Add json api

Cargo.lock

@@ -1402,6 +1402,12 @@ dependencies = [
  "windows-targets 0.48.5",
 ]
 
+[[package]]
+name = "paste"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "de3145af08024dea9fa9914f381a17b8fc6034dfb00f3a84013f7ff43f29ed4c"
+
 [[package]]
 name = "pear"
 version = "0.2.8"
@@ -1739,6 +1745,28 @@ dependencies = [
  "windows-sys 0.48.0",
 ]
 
+[[package]]
+name = "rmp"
+version = "0.8.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f9860a6cc38ed1da53456442089b4dfa35e7cedaa326df63017af88385e6b20"
+dependencies = [
+ "byteorder",
+ "num-traits",
+ "paste",
+]
+
+[[package]]
+name = "rmp-serde"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bffea85eea980d8a74453e5d02a8d93028f3c34725de143085a844ebe953258a"
+dependencies = [
+ "byteorder",
+ "rmp",
+ "serde",
+]
+
 [[package]]
 name = "rocket"
 version = "0.5.0"
@@ -1762,9 +1790,11 @@ dependencies = [
  "pin-project-lite",
  "rand",
  "ref-cast",
+ "rmp-serde",
  "rocket_codegen",
  "rocket_http",
  "serde",
+ "serde_json",
  "state",
  "tempfile",
  "time",