') + ')', 'gi'); if (regex.test(text)) { found = true; var frag = document.createDocumentFragment(); var parts = text.split(regex); parts.forEach(function(part, i) { if (i % 2 === 0) { frag.appendChild(document.createTextNode(part)); } else { var span = document.createElement('span'); span.className = 'userscript-highlight'; span.textContent = part; frag.appendChild(span); } }); node.parentNode.replaceChild(frag, node); } }); } else if (node.nodeType === 1 && node.childNodes) { // element var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT']; if (!skipTags.includes(node.tagName)) { Array.from(node.childNodes).forEach(highlight); } } } highlight(document.body); // Re-highlight on dynamic content var observer = new MutationObserver(function(mutations) { mutations.forEach(function(m) { m.addedNodes.forEach(function(node) { if (node.nodeType === 1 || node.nodeType === 3) highlight(node); }); }); }); observer.observe(document.body, { childList: true, subtree: true }); })(); } } catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + ', 'i'); if (__m === '*' || __re.test(location.href)) { // Strip utm_, fbclid, gclid, etc. from all links on page (function() { var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content', 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid', 'ref', 'ref_src', 'source', 'medium', 'campaign']; function cleanUrl(url) { try { var u = new URL(url, window.location.origin); var changed = false; trackingParams.forEach(function(p) { if (u.searchParams.has(p)) { u.searchParams.delete(p); changed = true; } }); return changed ? u.toString() : url; } catch (e) { return url; } } function cleanLinks() { document.querySelectorAll('a[href]').forEach(function(a) { var clean = cleanUrl(a.href); if (clean !== a.href) a.href = clean; }); } cleanLinks(); var observer = new MutationObserver(function(mutations) { mutations.forEach(function(m) { m.addedNodes.forEach(function(node) { if (node.nodeType === 1) { if (node.tagName === 'A') cleanLinks(); node.querySelectorAll('a[href]').forEach(function(a) { var clean = cleanUrl(a.href); if (clean !== a.href) a.href = clean; }); } }); }); }); observer.observe(document.body, { childList: true, subtree: true }); })(); } } catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); } })(); (function(){ try { var __m = "youtube.com"; var __re = new RegExp('^' + "youtube\\.com" + ', 'i'); if (__m === '*' || __re.test(location.href)) { // Auto-enable theater mode on YouTube (function() { function tryTheater() { var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]'); if (btn && !btn.classList.contains('activated')) { btn.click(); } } // Try immediately tryTheater(); // Try after navigation (SPA) var lastUrl = location.href; setInterval(function() { if (location.href !== lastUrl) { lastUrl = location.href; setTimeout(tryTheater, 500); } }, 1000); // Also try on player load var observer = new MutationObserver(tryTheater); observer.observe(document.body, { childList: true, subtree: true }); })(); } } catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + ', 'i'); if (__m === '*' || __re.test(location.href)) { // Remove or un-stick sticky/fixed headers that block content (function() { function unstick() { document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) { if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') { el.style.position = 'static'; el.style.top = 'auto'; el.style.zIndex = 'auto'; } }); } unstick(); var observer = new MutationObserver(unstick); observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] }); })(); } } catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); } })(); })(); fix(memory): strip injected user context from restored messages to prevent O(turns) accumulation by citizen204 · Pull Request #554 · aws/bedrock-agentcore-sdk-python · GitHub
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fix(memory): strip injected user context from restored messages to prevent O(turns) accumulation - #554

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citizen204:fix-420-strip-user-context-on-restore
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fix(memory): strip injected user context from restored messages to prevent O(turns) accumulation#554
citizen204 wants to merge 1 commit into
aws:mainfrom
citizen204:fix-420-strip-user-context-on-restore

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@citizen204

@citizen204citizen204 commented Jun 27, 2026

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Summary

When retrieval_config is configured, retrieve_customer_context() prepends a <context_tag> XML block to each user message, and the message is persisted to AgentCore Memory with that block embedded. On every subsequent turn, list_messages() reloads all historical messages verbatim — so every restored user message re-appears with its injected context block intact. The result is O(turns × records) token accumulation:

Turn 1: [user+XML, assistant]
Turn 2: [user+XML, assistant, user+XML, assistant]
Turn 3: [user+XML, assistant, user+XML, assistant, user+XML, assistant]

Observed with 5 turns and 3 preference records: 3,655 chars of repeated context (83% of total message content).

Fix

Added _filter_restored_user_context() — mirroring the existing _filter_restored_tool_context() pattern — which strips any content block whose text starts with the opening <context_tag> before the messages are handed to the Strands runtime. The filter is applied in list_messages() whenever retrieval_config is configured. Fresh context is re-injected on each new turn by retrieve_customer_context(), so no context is lost.

Fixes#420

Changes

  • src/bedrock_agentcore/memory/integrations/strands/session_manager.py:
    • Added _filter_restored_user_context() method (36 lines, analogous to _filter_restored_tool_context())
    • Called in list_messages() when self.config.retrieval_config is set

@citizen204
fix(memory): strip injected user context from restored messages to pr…
c5e35cf
…event O(turns) accumulation
When retrieval_config is set, retrieve_customer_context() prepends a
<context_tag> block to each user message and the message is persisted
with that block in storage. On every subsequent turn list_messages()
reloads all historical messages verbatim, so the injected block
reappears in every restored user message — O(turns × records) tokens.
Add _filter_restored_user_context() (mirroring the existing
_filter_restored_tool_context pattern) and call it from list_messages()
whenever retrieval_config is configured. The filter removes any content
block whose text starts with the opening context tag before the messages
are handed to the Strands runtime. Fresh context is re-injected on each
new turn by retrieve_customer_context(), so no context is lost.
Fixesaws#420
@citizen204
citizen204 requested a review from a teamJune 27, 2026 08:51
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AgentCoreMemorySessionManager: retrieval_config context accumulates O(turns × records) across multi-turn conversations

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@citizen204