diff --git a/INFRA.md b/INFRA.md
index 70807bd..f065318 100644
--- a/INFRA.md
+++ b/INFRA.md
@@ -7,8 +7,9 @@
 - WARP: Per-node identities in /etc/netvm/
 - Browsers: Headless Chromium via chrome-box
 - API: muse-chat-api.py via netvm-exec (CDP)
+- Sign-in: muse-signin.py --email <addr> [--otp <code>]
 - Hygiene: netvm-reaper.sh
-- Approvals: /etc/netvm/approvals/ + netvm-approve.sh
+- Approvals: In-browser via chat (see below)
 
 ## VM (34.139.37.135) — Gateway + Vault
 - E2 micro (2 vCPU, 1GB RAM)
@@ -24,3 +25,26 @@
 - Meta accounts: /etc/netvm/meta-credentials/store.age (VM)
 - WARP identities: /etc/netvm/node.conf (per-machine, root 600)
 - Operators handle transiently; never log values.
+
+## In-Browser Approvals
+When automation needs human input (OTP, confirmation):
+1. Script exits with code 2 and prints "APPROVAL_NEEDED: <details>"
+2. Operator sees this and asks user via chat
+3. User provides input (e.g., OTP code)
+4. Operator re-runs script with --otp <code>
+5. Script completes the flow
+
+No file-based queue needed — the chat IS the approval interface.
+The human is already in the chat; the automation just needs to
+signal when it's stuck.
+
+## Sign-In Flow (muse-signin.py)
+Automated login for muse.ai accounts:
+- Step 1: Check if already logged in (skip if yes)
+- Step 2: Click "Log in"
+- Step 3: Enter email
+- Step 4: Click "Continue"
+- Step 5: Detect OTP prompt
+  - If --otp provided: enter it, click Next, verify
+  - If not: exit 2 with APPROVAL_NEEDED
+- Credentials never stored; OTP is transient.