diff --git a/Cargo.lock b/Cargo.lock
index 8e31693..8d019c8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -460,6 +460,15 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "emojis"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9f619a926616ae7149a0d82610b051134a0d6c4ae2962d990c06c847a445c5d9"
+dependencies = [
+ "phf",
+]
+
 [[package]]
 name = "enum-iterator"
 version = "2.1.0"
@@ -526,6 +535,7 @@ dependencies = [
  "chrono",
  "clap",
  "color-print",
+ "emojis",
  "enum-iterator",
  "macros",
  "redis",
@@ -1104,6 +1114,24 @@ version = "2.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3148f5046208a5d56bcfc03053e3ca6334e51da8dfb19b6cdc8b306fae3283e"
 
+[[package]]
+name = "phf"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ade2d8b8f33c7333b51bcf0428d37e217e9f32192ae4772156f65063b8ce03dc"
+dependencies = [
+ "phf_shared",
+]
+
+[[package]]
+name = "phf_shared"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90fcb95eef784c2ac79119d1dd819e162b5da872ce6f3c3abe1e8ca1c082f72b"
+dependencies = [
+ "siphasher",
+]
+
 [[package]]
 name = "pin-project-lite"
 version = "0.2.14"
@@ -1444,6 +1472,12 @@ dependencies = [
  "rand_core",
 ]
 
+[[package]]
+name = "siphasher"
+version = "0.3.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "38b58827f4464d87d377d175e90bf58eb00fd8716ff0a62f80356b5e61555d0d"
+
 [[package]]
 name = "slab"
 version = "0.4.9"
diff --git a/Cargo.toml b/Cargo.toml
index d141765..95b00d3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,6 +8,7 @@ macros = { path = "macros" }
 chrono = "0.4"
 clap = "4.5"
 color-print = "0.3"
+emojis = "0.6"
 enum-iterator = "2.1"
 quote = "1.0"
 redis = "0.25"
diff --git a/fishctl/Cargo.toml b/fishctl/Cargo.toml
index 8f48a3d..e60d245 100644
--- a/fishctl/Cargo.toml
+++ b/fishctl/Cargo.toml
@@ -12,6 +12,7 @@ macros = { workspace = true }
 chrono = { workspace = true }
 clap = { workspace = true, features = ["derive"] }
 color-print = { workspace = true }
+emojis = { workspace = true }
 enum-iterator = { workspace = true }
 redis = { workspace = true, features = ["tokio-comp"] }
 serde = { workspace = true, features = ["derive"] }
diff --git a/fishctl/src/command/config/update/v1.rs b/fishctl/src/command/config/update/v1.rs
index d0dcae0..1fa1f8d 100644
--- a/fishctl/src/command/config/update/v1.rs
+++ b/fishctl/src/command/config/update/v1.rs
@@ -363,13 +363,14 @@ fn create_new_server_config(
 
     let mut server_config = server::Config {
         config_revision: Revision::V1,
-        info: Some(server::Info {
+        custom: Some(server::Custom {
             name: meta.name.to_owned(),
             description: meta.description.to_owned(),
             maintainer_name: meta.maintainer_name.to_owned(),
             contact_info: meta.maintainer_email.to_owned(),
             open_registrations: !meta.disable_registration,
             repository_url,
+            default_reaction: meta.default_reaction.to_owned(),
         }),
         timeline: Some(server::Timeline {
             local: !meta.disable_local_timeline,
diff --git a/fishctl/src/config/server.rs b/fishctl/src/config/server.rs
index de1ac16..7cf4903 100644
--- a/fishctl/src/config/server.rs
+++ b/fishctl/src/config/server.rs
@@ -7,7 +7,7 @@
 
 use crate::config::{ensure_latest_revision, Revision};
 use serde::{Deserialize, Serialize};
-use validator::Validate;
+use validator::{Validate, ValidationError};
 
 #[derive(Deserialize, Serialize, Validate, Debug, Clone)]
 pub struct Config {
@@ -16,7 +16,7 @@ pub struct Config {
     #[validate(nested)]
     pub network: Network,
     #[validate(nested)]
-    pub info: Option<Info>,
+    pub custom: Option<Custom>,
     #[validate(nested)]
     pub timeline: Option<Timeline>,
     #[validate(nested)]
@@ -63,7 +63,7 @@ pub struct Proxy {
 }
 
 #[derive(Deserialize, Serialize, Validate, Debug, Clone)]
-pub struct Info {
+pub struct Custom {
     /// Server name
     pub name: Option<String>,
     /// Server description
@@ -76,6 +76,9 @@ pub struct Info {
     pub open_registrations: bool,
     /// Repository URL
     pub repository_url: Option<String>,
+    #[validate(custom(function = "validate_emoji"))]
+    /// Default reaction emoji
+    pub default_reaction: String,
 }
 
 #[derive(Deserialize, Serialize, Validate, Debug, Clone)]
@@ -157,3 +160,26 @@ pub enum Captcha {
     #[serde(rename = "reCAPTCHA")]
     ReCaptcha,
 }
+
+fn validate_emoji(value: &str) -> Result<(), ValidationError> {
+    let error = Err(ValidationError::new("not a Unicode emoji or :emoji_code:"));
+
+    // check if `value` is a Unicode emoji
+    if emojis::get(value).is_some() {
+        return Ok(());
+    }
+
+    // check if `value` is a custom emoji
+    // "+", "-", "_" are allowed in emoji shortcodes in Misskey variants
+    // ref: <https://github.com/misskey-dev/mfm.js/blob/6aaf68089023c6adebe44123eebbc4dcd75955e0/docs/syntax.md?plain=1#L583>
+    if value.len() > 2 {
+        if value[1..value.len() - 1]
+            .chars()
+            .all(|c| c.is_ascii_alphanumeric() || c == '+' || c == '-' || c == '_')
+        {
+            return Ok(());
+        }
+    }
+
+    error
+}
diff --git a/macros/src/lib.rs b/macros/src/lib.rs
index e69de29..8b13789 100644
--- a/macros/src/lib.rs
+++ b/macros/src/lib.rs
@@ -0,0 +1 @@
+