From 7ac4fcae61ac0bdecb377c389f9d49d61556d5d6 Mon Sep 17 00:00:00 2001
From: Andrew Maguire <andrewm4894@gmail.com>
Date: Thu, 11 Jun 2026 10:44:48 +0100
Subject: [PATCH 1/2] feat(agent): guide cloud agents to use the PostHog memory
 MCP tool
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Appends persistent-memory guidance to every cloud-run system prompt so cloud agents recall durable context across runs and persist new learnings via the PostHog `memory` MCP tool — the shared, semantically-searchable memory store used by Max/PostHog AI.

The tool itself is added server-side in PostHog/posthog (the cloud agent already forwards every PostHog MCP tool, so no allowlist change is needed here).

Generated-By: PostHog Code
Task-Id: b2ae2f32-aa94-4532-b069-b03875e73a58
---
 packages/agent/src/server/agent-server.ts | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/packages/agent/src/server/agent-server.ts b/packages/agent/src/server/agent-server.ts
index 0d2a8fc48..2dcba303a 100644
--- a/packages/agent/src/server/agent-server.ts
+++ b/packages/agent/src/server/agent-server.ts
@@ -1629,7 +1629,7 @@ export class AgentServer {
     prUrl?: string | null,
     slackThreadUrl?: string | null,
   ): string | { append: string } {
-    const cloudAppend = this.buildCloudSystemPrompt(prUrl, slackThreadUrl);
+    const cloudAppend = `${this.buildCloudSystemPrompt(prUrl, slackThreadUrl)}\n${this.buildMemoryInstructions()}`;
     const userPrompt = this.config.claudeCode?.systemPrompt;
 
     // String override: combine user prompt with cloud instructions
@@ -1696,6 +1696,23 @@ export class AgentServer {
     );
   }
 
+  /**
+   * Guidance for the shared, semantically-searchable PostHog memory store exposed through the
+   * `memory` MCP tool. Appended to every cloud-run system prompt so cloud agents recall durable
+   * context across runs and persist new learnings — the same memory store Max/PostHog AI uses.
+   */
+  private buildMemoryInstructions(): string {
+    return `
+# Persistent Memory
+You have access to PostHog's persistent memory through the \`memory\` MCP tool — a shared,
+semantically-searchable store of durable facts about this user, their company, product, and
+preferences (the same memories used across PostHog AI). Memories persist across runs, so:
+- Before non-trivial work, recall context with the \`memory\` tool using \`action: "query"\` (semantic search) to surface durable facts, decisions, and prior discussions.
+- When you learn something durable — product setup, conventions, definitions, preferences, decisions — store it with \`action: "create"\`. Do this pre-emptively; you don't need to be asked. Query first to avoid duplicates.
+- Use \`action: "update"\`/\`"delete"\` to keep memories accurate, and \`action: "list_metadata_keys"\` to keep metadata tags consistent.
+- Memories are for durable facts, not transient task state. New memories become searchable once their embedding is processed.`;
+  }
+
   private buildCloudSystemPrompt(
     prUrl?: string | null,
     slackThreadUrl?: string | null,

From cb84a33a853d3ae268d638a30b256507042bc049 Mon Sep 17 00:00:00 2001
From: Andrew Maguire <andrewm4894@gmail.com>
Date: Thu, 11 Jun 2026 11:02:51 +0100
Subject: [PATCH 2/2] docs(agent): note memory tool is available to both cloud
 runtimes

Clarifies that the memory MCP tool guidance correctly applies to both Claude and Codex cloud runs: newSession passes the PostHog MCP server via mcpServers for both runtimes, and the Codex adapter forwards those servers to the Codex CLI, so buildCodexInstructions reusing this text is intentional. Addresses a P2 review note from greptile-apps.

Generated-By: PostHog Code
Task-Id: b2ae2f32-aa94-4532-b069-b03875e73a58
---
 packages/agent/src/server/agent-server.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/packages/agent/src/server/agent-server.ts b/packages/agent/src/server/agent-server.ts
index 2dcba303a..f1b12dc2d 100644
--- a/packages/agent/src/server/agent-server.ts
+++ b/packages/agent/src/server/agent-server.ts
@@ -1700,6 +1700,11 @@ export class AgentServer {
    * Guidance for the shared, semantically-searchable PostHog memory store exposed through the
    * `memory` MCP tool. Appended to every cloud-run system prompt so cloud agents recall durable
    * context across runs and persist new learnings — the same memory store Max/PostHog AI uses.
+   *
+   * Applies to both cloud runtimes: `_doInitializeSession` passes the PostHog MCP server (which
+   * carries the `memory` tool) via `newSession({ mcpServers })` for Claude and Codex alike, and
+   * the Codex adapter forwards those servers to the Codex CLI, so the tool is callable on both.
+   * `buildCodexInstructions` reusing this text for Codex runs is therefore intentional.
    */
   private buildMemoryInstructions(): string {
     return `