diff --git a/project_templates/fastapi_safir_app/example-uws/src/exampleuws/config.py b/project_templates/fastapi_safir_app/example-uws/src/exampleuws/config.py
index 10726c0..f1ff2e3 100644
--- a/project_templates/fastapi_safir_app/example-uws/src/exampleuws/config.py
+++ b/project_templates/fastapi_safir_app/example-uws/src/exampleuws/config.py
@@ -16,8 +16,16 @@
 class Config(UWSAppSettings):
     """Configuration for example-uws."""
 
+    model_config = SettingsConfigDict(
+        env_prefix="EXAMPLE_UWS_", case_sensitive=False
+    )
+
     name: str = Field("example-uws", title="Name of application")
 
+    log_level: LogLevel = Field(
+        LogLevel.INFO, title="Log level of the application's logger"
+    )
+
     path_prefix: str = Field(
         "/example-uws", title="URL prefix for application"
     )
@@ -26,12 +34,10 @@ class Config(UWSAppSettings):
         Profile.development, title="Application logging profile"
     )
 
-    log_level: LogLevel = Field(
-        LogLevel.INFO, title="Log level of the application's logger"
-    )
-
-    model_config = SettingsConfigDict(
-        env_prefix="EXAMPLE_UWS_", case_sensitive=False
+    slack_webhook: SecretStr | None = Field(
+        None,
+        title="Slack webhook for alerts",
+        description="If set, alerts will be posted to this Slack webhook",
     )
 
     @property
diff --git a/project_templates/fastapi_safir_app/example-uws/src/exampleuws/handlers/external.py b/project_templates/fastapi_safir_app/example-uws/src/exampleuws/handlers/external.py
index 1182a15..b4c418e 100644
--- a/project_templates/fastapi_safir_app/example-uws/src/exampleuws/handlers/external.py
+++ b/project_templates/fastapi_safir_app/example-uws/src/exampleuws/handlers/external.py
@@ -5,6 +5,7 @@
 from fastapi import APIRouter, Depends
 from safir.dependencies.logger import logger_dependency
 from safir.metadata import get_metadata
+from safir.slack.webhook import SlackRouteErrorHandler
 from structlog.stdlib import BoundLogger
 
 from ..config import config
@@ -12,7 +13,7 @@
 
 __all__ = ["external_router"]
 
-external_router = APIRouter()
+external_router = APIRouter(route_class=SlackRouteErrorHandler)
 """FastAPI router for all external handlers."""
 
 
diff --git a/project_templates/fastapi_safir_app/example-uws/src/exampleuws/handlers/internal.py b/project_templates/fastapi_safir_app/example-uws/src/exampleuws/handlers/internal.py
index 8096f14..bec3a34 100644
--- a/project_templates/fastapi_safir_app/example-uws/src/exampleuws/handlers/internal.py
+++ b/project_templates/fastapi_safir_app/example-uws/src/exampleuws/handlers/internal.py
@@ -10,12 +10,13 @@
 
 from fastapi import APIRouter
 from safir.metadata import Metadata, get_metadata
+from safir.slack.webhook import SlackRouteErrorHandler
 
 from ..config import config
 
 __all__ = ["internal_router"]
 
-internal_router = APIRouter()
+internal_router = APIRouter(route_class=SlackRouteErrorHandler)
 """FastAPI router for all internal handlers."""
 
 
diff --git a/project_templates/fastapi_safir_app/example-uws/src/exampleuws/main.py b/project_templates/fastapi_safir_app/example-uws/src/exampleuws/main.py
index f7bbcf1..7c1f2ca 100644
--- a/project_templates/fastapi_safir_app/example-uws/src/exampleuws/main.py
+++ b/project_templates/fastapi_safir_app/example-uws/src/exampleuws/main.py
@@ -15,6 +15,7 @@
 from safir.dependencies.http_client import http_client_dependency
 from safir.logging import configure_logging, configure_uvicorn_logging
 from safir.middleware.x_forwarded import XForwardedMiddleware
+from safir.slack.webhook import SlackRouteErrorHandler
 
 from .config import config, uws
 from .handlers.external import external_router
@@ -65,3 +66,11 @@ async def lifespan(app: FastAPI) -> AsyncIterator[None]:
 
 # Install error handlers.
 uws.install_error_handlers(app)
+
+# Configure Slack alerts.
+if config.slack_webhook:
+    logger = structlog.get_logger("exampleuws")
+    SlackRouteErrorHandler.initialize(
+        config.slack_webhook, "example-uws", logger
+    )
+    logger.debug("Initialized Slack webhook")
diff --git a/project_templates/fastapi_safir_app/example/src/example/config.py b/project_templates/fastapi_safir_app/example/src/example/config.py
index 72ac076..38640eb 100644
--- a/project_templates/fastapi_safir_app/example/src/example/config.py
+++ b/project_templates/fastapi_safir_app/example/src/example/config.py
@@ -12,8 +12,16 @@
 class Config(BaseSettings):
     """Configuration for example."""
 
+    model_config = SettingsConfigDict(
+        env_prefix="EXAMPLE_", case_sensitive=False
+    )
+
     name: str = Field("example", title="Name of application")
 
+    log_level: LogLevel = Field(
+        LogLevel.INFO, title="Log level of the application's logger"
+    )
+
     path_prefix: str = Field(
         "/example", title="URL prefix for application"
     )
@@ -22,12 +30,10 @@ class Config(BaseSettings):
         Profile.development, title="Application logging profile"
     )
 
-    log_level: LogLevel = Field(
-        LogLevel.INFO, title="Log level of the application's logger"
-    )
-
-    model_config = SettingsConfigDict(
-        env_prefix="EXAMPLE_", case_sensitive=False
+    slack_webhook: SecretStr | None = Field(
+        None,
+        title="Slack webhook for alerts",
+        description="If set, alerts will be posted to this Slack webhook",
     )
 
 
diff --git a/project_templates/fastapi_safir_app/example/src/example/handlers/external.py b/project_templates/fastapi_safir_app/example/src/example/handlers/external.py
index fa1ccd4..8ac6b18 100644
--- a/project_templates/fastapi_safir_app/example/src/example/handlers/external.py
+++ b/project_templates/fastapi_safir_app/example/src/example/handlers/external.py
@@ -5,6 +5,7 @@
 from fastapi import APIRouter, Depends
 from safir.dependencies.logger import logger_dependency
 from safir.metadata import get_metadata
+from safir.slack.webhook import SlackRouteErrorHandler
 from structlog.stdlib import BoundLogger
 
 from ..config import config
@@ -12,7 +13,7 @@
 
 __all__ = ["external_router"]
 
-external_router = APIRouter()
+external_router = APIRouter(route_class=SlackRouteErrorHandler)
 """FastAPI router for all external handlers."""
 
 
diff --git a/project_templates/fastapi_safir_app/example/src/example/handlers/internal.py b/project_templates/fastapi_safir_app/example/src/example/handlers/internal.py
index ed956e4..c59985f 100644
--- a/project_templates/fastapi_safir_app/example/src/example/handlers/internal.py
+++ b/project_templates/fastapi_safir_app/example/src/example/handlers/internal.py
@@ -10,12 +10,13 @@
 
 from fastapi import APIRouter
 from safir.metadata import Metadata, get_metadata
+from safir.slack.webhook import SlackRouteErrorHandler
 
 from ..config import config
 
 __all__ = ["internal_router"]
 
-internal_router = APIRouter()
+internal_router = APIRouter(route_class=SlackRouteErrorHandler)
 """FastAPI router for all internal handlers."""
 
 
diff --git a/project_templates/fastapi_safir_app/example/src/example/main.py b/project_templates/fastapi_safir_app/example/src/example/main.py
index e649f64..486701e 100644
--- a/project_templates/fastapi_safir_app/example/src/example/main.py
+++ b/project_templates/fastapi_safir_app/example/src/example/main.py
@@ -15,6 +15,7 @@
 from safir.dependencies.http_client import http_client_dependency
 from safir.logging import configure_logging, configure_uvicorn_logging
 from safir.middleware.x_forwarded import XForwardedMiddleware
+from safir.slack.webhook import SlackRouteErrorHandler
 
 from .config import config
 from .handlers.external import external_router
@@ -58,3 +59,11 @@ async def lifespan(app: FastAPI) -> AsyncIterator[None]:
 
 # Add middleware.
 app.add_middleware(XForwardedMiddleware)
+
+# Configure Slack alerts.
+if config.slack_webhook:
+    logger = structlog.get_logger("example")
+    SlackRouteErrorHandler.initialize(
+        config.slack_webhook, "example", logger
+    )
+    logger.debug("Initialized Slack webhook")
diff --git a/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/config.py b/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/config.py
index 0c9b96f..e94c805 100644
--- a/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/config.py
+++ b/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/config.py
@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from pydantic import Field
+from pydantic import Field, SecretStr
 from pydantic_settings import {% if cookiecutter.flavor != "UWS" %}BaseSettings, {% endif %}SettingsConfigDict
 from safir.logging import LogLevel, Profile
 {%- if cookiecutter.flavor == "UWS" %}
@@ -18,8 +18,16 @@
 class Config({% if cookiecutter.flavor == "UWS" %}UWSAppSettings{% else %}BaseSettings{% endif %}):
     """Configuration for {{ cookiecutter.name }}."""
 
+    model_config = SettingsConfigDict(
+        env_prefix="{{ cookiecutter.name | upper | replace('-', '_') }}_", case_sensitive=False
+    )
+
     name: str = Field("{{ cookiecutter.name }}", title="Name of application")
 
+    log_level: LogLevel = Field(
+        LogLevel.INFO, title="Log level of the application's logger"
+    )
+
     path_prefix: str = Field(
         "/{{ cookiecutter.name | lower }}", title="URL prefix for application"
     )
@@ -28,12 +36,10 @@ class Config({% if cookiecutter.flavor == "UWS" %}UWSAppSettings{% else %}BaseSe
         Profile.development, title="Application logging profile"
     )
 
-    log_level: LogLevel = Field(
-        LogLevel.INFO, title="Log level of the application's logger"
-    )
-
-    model_config = SettingsConfigDict(
-        env_prefix="{{ cookiecutter.name | upper | replace('-', '_') }}_", case_sensitive=False
+    slack_webhook: SecretStr | None = Field(
+        None,
+        title="Slack webhook for alerts",
+        description="If set, alerts will be posted to this Slack webhook",
     )
 {%- if cookiecutter.flavor == "UWS" %}
 
diff --git a/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/handlers/external.py b/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/handlers/external.py
index 338c308..5c403f7 100644
--- a/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/handlers/external.py
+++ b/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/handlers/external.py
@@ -5,6 +5,7 @@
 from fastapi import APIRouter, Depends
 from safir.dependencies.logger import logger_dependency
 from safir.metadata import get_metadata
+from safir.slack.webhook import SlackRouteErrorHandler
 from structlog.stdlib import BoundLogger
 
 from ..config import config
@@ -12,7 +13,7 @@
 
 __all__ = ["external_router"]
 
-external_router = APIRouter()
+external_router = APIRouter(route_class=SlackRouteErrorHandler)
 """FastAPI router for all external handlers."""
 
 
diff --git a/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/handlers/internal.py b/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/handlers/internal.py
index 8482c5f..9c6afe5 100644
--- a/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/handlers/internal.py
+++ b/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/handlers/internal.py
@@ -10,12 +10,13 @@
 
 from fastapi import APIRouter
 from safir.metadata import Metadata, get_metadata
+from safir.slack.webhook import SlackRouteErrorHandler
 
 from ..config import config
 
 __all__ = ["internal_router"]
 
-internal_router = APIRouter()
+internal_router = APIRouter(route_class=SlackRouteErrorHandler)
 """FastAPI router for all internal handlers."""
 
 
diff --git a/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/main.py b/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/main.py
index a0c6201..0667652 100644
--- a/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/main.py
+++ b/project_templates/fastapi_safir_app/{{cookiecutter.name}}/src/{{cookiecutter.module_name}}/main.py
@@ -11,10 +11,12 @@
 from contextlib import asynccontextmanager
 from importlib.metadata import metadata, version
 
+import structlog
 from fastapi import FastAPI
 from safir.dependencies.http_client import http_client_dependency
 from safir.logging import configure_logging, configure_uvicorn_logging
 from safir.middleware.x_forwarded import XForwardedMiddleware
+from safir.slack.webhook import SlackRouteErrorHandler
 
 from .config import config{% if cookiecutter.flavor == "UWS" %}, uws{% endif %}
 from .handlers.external import external_router
@@ -73,3 +75,11 @@ async def lifespan(app: FastAPI) -> AsyncIterator[None]:
 # Install error handlers.
 uws.install_error_handlers(app)
 {%- endif %}
+
+# Configure Slack alerts.
+if config.slack_webhook:
+    logger = structlog.get_logger("{{ cookiecutter.module_name }}")
+    SlackRouteErrorHandler.initialize(
+        config.slack_webhook, "{{ cookiecutter.name }}", logger
+    )
+    logger.debug("Initialized Slack webhook")
diff --git a/project_templates/technote_md/testn-000/technote.toml b/project_templates/technote_md/testn-000/technote.toml
index 8aa7d52..116c434 100644
--- a/project_templates/technote_md/testn-000/technote.toml
+++ b/project_templates/technote_md/testn-000/technote.toml
@@ -4,7 +4,7 @@ series_id = "TESTN"
 canonical_url = "https://testn-000.lsst.io"
 github_url = "https://github.com/lsst/testn-000"
 github_default_branch = "main"
-date_created = 2024-11-25T21:31:10Z
+date_created = 2024-11-25T21:45:02Z
 organization.name = "Vera C. Rubin Observatory"
 organization.ror = "https://ror.org/048g3cy84"
 license.id = "CC-BY-4.0"
diff --git a/project_templates/technote_rst/testn-000/technote.toml b/project_templates/technote_rst/testn-000/technote.toml
index ce19c4b..bf045d1 100644
--- a/project_templates/technote_rst/testn-000/technote.toml
+++ b/project_templates/technote_rst/testn-000/technote.toml
@@ -4,7 +4,7 @@ series_id = "TESTN"
 canonical_url = "https://testn-000.lsst.io"
 github_url = "https://github.com/lsst/testn-000"
 github_default_branch = "main"
-date_created = 2024-11-25T21:31:10Z
+date_created = 2024-11-25T21:45:02Z
 organization.name = "Vera C. Rubin Observatory"
 organization.ror = "https://ror.org/048g3cy84"
 license.id = "CC-BY-4.0"