diff --git a/CHANGELOG.md b/CHANGELOG.md
index 081845d..f3e3746 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- `mastodon`, `telegram` and `discord` in `PLATFORMS` and the `Platform` type,
+  matching the `/v1` spec's `Channel.platform` enum.
+
 ### Changed
 
 - The PyPI distribution name is now `postify-sdk` (was `postify`), matching the
diff --git a/scripts/sync-spec.sh b/scripts/sync-spec.sh
index 4b82bde..18d19c3 100644
--- a/scripts/sync-spec.sh
+++ b/scripts/sync-spec.sh
@@ -18,14 +18,26 @@ url="${POSTIFY_SPEC_URL:-https://app.usepostify.com/v1/openapi.json}"
 
 if [[ -n "${POSTIFY_SPEC_SOURCE:-}" ]]; then
   echo "Vendoring spec from ${POSTIFY_SPEC_SOURCE}"
-  cp "${POSTIFY_SPEC_SOURCE}" "${dest}"
+  cp "${POSTIFY_SPEC_SOURCE}" "${dest}.tmp"
 else
   echo "Fetching spec from ${url}"
   curl -fsSL "${url}" -o "${dest}.tmp"
-  python -c "import json,sys; json.load(open(sys.argv[1]))" "${dest}.tmp"
-  mv "${dest}.tmp" "${dest}"
 fi
 
+# Production serves the spec minified. Re-serialise it the way spec/v1.json is
+# committed (2-space indent, UTF-8, trailing newline) so a drift PR shows only
+# the real change instead of rewriting all 5,000+ lines onto one.
+python - "${dest}.tmp" "${dest}" <<'PY'
+import json, sys
+
+with open(sys.argv[1], encoding="utf-8") as src:
+    doc = json.load(src)
+with open(sys.argv[2], "w", encoding="utf-8", newline="\n") as out:
+    json.dump(doc, out, indent=2, ensure_ascii=False)
+    out.write("\n")
+PY
+rm -f "${dest}.tmp"
+
 ops=$(python - "$dest" <<'PY'
 import json, sys
 
diff --git a/spec/v1.json b/spec/v1.json
index 0b4f866..414cf61 100644
--- a/spec/v1.json
+++ b/spec/v1.json
@@ -4277,7 +4277,10 @@
               "pinterest",
               "youtube",
               "bluesky",
-              "reddit"
+              "reddit",
+              "mastodon",
+              "telegram",
+              "discord"
             ],
             "description": "Social platform this channel publishes to."
           },
@@ -4766,7 +4769,7 @@
                 "type": "null"
               }
             ],
-            "description": "Most recent delivery error, if any."
+            "description": "Why the latest delivery failed, as a sentence you can show your users. Present only when `stage` is `failed` or `dlq`; otherwise null."
           }
         },
         "required": [
diff --git a/src/postify/models.py b/src/postify/models.py
index da682d7..fcc212d 100644
--- a/src/postify/models.py
+++ b/src/postify/models.py
@@ -83,6 +83,9 @@
     "youtube",
     "bluesky",
     "reddit",
+    "mastodon",
+    "telegram",
+    "discord",
 )
 Platform = Union[
     Literal[
@@ -96,6 +99,9 @@
         "youtube",
         "bluesky",
         "reddit",
+        "mastodon",
+        "telegram",
+        "discord",
     ],
     str,
 ]
diff --git a/tests/unit/test_models.py b/tests/unit/test_models.py
index 896fccf..f69b711 100644
--- a/tests/unit/test_models.py
+++ b/tests/unit/test_models.py
@@ -147,7 +147,7 @@ def test_an_unknown_platform_or_status_does_not_raise() -> None:
     channel = models.Channel.model_validate(
         {
             "id": "chn_1",
-            "platform": "mastodon",  # not in this SDK's PLATFORMS tuple
+            "platform": "friendster",  # not in this SDK's PLATFORMS tuple
             "handle": "@acme",
             "avatar_url": None,
             "followers": None,
@@ -157,7 +157,7 @@ def test_an_unknown_platform_or_status_does_not_raise() -> None:
             "created_at": "2026-08-05T12:00:00.000Z",
         }
     )
-    assert channel.platform == "mastodon"
+    assert channel.platform == "friendster"
     assert channel.status == "quarantined"