prune reasoning for anthropic models

Author: jorgenwh

index.ts

@@ -67,17 +67,18 @@ const plugin: Plugin = (async (ctx) => {
                 if (body.messages && Array.isArray(body.messages)) {
                     cacheToolParameters(body.messages)
 
+                    // Check for tool messages in both formats:
+                    // 1. OpenAI style: role === 'tool'
+                    // 2. Anthropic style: role === 'user' with content containing tool_result
                     const toolMessages = body.messages.filter((m: any) => {
-                        if (m.role === 'tool') return true;
-                        if (m.role === 'assistant') {
-                            if (Array.isArray(m.content)) {
-                                for (const part of m.content) {
-                                    if (part.type === 'tool_use') return true;
-                                }
+                        if (m.role === 'tool') return true
+                        if (m.role === 'user' && Array.isArray(m.content)) {
+                            for (const part of m.content) {
+                                if (part.type === 'tool_result') return true
                             }
                         }
-                        return false;
-                    });
+                        return false
+                    })
 
                     const allSessions = await ctx.client.session.list()
                     const allPrunedIds = new Set<string>()
@@ -94,17 +95,37 @@ const plugin: Plugin = (async (ctx) => {
                         let replacedCount = 0
 
                         body.messages = body.messages.map((m: any) => {
+                            // OpenAI style: role === 'tool' with tool_call_id
                             if (m.role === 'tool' && allPrunedIds.has(m.tool_call_id?.toLowerCase())) {
                                 replacedCount++
                                 return {
                                     ...m,
                                     content: '[Output removed to save context - information superseded or no longer needed]'
                                 }
                             }
+
+                            // Anthropic style: role === 'user' with content array containing tool_result
+                            if (m.role === 'user' && Array.isArray(m.content)) {
+                                let messageModified = false
+                                const newContent = m.content.map((part: any) => {
+                                    if (part.type === 'tool_result' && allPrunedIds.has(part.tool_use_id?.toLowerCase())) {
+                                        messageModified = true
+                                        replacedCount++
+                                        return {
+                                            ...part,
+                                            content: '[Output removed to save context - information superseded or no longer needed]'
+                                        }
+                                    }
+                                    return part
+                                })
+                                if (messageModified) {
+                                    return { ...m, content: newContent }
+                                }
+                            }
+
                             return m
                         })
 
-                        console.log(replacedCount);
                         if (replacedCount > 0) {
                             logger.info("fetch", "Replaced pruned tool outputs", {
                                 replaced: replacedCount,