diff --git a/core/core/src/raw/time.rs b/core/core/src/raw/time.rs
index f1a3e3c4dc6d..4ff95f4463a8 100644
--- a/core/core/src/raw/time.rs
+++ b/core/core/src/raw/time.rs
@@ -18,11 +18,12 @@
 //! Time related utils.
 
 use crate::*;
-use jiff::SignedDuration;
+
 use std::fmt;
 use std::ops::{Add, AddAssign, Sub, SubAssign};
 use std::str::FromStr;
 
+pub use jiff::SignedDuration;
 pub use std::time::{Duration, UNIX_EPOCH};
 #[cfg(not(all(target_arch = "wasm32", target_os = "unknown")))]
 pub use std::time::{Instant, SystemTime};
@@ -254,7 +255,6 @@ impl SubAssign<Duration> for Timestamp {
     }
 }
 
-/// Convert an unsigned [`Duration`] into a jiff [`SignedDuration`].
 /// Parse a duration encoded either as ISO-8601 (e.g. `PT5M`) or friendly (e.g. `5m`).
 #[inline]
 pub fn signed_to_duration(value: &str) -> Result<Duration> {
@@ -262,7 +262,13 @@ pub fn signed_to_duration(value: &str) -> Result<Duration> {
         Error::new(ErrorKind::ConfigInvalid, "failed to parse duration").set_source(err)
     })?;
 
-    Duration::try_from(signed).map_err(|err| {
+    signed_duration_to_duration(signed)
+}
+
+/// Convert a jiff [`SignedDuration`] into an unsigned [`Duration`].
+#[inline]
+pub fn signed_duration_to_duration(value: SignedDuration) -> Result<Duration> {
+    Duration::try_from(value).map_err(|err| {
         Error::new(
             ErrorKind::ConfigInvalid,
             "duration must not be negative or overflow",
@@ -304,4 +310,9 @@ mod tests {
         let v = Timestamp::parse_rfc2822(s).unwrap();
         assert_eq!("Sat, 29 Oct 1994 19:43:31 GMT", v.format_http_date());
     }
+
+    #[test]
+    fn test_signed_duration_to_duration_rejects_negative_values() {
+        assert!(signed_duration_to_duration(SignedDuration::from_secs(-1)).is_err());
+    }
 }
diff --git a/core/services/cloudflare-kv/src/backend.rs b/core/services/cloudflare-kv/src/backend.rs
index a900fb6036fc..bd536df6ab39 100644
--- a/core/services/cloudflare-kv/src/backend.rs
+++ b/core/services/cloudflare-kv/src/backend.rs
@@ -37,6 +37,7 @@ use super::writer::CloudflareWriter;
 #[derive(Default)]
 pub struct CloudflareKvBuilder {
     pub(super) config: CloudflareKvConfig,
+    pub(super) default_ttl: Option<Duration>,
 }
 
 impl Debug for CloudflareKvBuilder {
@@ -76,7 +77,7 @@ impl CloudflareKvBuilder {
     ///
     /// If set, we will specify `EX` for write operations.
     pub fn default_ttl(mut self, ttl: Duration) -> Self {
-        self.config.default_ttl = Some(ttl);
+        self.default_ttl = Some(ttl);
         self
     }
 
@@ -96,6 +97,14 @@ impl Builder for CloudflareKvBuilder {
     type Config = CloudflareKvConfig;
 
     fn build(self) -> Result<impl Service> {
+        let default_ttl = match self.default_ttl {
+            Some(ttl) => Some(ttl),
+            None => self
+                .config
+                .default_ttl
+                .map(signed_duration_to_duration)
+                .transpose()?,
+        };
         let api_token = match &self.config.api_token {
             Some(api_token) => format_authorization_by_bearer(api_token)?,
             None => {
@@ -121,7 +130,7 @@ impl Builder for CloudflareKvBuilder {
         };
 
         // Validate default TTL is at least 60 seconds if specified
-        if let Some(ttl) = self.config.default_ttl
+        if let Some(ttl) = default_ttl
             && ttl < Duration::from_secs(60)
         {
             return Err(Error::new(
@@ -143,7 +152,7 @@ impl Builder for CloudflareKvBuilder {
                 api_token,
                 account_id,
                 namespace_id,
-                expiration_ttl: self.config.default_ttl,
+                expiration_ttl: default_ttl,
                 info: ServiceInfo::new(CLOUDFLARE_KV_SCHEME, &root, ""),
                 capability: Capability {
                     create_dir: true,
diff --git a/core/services/cloudflare-kv/src/config.rs b/core/services/cloudflare-kv/src/config.rs
index cad44d7ea3e3..7f5f2bae8f3d 100644
--- a/core/services/cloudflare-kv/src/config.rs
+++ b/core/services/cloudflare-kv/src/config.rs
@@ -34,7 +34,7 @@ pub struct CloudflareKvConfig {
     /// The namespace ID. Used as URI path parameter.
     pub namespace_id: Option<String>,
     /// The default ttl for write operations.
-    pub default_ttl: Option<Duration>,
+    pub default_ttl: Option<SignedDuration>,
 
     /// Root within this backend.
     pub root: Option<String>,
@@ -94,7 +94,10 @@ impl opendal_core::Configurator for CloudflareKvConfig {
     }
 
     fn into_builder(self) -> Self::Builder {
-        CloudflareKvBuilder { config: self }
+        CloudflareKvBuilder {
+            config: self,
+            default_ttl: None,
+        }
     }
 }
 
@@ -125,4 +128,12 @@ mod tests {
 
         assert!(CloudflareKvConfig::from_uri(&uri).is_err());
     }
+
+    #[test]
+    fn from_iter_parses_default_ttl() {
+        let cfg = CloudflareKvConfig::from_iter([("default_ttl".to_string(), "PT1M".to_string())])
+            .unwrap();
+
+        assert_eq!(cfg.default_ttl, Some(SignedDuration::from_mins(1)));
+    }
 }
diff --git a/core/services/memcached/src/backend.rs b/core/services/memcached/src/backend.rs
index 7d6e4a2d85b7..2a259892fe9b 100644
--- a/core/services/memcached/src/backend.rs
+++ b/core/services/memcached/src/backend.rs
@@ -34,6 +34,7 @@ use super::writer::MemcachedWriter;
 #[derive(Debug, Default)]
 pub struct MemcachedBuilder {
     pub(super) config: MemcachedConfig,
+    pub(super) default_ttl: Option<Duration>,
 }
 
 impl MemcachedBuilder {
@@ -74,7 +75,7 @@ impl MemcachedBuilder {
 
     /// Set the default ttl for memcached services.
     pub fn default_ttl(mut self, ttl: Duration) -> Self {
-        self.config.default_ttl = Some(ttl);
+        self.default_ttl = Some(ttl);
         self
     }
 
@@ -97,6 +98,14 @@ impl Builder for MemcachedBuilder {
     type Config = MemcachedConfig;
 
     fn build(self) -> Result<impl Service> {
+        let default_ttl = match self.default_ttl {
+            Some(ttl) => Some(ttl),
+            None => self
+                .config
+                .default_ttl
+                .map(signed_duration_to_duration)
+                .transpose()?,
+        };
         let endpoint_raw = self.config.endpoint.clone().ok_or_else(|| {
             Error::new(ErrorKind::ConfigInvalid, "endpoint is empty")
                 .with_context("service", MEMCACHED_SCHEME)
@@ -171,7 +180,7 @@ impl Builder for MemcachedBuilder {
             endpoint,
             self.config.username,
             self.config.password,
-            self.config.default_ttl,
+            default_ttl,
             self.config.connection_pool_max_size,
         ))
         .with_normalized_root(root))
diff --git a/core/services/memcached/src/config.rs b/core/services/memcached/src/config.rs
index df8ab16b0c45..4cc2ad2b81b9 100644
--- a/core/services/memcached/src/config.rs
+++ b/core/services/memcached/src/config.rs
@@ -44,7 +44,7 @@ pub struct MemcachedConfig {
     /// Memcached password, optional.
     pub password: Option<String>,
     /// The default ttl for put operations.
-    pub default_ttl: Option<Duration>,
+    pub default_ttl: Option<SignedDuration>,
     /// The maximum number of connections allowed.
     ///
     /// default is 10
@@ -81,7 +81,10 @@ impl Configurator for MemcachedConfig {
     }
 
     fn into_builder(self) -> Self::Builder {
-        MemcachedBuilder { config: self }
+        MemcachedBuilder {
+            config: self,
+            default_ttl: None,
+        }
     }
 }
 
@@ -101,4 +104,12 @@ mod tests {
         assert_eq!(cfg.root.as_deref(), Some("app/session"));
         Ok(())
     }
+
+    #[test]
+    fn from_iter_parses_default_ttl() -> Result<()> {
+        let cfg = MemcachedConfig::from_iter([("default_ttl".to_string(), "1500ms".to_string())])?;
+
+        assert_eq!(cfg.default_ttl, Some(SignedDuration::from_millis(1500)));
+        Ok(())
+    }
 }
diff --git a/core/services/redis/src/backend.rs b/core/services/redis/src/backend.rs
index 67aa3896d37c..a86665159ef5 100644
--- a/core/services/redis/src/backend.rs
+++ b/core/services/redis/src/backend.rs
@@ -44,6 +44,7 @@ const DEFAULT_REDIS_PORT: u16 = 6379;
 #[derive(Debug, Default)]
 pub struct RedisBuilder {
     pub(super) config: RedisConfig,
+    pub(super) default_ttl: Option<Duration>,
 }
 
 impl RedisBuilder {
@@ -108,7 +109,7 @@ impl RedisBuilder {
     ///
     /// If set, we will specify `EX` for write operations.
     pub fn default_ttl(mut self, ttl: Duration) -> Self {
-        self.config.default_ttl = Some(ttl);
+        self.default_ttl = Some(ttl);
         self
     }
 
@@ -144,6 +145,14 @@ impl Builder for RedisBuilder {
     type Config = RedisConfig;
 
     fn build(self) -> Result<impl Service> {
+        let default_ttl = match self.default_ttl {
+            Some(ttl) => Some(ttl),
+            None => self
+                .config
+                .default_ttl
+                .map(signed_duration_to_duration)
+                .transpose()?,
+        };
         let root = normalize_root(
             self.config
                 .root
@@ -170,7 +179,7 @@ impl Builder for RedisBuilder {
                 endpoints,
                 None,
                 Some(client),
-                self.config.default_ttl,
+                default_ttl,
                 self.config.connection_pool_max_size,
             ))
             .with_normalized_root(root))
@@ -194,7 +203,7 @@ impl Builder for RedisBuilder {
                 endpoint,
                 Some(client),
                 None,
-                self.config.default_ttl,
+                default_ttl,
                 self.config.connection_pool_max_size,
             ))
             .with_normalized_root(root))
diff --git a/core/services/redis/src/config.rs b/core/services/redis/src/config.rs
index e617be4990a2..4f488dac8e9a 100644
--- a/core/services/redis/src/config.rs
+++ b/core/services/redis/src/config.rs
@@ -59,7 +59,7 @@ pub struct RedisConfig {
     /// default is db 0
     pub db: i64,
     /// The default ttl for put operations.
-    pub default_ttl: Option<Duration>,
+    pub default_ttl: Option<SignedDuration>,
 }
 
 impl Debug for RedisConfig {
@@ -120,7 +120,10 @@ impl Configurator for RedisConfig {
     }
 
     fn into_builder(self) -> Self::Builder {
-        RedisBuilder { config: self }
+        RedisBuilder {
+            config: self,
+            default_ttl: None,
+        }
     }
 }
 
@@ -156,6 +159,14 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn from_iter_parses_default_ttl() -> Result<()> {
+        let cfg = RedisConfig::from_iter([("default_ttl".to_string(), "5s".to_string())])?;
+
+        assert_eq!(cfg.default_ttl, Some(SignedDuration::from_secs(5)));
+        Ok(())
+    }
+
     #[test]
     fn test_redis_builder_interface() {
         // Test that RedisBuilder still works with the new implementation
diff --git a/dev/src/generate/parser.rs b/dev/src/generate/parser.rs
index f46eaf697bd3..df200daaa084 100644
--- a/dev/src/generate/parser.rs
+++ b/dev/src/generate/parser.rs
@@ -83,7 +83,7 @@ pub enum ConfigType {
     Bool,
     /// Mapping to rust's `String`
     String,
-    /// Mapping to rust's `Duration`
+    /// Mapping to rust's `Duration` and `SignedDuration`
     Duration,
 
     /// Mapping to rust's `usize`
@@ -113,7 +113,7 @@ impl FromStr for ConfigType {
         Ok(match s {
             "bool" => ConfigType::Bool,
             "String" => ConfigType::String,
-            "Duration" => ConfigType::Duration,
+            "Duration" | "SignedDuration" => ConfigType::Duration,
 
             "usize" => ConfigType::Usize,
             "u64" => ConfigType::U64,
@@ -514,6 +514,19 @@ mod tests {
                     example: None,
                 },
             ),
+            (
+                "default_ttl: Option<SignedDuration>",
+                Config {
+                    name: "default_ttl".to_string(),
+                    value: ConfigType::Duration,
+                    optional: true,
+                    deprecated: None,
+                    comments: "".to_string(),
+                    group: None,
+                    default_value: None,
+                    example: None,
+                },
+            ),
         ];
 
         for (input, expected) in cases {
diff --git a/dev/src/generate/python.rs b/dev/src/generate/python.rs
index b866349ffc5d..963048f2d0e8 100644
--- a/dev/src/generate/python.rs
+++ b/dev/src/generate/python.rs
@@ -264,8 +264,7 @@ fn is_path_like_field(name: &str) -> bool {
 fn make_config_field_type(field: ViaDeserialize<Config>) -> Result<String, minijinja::Error> {
     Ok(match field.value {
         ConfigType::Bool => "bool".to_string(),
-        // Duration is typed `str` (a humantime string, e.g. "5s"). See #7887:
-        // core cannot yet deserialize Duration config fields from strings.
+        // Duration values cross the Python binding as strings, e.g. "5s".
         ConfigType::Duration => "str".to_string(),
         ConfigType::Usize
         | ConfigType::U64