From 439575acd0afa700b0329dc6c6c7555550144cd5 Mon Sep 17 00:00:00 2001
From: jude <jude@jellywx.com>
Date: Sun, 11 Oct 2026 13:16:02 +0100
Subject: [PATCH] Extend message features

---
 Cargo.lock                                    | 321 ++++++++++++++----
 Cargo.toml                                    |   2 +-
 reminder-dashboard/package.json               |   1 +
 reminder-dashboard/src/api.ts                 |  16 +-
 .../src/components/Reminder/Embed/Embeds.tsx  |  69 ++++
 .../Reminder/Embed/Fields/index.tsx           |   5 +-
 .../src/components/Reminder/Embed/index.tsx   |   7 +-
 .../src/components/Reminder/LinkButtons.tsx   |  82 +++++
 .../src/components/Reminder/LoadTemplate.tsx  |   1 +
 .../src/components/Reminder/Message.tsx       |   6 +-
 .../src/components/Reminder/message.ts        | 303 +++++++++++++++++
 .../src/components/Reminder/styles.scss       |  52 +++
 reminder-dashboard/tests/message.test.mjs     | 186 ++++++++++
 src/message.rs                                | 231 ++++++++++++-
 src/postman/sender.rs                         |   2 +-
 src/web/macros.rs                             |  12 +-
 .../routes/dashboard/api/guild/reminders.rs   |   5 +
 src/web/routes/dashboard/api/user/models.rs   |  59 ++--
 .../routes/dashboard/api/user/reminders.rs    |   5 +
 src/web/routes/dashboard/mod.rs               | 116 +++++--
 20 files changed, 1326 insertions(+), 155 deletions(-)
 create mode 100644 reminder-dashboard/src/components/Reminder/Embed/Embeds.tsx
 create mode 100644 reminder-dashboard/src/components/Reminder/LinkButtons.tsx
 create mode 100644 reminder-dashboard/src/components/Reminder/message.ts
 create mode 100644 reminder-dashboard/tests/message.test.mjs

diff --git a/Cargo.lock b/Cargo.lock
index 07f29dd..a18f360 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -35,7 +35,7 @@ checksum = "b169f7a6d4742236a0a00c541b845991d0ac43e546831af1249753ab4c3aa3a0"
 dependencies = [
  "cfg-if",
  "cipher",
- "cpufeatures",
+ "cpufeatures 0.2.15",
 ]
 
 [[package]]
@@ -389,6 +389,23 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "cfg_aliases"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f079e83a288787bcd14a6aea84cee5c87a67c5a3e660c30f557a3d24761b3527"
+
+[[package]]
+name = "chacha20"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "65c35e4b699c7e15ccbe7ee35c005e4fc0a278d22238a2857e6ce2dadeda1b06"
+dependencies = [
+ "cfg-if",
+ "cpufeatures 0.3.1",
+ "rand_core 0.10.1",
+]
+
 [[package]]
 name = "chrono"
 version = "0.4.38"
@@ -468,7 +485,7 @@ dependencies = [
  "base64 0.22.1",
  "hkdf",
  "percent-encoding",
- "rand",
+ "rand 0.8.5",
  "sha2",
  "subtle",
  "time",
@@ -500,6 +517,15 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "cpufeatures"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ca28b0ae3115b884660db4118d803791fd6756b6e88f39c0f3f7859060d7566"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "crc"
 version = "3.2.1"
@@ -583,7 +609,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1bfb12502f3fc46cca1bb51ac28df9d618d813cdc3d2f25b9fe775a34af26bb3"
 dependencies = [
  "generic-array",
- "rand_core",
+ "rand_core 0.6.4",
  "typenum",
 ]
 
@@ -1066,15 +1092,6 @@ dependencies = [
  "slab",
 ]
 
-[[package]]
-name = "fxhash"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c31b6d751ae2c7f11320402d34e41349dd1016f8d5d45e48c4312bc8625af50c"
-dependencies = [
- "byteorder",
-]
-
 [[package]]
 name = "generator"
 version = "0.7.5"
@@ -1111,6 +1128,20 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "300e883d756b2e4ec94e02791f39b04b522276138852cfc41d9fb7e904106099"
+dependencies = [
+ "cfg-if",
+ "js-sys",
+ "libc",
+ "r-efi",
+ "rand_core 0.10.1",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "ghash"
 version = "0.5.1"
@@ -1427,6 +1458,7 @@ dependencies = [
  "tokio",
  "tokio-rustls 0.26.0",
  "tower-service",
+ "webpki-roots 0.26.6",
 ]
 
 [[package]]
@@ -1725,10 +1757,12 @@ checksum = "49f1f14873335454500d59611f1cf4a4b0f786f9ac11f4312a78e4cf2566695b"
 
 [[package]]
 name = "js-sys"
-version = "0.3.72"
+version = "0.3.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a88f1bda2bd75b0452a14784937d796722fdebfe50df998aeb3f0b7603019a9"
+checksum = "ce57d20d1ea864ce2ac172ab472d409214f4fd359f0b2a2775abdf522e2af99e"
 dependencies = [
+ "cfg-if",
+ "futures-util",
  "wasm-bindgen",
 ]
 
@@ -1844,6 +1878,12 @@ dependencies = [
  "tracing-subscriber",
 ]
 
+[[package]]
+name = "lru-slab"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "112b39cec0b298b6c1999fee3e31427f74f676e4cb9879ed1a121b43661a4154"
+
 [[package]]
 name = "matchers"
 version = "0.1.0"
@@ -2045,7 +2085,7 @@ dependencies = [
  "num-integer",
  "num-iter",
  "num-traits",
- "rand",
+ "rand 0.8.5",
  "smallvec",
  "zeroize",
 ]
@@ -2104,15 +2144,15 @@ checksum = "c38841cdd844847e3e7c8d29cef9dcfed8877f8f56f9071f77843ecf3baf937f"
 dependencies = [
  "base64 0.13.1",
  "chrono",
- "getrandom",
+ "getrandom 0.2.15",
  "http 0.2.12",
- "rand",
+ "rand 0.8.5",
  "reqwest 0.11.27",
  "serde",
  "serde_json",
  "serde_path_to_error",
  "sha2",
- "thiserror",
+ "thiserror 1.0.69",
  "url",
 ]
 
@@ -2276,7 +2316,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "879952a81a83930934cbf1786752d6dedc3b1f29e8f8fb2ad1d0a36f377cf442"
 dependencies = [
  "memchr",
- "thiserror",
+ "thiserror 1.0.69",
  "ucd-trie",
 ]
 
@@ -2340,7 +2380,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "48e4cc64c2ad9ebe670cb8fd69dd50ae301650392e81c05f9bfcb2d5bdbc24b0"
 dependencies = [
  "phf_shared",
- "rand",
+ "rand 0.8.5",
 ]
 
 [[package]]
@@ -2427,7 +2467,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9d1fe60d06143b2430aa532c94cfe9e29783047f06c0d7fd359a9a51b729fa25"
 dependencies = [
  "cfg-if",
- "cpufeatures",
+ "cpufeatures 0.2.15",
  "opaque-debug",
  "universal-hash",
 ]
@@ -2449,9 +2489,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.89"
+version = "1.0.107"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f139b0662de085916d1fb67d2b4169d1addddda1919e696f3252b740b629986e"
+checksum = "985e7ec9bb745e6ce6535b544d84d6cd6f7ad8bd711c398938ae983b91a766d9"
 dependencies = [
  "unicode-ident",
 ]
@@ -2481,7 +2521,7 @@ dependencies = [
  "memchr",
  "parking_lot",
  "protobuf",
- "thiserror",
+ "thiserror 1.0.69",
 ]
 
 [[package]]
@@ -2501,6 +2541,62 @@ dependencies = [
  "unicase",
 ]
 
+[[package]]
+name = "quinn"
+version = "0.11.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c1a41e437b6bbd489372cd4971de128e85c855f56c57f283d20ff016cf7c0a8"
+dependencies = [
+ "bytes",
+ "cfg_aliases",
+ "pin-project-lite",
+ "quinn-proto",
+ "quinn-udp",
+ "rustc-hash",
+ "rustls 0.23.16",
+ "socket2",
+ "thiserror 2.0.20",
+ "tokio",
+ "tracing",
+ "web-time",
+]
+
+[[package]]
+name = "quinn-proto"
+version = "0.11.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "04759210543be93709136e28212294a659ef5001836ff4eab4d663e4529bba83"
+dependencies = [
+ "bytes",
+ "getrandom 0.4.3",
+ "lru-slab",
+ "rand 0.10.2",
+ "rand_pcg",
+ "ring",
+ "rustc-hash",
+ "rustls 0.23.16",
+ "rustls-pki-types",
+ "slab",
+ "thiserror 2.0.20",
+ "tinyvec",
+ "tracing",
+ "web-time",
+]
+
+[[package]]
+name = "quinn-udp"
+version = "0.5.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "35a133f956daabe89a61a685c2649f13d82d5aa4bd5d12d1277e1072a21c0694"
+dependencies = [
+ "cfg_aliases",
+ "libc",
+ "once_cell",
+ "socket2",
+ "tracing",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.37"
@@ -2510,6 +2606,12 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "r-efi"
+version = "6.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8dcc9c7d52a811697d2151c701e0d08956f92b0e24136cf4cf27b57a6a0d9bf"
+
 [[package]]
 name = "rand"
 version = "0.8.5"
@@ -2518,7 +2620,18 @@ checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
 dependencies = [
  "libc",
  "rand_chacha",
- "rand_core",
+ "rand_core 0.6.4",
+]
+
+[[package]]
+name = "rand"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7f5fa3a058cd35567ef9bfa5e75732bee0f9e4c55fa90477bef2dfcdbc4be80"
+dependencies = [
+ "chacha20",
+ "getrandom 0.4.3",
+ "rand_core 0.10.1",
 ]
 
 [[package]]
@@ -2528,7 +2641,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
 dependencies = [
  "ppv-lite86",
- "rand_core",
+ "rand_core 0.6.4",
 ]
 
 [[package]]
@@ -2537,7 +2650,22 @@ version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
 dependencies = [
- "getrandom",
+ "getrandom 0.2.15",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63b8176103e19a2643978565ca18b50549f6101881c443590420e4dc998a3c69"
+
+[[package]]
+name = "rand_pcg"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "caa0f4137e1c0a72f4c651489402276c8e8e1cf081f3b0ba156d2cbeef09e86a"
+dependencies = [
+ "rand_core 0.10.1",
 ]
 
 [[package]]
@@ -2641,7 +2769,7 @@ dependencies = [
  "oauth2",
  "poise",
  "prometheus",
- "rand",
+ "rand 0.8.5",
  "recordable_derive",
  "regex",
  "reqwest 0.12.9",
@@ -2678,7 +2806,6 @@ dependencies = [
  "js-sys",
  "log",
  "mime",
- "mime_guess",
  "once_cell",
  "percent-encoding",
  "pin-project-lite",
@@ -2691,12 +2818,10 @@ dependencies = [
  "system-configuration 0.5.1",
  "tokio",
  "tokio-rustls 0.24.1",
- "tokio-util",
  "tower-service",
  "url",
  "wasm-bindgen",
  "wasm-bindgen-futures",
- "wasm-streams",
  "web-sys",
  "webpki-roots 0.25.4",
  "winreg",
@@ -2725,11 +2850,15 @@ dependencies = [
  "js-sys",
  "log",
  "mime",
+ "mime_guess",
  "native-tls",
  "once_cell",
  "percent-encoding",
  "pin-project-lite",
+ "quinn",
+ "rustls 0.23.16",
  "rustls-pemfile 2.2.0",
+ "rustls-pki-types",
  "serde",
  "serde_json",
  "serde_urlencoded",
@@ -2737,11 +2866,15 @@ dependencies = [
  "system-configuration 0.6.1",
  "tokio",
  "tokio-native-tls",
+ "tokio-rustls 0.26.0",
+ "tokio-util",
  "tower-service",
  "url",
  "wasm-bindgen",
  "wasm-bindgen-futures",
+ "wasm-streams",
  "web-sys",
+ "webpki-roots 0.26.6",
  "windows-registry",
 ]
 
@@ -2753,7 +2886,7 @@ checksum = "c17fa4cb658e3583423e915b9f3acc01cceaee1860e33d59ebae66adc3a2dc0d"
 dependencies = [
  "cc",
  "cfg-if",
- "getrandom",
+ "getrandom 0.2.15",
  "libc",
  "spin",
  "untrusted",
@@ -2803,7 +2936,7 @@ dependencies = [
  "num_cpus",
  "parking_lot",
  "pin-project-lite",
- "rand",
+ "rand 0.8.5",
  "ref-cast",
  "rocket_codegen",
  "rocket_http",
@@ -2893,7 +3026,7 @@ dependencies = [
  "num-traits",
  "pkcs1",
  "pkcs8",
- "rand_core",
+ "rand_core 0.6.4",
  "signature",
  "spki",
  "subtle",
@@ -2906,6 +3039,12 @@ version = "0.1.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "719b953e2095829ee67db738b3bfa9fa368c94900df327b3f07fe6e794d2fe1f"
 
+[[package]]
+name = "rustc-hash"
+version = "2.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6b1e7f9a428571be2dc5bc0505c13fb6bf936822b894ec87abf8a08a4e51742d"
+
 [[package]]
 name = "rustix"
 version = "0.38.40"
@@ -2982,6 +3121,9 @@ name = "rustls-pki-types"
 version = "1.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "16f1201b3c9a7ee8039bcadc17b7e605e2945b27eee7631788c1bd2b0643674b"
+dependencies = [
+ "web-time",
+]
 
 [[package]]
 name = "rustls-webpki"
@@ -3189,9 +3331,9 @@ dependencies = [
 
 [[package]]
 name = "serenity"
-version = "0.12.4"
+version = "0.12.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3d72ec4323681bf9a3cabe40fd080abc2435859b502a1b5aa9bf693f125bfa76"
+checksum = "9bde37f42765dfdc34e2a039e0c84afbf79a3101c1941763b0beb816c2f17541"
 dependencies = [
  "arrayvec",
  "async-trait",
@@ -3202,11 +3344,11 @@ dependencies = [
  "dashmap",
  "flate2",
  "futures",
- "fxhash",
  "mime_guess",
  "parking_lot",
  "percent-encoding",
- "reqwest 0.11.27",
+ "reqwest 0.12.9",
+ "rustc-hash",
  "secrecy",
  "serde",
  "serde_cow",
@@ -3227,7 +3369,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e3bf829a2d51ab4a5ddf1352d8470c140cadc8301b2ae1789db023f01cedd6ba"
 dependencies = [
  "cfg-if",
- "cpufeatures",
+ "cpufeatures 0.2.15",
  "digest",
 ]
 
@@ -3238,7 +3380,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "793db75ad2bcafc3ffa7c68b215fee268f537982cd901d132f89c6343f3a3dc8"
 dependencies = [
  "cfg-if",
- "cpufeatures",
+ "cpufeatures 0.2.15",
  "digest",
 ]
 
@@ -3273,7 +3415,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "77549399552de45a898a580c1b41d445bf730df867cc44e6c0233bbc4b8329de"
 dependencies = [
  "digest",
- "rand_core",
+ "rand_core 0.6.4",
 ]
 
 [[package]]
@@ -3413,7 +3555,7 @@ dependencies = [
  "sha2",
  "smallvec",
  "sqlformat",
- "thiserror",
+ "thiserror 1.0.69",
  "tokio",
  "tokio-stream",
  "tracing",
@@ -3491,7 +3633,7 @@ dependencies = [
  "memchr",
  "once_cell",
  "percent-encoding",
- "rand",
+ "rand 0.8.5",
  "rsa",
  "serde",
  "sha1",
@@ -3499,7 +3641,7 @@ dependencies = [
  "smallvec",
  "sqlx-core",
  "stringprep",
- "thiserror",
+ "thiserror 1.0.69",
  "tracing",
  "whoami",
 ]
@@ -3533,14 +3675,14 @@ dependencies = [
  "memchr",
  "num-bigint",
  "once_cell",
- "rand",
+ "rand 0.8.5",
  "serde",
  "serde_json",
  "sha2",
  "smallvec",
  "sqlx-core",
  "stringprep",
- "thiserror",
+ "thiserror 1.0.69",
  "tracing",
  "whoami",
 ]
@@ -3638,6 +3780,17 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "syn"
+version = "3.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8593e8e72159ed2257d083c7a454a85cbf854f37a0966d8d483aff8c8a3ebcee"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "sync_wrapper"
 version = "0.1.2"
@@ -3739,7 +3892,7 @@ dependencies = [
  "percent-encoding",
  "pest",
  "pest_derive",
- "rand",
+ "rand 0.8.5",
  "regex",
  "serde",
  "serde_json",
@@ -3753,7 +3906,16 @@ version = "1.0.69"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b6aaf5339b578ea85b50e080feb250a3e8ae8cfcdff9a461c9ec2904bc923f52"
 dependencies = [
- "thiserror-impl",
+ "thiserror-impl 1.0.69",
+]
+
+[[package]]
+name = "thiserror"
+version = "2.0.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec86235f5fcc2a73650310756d2ac5b138a5780bbbdfae3eeccec992c435ba4f"
+dependencies = [
+ "thiserror-impl 2.0.20",
 ]
 
 [[package]]
@@ -3767,6 +3929,17 @@ dependencies = [
  "syn 2.0.87",
 ]
 
+[[package]]
+name = "thiserror-impl"
+version = "2.0.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bc04cd3e1236dd4a98afca4569f2deb3f120e5422a4023be2cb683f8486292af"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 3.0.6",
+]
+
 [[package]]
 name = "thread_local"
 version = "1.1.8"
@@ -4070,11 +4243,11 @@ dependencies = [
  "http 1.1.0",
  "httparse",
  "log",
- "rand",
+ "rand 0.8.5",
  "rustls 0.22.4",
  "rustls-pki-types",
  "sha1",
- "thiserror",
+ "thiserror 1.0.69",
  "url",
  "utf-8",
 ]
@@ -4343,27 +4516,14 @@ checksum = "b8dad83b4f25e74f184f64c43b150b91efe7647395b42289f38e50566d82855b"
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.95"
+version = "0.2.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "128d1e363af62632b8eb57219c8fd7877144af57558fb2ef0368d0087bddeb2e"
+checksum = "aecb87a33d3b0c5e3b7aa46336eaf486cffafbd281b195e4c8b80d50df2351bf"
 dependencies = [
  "cfg-if",
  "once_cell",
+ "rustversion",
  "wasm-bindgen-macro",
-]
-
-[[package]]
-name = "wasm-bindgen-backend"
-version = "0.2.95"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb6dd4d3ca0ddffd1dd1c9c04f94b868c37ff5fac97c30b97cff2d74fce3a358"
-dependencies = [
- "bumpalo",
- "log",
- "once_cell",
- "proc-macro2",
- "quote",
- "syn 2.0.87",
  "wasm-bindgen-shared",
 ]
 
@@ -4381,9 +4541,9 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.95"
+version = "0.2.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e79384be7f8f5a9dd5d7167216f022090cf1f9ec128e6e6a482a2cb5c5422c56"
+checksum = "a690d511e3c1a8b3a55e33511e3c2c00c78415cd23650f32b808627f5696b9ed"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -4391,22 +4551,25 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.95"
+version = "0.2.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26c6ab57572f7a24a4985830b120de1594465e5d500f24afe89e16b4e833ef68"
+checksum = "411e4887f0071ef2d2164a9d5fdf2d20efbef78fccd3a78b0c10a1dc5295e48a"
 dependencies = [
+ "bumpalo",
  "proc-macro2",
  "quote",
- "syn 2.0.87",
- "wasm-bindgen-backend",
+ "syn 3.0.6",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.95"
+version = "0.2.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "65fc09f10666a9f147042251e0dda9c18f166ff7de300607007e96bdebc1068d"
+checksum = "81941cd78d0c92026c33e5e01312845a4cb1e9af3407f9134b100dd03144103e"
+dependencies = [
+ "unicode-ident",
+]
 
 [[package]]
 name = "wasm-streams"
@@ -4431,6 +4594,16 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "web-time"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a6580f308b1fad9207618087a65c04e7a10bc77e02c8e84e9b00dd4b12fa0bb"
+dependencies = [
+ "js-sys",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "webpki-roots"
 version = "0.25.4"
diff --git a/Cargo.toml b/Cargo.toml
index 871cce9..8c93ba3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -31,7 +31,7 @@ futures = "0.3.30"
 prometheus = "0.13.3"
 rocket = { version = "0.5.0", features = ["tls", "secrets", "json"] }
 rocket_dyn_templates = { version = "0.2.0", features = ["tera"] }
-serenity = { version = "0.12", default-features = false, features = ["builder", "cache", "client", "gateway", "http", "model", "utils", "rustls_backend"] }
+serenity = { version = "0.12.5", default-features = false, features = ["builder", "cache", "client", "gateway", "http", "model", "utils", "rustls_backend"] }
 oauth2 = "4"
 csv = "1.2"
 sd-notify = "0.4.1"
diff --git a/reminder-dashboard/package.json b/reminder-dashboard/package.json
index 875efee..17f85a1 100644
--- a/reminder-dashboard/package.json
+++ b/reminder-dashboard/package.json
@@ -5,6 +5,7 @@
 	"scripts": {
 		"dev": "vite build --watch --mode development",
 		"build": "vite build",
+		"test": "node --test tests/*.test.mjs",
 		"preview": "vite preview",
                 "prettier": "prettier -w src/"
 	},
diff --git a/reminder-dashboard/src/api.ts b/reminder-dashboard/src/api.ts
index de689b4..1bc2779 100644
--- a/reminder-dashboard/src/api.ts
+++ b/reminder-dashboard/src/api.ts
@@ -1,3 +1,5 @@
+import { prepareReminder } from "./components/Reminder/message";
+import type { MessagePayload } from "./components/Reminder/message";
 import axios from "axios";
 
 enum ColorScheme {
@@ -38,6 +40,7 @@ type EmbedField = {
 };
 
 export type Reminder = {
+    message_json?: MessagePayload | null;
     attachment: string | null;
     attachment_name: string | null;
     avatar: string | null;
@@ -186,12 +189,14 @@ export const fetchGuildReminders = (guild: string) => ({
 
 export const patchGuildReminder = (guild: string) => ({
     mutationFn: (reminder: Reminder) =>
-        axios.patch(`/dashboard/api/guild/${guild}/reminders`, reminder),
+        axios.patch(`/dashboard/api/guild/${guild}/reminders`, prepareReminder(reminder)),
 });
 
 export const postGuildReminder = (guild: string) => ({
     mutationFn: (reminder: Reminder) =>
-        axios.post(`/dashboard/api/guild/${guild}/reminders`, reminder).then((resp) => resp.data),
+        axios
+            .post(`/dashboard/api/guild/${guild}/reminders`, prepareReminder(reminder))
+            .then((resp) => resp.data),
 });
 
 export const deleteReminder = () => ({
@@ -257,9 +262,12 @@ export const fetchUserReminders = () => ({
 
 export const postUserReminder = () => ({
     mutationFn: (reminder: Reminder) =>
-        axios.post(`/dashboard/api/user/reminders`, reminder).then((resp) => resp.data),
+        axios
+            .post(`/dashboard/api/user/reminders`, prepareReminder(reminder))
+            .then((resp) => resp.data),
 });
 
 export const patchUserReminder = () => ({
-    mutationFn: (reminder: Reminder) => axios.patch(`/dashboard/api/user/reminders`, reminder),
+    mutationFn: (reminder: Reminder) =>
+        axios.patch(`/dashboard/api/user/reminders`, prepareReminder(reminder)),
 });
diff --git a/reminder-dashboard/src/components/Reminder/Embed/Embeds.tsx b/reminder-dashboard/src/components/Reminder/Embed/Embeds.tsx
new file mode 100644
index 0000000..7d300ed
--- /dev/null
+++ b/reminder-dashboard/src/components/Reminder/Embed/Embeds.tsx
@@ -0,0 +1,69 @@
+import { Embed } from "./index";
+import { ReminderContext, useReminder } from "../ReminderContext";
+import { Reminder } from "../../../api";
+import {
+    addEmbed,
+    embedFields,
+    embedTextLength,
+    MAX_EMBEDS,
+    MAX_EMBED_TEXT,
+    reminderEmbeds,
+    removeEmbed,
+    updateEmbed,
+} from "../message";
+
+const EmbedEditor = ({ index }: { index: number }) => {
+    const [reminder, setReminder] = useReminder();
+    const embed = reminderEmbeds(reminder)[index];
+    const update = (change: (r: Reminder) => Reminder) => {
+        setReminder((current) => updateEmbed(current, index, change));
+    };
+
+    return (
+        <div class="reminder-embed-editor" role="group" aria-label={`Embed ${index + 1}`}>
+            <ReminderContext.Provider value={[{ ...reminder, ...embedFields(embed) }, update]}>
+                <Embed />
+            </ReminderContext.Provider>
+            <button
+                type="button"
+                class="button is-small is-text remove-embed"
+                aria-label={`Remove embed ${index + 1}`}
+                onClick={() => setReminder((current) => removeEmbed(current, index))}
+            >
+                <i class="fas fa-trash" aria-hidden="true" />
+            </button>
+        </div>
+    );
+};
+
+export const Embeds = () => {
+    const [reminder, setReminder] = useReminder();
+    const embeds = reminderEmbeds(reminder);
+    const textLength = embedTextLength(embeds);
+
+    return (
+        <div class="reminder-embeds">
+            {embeds.map((_, index) => (
+                <EmbedEditor key={index} index={index} />
+            ))}
+            <div class="add-embed-row">
+                <button
+                    type="button"
+                    class="button is-small is-rounded add-embed"
+                    aria-label="Add embed"
+                    title={embeds.length >= MAX_EMBEDS ? "Maximum of 10 embeds" : "Add embed"}
+                    disabled={embeds.length >= MAX_EMBEDS}
+                    onClick={() => setReminder(addEmbed)}
+                >
+                    <i class="fas fa-plus" aria-hidden="true" />
+                </button>
+                <span
+                    class={`embed-limit${textLength > MAX_EMBED_TEXT ? " has-text-danger" : ""}`}
+                    aria-live="polite"
+                >
+                    {embeds.length}/{MAX_EMBEDS} embeds · {textLength}/{MAX_EMBED_TEXT} characters
+                </span>
+            </div>
+        </div>
+    );
+};
diff --git a/reminder-dashboard/src/components/Reminder/Embed/Fields/index.tsx b/reminder-dashboard/src/components/Reminder/Embed/Fields/index.tsx
index cb5b648..9d3d5e2 100644
--- a/reminder-dashboard/src/components/Reminder/Embed/Fields/index.tsx
+++ b/reminder-dashboard/src/components/Reminder/Embed/Fields/index.tsx
@@ -6,7 +6,10 @@ export const Fields = () => {
 
     return (
         <div class={"embed-multifield-box"}>
-            {[...embed_fields, { value: "", title: "", inline: true }].map((field, index) => (
+            {[
+                ...(embed_fields || []),
+                ...(embed_fields?.length >= 25 ? [] : [{ value: "", title: "", inline: true }]),
+            ].map((field, index) => (
                 <Field
                     {...field}
                     index={index}
diff --git a/reminder-dashboard/src/components/Reminder/Embed/index.tsx b/reminder-dashboard/src/components/Reminder/Embed/index.tsx
index 7843973..4ef4241 100644
--- a/reminder-dashboard/src/components/Reminder/Embed/index.tsx
+++ b/reminder-dashboard/src/components/Reminder/Embed/index.tsx
@@ -6,13 +6,14 @@ import { Color } from "./Color";
 import { Fields } from "./Fields";
 import { Reminder } from "../../../api";
 import { ImagePicker } from "../ImagePicker";
+import { DEFAULT_EMBED_COLOR } from "../message";
 import { useReminder } from "../ReminderContext";
 
 function intToColor(num: number) {
     return `#${num.toString(16).padStart(6, "0")}`;
 }
 
-export const DEFAULT_COLOR = 9418359;
+export const DEFAULT_COLOR = DEFAULT_EMBED_COLOR;
 
 export const Embed = () => {
     const [reminder, setReminder] = useReminder();
@@ -21,12 +22,12 @@ export const Embed = () => {
         <div
             class="discord-embed"
             style={{
-                borderLeftColor: intToColor(reminder.embed_color || DEFAULT_COLOR),
+                borderLeftColor: intToColor(reminder.embed_color ?? DEFAULT_COLOR),
             }}
         >
             <div class="embed-body">
                 <Color
-                    color={intToColor(reminder.embed_color || DEFAULT_COLOR)}
+                    color={intToColor(reminder.embed_color ?? DEFAULT_COLOR)}
                     setReminder={setReminder}
                 ></Color>
                 <div class="a">
diff --git a/reminder-dashboard/src/components/Reminder/LinkButtons.tsx b/reminder-dashboard/src/components/Reminder/LinkButtons.tsx
new file mode 100644
index 0000000..3d23ac3
--- /dev/null
+++ b/reminder-dashboard/src/components/Reminder/LinkButtons.tsx
@@ -0,0 +1,82 @@
+import { useReminder } from "./ReminderContext";
+import {
+    addLinkButton,
+    canAddLinkButton,
+    linkButtons,
+    MAX_LINK_BUTTONS,
+    updateLinkButton,
+} from "./message";
+
+export const LinkButtons = () => {
+    const [reminder, setReminder] = useReminder();
+    const buttons = linkButtons(reminder);
+
+    return (
+        <div class="reminder-link-buttons" role="group" aria-label="Link buttons">
+            {buttons.map(({ button, rowIndex, buttonIndex }, index) => (
+                <div class="link-button-editor" key={`${rowIndex}-${buttonIndex}`}>
+                    <label class="link-button-label">
+                        Button label
+                        <input
+                            class="input is-small"
+                            aria-label={`Link button ${index + 1} label`}
+                            maxLength={80}
+                            value={button.label || ""}
+                            onInput={(event) => {
+                                const label = event.currentTarget.value;
+                                setReminder((current) =>
+                                    updateLinkButton(current, rowIndex, buttonIndex, { label }),
+                                );
+                            }}
+                        />
+                    </label>
+                    <label class="link-button-url">
+                        URL
+                        <input
+                            class="input is-small"
+                            type="url"
+                            aria-label={`Link button ${index + 1} URL`}
+                            placeholder="https://example.com"
+                            maxLength={512}
+                            value={button.url || ""}
+                            onInput={(event) => {
+                                const url = event.currentTarget.value;
+                                setReminder((current) =>
+                                    updateLinkButton(current, rowIndex, buttonIndex, { url }),
+                                );
+                            }}
+                        />
+                    </label>
+                    <button
+                        type="button"
+                        class="button is-small is-text"
+                        aria-label={`Remove link button ${index + 1}`}
+                        onClick={() =>
+                            setReminder((current) =>
+                                updateLinkButton(current, rowIndex, buttonIndex, null),
+                            )
+                        }
+                    >
+                        <i class="fas fa-trash" aria-hidden="true" />
+                    </button>
+                </div>
+            ))}
+            <div class="add-link-button-row">
+                <button
+                    type="button"
+                    class="button is-small is-rounded"
+                    disabled={!canAddLinkButton(reminder)}
+                    onClick={() => setReminder(addLinkButton)}
+                >
+                    <span class="icon is-small">
+                        <i class="fas fa-plus" aria-hidden="true" />
+                    </span>
+                    <span>Add link button</span>
+                </button>
+                <span class="link-button-limit" aria-live="polite">
+                    {buttons.length}/{MAX_LINK_BUTTONS} link buttons
+                </span>
+            </div>
+        </div>
+    );
+};
diff --git a/reminder-dashboard/src/components/Reminder/LoadTemplate.tsx b/reminder-dashboard/src/components/Reminder/LoadTemplate.tsx
index 8f58e95..f719f37 100644
--- a/reminder-dashboard/src/components/Reminder/LoadTemplate.tsx
+++ b/reminder-dashboard/src/components/Reminder/LoadTemplate.tsx
@@ -82,6 +82,7 @@ const LoadTemplateModal = ({ setModalOpen }) => {
                         setReminder((reminder) => ({
                             ...reminder,
                             ...template,
+                            message_json: null,
                             // drop the template's ID
                             id: undefined,
                         }));
diff --git a/reminder-dashboard/src/components/Reminder/Message.tsx b/reminder-dashboard/src/components/Reminder/Message.tsx
index 07e7e7a..cca82fc 100644
--- a/reminder-dashboard/src/components/Reminder/Message.tsx
+++ b/reminder-dashboard/src/components/Reminder/Message.tsx
@@ -1,7 +1,8 @@
 import { Username } from "./Username";
 import { Content } from "./Content";
-import { Embed } from "./Embed";
+import { Embeds } from "./Embed/Embeds";
 import { Avatar } from "./Avatar";
+import { LinkButtons } from "./LinkButtons";
 
 export const Message = () => (
     <div class="column discord-frame">
@@ -15,7 +16,8 @@ export const Message = () => (
                 <div class="content">
                     <Username />
                     <Content />
-                    <Embed />
+                    <Embeds />
+                    <LinkButtons />
                 </div>
             </div>
         </article>
diff --git a/reminder-dashboard/src/components/Reminder/message.ts b/reminder-dashboard/src/components/Reminder/message.ts
new file mode 100644
index 0000000..8fc1c38
--- /dev/null
+++ b/reminder-dashboard/src/components/Reminder/message.ts
@@ -0,0 +1,303 @@
+import type { Reminder } from "../../api";
+
+export const MAX_EMBEDS = 10;
+export const MAX_EMBED_TEXT = 6000;
+export const DEFAULT_EMBED_COLOR = 9418359;
+export const MAX_BUTTON_ROWS = 5;
+export const MAX_BUTTONS_PER_ROW = 5;
+export const MAX_LINK_BUTTONS = MAX_BUTTON_ROWS * MAX_BUTTONS_PER_ROW;
+
+export type MessageComponent = {
+    type: number;
+    style?: number;
+    label?: string;
+    url?: string;
+    components?: MessageComponent[];
+    [key: string]: unknown;
+};
+
+export type DiscordEmbed = {
+    title?: string;
+    description?: string;
+    color?: number;
+    author?: { name?: string; icon_url?: string; [key: string]: unknown };
+    footer?: { text?: string; icon_url?: string; [key: string]: unknown };
+    image?: { url?: string; [key: string]: unknown };
+    thumbnail?: { url?: string; [key: string]: unknown };
+    fields?: { name: string; value: string; inline?: boolean }[];
+    [key: string]: unknown;
+};
+
+export type MessagePayload = {
+    content?: string;
+    tts?: boolean;
+    username?: string;
+    avatar_url?: string;
+    embeds?: DiscordEmbed[];
+    attachments?: { id: number; filename: string }[];
+    components?: MessageComponent[];
+    [key: string]: unknown;
+};
+
+export function embedFields(embed: DiscordEmbed) {
+    return {
+        embed_title: embed.title || "",
+        embed_description: embed.description || "",
+        embed_color: embed.color ?? DEFAULT_EMBED_COLOR,
+        embed_author: embed.author?.name || "",
+        embed_author_url: embed.author?.icon_url || null,
+        embed_footer: embed.footer?.text || "",
+        embed_footer_url: embed.footer?.icon_url || null,
+        embed_image_url: embed.image?.url || null,
+        embed_thumbnail_url: embed.thumbnail?.url || null,
+        embed_fields: (embed.fields || []).map(({ name, value, inline }) => ({
+            title: name,
+            value,
+            inline: inline ?? false,
+        })),
+    };
+}
+
+export function toEmbed(reminder: Reminder, original: DiscordEmbed = {}): DiscordEmbed {
+    const embed: DiscordEmbed = { ...original, color: reminder.embed_color };
+    for (const [key, value] of [
+        ["title", reminder.embed_title],
+        ["description", reminder.embed_description],
+    ]) {
+        if (value) embed[key] = value;
+        else delete embed[key];
+    }
+    for (const [key, textKey, text, icon] of [
+        ["author", "name", reminder.embed_author, reminder.embed_author_url],
+        ["footer", "text", reminder.embed_footer, reminder.embed_footer_url],
+    ]) {
+        const part = { ...(original[key] as object) };
+        if (text) part[textKey] = text;
+        else delete part[textKey];
+        if (icon) part["icon_url"] = icon;
+        else delete part["icon_url"];
+        if (Object.keys(part).length) embed[key] = part;
+        else delete embed[key];
+    }
+    for (const [key, url] of [
+        ["image", reminder.embed_image_url],
+        ["thumbnail", reminder.embed_thumbnail_url],
+    ]) {
+        if (url) embed[key] = { ...(original[key] as object), url };
+        else delete embed[key];
+    }
+    const fields = (reminder.embed_fields || []).map(({ title, value, inline }) => ({
+        name: title,
+        value,
+        inline,
+    }));
+    if (fields.length) embed.fields = fields;
+    else delete embed.fields;
+    return embed;
+}
+
+export function hasEmbedContent(embed: DiscordEmbed): boolean {
+    return (
+        [
+            embed.title,
+            embed.description,
+            embed.author?.name,
+            embed.footer?.text,
+            embed.footer?.icon_url,
+            embed.image?.url,
+            embed.thumbnail?.url,
+        ].some((value) => !!value?.trim()) ||
+        !!embed.fields?.length ||
+        Object.keys(embed).some(
+            (key) =>
+                ![
+                    "title",
+                    "description",
+                    "author",
+                    "footer",
+                    "image",
+                    "thumbnail",
+                    "color",
+                    "fields",
+                ].includes(key),
+        )
+    );
+}
+
+export function reminderEmbeds(reminder: Reminder): DiscordEmbed[] {
+    const embeds = reminder.message_json?.embeds;
+    if (embeds) return embeds.length ? embeds : [{ color: DEFAULT_EMBED_COLOR }];
+    return [toEmbed(reminder)];
+}
+
+export function updateEmbed(
+    reminder: Reminder,
+    index: number,
+    update: (r: Reminder) => Reminder,
+): Reminder {
+    const embeds = [...reminderEmbeds(reminder)];
+    const original = embeds[index];
+    if (!original) return reminder;
+    const changed = update({ ...reminder, ...embedFields(original) });
+    embeds[index] = toEmbed(changed, original);
+    return {
+        ...reminder,
+        ...embedFields(embeds[0]),
+        message_json: { ...reminder.message_json, embeds },
+    };
+}
+
+export function addEmbed(reminder: Reminder): Reminder {
+    const embeds = reminderEmbeds(reminder);
+    if (embeds.length >= MAX_EMBEDS) return reminder;
+    return {
+        ...reminder,
+        message_json: {
+            ...reminder.message_json,
+            embeds: [...embeds, { color: DEFAULT_EMBED_COLOR }],
+        },
+    };
+}
+
+export function removeEmbed(reminder: Reminder, index: number): Reminder {
+    const embeds = reminderEmbeds(reminder).filter((_, i) => i !== index);
+    return {
+        ...reminder,
+        ...embedFields(embeds[0] || {}),
+        message_json: { ...reminder.message_json, embeds },
+    };
+}
+
+export function embedTextLength(embeds: DiscordEmbed[]): number {
+    return embeds.reduce(
+        (sum, embed) =>
+            sum +
+            [
+                embed.title,
+                embed.description,
+                embed.author?.name,
+                embed.footer?.text,
+                ...(embed.fields || []).flatMap((field) => [field.name, field.value]),
+            ].reduce((sum, value) => sum + Array.from((value || "").trim()).length, 0),
+        0,
+    );
+}
+
+export function linkButtons(reminder: Reminder) {
+    return (reminder.message_json?.components || []).flatMap((row, rowIndex) =>
+        row.type === 1
+            ? (row.components || []).flatMap((button, buttonIndex) =>
+                  button.type === 2 && button.style === 5
+                      ? [{ button, rowIndex, buttonIndex }]
+                      : [],
+              )
+            : [],
+    );
+}
+
+function availableButtonRow(components: MessageComponent[]): number {
+    return components.findIndex(
+        (row) =>
+            row.type === 1 &&
+            !!row.components &&
+            row.components.length < MAX_BUTTONS_PER_ROW &&
+            row.components.every((button) => button.type === 2),
+    );
+}
+
+export function canAddLinkButton(reminder: Reminder): boolean {
+    const components = reminder.message_json?.components || [];
+    return availableButtonRow(components) >= 0 || components.length < MAX_BUTTON_ROWS;
+}
+
+export function addLinkButton(reminder: Reminder): Reminder {
+    if (!canAddLinkButton(reminder)) return reminder;
+    const components = [...(reminder.message_json?.components || [])];
+    const rowIndex = availableButtonRow(components);
+    const button: MessageComponent = { type: 2, style: 5, label: "Open link", url: "" };
+    if (rowIndex >= 0) {
+        const row = components[rowIndex];
+        components[rowIndex] = { ...row, components: [...row.components, button] };
+    } else components.push({ type: 1, components: [button] });
+    return { ...reminder, message_json: { ...reminder.message_json, components } };
+}
+
+export function updateLinkButton(
+    reminder: Reminder,
+    rowIndex: number,
+    buttonIndex: number,
+    change: { label?: string; url?: string } | null,
+): Reminder {
+    const components = [...(reminder.message_json?.components || [])];
+    const row = components[rowIndex];
+    const button = row?.components?.[buttonIndex];
+    if (row?.type !== 1 || button?.type !== 2 || button.style !== 5) return reminder;
+    const buttons = [...row.components];
+    if (change) buttons[buttonIndex] = { ...button, ...change };
+    else buttons.splice(buttonIndex, 1);
+    if (buttons.length) components[rowIndex] = { ...row, components: buttons };
+    else components.splice(rowIndex, 1);
+    return { ...reminder, message_json: { ...reminder.message_json, components } };
+}
+
+function validateComponents(components: MessageComponent[] = []) {
+    if (components.length > MAX_BUTTON_ROWS)
+        throw new Error(`A reminder can have at most ${MAX_BUTTON_ROWS} button rows.`);
+    for (const row of components) {
+        if (row.type !== 1) continue;
+        if (
+            !Array.isArray(row.components) ||
+            !row.components.length ||
+            row.components.length > MAX_BUTTONS_PER_ROW
+        )
+            throw new Error(
+                `A button row must have between 1 and ${MAX_BUTTONS_PER_ROW} components.`,
+            );
+        for (const button of row.components) {
+            if (button.type !== 2 || button.style !== 5) continue;
+            if (
+                (button.label !== undefined && typeof button.label !== "string") ||
+                Array.from(button.label || "").length > 80 ||
+                (!button.label && (!button.emoji || typeof button.emoji !== "object"))
+            )
+                throw new Error(
+                    "Link buttons require a label of at most 80 characters or an emoji.",
+                );
+            let url: URL;
+            try {
+                url = new URL(button.url);
+            } catch {
+                throw new Error("Link buttons require a valid HTTP or HTTPS URL.");
+            }
+            if (!["http:", "https:"].includes(url.protocol) || Array.from(button.url).length > 512)
+                throw new Error(
+                    "Link buttons require an HTTP or HTTPS URL of at most 512 characters.",
+                );
+            if (button.custom_id !== undefined || button.sku_id !== undefined)
+                throw new Error("Link buttons cannot have a custom_id or sku_id.");
+        }
+    }
+}
+
+export function prepareReminder(reminder: Reminder): Reminder {
+    validateComponents(reminder.message_json?.components);
+    const embeds = reminderEmbeds(reminder).filter(hasEmbedContent);
+    if (embeds.length > MAX_EMBEDS)
+        throw new Error(`A reminder can have at most ${MAX_EMBEDS} embeds.`);
+    if (embedTextLength(embeds) > MAX_EMBED_TEXT)
+        throw new Error(`Embed text exceeds ${MAX_EMBED_TEXT} characters across all embeds.`);
+    const message: MessagePayload = {
+        ...reminder.message_json,
+        content: reminder.content,
+        tts: reminder.tts,
+        embeds,
+    };
+    if (reminder.username) message.username = reminder.username;
+    else delete message.username;
+    if (reminder.avatar) message.avatar_url = reminder.avatar;
+    else delete message.avatar_url;
+    if (reminder.attachment_name)
+        message.attachments = [{ id: 0, filename: reminder.attachment_name }];
+    else delete message.attachments;
+    return { ...reminder, ...embedFields(embeds[0] || {}), message_json: message };
+}
diff --git a/reminder-dashboard/src/components/Reminder/styles.scss b/reminder-dashboard/src/components/Reminder/styles.scss
index 6edff79..1007c54 100644
--- a/reminder-dashboard/src/components/Reminder/styles.scss
+++ b/reminder-dashboard/src/components/Reminder/styles.scss
@@ -34,3 +34,55 @@ div.reminderContent {
     background-color: #f5f5f5;
     border-radius: 8px;
 }
+
+.reminder-embed-editor {
+    position: relative;
+    margin-bottom: 12px;
+
+    .discord-embed {
+        padding-bottom: 36px;
+    }
+
+    .remove-embed {
+        position: absolute;
+        right: 24px;
+        bottom: 4px;
+    }
+}
+
+.add-embed-row,
+.add-link-button-row {
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    margin-top: 8px;
+
+    .embed-limit,
+    .link-button-limit {
+        font-size: 0.8rem;
+        color: #737373;
+    }
+}
+
+.reminder-link-buttons {
+    margin-top: 16px;
+}
+
+.link-button-editor {
+    display: flex;
+    align-items: flex-end;
+    flex-wrap: wrap;
+    gap: 8px;
+    margin-bottom: 8px;
+
+    label {
+        font-size: 0.8rem;
+    }
+
+    .link-button-label {
+        flex: 1 1 140px;
+    }
+    .link-button-url {
+        flex: 2 1 200px;
+    }
+}
diff --git a/reminder-dashboard/tests/message.test.mjs b/reminder-dashboard/tests/message.test.mjs
new file mode 100644
index 0000000..4b9a6f6
--- /dev/null
+++ b/reminder-dashboard/tests/message.test.mjs
@@ -0,0 +1,186 @@
+import assert from "node:assert/strict";
+import { readFile } from "node:fs/promises";
+import test from "node:test";
+import ts from "typescript";
+
+// Run the pure editor helpers without a browser or additional test dependencies.
+const source = await readFile(
+    new URL("../src/components/Reminder/message.ts", import.meta.url),
+    "utf8",
+);
+const { outputText } = ts.transpileModule(source, {
+    compilerOptions: { module: ts.ModuleKind.ESNext, target: ts.ScriptTarget.ES2020 },
+});
+const {
+    addEmbed,
+    embedFields,
+    prepareReminder,
+    reminderEmbeds,
+    removeEmbed,
+    updateEmbed,
+    addLinkButton,
+    canAddLinkButton,
+    linkButtons,
+    updateLinkButton,
+} = await import(`data:text/javascript;base64,${Buffer.from(outputText).toString("base64")}`);
+
+function reminder(embeds) {
+    return {
+        content: "hello",
+        tts: false,
+        username: "",
+        avatar: null,
+        attachment_name: null,
+        uid: "unchanged",
+        utc_time: "2026-10-12T12:00:00",
+        ...embedFields(embeds?.[0] || {}),
+        message_json: embeds ? { embeds, allowed_mentions: { parse: [] } } : null,
+    };
+}
+
+test("editing one embed preserves the others and unedited payload properties", () => {
+    const original = reminder([
+        { title: "first" },
+        { description: "second", author: { name: "author", url: "https://example.com" } },
+    ]);
+    const edited = updateEmbed(original, 1, (r) => ({ ...r, embed_description: "updated" }));
+    const payload = prepareReminder(edited).message_json;
+    assert.equal(payload.embeds[0].title, "first");
+    assert.equal(payload.embeds[1].description, "updated");
+    assert.equal(payload.embeds[1].author.url, "https://example.com");
+    assert.deepEqual(payload.allowed_mentions, { parse: [] });
+    assert.equal(edited.uid, original.uid);
+    assert.equal(original.message_json.embeds[1].description, "second");
+});
+
+test("adding stops at ten embeds and removal permits another", () => {
+    let value = reminder([{ title: "first" }]);
+    for (let i = 0; i < 12; i++) value = addEmbed(value);
+    assert.equal(reminderEmbeds(value).length, 10);
+    assert.equal(addEmbed(value), value);
+    value = removeEmbed(value, 0);
+    assert.equal(reminderEmbeds(value).length, 9);
+    value = updateEmbed(value, 0, (r) => ({ ...r, embed_title: "new first" }));
+    assert.equal(prepareReminder(value).message_json.embeds[0].title, "new first");
+    assert.equal(reminderEmbeds(addEmbed(value)).length, 10);
+});
+
+test("saving and reloading multiple embeds preserves order and drops blank editors", () => {
+    let value = addEmbed(reminder([{ description: "first" }]));
+    value = updateEmbed(value, 1, (r) => ({ ...r, embed_description: "second" }));
+    value = addEmbed(value);
+    const saved = prepareReminder(value);
+    assert.deepEqual(
+        saved.message_json.embeds.map((embed) => embed.description),
+        ["first", "second"],
+    );
+    assert.deepEqual(reminderEmbeds(JSON.parse(JSON.stringify(saved))), saved.message_json.embeds);
+    assert.deepEqual(prepareReminder(reminder()).message_json.embeds, []);
+});
+
+test("legacy embeds are retained when a second embed is added", () => {
+    const legacy = {
+        ...reminder(),
+        embed_title: "legacy",
+        embed_fields: [{ title: "name", value: "value", inline: true }],
+    };
+    const saved = prepareReminder(addEmbed(legacy));
+    assert.equal(saved.message_json.embeds[0].title, "legacy");
+    assert.deepEqual(saved.message_json.embeds[0].fields, [
+        { name: "name", value: "value", inline: true },
+    ]);
+});
+
+test("combined embed text accepts 6000 characters and rejects 6001", () => {
+    const embeds = [{ description: "x".repeat(3000) }, { description: "y".repeat(3000) }];
+    assert.equal(prepareReminder(reminder(embeds)).message_json.embeds.length, 2);
+    assert.throws(
+        () => prepareReminder(reminder([embeds[0], { description: "y".repeat(3001) }])),
+        /6000/,
+    );
+    assert.throws(
+        () => prepareReminder(reminder(Array.from({ length: 11 }, () => ({ title: "embed" })))),
+        /10 embeds/,
+    );
+});
+
+test("link buttons can be added, edited, saved, reloaded and removed without losing embeds", () => {
+    const original = reminder([{ title: "first" }, { title: "second" }]);
+    let value = addLinkButton(original);
+    value = updateLinkButton(value, 0, 0, { label: "Visit", url: "https://example.com" });
+    const saved = prepareReminder(value);
+    assert.deepEqual(saved.message_json.components, [
+        {
+            type: 1,
+            components: [{ type: 2, style: 5, label: "Visit", url: "https://example.com" }],
+        },
+    ]);
+    assert.deepEqual(saved.message_json.embeds, original.message_json.embeds);
+    assert.deepEqual(saved.message_json.allowed_mentions, { parse: [] });
+    assert.equal(
+        linkButtons(JSON.parse(JSON.stringify(saved)))[0].button.url,
+        "https://example.com",
+    );
+    assert.deepEqual(
+        prepareReminder(updateLinkButton(saved, 0, 0, null)).message_json.components,
+        [],
+    );
+    assert.equal(original.message_json.components, undefined);
+    const legacy = updateLinkButton(addLinkButton({ ...reminder(), embed_title: "legacy" }), 0, 0, {
+        url: "https://example.com",
+    });
+    assert.equal(prepareReminder(legacy).message_json.embeds[0].title, "legacy");
+});
+
+test("link buttons fill five rows of five and preserve other components", () => {
+    let value = reminder();
+    for (let i = 0; i < 26; i++) value = addLinkButton(value);
+    assert.equal(linkButtons(value).length, 25);
+    assert.deepEqual(
+        value.message_json.components.map((row) => row.components.length),
+        [5, 5, 5, 5, 5],
+    );
+    assert.equal(canAddLinkButton(value), false);
+    assert.equal(addLinkButton(value), value);
+    value = updateLinkButton(value, 2, 2, null);
+    assert.equal(canAddLinkButton(value), true);
+    assert.equal(linkButtons(addLinkButton(value)).length, 25);
+    const other = { type: 1, id: 7, components: [{ type: 3, custom_id: "select", options: [] }] };
+    value = { ...reminder(), message_json: { components: [other] } };
+    value = addLinkButton(value);
+    assert.deepEqual(value.message_json.components[0], other);
+    assert.equal(linkButtons(value)[0].rowIndex, 1);
+});
+
+test("invalid link button URLs, labels and row limits are rejected on save", () => {
+    let value = addLinkButton(reminder());
+    assert.throws(() => prepareReminder(value), /URL/);
+    value = updateLinkButton(value, 0, 0, {
+        url: "https://example.com/" + "x".repeat(492),
+        label: "x".repeat(80),
+    });
+    assert.equal(prepareReminder(value).message_json.components.length, 1);
+    for (const change of [
+        { url: "invalid" },
+        { url: "javascript:alert(1)" },
+        { url: "https://example.com/" + "x".repeat(493) },
+        { label: "" },
+        { label: "x".repeat(81) },
+    ])
+        assert.throws(() => prepareReminder(updateLinkButton(value, 0, 0, change)));
+    const row = value.message_json.components[0];
+    assert.throws(
+        () => prepareReminder({ ...value, message_json: { components: Array(6).fill(row) } }),
+        /5 button rows/,
+    );
+    assert.throws(
+        () =>
+            prepareReminder({
+                ...value,
+                message_json: {
+                    components: [{ ...row, components: Array(6).fill(row.components[0]) }],
+                },
+            }),
+        /5 components/,
+    );
+});
diff --git a/src/message.rs b/src/message.rs
index 402d554..c3610dd 100644
--- a/src/message.rs
+++ b/src/message.rs
@@ -114,6 +114,126 @@ pub fn payload(reminder: &impl Serialize) -> Value {
     payload
 }
 
+/// Validate Discord's link buttons, embed count and text limits.
+pub fn validate_payload(message: &Value) -> Result<(), String> {
+    if !message.is_object() {
+        return Err("message_json must be an object".into());
+    }
+    if let Some(content) = message.get("content") {
+        if content.as_str().is_none_or(|text| text.chars().count() > 2000) {
+            return Err("Message content exceeds 2000 characters or is not text".into());
+        }
+    }
+    validate_components(message)?;
+    let Some(embeds) = message.get("embeds") else {
+        return Ok(());
+    };
+    let embeds = embeds.as_array().ok_or("embeds must be an array")?;
+    if embeds.len() > 10 {
+        return Err("A reminder can have at most 10 embeds".into());
+    }
+    let mut total = 0;
+    for (index, embed) in embeds.iter().enumerate() {
+        if !embed.is_object() {
+            return Err(format!("Embed {} must be an object", index + 1));
+        }
+        let mut check_text = |value: Option<&Value>, limit: usize| -> Result<(), String> {
+            if let Some(value) = value {
+                let text = value
+                    .as_str()
+                    .ok_or_else(|| format!("Embed {} has a non-text field", index + 1))?;
+                let length = text.trim().chars().count();
+                if length > limit {
+                    return Err(format!(
+                        "Embed {} exceeds a {} character field limit",
+                        index + 1,
+                        limit
+                    ));
+                }
+                total += length;
+            }
+            Ok(())
+        };
+        for (path, limit) in
+            [("/title", 256), ("/description", 4096), ("/author/name", 256), ("/footer/text", 2048)]
+        {
+            check_text(embed.pointer(path), limit)?;
+        }
+        if let Some(fields) = embed.get("fields") {
+            let fields = fields.as_array().ok_or("Embed fields must be an array")?;
+            if fields.len() > 25 {
+                return Err("An embed can have at most 25 fields".into());
+            }
+            for field in fields {
+                if !field.is_object() {
+                    return Err("Embed fields must be objects".into());
+                }
+                for (name, limit) in [("name", 256), ("value", 1024)] {
+                    let text = field.get(name).ok_or("Embed fields require a name and value")?;
+                    if text.as_str().is_none_or(|text| text.trim().is_empty()) {
+                        return Err("Embed fields require a non-empty name and value".into());
+                    }
+                    check_text(Some(text), limit)?;
+                }
+            }
+        }
+    }
+    if total > 6000 {
+        return Err("Embed text exceeds 6000 characters across all embeds".into());
+    }
+    Ok(())
+}
+
+fn validate_components(message: &Value) -> Result<(), String> {
+    let Some(components) = message.get("components") else {
+        return Ok(());
+    };
+    let rows = components.as_array().ok_or("components must be an array")?;
+    // Components V2 has a different layout and count limit. Leave its validation to Discord.
+    if message["flags"].as_u64().is_some_and(|flags| flags & (1 << 15) != 0) {
+        return Ok(());
+    }
+    if rows.len() > 5 {
+        return Err("A reminder can have at most 5 button rows (25 buttons)".into());
+    }
+    for row in rows {
+        if row["type"].as_u64() != Some(1) {
+            continue;
+        }
+        let buttons = row["components"].as_array().ok_or("Button rows require components")?;
+        if buttons.is_empty() || buttons.len() > 5 {
+            return Err("A button row must have between 1 and 5 components".into());
+        }
+        for button in buttons {
+            if button["type"].as_u64() != Some(2) || button["style"].as_u64() != Some(5) {
+                continue;
+            }
+            let label = button.get("label").and_then(Value::as_str);
+            if label.is_some_and(|label| label.chars().count() > 80)
+                || (label.is_none_or(str::is_empty) && !button["emoji"].is_object())
+                || button.get("label").is_some_and(|label| !label.is_string())
+            {
+                return Err(
+                    "Link buttons require a label of at most 80 characters or an emoji".into()
+                );
+            }
+            let url = button["url"].as_str().ok_or("Link buttons require a URL")?;
+            if url.chars().count() > 512
+                || !reqwest::Url::parse(url)
+                    .is_ok_and(|url| ["http", "https"].contains(&url.scheme()))
+            {
+                return Err(
+                    "Link buttons require an HTTP or HTTPS URL of at most 512 characters".into()
+                );
+            }
+            if button.get("custom_id").is_some() || button.get("sku_id").is_some() {
+                return Err("Link buttons cannot have a custom_id or sku_id".into());
+            }
+        }
+    }
+    Ok(())
+}
+
 /// Present the first embed through the existing dashboard controls.
 pub fn response(reminder: impl Serialize) -> Value {
     let mut reminder = serde_json::to_value(reminder).expect("Reminder fields are serializable");
@@ -123,10 +243,7 @@ pub fn response(reminder: impl Serialize) -> Value {
         }
         return reminder;
     }
-    let payload = reminder
-        .as_object_mut()
-        .and_then(|object| object.remove("message_json"))
-        .unwrap_or(Value::Null);
+    let payload = reminder["message_json"].clone();
     if payload.is_null() {
         return reminder;
     }
@@ -211,6 +328,7 @@ pub async fn update_field(
         serde_json::to_value(value).map_err(|e| sqlx::Error::Encode(e.into()))?
     };
     patch(&mut message, field, value);
+    validate_payload(&message).map_err(sqlx::Error::Protocol)?;
     sqlx::query("UPDATE reminders SET message_json = ? WHERE uid = ?")
         .bind(Json(message))
         .bind(uid)
@@ -260,8 +378,8 @@ mod tests {
                 "avatar_url": "https://example.com/avatar.png"
             })
         );
-        let mut expected_response = legacy.clone();
-        expected_response.as_object_mut().unwrap().remove("message_json");
+        let expected_response = legacy.clone();
+
         assert_eq!(response(legacy), expected_response);
     }
 
@@ -286,7 +404,7 @@ mod tests {
         assert_eq!(reminder["uid"], "reminder-id");
         assert_eq!(reminder["utc_time"], "2026-10-12T12:00:00");
         assert_eq!(reminder["enabled"], true);
-        assert!(reminder.get("message_json").is_none());
+        assert_eq!(reminder["message_json"]["embeds"].as_array().unwrap().len(), 1);
     }
 
     #[test]
@@ -322,6 +440,105 @@ mod tests {
         assert_eq!(message["embeds"], json!([]));
     }
 
+    #[test]
+    fn validates_embed_count_and_combined_text_boundaries() {
+        assert!(validate_payload(&json!({"embeds": vec![json!({"title": "embed"}); 10]})).is_ok());
+        assert!(validate_payload(&json!({"embeds": vec![json!({"title": "embed"}); 11]})).is_err());
+        let mut message = json!({"embeds": [{"description": "x".repeat(3000)}, {"description": "y".repeat(3000)}]});
+        assert!(validate_payload(&message).is_ok());
+        message["embeds"][1]["title"] = json!("x");
+        assert!(validate_payload(&message).is_err());
+    }
+
+    #[test]
+    fn validates_each_embed_and_field() {
+        assert!(validate_payload(&json!({"embeds": [{"description": "x".repeat(4097)}]})).is_err());
+        assert!(validate_payload(
+            &json!({"embeds": [{"fields": vec![json!({"name": "x", "value": "y"}); 26]}]})
+        )
+        .is_err());
+        for message in [
+            json!([]),
+            json!({"embeds": {}}),
+            json!({"embeds": [null]}),
+            json!({"embeds": [{"fields": [{"name": "x"}]}]}),
+            json!({"embeds": [{"description": 1}]}),
+        ] {
+            assert!(validate_payload(&message).is_err());
+        }
+    }
+
+    #[test]
+    fn dashboard_response_retains_all_embeds_for_editing() {
+        let message = json!({"embeds": [{"title": "first"}, {"title": "second"}], "allowed_mentions": {"parse": []}});
+        let displayed =
+            response(json!({"message_json": message, "content": "", "uid": "unchanged"}));
+        assert_eq!(displayed["message_json"], message);
+        assert_eq!(displayed["embed_title"], "first");
+        assert_eq!(displayed["uid"], "unchanged");
+    }
+
+    #[test]
+    fn link_buttons_survive_payload_response_and_legacy_edits() {
+        let components = json!([{"type": 1, "components": [{
+            "type": 2, "style": 5, "label": "Open link", "url": "https://example.com"
+        }]}]);
+        let mut message = json!({"content": "hello", "components": components});
+        assert!(validate_payload(&message).is_ok());
+        assert_eq!(payload(&json!({"message_json": message})), message);
+        assert_eq!(response(json!({"message_json": message}))["message_json"], message);
+        patch(&mut message, "content", json!("updated"));
+        patch(&mut message, "embed_description", json!("embed"));
+        assert_eq!(message["components"], components);
+    }
+
+    #[test]
+    fn validates_link_button_count_and_text_boundaries() {
+        let button = json!({"type": 2, "style": 5, "label": "x".repeat(80),
+            "url": format!("https://example.com/{}", "x".repeat(492))});
+        let row = json!({"type": 1, "components": vec![button.clone(); 5]});
+        assert!(validate_payload(&json!({"components": vec![row.clone(); 5]})).is_ok());
+        assert!(validate_payload(&json!({"components": vec![row; 6]})).is_err());
+        assert!(validate_payload(
+            &json!({"components": [{"type": 1, "components": vec![button.clone(); 6]}]})
+        )
+        .is_err());
+        for (field, value) in [
+            ("label", json!("x".repeat(81))),
+            ("url", json!(format!("https://example.com/{}", "x".repeat(493)))),
+        ] {
+            let mut invalid = button.clone();
+            invalid[field] = value;
+            assert!(validate_payload(
+                &json!({"components": [{"type": 1, "components": [invalid]}]})
+            )
+            .is_err());
+        }
+    }
+
+    #[test]
+    fn rejects_invalid_link_buttons_without_embeds() {
+        for change in [
+            json!({"url": ""}),
+            json!({"url": "javascript:alert(1)"}),
+            json!({"url": "not a URL"}),
+            json!({"label": ""}),
+            json!({"label": 1}),
+            json!({"custom_id": "interactive"}),
+        ] {
+            let mut button =
+                json!({"type": 2, "style": 5, "label": "Open", "url": "https://example.com"});
+            button.as_object_mut().unwrap().extend(change.as_object().unwrap().clone());
+            assert!(validate_payload(
+                &json!({"components": [{"type": 1, "components": [button]}]})
+            )
+            .is_err());
+        }
+        assert!(validate_payload(&json!({"components": {}})).is_err());
+        assert!(validate_payload(&json!({"components": [{"type": 1, "components": []}]})).is_err());
+        assert!(validate_payload(&json!({"components": [{"type": 1, "components": [{"type": 2, "style": 5, "emoji": {"name": "🔗"}, "url": "https://example.com"}]}]})).is_ok());
+    }
+
     #[tokio::test]
     #[ignore = "requires MESSAGE_JSON_TEST_DATABASE_URL pointing to an isolated MySQL database"]
     async fn database_edits_convert_legacy_messages_and_preserve_payload() {
diff --git a/src/postman/sender.rs b/src/postman/sender.rs
index 10ac1e8..a033efa 100644
--- a/src/postman/sender.rs
+++ b/src/postman/sender.rs
@@ -682,7 +682,7 @@ impl Reminder {
                 let token = webhook.token.as_ref().ok_or(Error::Other("Webhook token missing"))?;
                 let message = cache_http
                     .http()
-                    .execute_webhook(
+                    .execute_webhook_with_components(
                         webhook.id,
                         reminder.thread_id.map(ChannelId::new),
                         token.expose_secret(),
diff --git a/src/web/macros.rs b/src/web/macros.rs
index a92ac12..cd11e90 100644
--- a/src/web/macros.rs
+++ b/src/web/macros.rs
@@ -57,7 +57,12 @@ macro_rules! check_url_opt {
 macro_rules! update_field {
     ($pool:expr, $error:ident, $reminder:ident.[$field:ident]) => {
         if let Some(value) = &$reminder.$field {
-            let result = if crate::message::is_message_field(stringify!($field)) {
+            // The complete payload takes precedence over legacy message controls.
+            let result = if crate::message::is_message_field(stringify!($field))
+                && $reminder.message_json.is_some()
+            {
+                Ok(())
+            } else if crate::message::is_message_field(stringify!($field)) {
                 crate::message::update_field($pool, &$reminder.uid, stringify!($field), value).await
             } else {
                 let result = sqlx::query(concat!(
@@ -70,7 +75,10 @@ macro_rules! update_field {
                 .execute($pool)
                 .await
                 .map(|_| ());
-                if result.is_ok() && ["attachment", "attachment_name"].contains(&stringify!($field)) {
+                if result.is_ok()
+                    && $reminder.message_json.is_none()
+                    && ["attachment", "attachment_name"].contains(&stringify!($field))
+                {
                     crate::message::update_field($pool, &$reminder.uid, "attachments", &()).await
                 } else {
                     result
diff --git a/src/web/routes/dashboard/api/guild/reminders.rs b/src/web/routes/dashboard/api/guild/reminders.rs
index b307aaa..64e22ab 100644
--- a/src/web/routes/dashboard/api/guild/reminders.rs
+++ b/src/web/routes/dashboard/api/guild/reminders.rs
@@ -153,6 +153,11 @@ pub async fn edit_reminder(
     let user_id =
         cookies.get_private("userid").map(|c| c.value().parse::<u64>().ok()).flatten().unwrap();
 
+    if let Some(message) = &reminder.message_json {
+        crate::message::validate_payload(message).map_err(|error| json!({"error": error}))?;
+        update_field!(transaction.executor(), error, reminder.[message_json]);
+    }
+
     if reminder.message_ok() {
         update_field!(transaction.executor(), error, reminder.[
             content,
diff --git a/src/web/routes/dashboard/api/user/models.rs b/src/web/routes/dashboard/api/user/models.rs
index ad68f59..56e1ec3 100644
--- a/src/web/routes/dashboard/api/user/models.rs
+++ b/src/web/routes/dashboard/api/user/models.rs
@@ -87,39 +87,42 @@ pub async fn create_reminder(
 
     let channel = channel.unwrap();
 
-    if reminder.message_json.as_ref().is_some_and(|message| !message.is_object()) {
-        return Err(json!({"error": "message_json must be an object"}));
+    let message_json = Json(crate::message::payload(&reminder));
+    if let Err(error) = crate::message::validate_payload(&message_json) {
+        return Err(json!({"error": error}));
     }
 
     // validate lengths
     check_length!(MAX_NAME_LENGTH, reminder.name);
-    check_length!(MAX_CONTENT_LENGTH, reminder.content);
-    check_length!(MAX_EMBED_DESCRIPTION_LENGTH, reminder.embed_description);
-    check_length!(MAX_EMBED_TITLE_LENGTH, reminder.embed_title);
-    check_length!(MAX_EMBED_AUTHOR_LENGTH, reminder.embed_author);
-    check_length!(MAX_EMBED_FOOTER_LENGTH, reminder.embed_footer);
-    check_length_opt!(MAX_EMBED_FIELDS, reminder.embed_fields);
-    if let Some(fields) = &reminder.embed_fields {
-        for field in &fields.0 {
-            check_length!(MAX_EMBED_FIELD_VALUE_LENGTH, field.value);
-            check_length!(MAX_EMBED_FIELD_TITLE_LENGTH, field.title);
+    if reminder.message_json.is_none() {
+        check_length!(MAX_CONTENT_LENGTH, reminder.content);
+        check_length!(MAX_EMBED_DESCRIPTION_LENGTH, reminder.embed_description);
+        check_length!(MAX_EMBED_TITLE_LENGTH, reminder.embed_title);
+        check_length!(MAX_EMBED_AUTHOR_LENGTH, reminder.embed_author);
+        check_length!(MAX_EMBED_FOOTER_LENGTH, reminder.embed_footer);
+        check_length_opt!(MAX_EMBED_FIELDS, reminder.embed_fields);
+        if let Some(fields) = &reminder.embed_fields {
+            for field in &fields.0 {
+                check_length!(MAX_EMBED_FIELD_VALUE_LENGTH, field.value);
+                check_length!(MAX_EMBED_FIELD_TITLE_LENGTH, field.title);
+            }
         }
-    }
-    check_length_opt!(
-        MAX_URL_LENGTH,
-        reminder.embed_footer_url,
-        reminder.embed_thumbnail_url,
-        reminder.embed_author_url,
-        reminder.embed_image_url
-    );
+        check_length_opt!(
+            MAX_URL_LENGTH,
+            reminder.embed_footer_url,
+            reminder.embed_thumbnail_url,
+            reminder.embed_author_url,
+            reminder.embed_image_url
+        );
 
-    // validate urls
-    check_url_opt!(
-        reminder.embed_footer_url,
-        reminder.embed_thumbnail_url,
-        reminder.embed_author_url,
-        reminder.embed_image_url
-    );
+        // validate urls
+        check_url_opt!(
+            reminder.embed_footer_url,
+            reminder.embed_thumbnail_url,
+            reminder.embed_author_url,
+            reminder.embed_image_url
+        );
+    }
 
     // validate time and interval
     if reminder.utc_time < Utc::now().naive_utc() {
@@ -151,8 +154,6 @@ pub async fn create_reminder(
     let name = if reminder.name.is_empty() { name_default() } else { reminder.name.clone() };
     let new_uid = generate_uid();
 
-    let message_json = Json(crate::message::payload(&reminder));
-
     // write to db
     match sqlx::query!(
         "INSERT INTO reminders (
diff --git a/src/web/routes/dashboard/api/user/reminders.rs b/src/web/routes/dashboard/api/user/reminders.rs
index f3d9859..9ff3a68 100644
--- a/src/web/routes/dashboard/api/user/reminders.rs
+++ b/src/web/routes/dashboard/api/user/reminders.rs
@@ -131,6 +131,11 @@ pub async fn edit_reminder(
     let mut error = vec![];
     let user_id = user_id_cookie.unwrap();
 
+    if let Some(message) = &reminder.message_json {
+        crate::message::validate_payload(message).map_err(|error| json!({"error": error}))?;
+        update_field!(transaction.executor(), error, reminder.[message_json]);
+    }
+
     if reminder.message_ok() {
         update_field!(transaction.executor(), error, reminder.[
             content,
diff --git a/src/web/routes/dashboard/mod.rs b/src/web/routes/dashboard/mod.rs
index 44138ce..7bf15fa 100644
--- a/src/web/routes/dashboard/mod.rs
+++ b/src/web/routes/dashboard/mod.rs
@@ -254,6 +254,8 @@ pub struct ReminderCsv {
 
 #[derive(Deserialize)]
 pub struct PatchReminder {
+    #[serde(default)]
+    message_json: Option<Json<serde_json::Value>>,
     uid: String,
     #[serde(default)]
     #[serde(deserialize_with = "deserialize_optional_field")]
@@ -322,6 +324,9 @@ pub struct PatchReminder {
 
 impl PatchReminder {
     fn message_ok(&self) -> bool {
+        if let Some(message) = &self.message_json {
+            return crate::message::validate_payload(message).is_ok();
+        }
         self.content.as_ref().map_or(true, |c| c.len() <= MAX_CONTENT_LENGTH)
             && self.embed_author.as_ref().map_or(true, |c| c.len() <= MAX_EMBED_AUTHOR_LENGTH)
             && self
@@ -433,42 +438,45 @@ pub(crate) async fn create_reminder(
 
     let channel = channel.unwrap();
 
-    if reminder.message_json.as_ref().is_some_and(|message| !message.is_object()) {
-        return Err(json!({"error": "message_json must be an object"}));
+    let message_json = Json(crate::message::payload(&reminder));
+    if let Err(error) = crate::message::validate_payload(&message_json) {
+        return Err(json!({"error": error}));
     }
 
     // validate lengths
     check_length!(MAX_NAME_LENGTH, reminder.name);
-    check_length!(MAX_CONTENT_LENGTH, reminder.content);
-    check_length!(MAX_EMBED_DESCRIPTION_LENGTH, reminder.embed_description);
-    check_length!(MAX_EMBED_TITLE_LENGTH, reminder.embed_title);
-    check_length!(MAX_EMBED_AUTHOR_LENGTH, reminder.embed_author);
-    check_length!(MAX_EMBED_FOOTER_LENGTH, reminder.embed_footer);
-    check_length_opt!(MAX_EMBED_FIELDS, reminder.embed_fields);
-    if let Some(fields) = &reminder.embed_fields {
-        for field in &fields.0 {
-            check_length!(MAX_EMBED_FIELD_VALUE_LENGTH, field.value);
-            check_length!(MAX_EMBED_FIELD_TITLE_LENGTH, field.title);
+    if reminder.message_json.is_none() {
+        check_length!(MAX_CONTENT_LENGTH, reminder.content);
+        check_length!(MAX_EMBED_DESCRIPTION_LENGTH, reminder.embed_description);
+        check_length!(MAX_EMBED_TITLE_LENGTH, reminder.embed_title);
+        check_length!(MAX_EMBED_AUTHOR_LENGTH, reminder.embed_author);
+        check_length!(MAX_EMBED_FOOTER_LENGTH, reminder.embed_footer);
+        check_length_opt!(MAX_EMBED_FIELDS, reminder.embed_fields);
+        if let Some(fields) = &reminder.embed_fields {
+            for field in &fields.0 {
+                check_length!(MAX_EMBED_FIELD_VALUE_LENGTH, field.value);
+                check_length!(MAX_EMBED_FIELD_TITLE_LENGTH, field.title);
+            }
         }
-    }
-    check_length_opt!(MAX_USERNAME_LENGTH, reminder.username);
-    check_length_opt!(
-        MAX_URL_LENGTH,
-        reminder.embed_footer_url,
-        reminder.embed_thumbnail_url,
-        reminder.embed_author_url,
-        reminder.embed_image_url,
-        reminder.avatar
-    );
+        check_length_opt!(MAX_USERNAME_LENGTH, reminder.username);
+        check_length_opt!(
+            MAX_URL_LENGTH,
+            reminder.embed_footer_url,
+            reminder.embed_thumbnail_url,
+            reminder.embed_author_url,
+            reminder.embed_image_url,
+            reminder.avatar
+        );
 
-    // validate urls
-    check_url_opt!(
-        reminder.embed_footer_url,
-        reminder.embed_thumbnail_url,
-        reminder.embed_author_url,
-        reminder.embed_image_url,
-        reminder.avatar
-    );
+        // validate urls
+        check_url_opt!(
+            reminder.embed_footer_url,
+            reminder.embed_thumbnail_url,
+            reminder.embed_author_url,
+            reminder.embed_image_url,
+            reminder.avatar
+        );
+    }
 
     // validate time and interval
     if reminder.utc_time < Utc::now().naive_utc() {
@@ -498,7 +506,6 @@ pub(crate) async fn create_reminder(
     }
 
     let name = if reminder.name.is_empty() { name_default() } else { reminder.name.clone() };
-    let message_json = Json(crate::message::payload(&reminder));
 
     let new_uid = generate_uid();
 
@@ -845,3 +852,50 @@ async fn render_dashboard(cookies: &CookieJar<'_>) -> DashboardPage {
         DashboardPage::Unauthorised(Redirect::to("/login/discord"))
     }
 }
+
+#[cfg(test)]
+mod message_json_tests {
+    use super::*;
+
+    #[tokio::test]
+    #[ignore = "requires MESSAGE_JSON_TEST_DATABASE_URL pointing to an isolated MySQL database"]
+    async fn patch_keeps_embeds_and_buttons_and_ignores_legacy_message_fields() {
+        let pool =
+            sqlx::MySqlPool::connect(&std::env::var("MESSAGE_JSON_TEST_DATABASE_URL").unwrap())
+                .await
+                .unwrap();
+        let mut transaction = pool.begin().await.unwrap();
+        let channel = sqlx::query("INSERT INTO channels (channel) VALUES (?)")
+            .bind(rand::random::<u64>())
+            .execute(&mut *transaction)
+            .await
+            .unwrap()
+            .last_insert_id();
+        let uid = format!("multi-embed-test-{}", rand::random::<u64>());
+        sqlx::query("INSERT INTO reminders (uid, channel_id, `utc_time`) VALUES (?, ?, NOW())")
+            .bind(&uid)
+            .bind(channel)
+            .execute(&mut *transaction)
+            .await
+            .unwrap();
+        let payload = json!({"content": "current", "embeds": [{"title": "first"}, {"title": "second"}],
+            "components": [{"type": 1, "components": [{"type": 2, "style": 5,
+                "label": "Open link", "url": "https://example.com"}]}]});
+        let reminder: PatchReminder = serde_json::from_value(json!({
+            "uid": uid, "message_json": payload, "content": "stale", "embed_title": "stale"
+        }))
+        .unwrap();
+        let mut errors = vec![];
+        assert!(reminder.message_ok());
+        update_field!(&mut *transaction, errors, reminder.[message_json, content, embed_title]);
+        assert!(errors.is_empty());
+        let stored: (Json<serde_json::Value>,) =
+            sqlx::query_as("SELECT message_json FROM reminders WHERE uid = ?")
+                .bind(&uid)
+                .fetch_one(&mut *transaction)
+                .await
+                .unwrap();
+        assert_eq!(stored.0 .0, payload);
+        transaction.rollback().await.unwrap();
+    }
+}