feat: add Letta Code detection and restore (#3107)

refs #3106

Co-authored-by: Cameron <cameron@pfiffer.org>

2 files changed, 107 insertions, 0 deletions

diff --git a/src/integration/assets/letta/herdr-agent-session.ps1 b/src/integration/assets/letta/herdr-agent-session.ps1
new file mode 100644
index 00000000..27f40e9b
--- /dev/null
+++ b/src/integration/assets/letta/herdr-agent-session.ps1
@@ -0,0 +1,51 @@
+# managed by herdr; reinstalling the integration replaces this file.
+# HERDR_INTEGRATION_ID=letta
+# HERDR_INTEGRATION_VERSION=1
+
+param([string]$Action = "")
+
+if ($Action -ne "session") { exit 0 }
+if ($env:HERDR_ENV -ne "1") { exit 0 }
+if ([string]::IsNullOrWhiteSpace($env:HERDR_PANE_ID)) { exit 0 }
+if ([string]::IsNullOrWhiteSpace($env:HERDR_SOCKET_PATH)) { exit 0 }
+
+$inputText = [Console]::In.ReadToEnd()
+try {
+    $payload = if ([string]::IsNullOrWhiteSpace($inputText)) { $null } else { $inputText | ConvertFrom-Json }
+} catch {
+    $payload = $null
+}
+if ($null -eq $payload -or [string]::IsNullOrWhiteSpace($payload.conversation_id)) { exit 0 }
+
+$sessionId = [string]$payload.conversation_id
+if ($sessionId -eq "default") {
+    if ([string]::IsNullOrWhiteSpace($payload.agent_id)) { exit 0 }
+    $sessionId = "default:" + [string]$payload.agent_id
+}
+
+$herdr = if ([string]::IsNullOrWhiteSpace($env:HERDR_BIN_PATH)) { "herdr" } else { $env:HERDR_BIN_PATH }
+$source = if ($payload.is_new_session -eq $true) { "new" } else { "resume" }
+$commandArgs = @(
+    "pane", "report-agent-session", $env:HERDR_PANE_ID,
+    "--source", "herdr:letta", "--agent", "letta",
+    "--agent-session-id", $sessionId,
+    "--seq", [string][DateTime]::UtcNow.Ticks,
+    "--session-start-source", $source
+)
+$job = $null
+try {
+    $job = Start-Job -ScriptBlock {
+        param($Executable, [object[]]$Arguments)
+        & $Executable @Arguments *> $null
+    } -ArgumentList $herdr, (,$commandArgs)
+    if ($null -eq (Wait-Job -Job $job -Timeout 1)) {
+        Stop-Job -Job $job
+    }
+} catch {
+    # Hook failures must stay silent because Letta injects output into the next prompt.
+    $null = $_
+} finally {
+    if ($null -ne $job) {
+        Remove-Job -Job $job -Force -ErrorAction SilentlyContinue
+    }
+}
diff --git a/src/integration/assets/letta/herdr-agent-session.sh b/src/integration/assets/letta/herdr-agent-session.sh
new file mode 100644
index 00000000..d6e052d6
--- /dev/null
+++ b/src/integration/assets/letta/herdr-agent-session.sh
@@ -0,0 +1,56 @@
+#!/bin/sh
+# managed by herdr; reinstalling the integration replaces this file.
+# HERDR_INTEGRATION_ID=letta
+# HERDR_INTEGRATION_VERSION=1
+
+[ "${1:-}" = "session" ] || exit 0
+[ "${HERDR_ENV:-}" = "1" ] || exit 0
+[ -n "${HERDR_PANE_ID:-}" ] || exit 0
+[ -n "${HERDR_SOCKET_PATH:-}" ] || exit 0
+if [ -n "${HERDR_BIN_PATH:-}" ]; then
+    [ -x "$HERDR_BIN_PATH" ] || exit 0
+else
+    command -v herdr >/dev/null 2>&1 || exit 0
+fi
+command -v python3 >/dev/null 2>&1 || exit 0
+
+# SessionStart stdout is injected into Letta's next user message. Keep every
+# path silent, including successful reports and malformed hook input.
+python3 -c '
+import json
+import os
+import subprocess
+import sys
+import time
+
+try:
+    payload = json.load(sys.stdin)
+    conversation_id = payload.get("conversation_id")
+    agent_id = payload.get("agent_id")
+    if not isinstance(conversation_id, str) or not conversation_id:
+        raise ValueError
+    if conversation_id == "default":
+        if not isinstance(agent_id, str) or not agent_id:
+            raise ValueError
+        session_id = "default:" + agent_id
+    else:
+        session_id = conversation_id
+
+    command = os.environ.get("HERDR_BIN_PATH") or "herdr"
+    args = [
+        command, "pane", "report-agent-session", os.environ["HERDR_PANE_ID"],
+        "--source", "herdr:letta", "--agent", "letta",
+        "--agent-session-id", session_id, "--seq", str(time.time_ns()),
+        "--session-start-source", "new" if payload.get("is_new_session") else "resume",
+    ]
+    subprocess.run(
+        args,
+        stdin=subprocess.DEVNULL,
+        stdout=subprocess.DEVNULL,
+        stderr=subprocess.DEVNULL,
+        timeout=1,
+        check=False,
+    )
+except Exception:
+    pass
+' 2>/dev/null || true