fix: various fixes

lib/deduplicator.ts

@@ -18,9 +18,10 @@ export function detectDuplicates(
 ): DuplicateDetectionResult {
     const signatureMap = new Map<string, string[]>()
 
+    const protectedToolsLower = protectedTools.map(t => t.toLowerCase())
     const deduplicatableIds = unprunedToolCallIds.filter(id => {
         const metadata = toolMetadata.get(id)
-        return !metadata || !protectedTools.includes(metadata.tool)
+        return !metadata || !protectedToolsLower.includes(metadata.tool.toLowerCase())
     })
 
     for (const id of deduplicatableIds) {

lib/fetch-wrapper/index.ts

@@ -53,6 +53,8 @@ export function installFetchWrapper(
                 const body = JSON.parse(init.body)
                 const inputUrl = typeof input === 'string' ? input : 'URL object'
                 let modified = false
+                // Track tool IDs cached from this request for session-scoped deduplication
+                const cachedToolIds: string[] = []
 
                 // Try each format handler in order
                 // OpenAI Chat Completions & Anthropic style (body.messages)
@@ -61,6 +63,9 @@ export function installFetchWrapper(
                     if (result.modified) {
                         modified = true
                     }
+                    if (result.cachedToolIds) {
+                        cachedToolIds.push(...result.cachedToolIds)
+                    }
                 }
 
                 // Google/Gemini style (body.contents)
@@ -77,15 +82,17 @@ export function installFetchWrapper(
                     if (result.modified) {
                         modified = true
                     }
+                    if (result.cachedToolIds) {
+                        cachedToolIds.push(...result.cachedToolIds)
+                    }
                 }
 
-                // Run deduplication after handlers have populated toolParameters cache
+                // Run deduplication only on tool IDs from the current request (session-scoped)
                 const sessionId = state.lastSeenSessionId
-                if (sessionId && state.toolParameters.size > 0) {
-                    const toolIds = Array.from(state.toolParameters.keys())
+                if (sessionId && cachedToolIds.length > 1) {
                     const alreadyPruned = state.prunedIds.get(sessionId) ?? []
                     const alreadyPrunedLower = new Set(alreadyPruned.map(id => id.toLowerCase()))
-                    const unpruned = toolIds.filter(id => !alreadyPrunedLower.has(id.toLowerCase()))
+                    const unpruned = cachedToolIds.filter(id => !alreadyPrunedLower.has(id.toLowerCase()))
                     if (unpruned.length > 1) {
                         const { duplicateIds } = detectDuplicates(state.toolParameters, unpruned, config.protectedTools)
                         if (duplicateIds.length > 0) {

lib/fetch-wrapper/openai-chat.ts

@@ -21,8 +21,8 @@ export async function handleOpenAIChatAndAnthropic(
         return { modified: false, body }
     }
 
-    // Cache tool parameters from messages
-    cacheToolParametersFromMessages(body.messages, ctx.state)
+    // Cache tool parameters from messages and track which IDs were cached
+    const cachedToolIds = cacheToolParametersFromMessages(body.messages, ctx.state)
 
     let modified = false
 
@@ -64,7 +64,7 @@ export async function handleOpenAIChatAndAnthropic(
     const { allSessions, allPrunedIds } = await getAllPrunedIds(ctx.client, ctx.state, ctx.logger)
 
     if (toolMessages.length === 0 || allPrunedIds.size === 0) {
-        return { modified, body }
+        return { modified, body, cachedToolIds }
     }
 
     let replacedCount = 0
@@ -125,8 +125,8 @@ export async function handleOpenAIChatAndAnthropic(
             )
         }
 
-        return { modified: true, body }
+        return { modified: true, body, cachedToolIds }
     }
 
-    return { modified, body }
+    return { modified, body, cachedToolIds }
 }

lib/fetch-wrapper/openai-responses.ts

@@ -21,8 +21,8 @@ export async function handleOpenAIResponses(
         return { modified: false, body }
     }
 
-    // Cache tool parameters from input
-    cacheToolParametersFromInput(body.input, ctx.state)
+    // Cache tool parameters from input and track which IDs were cached
+    const cachedToolIds = cacheToolParametersFromInput(body.input, ctx.state)
 
     let modified = false
 
@@ -52,13 +52,13 @@ export async function handleOpenAIResponses(
     const functionOutputs = body.input.filter((item: any) => item.type === 'function_call_output')
 
     if (functionOutputs.length === 0) {
-        return { modified, body }
+        return { modified, body, cachedToolIds }
     }
 
     const { allSessions, allPrunedIds } = await getAllPrunedIds(ctx.client, ctx.state, ctx.logger)
 
     if (allPrunedIds.size === 0) {
-        return { modified, body }
+        return { modified, body, cachedToolIds }
     }
 
     let replacedCount = 0
@@ -99,8 +99,8 @@ export async function handleOpenAIResponses(
             )
         }
 
-        return { modified: true, body }
+        return { modified: true, body, cachedToolIds }
     }
 
-    return { modified, body }
+    return { modified, body, cachedToolIds }
 }

lib/fetch-wrapper/types.ts

@@ -28,6 +28,8 @@ export interface FetchHandlerResult {
     modified: boolean
     /** The potentially modified body object */
     body: any
+    /** Tool call IDs that were cached from this request (for session-scoped deduplication) */
+    cachedToolIds?: string[]
 }
 
 /** Session data returned from getAllPrunedIds */

lib/tool-cache.ts

@@ -1,13 +1,32 @@
 import type { PluginState } from "./state"
 
+/** Maximum number of tool parameters to cache to prevent unbounded memory growth */
+const MAX_TOOL_PARAMETERS_CACHE_SIZE = 500
+
+/**
+ * Ensures the toolParameters cache doesn't exceed the maximum size.
+ * Removes oldest entries (first inserted) when limit is exceeded.
+ */
+function trimToolParametersCache(state: PluginState): void {
+    if (state.toolParameters.size > MAX_TOOL_PARAMETERS_CACHE_SIZE) {
+        const excess = state.toolParameters.size - MAX_TOOL_PARAMETERS_CACHE_SIZE
+        const keys = Array.from(state.toolParameters.keys())
+        for (let i = 0; i < excess; i++) {
+            state.toolParameters.delete(keys[i])
+        }
+    }
+}
+
 /**
  * Cache tool parameters from OpenAI Chat Completions style messages.
  * Extracts tool call IDs and their parameters from assistant messages with tool_calls.
+ * Returns the list of tool call IDs that were cached from this request.
  */
 export function cacheToolParametersFromMessages(
     messages: any[],
     state: PluginState
-): void {
+): string[] {
+    const cachedIds: string[] = []
     for (const message of messages) {
         if (message.role !== 'assistant' || !Array.isArray(message.tool_calls)) {
             continue
@@ -26,21 +45,26 @@ export function cacheToolParametersFromMessages(
                     tool: toolCall.function.name,
                     parameters: params
                 })
+                cachedIds.push(toolCall.id)
             } catch (error) {
                 // Silently ignore parse errors
             }
         }
     }
+    trimToolParametersCache(state)
+    return cachedIds
 }
 
 /**
  * Cache tool parameters from OpenAI Responses API format.
  * Extracts from input array items with type='function_call'.
+ * Returns the list of tool call IDs that were cached from this request.
  */
 export function cacheToolParametersFromInput(
     input: any[],
     state: PluginState
-): void {
+): string[] {
+    const cachedIds: string[] = []
     for (const item of input) {
         if (item.type !== 'function_call' || !item.call_id || !item.name) {
             continue
@@ -54,8 +78,11 @@ export function cacheToolParametersFromInput(
                 tool: item.name,
                 parameters: params
             })
+            cachedIds.push(item.call_id)
         } catch (error) {
             // Silently ignore parse errors
         }
     }
+    trimToolParametersCache(state)
+    return cachedIds
 }