    error = %e,
                    "Failed to record external MCP tool execution"
                );
                return;
            }
            if let Some(ingest) = ingest {
                ingest_proxied_result(&ingest, &request, result, mcp_execution_id).await;
            }
        });
    }
}

async fn claim_intent(
    repo: &ToolUsageRepository,
    request: &mut ToolExecutionRequest,
    mcp_execution_id: &McpExecutionId,
) -> Correlation {
    match repo
        .claim_unclaimed_intent(
            request.context.session_id(),
            &request.tool_name,
            mcp_execution_id,
            INTENT_CLAIM_WINDOW_SECONDS,
        )
        .await
    {
        Ok(Some(call_id)) => {
            request.ai_tool_call_id = Some(call_id);
            Correlation::Inferred
        },
        Ok(None) => Correlation::Inferred,
        Err(e) => {
            tracing::warn!(
                tool = %request.tool_name,
                server = %request.server_name,
                %mcp_execution_id,
                error = %e,
                "Proxy intent claim failed"
            );
            Correlation::Inferred
        },
    }
}

async fn ingest_proxied_result(
    ingest: &ArtifactIngest,
    request: &ToolExecutionRequest,
    result: Option<Value>,
    mcp_execution_id: McpExecutionId,
) {
    let Some(wire) = result.as_ref().and_then(from_wire_value) else {
        return;
    };
    let ingest_request = IngestRequest {
        result: wire,
        tool_name: request.tool_name.clone(),
        server_name: Some(request.server_name.clone()),
        ai_tool_call_id: request.ai_tool_call_id.clone(),
        mcp_execution_id: Some(mcp_execution_id),
        ctx: request.context.clone(),
        skill: None,
        source: ExecutionSource::Proxy,
        started_at: Some(request.started_at),
        input: Some(request.input.clone()),
    };
    if let Err(e) = ingest.ingest(ingest_request).await {
        tracing::warn!(
            tool = %request.tool_name,
            server = %request.server_name,
            error = %e,
            "Failed to ingest external MCP tool result as an artifact"
        );
    }
}