diff --git a/daybook_project/settings.py b/daybook_project/settings.py
index 3b396a6..db820ce 100644
--- a/daybook_project/settings.py
+++ b/daybook_project/settings.py
@@ -9,6 +9,12 @@ SECRET_KEY = os.environ.get("DJANGO_SECRET_KEY", "dev-only-change-me")
 DEBUG = os.environ.get("DJANGO_DEBUG", "1").lower() in {"1", "true", "yes", "on"}
 ALLOWED_HOSTS = [host.strip() for host in os.environ.get("DJANGO_ALLOWED_HOSTS", "*").split(",") if host.strip()]
 
+# Needed when running behind a TLS-terminating reverse proxy (Apache/Nginx/etc.):
+# Django otherwise thinks every request is plain HTTP, which breaks CSRF checks
+# on login/POST. The proxy must forward X-Forwarded-Proto: https.
+CSRF_TRUSTED_ORIGINS = [origin.strip() for origin in os.environ.get("DJANGO_CSRF_TRUSTED_ORIGINS", "").split(",") if origin.strip()]
+SECURE_PROXY_SSL_HEADER = ("HTTP_X_FORWARDED_PROTO", "https")
+
 INSTALLED_APPS = [
     "django.contrib.admin",
     "django.contrib.auth",
diff --git a/deploy/cloud_agent_deploy.md b/deploy/cloud_agent_deploy.md
index f320de1..82d8003 100644
--- a/deploy/cloud_agent_deploy.md
+++ b/deploy/cloud_agent_deploy.md
@@ -223,6 +223,11 @@ network/VPN), do this before calling the deployment done:
 - Put a reverse proxy in front with TLS. Bearer tokens go over plaintext HTTP
   otherwise.
 - Add the proxy's public hostname to `DJANGO_ALLOWED_HOSTS`.
+- Set `DJANGO_CSRF_TRUSTED_ORIGINS=https://<public-hostname>` in `deploy/.env`,
+  **and** make sure the proxy forwards `X-Forwarded-Proto: https` (examples
+  below). Without both, login fails with "CSRF verification failed" — Django
+  can't tell the original request was HTTPS once a proxy terminates TLS and
+  forwards plain HTTP to the container.
 - Keep `DJANGO_DEBUG=0` (already set above).
 - Restrict SSH to key-based auth only; disable password login if you have
   access to do so.
@@ -241,6 +246,7 @@ instead. Apache example:
 <VirtualHost *:443>
     ServerName daybook.example.com
     ProxyPreserveHost On
+    RequestHeader set X-Forwarded-Proto "https"
     ProxyPass / http://127.0.0.1:8000/
     ProxyPassReverse / http://127.0.0.1:8000/
     SSLEngine on
@@ -249,14 +255,18 @@ instead. Apache example:
 </VirtualHost>
 ```
 
-(`certbot --apache` will provision and wire up the certificate for you.)
+`RequestHeader set X-Forwarded-Proto "https"` requires `a2enmod headers`; it's
+not optional (see the CSRF note above). (`certbot --apache` will provision and
+wire up the certificate for you.)
 
 Only reach for a standalone proxy like Caddy if the target genuinely has
-nothing on 80/443 yet:
+nothing on 80/443 yet — it still needs the same header:
 
 ```text
 daybook.example.com {
-    reverse_proxy 127.0.0.1:8000
+    reverse_proxy 127.0.0.1:8000 {
+        header_up X-Forwarded-Proto https
+    }
 }
 ```
 
@@ -284,6 +294,10 @@ Before reporting the deployment complete, confirm all of these:
 - [ ] Cloned via git (not copied), with a working `git pull`.
 - [ ] `deploy/.env` has a real, non-placeholder `DJANGO_SECRET_KEY`.
 - [ ] `DJANGO_ALLOWED_HOSTS` includes the actual hostname/IP being used.
+- [ ] If behind a reverse proxy: `DJANGO_CSRF_TRUSTED_ORIGINS` is set to the
+      public HTTPS origin, and the proxy forwards `X-Forwarded-Proto: https`.
+      Verify by actually logging in through the proxy, not just curling
+      `/api/capabilities` — CSRF only bites on POST (login, artifact writes).
 - [ ] `docker compose -f deploy/docker-compose.yml ps` shows `daybook` healthy.
 - [ ] `/api/capabilities` returns `403` unauthenticated, `200` with a token.
 - [ ] At least one superuser exists with a working personal API token.
diff --git a/deploy/env.example b/deploy/env.example
index 133e497..5fe9ca3 100644
--- a/deploy/env.example
+++ b/deploy/env.example
@@ -1,6 +1,11 @@
 DJANGO_DEBUG=0
 DJANGO_SECRET_KEY=replace-with-a-long-random-secret
 DJANGO_ALLOWED_HOSTS=localhost,127.0.0.1,your-vm-ip,your-domain.example
+# Required if Daybook sits behind a TLS-terminating reverse proxy (Apache,
+# Nginx, Traefik, a cloud load balancer). Without it, login/POST fails with
+# "CSRF verification failed" because Django can't tell the original request
+# was HTTPS. Set to the public HTTPS origin(s) users actually visit:
+DJANGO_CSRF_TRUSTED_ORIGINS=https://your-domain.example
 DAYBOOK_DATA_DIR=/data
 DATABASE_PATH=/data/db.sqlite3
 ARTIFACTS_ROOT=/data/artifacts_store
diff --git a/docs/deployment.md b/docs/deployment.md
index 5db5657..5f69b0f 100644
--- a/docs/deployment.md
+++ b/docs/deployment.md
@@ -159,9 +159,23 @@ If putting Daybook behind Nginx, Caddy, Traefik, or a cloud load balancer:
 - Proxy to `http://<vm-ip>:8000`.
 - Add the public hostname to `DJANGO_ALLOWED_HOSTS`.
 - Terminate TLS at the proxy; keep `DJANGO_DEBUG=0`.
+- Set `DJANGO_CSRF_TRUSTED_ORIGINS` to the public HTTPS origin, **and**
+  configure the proxy to forward `X-Forwarded-Proto: https`. Without both,
+  login and any other POST fails with "CSRF verification failed" — Django
+  has no way to know the original request was HTTPS once the proxy
+  terminates TLS and forwards plain HTTP to the container.
 
 ```text
 DJANGO_ALLOWED_HOSTS=daybook.example.com,localhost,127.0.0.1
+DJANGO_CSRF_TRUSTED_ORIGINS=https://daybook.example.com
+```
+
+Forwarding the proto header, by proxy:
+
+```text
+Nginx:   proxy_set_header X-Forwarded-Proto $scheme;
+Apache:  RequestHeader set X-Forwarded-Proto "https"   (requires a2enmod headers)
+Caddy:   header_up X-Forwarded-Proto https
 ```
 
 ## Deployment Checklist
@@ -169,6 +183,8 @@ DJANGO_ALLOWED_HOSTS=daybook.example.com,localhost,127.0.0.1
 - `deploy/.env` exists with a real (non-placeholder) `DJANGO_SECRET_KEY`.
 - `DJANGO_DEBUG=0`.
 - `DJANGO_ALLOWED_HOSTS` includes the hostname/IP being used.
+- If behind a reverse proxy: `DJANGO_CSRF_TRUSTED_ORIGINS` is set and the
+  proxy forwards `X-Forwarded-Proto: https` (login will 403 otherwise).
 - `deploy/data/` exists and persists across `git pull` + rebuild.
 - `docker compose -f deploy/docker-compose.yml ps` shows `daybook` healthy.
 - `curl -fsS http://127.0.0.1:8000/api/capabilities` returns 403 without auth,
diff --git a/issues/001-csrf-behind-reverse-proxy.md b/issues/001-csrf-behind-reverse-proxy.md
new file mode 100644
index 0000000..ba28e14
--- /dev/null
+++ b/issues/001-csrf-behind-reverse-proxy.md
@@ -0,0 +1,71 @@
+# 001 — CSRF verification fails behind a TLS-terminating reverse proxy
+
+**Status:** Fixed
+
+## Description
+
+Deploying Daybook behind Apache (TLS-terminating reverse proxy → plain HTTP
+to the container) on `cloud-vm-1`, login failed with:
+
+```
+Forbidden (403)
+CSRF verification failed. Request aborted.
+```
+
+**Root cause:** `daybook_project/settings.py` set `ALLOWED_HOSTS` from an env
+var but never set `CSRF_TRUSTED_ORIGINS` or `SECURE_PROXY_SSL_HEADER`. Without
+the latter, Django has no way to know the original request was HTTPS — the
+proxy terminates TLS and forwards plain HTTP — so it treats every request as
+insecure, which breaks CSRF checks on any POST (including login) once a
+browser connects over `https://`.
+
+This isn't specific to `cloud-vm-1` — it'll happen on any reverse-proxied
+deployment (Apache, Nginx, Traefik, a cloud load balancer), which is the
+explicitly recommended setup in `deploy/cloud_agent_deploy.md` §8. The
+runbook doesn't mention CSRF or proxy-awareness anywhere.
+
+## Fix
+
+**App (`daybook_project/settings.py`):**
+
+```python
+CSRF_TRUSTED_ORIGINS = [origin.strip() for origin in os.environ.get("DJANGO_CSRF_TRUSTED_ORIGINS", "").split(",") if origin.strip()]
+SECURE_PROXY_SSL_HEADER = ("HTTP_X_FORWARDED_PROTO", "https")
+```
+
+Committed locally as `d458cd3` ("Fix CSRF failure behind a TLS-terminating
+reverse proxy") — **needs to be pushed to `main`**, the deploy agent that
+made this fix didn't have push access to the Forgejo repo.
+
+**Deploy env (`deploy/env.example` / runbook):** needs a new var,
+`DJANGO_CSRF_TRUSTED_ORIGINS`, set to the public HTTPS origin, e.g.:
+
+```
+DJANGO_CSRF_TRUSTED_ORIGINS=https://daybook.example.com
+```
+
+**Proxy config:** `SECURE_PROXY_SSL_HEADER` only works if the proxy actually
+sends that header. The Apache example in `cloud_agent_deploy.md` §8 is
+missing it — needs:
+
+```apache
+RequestHeader set X-Forwarded-Proto "https"
+```
+
+inside the `<VirtualHost *:443>` block (requires `a2enmod headers`). The
+equivalent for Nginx is `proxy_set_header X-Forwarded-Proto $scheme;`, worth
+adding to `docs/deployment.md`'s reverse-proxy notes too since that doc
+mentions Nginx/Traefik as options without this caveat.
+
+## Resolution
+
+- [x] Pushed commit `d458cd3` to `main`.
+- [x] Added `DJANGO_CSRF_TRUSTED_ORIGINS` to `deploy/env.example` with an
+      explanatory comment.
+- [x] Updated `cloud_agent_deploy.md` §8's Apache example to include
+      `RequestHeader set X-Forwarded-Proto "https"`, plus a Caddy equivalent
+      and a checklist item that verifies by actually logging in through the
+      proxy (not just curling `/api/capabilities`, which is unauthenticated
+      GET and wouldn't have caught this).
+- [x] Updated `docs/deployment.md`'s "Reverse Proxy Notes" and checklist with
+      the same requirement, plus an Nginx/Apache/Caddy header cheat sheet.
diff --git a/issues/README.md b/issues/README.md
new file mode 100644
index 0000000..662618b
--- /dev/null
+++ b/issues/README.md
@@ -0,0 +1,5 @@
+# Issues
+
+One file per issue: `NNN-short-slug.md`, numbered sequentially. Each file
+has a title, status (Open / Fixed / By design), description, and resolution
+once closed.