Add body_key support to managed tool execution

When body_key is set on a tool execution entry, the proxy wraps
the tool arguments as {body_key: args} instead of sending args flat.

Author: mostlydev

internal/agentctx/agentctx.go

@@ -53,6 +53,7 @@ type ToolExecution struct {
 	BaseURL   string     `json:"base_url"`
 	Method    string     `json:"method"`
 	Path      string     `json:"path"`
+	BodyKey   string     `json:"body_key,omitempty"`
 	Auth      *AuthEntry `json:"auth,omitempty"`
 }
 

internal/agentctx/agentctx_test.go

@@ -220,16 +220,17 @@ func TestLoadReadsToolsManifest(t *testing.T) {
 		"version": 1,
 		"tools": [
 			{
-				"name": "trading-api.get_market_context",
-				"description": "Retrieve market context",
+				"name": "trading-api.propose_trade",
+				"description": "Submit trade proposal",
 				"inputSchema": {"type": "object"},
 				"annotations": {"readOnly": true},
 				"execution": {
 					"transport": "http",
 					"service": "trading-api",
 					"base_url": "http://trading-api:4000",
-					"method": "GET",
-					"path": "/api/v1/market_context/{claw_id}",
+					"method": "POST",
+					"path": "/api/v1/trades",
+					"body_key": "trade",
 					"auth": {"type": "bearer", "token": "tool-token"}
 				}
 			}
@@ -255,12 +256,15 @@ func TestLoadReadsToolsManifest(t *testing.T) {
 		t.Fatalf("unexpected tools manifest header: %+v", ctx.Tools)
 	}
 	tool := ctx.Tools.Tools[0]
-	if tool.Name != "trading-api.get_market_context" {
+	if tool.Name != "trading-api.propose_trade" {
 		t.Fatalf("unexpected tool name: %+v", tool)
 	}
 	if tool.Execution.Service != "trading-api" || tool.Execution.Auth == nil || tool.Execution.Auth.Token != "tool-token" {
 		t.Fatalf("unexpected tool execution: %+v", tool.Execution)
 	}
+	if tool.Execution.BodyKey != "trade" {
+		t.Fatalf("unexpected tool body key: %+v", tool.Execution)
+	}
 	if ctx.Tools.Policy.MaxRounds != 8 || ctx.Tools.Policy.TimeoutPerToolMS != 30000 || ctx.Tools.Policy.TotalTimeoutMS != 120000 {
 		t.Fatalf("unexpected tool policy: %+v", ctx.Tools.Policy)
 	}

internal/proxy/toolmediation.go

@@ -693,7 +693,7 @@ func (h *Handler) callManagedHTTPTool(ctx context.Context, agentID string, tool
 	if err != nil {
 		return toolErrorPayload("invalid_arguments", err.Error(), 0, nil), 0, nil
 	}
-	targetURL, body, err := buildManagedToolRequest(tool.Execution.BaseURL, strings.ToUpper(tool.Execution.Method), renderedPath, remaining)
+	targetURL, body, err := buildManagedToolRequest(tool.Execution.BaseURL, strings.ToUpper(tool.Execution.Method), renderedPath, tool.Execution.BodyKey, remaining)
 	if err != nil {
 		return toolErrorPayload("request_build_failed", err.Error(), 0, nil), 0, nil
 	}
@@ -765,7 +765,7 @@ func renderManagedToolPath(path string, agentID string, args map[string]any) (st
 	return rendered, remaining, nil
 }
 
-func buildManagedToolRequest(baseURL string, method string, path string, args map[string]any) (string, io.Reader, error) {
+func buildManagedToolRequest(baseURL string, method string, path string, bodyKey string, args map[string]any) (string, io.Reader, error) {
 	u, err := url.Parse(strings.TrimSpace(baseURL))
 	if err != nil {
 		return "", nil, err
@@ -785,7 +785,11 @@ func buildManagedToolRequest(baseURL string, method string, path string, args ma
 	if len(args) == 0 {
 		args = map[string]any{}
 	}
-	body, err := json.Marshal(args)
+	payload := any(args)
+	if strings.TrimSpace(bodyKey) != "" {
+		payload = map[string]any{strings.TrimSpace(bodyKey): args}
+	}
+	body, err := json.Marshal(payload)
 	if err != nil {
 		return "", nil, err
 	}

internal/proxy/toolmediation_test.go

@@ -0,0 +1,59 @@
+package proxy
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+	"testing"
+)
+
+func TestBuildManagedToolRequestPreservesFlatJSONBodyByDefault(t *testing.T) {
+	targetURL, body, err := buildManagedToolRequest("http://trading-api:4000", http.MethodPost, "/api/v1/trades", "", map[string]any{
+		"ticker":        "NVDA",
+		"qty_requested": float64(50),
+	})
+	if err != nil {
+		t.Fatalf("buildManagedToolRequest: %v", err)
+	}
+	if targetURL != "http://trading-api:4000/api/v1/trades" {
+		t.Fatalf("unexpected target URL: %q", targetURL)
+	}
+
+	raw, err := io.ReadAll(body)
+	if err != nil {
+		t.Fatalf("read body: %v", err)
+	}
+	var payload map[string]any
+	if err := json.Unmarshal(raw, &payload); err != nil {
+		t.Fatalf("unmarshal body: %v", err)
+	}
+	if payload["ticker"] != "NVDA" || payload["qty_requested"] != float64(50) {
+		t.Fatalf("unexpected flat payload: %#v", payload)
+	}
+}
+
+func TestBuildManagedToolRequestWrapsJSONBodyWhenBodyKeyIsSet(t *testing.T) {
+	targetURL, body, err := buildManagedToolRequest("http://trading-api:4000", http.MethodPost, "/api/v1/trades", "trade", map[string]any{
+		"ticker":        "NVDA",
+		"qty_requested": float64(50),
+	})
+	if err != nil {
+		t.Fatalf("buildManagedToolRequest: %v", err)
+	}
+	if targetURL != "http://trading-api:4000/api/v1/trades" {
+		t.Fatalf("unexpected target URL: %q", targetURL)
+	}
+
+	raw, err := io.ReadAll(body)
+	if err != nil {
+		t.Fatalf("read body: %v", err)
+	}
+	var payload map[string]map[string]any
+	if err := json.Unmarshal(raw, &payload); err != nil {
+		t.Fatalf("unmarshal body: %v", err)
+	}
+	trade := payload["trade"]
+	if trade["ticker"] != "NVDA" || trade["qty_requested"] != float64(50) {
+		t.Fatalf("unexpected wrapped payload: %#v", payload)
+	}
+}