feat: add Mem0 plugin for Claude Code and Cursor (#4518)

mem0-plugin/scripts/on_user_prompt.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+# Hook: UserPromptSubmit
+#
+# Fires on every user message. Searches mem0 for relevant memories
+# and injects them into Claude's context before processing.
+#
+# Input:  JSON on stdin with prompt, session_id, cwd, transcript_path
+# Output: Matching memories as context text (exit 0)
+#
+# Skips search for very short prompts (< 20 chars) and when
+# MEM0_API_KEY is not set. Uses a 3s timeout to minimize latency.
+
+# Intentionally omit -e so the script always exits 0 even if
+# curl or jq fail — must never block the user's prompt.
+set -uo pipefail
+
+INPUT=$(cat)
+PROMPT=$(echo "$INPUT" | jq -r '.prompt // ""' 2>/dev/null || echo "")
+
+# Skip trivial prompts — not worth a network call
+if [ ${#PROMPT} -lt 20 ]; then
+  exit 0
+fi
+
+API_KEY="${MEM0_API_KEY:-}"
+if [ -z "$API_KEY" ]; then
+  exit 0
+fi
+
+USER_ID="${MEM0_USER_ID:-${USER:-default}}"
+
+# Build request body safely via jq to avoid injection
+BODY=$(jq -n --arg query "$PROMPT" --arg user_id "$USER_ID" \
+  '{query: $query, filters: {user_id: $user_id}, top_k: 5}')
+
+# Search mem0 for memories relevant to this prompt
+RESPONSE=$(curl -s --max-time 3 \
+  -X POST "https://api.mem0.ai/v2/memories/search/" \
+  -H "Authorization: Token $API_KEY" \
+  -H "Content-Type: application/json" \
+  -d "$BODY" \
+  2>/dev/null || echo "")
+
+if [ -z "$RESPONSE" ]; then
+  exit 0
+fi
+
+# Extract memories from response (API returns a flat array)
+MEMORIES=$(echo "$RESPONSE" | jq -r '
+  if type == "array" then . else .results // [] end |
+  if length == 0 then empty else
+  "## Relevant memories from mem0\n\n" +
+  (map(select(.memory != null) | "- " + .memory) | join("\n"))
+  end
+' 2>/dev/null || echo "")
+
+if [ -n "$MEMORIES" ]; then
+  echo "$MEMORIES"
+fi
+
+exit 0