diff --git a/CHANGELOG.md b/CHANGELOG.md
index 948169c..ea43476 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,8 @@
 `identity.create_api_key` takes `connected_app` on both clients. A key made with `connected_app=True` is bound by the auto-send setting like an OAuth connection.
 The field is sent only when given, so existing calls send the same body. Needs API 1.12.0.
 
+The saved spec follows the public document at API 1.13.1. No operation or schema changed.
+
 ## 0.3.1 (2026-11-10)
 
 `faxes.list` takes `idempotency_key`, a filter that finds the send made with that key.
diff --git a/README.md b/README.md
index 9d44c9f..e8c4aea 100644
--- a/README.md
+++ b/README.md
@@ -223,7 +223,7 @@ ruff check src tests && mypy src
 sh scripts/truthcheck.sh
 ```
 
-`spec/openapi.yaml` follows the public document at API version 1.12.0 and keeps the schemas of the earlier live documents.
+`spec/openapi.yaml` follows the public document at API version 1.13.1 and keeps the schemas of the earlier live documents.
 It also retains earlier public model names and route-documented response additions.
 To refresh it, merge the live schemas while preserving existing declarations, then run `uv run python scripts/gen_models.py`.
 Keep new response fields optional so older payloads and existing callers remain valid.
diff --git a/spec/openapi.yaml b/spec/openapi.yaml
index cb322e2..95f1fc6 100644
--- a/spec/openapi.yaml
+++ b/spec/openapi.yaml
@@ -1,4 +1,4 @@
-# Fax for Agents API, refreshed from the public document of https://github.com/faxforagents/openapi at API 1.12.0.
+# Fax for Agents API, refreshed from the public document of https://github.com/faxforagents/openapi at API 1.13.1.
 # All earlier schemas are kept. Existing SDK routes, model names and serializer additions are retained.
 openapi: 3.1.0
 info:
@@ -26,7 +26,7 @@ info:
   x-logo:
     url: https://faxforagents.com/brand/logo-512.png
     altText: Fax for Agents
-  version: 1.12.0
+  version: 1.13.1
 servers:
 - url: https://api.faxforagents.com
   description: Production (live and test keys)
diff --git a/src/faxforagents/models.py b/src/faxforagents/models.py
index 3095af3..e25d8fb 100644
--- a/src/faxforagents/models.py
+++ b/src/faxforagents/models.py
@@ -1,6 +1,6 @@
 """Typed models of the Fax for Agents API.
 
-GENERATED by scripts/gen_models.py from spec/openapi.yaml (API version 1.12.0). Do not edit by hand.
+GENERATED by scripts/gen_models.py from spec/openapi.yaml (API version 1.13.1). Do not edit by hand.
 Money fields ending in ``_micro`` are integer USD micro-units (39000 is $0.039). Timestamps are ISO 8601
 strings in UTC. Response models accept fields the API adds later. Request models refuse unknown fields.
 """