diff --git a/elm.json b/elm.json
index 168fd69..3c502e6 100644
--- a/elm.json
+++ b/elm.json
@@ -16,6 +16,7 @@
         "Internal.Tools.Iddict",
         "Internal.Tools.Timestamp",
         "Internal.Tools.VersionControl",
+        "Internal.Values.Context",
         "Internal.Values.Envelope",
         "Internal.Values.Vault",
         "Types"
diff --git a/src/Internal/Config/Leaks.elm b/src/Internal/Config/Leaks.elm
index c71b81c..d9f2d07 100644
--- a/src/Internal/Config/Leaks.elm
+++ b/src/Internal/Config/Leaks.elm
@@ -1,4 +1,4 @@
-module Internal.Config.Leaks exposing (accessToken)
+module Internal.Config.Leaks exposing (accessToken, baseUrl, transaction, versions)
 
 {-|
 
@@ -27,7 +27,7 @@ know 100% sure that the value isn't `Nothing`.
 
     Just 5 |> Maybe.withDefault Leaks.number
 
-@docs accessToken
+@docs accessToken, baseUrl, transaction, versions
 
 -}
 
@@ -37,3 +37,24 @@ know 100% sure that the value isn't `Nothing`.
 accessToken : String
 accessToken =
     "elm-sdk-placeholder-access-token-leaks"
+
+
+{-| Placeholder base URL.
+-}
+baseUrl : String
+baseUrl =
+    "elm-sdk-placeholder-baseurl-leaks.example.org"
+
+
+{-| Placeholder transaction id.
+-}
+transaction : String
+transaction =
+    "elm-sdk-placeholder-transaction-leaks"
+
+
+{-| Placeholder versions list.
+-}
+versions : List String
+versions =
+    [ "elm-sdk-placeholder-versions-leaks" ]
diff --git a/src/Internal/Values/Context.elm b/src/Internal/Values/Context.elm
new file mode 100644
index 0000000..88efd33
--- /dev/null
+++ b/src/Internal/Values/Context.elm
@@ -0,0 +1,196 @@
+module Internal.Values.Context exposing
+    ( Context, init, encode, decoder
+    , APIContext, apiFormat
+    , setAccessToken, getAccessToken
+    , setBaseUrl, getBaseUrl
+    , setTransaction, getTransaction
+    , setVersions, getVersions
+    )
+
+{-| The Context is the set of variables that the user (mostly) cannot control.
+The Context contains tokens, values and other bits that the Vault receives from
+the Matrix API.
+
+
+## Context
+
+@docs Context, init, encode, decoder
+
+
+## APIContext
+
+Once the API starts needing information, that's when we use the APIContext type
+to build the right environment for the API communication to work with.
+
+@docs APIContext, apiFormat
+
+Once the APIContext is ready, there's helper functions for each piece of
+information that can be inserted.
+
+
+### Access token
+
+@docs setAccessToken, getAccessToken
+
+
+### Base URL
+
+@docs setBaseUrl, getBaseUrl
+
+
+### Transaction id
+
+@docs setTransaction, getTransaction
+
+
+### Versions
+
+@docs setVersions, getVersions
+
+-}
+
+import Internal.Config.Leaks as L
+import Internal.Tools.Decode as D
+import Internal.Tools.Encode as E
+import Json.Decode as D
+import Json.Encode as E
+
+
+{-| The Context type stores all the information in the Vault. This data type is
+static and hence can be passed on easily.
+-}
+type alias Context =
+    { accessToken : Maybe String
+    , baseUrl : Maybe String
+    , password : Maybe String
+    , refreshToken : Maybe String
+    , username : Maybe String
+    , transaction : Maybe String
+    , versions : Maybe (List String)
+    }
+
+
+{-| The APIContext is a separate type that uses a phantom type to trick the
+compiler into requiring values to be present. This data type is used to gather
+the right variables (like an access token) before accessing the Matrix API.
+-}
+type APIContext ph
+    = APIContext
+        { accessToken : String
+        , baseUrl : String
+        , context : Context
+        , transaction : String
+        , versions : List String
+        }
+
+
+{-| Create an unformatted APIContext type.
+-}
+apiFormat : Context -> APIContext {}
+apiFormat context =
+    APIContext
+        { accessToken = context.accessToken |> Maybe.withDefault L.accessToken
+        , baseUrl = context.baseUrl |> Maybe.withDefault L.baseUrl
+        , context = context
+        , transaction = context.transaction |> Maybe.withDefault L.transaction
+        , versions = context.versions |> Maybe.withDefault L.versions
+        }
+
+
+{-| Decode a Context type from a JSON value.
+-}
+decoder : D.Decoder Context
+decoder =
+    D.map7 Context
+        (D.opField "accessToken" D.string)
+        (D.opField "baseUrl" D.string)
+        (D.opField "password" D.string)
+        (D.opField "refreshToken" D.string)
+        (D.opField "username" D.string)
+        (D.opField "transaction" D.string)
+        (D.opField "versions" (D.list D.string))
+
+
+{-| Encode a Context type into a JSON value.
+-}
+encode : Context -> E.Value
+encode context =
+    E.maybeObject
+        [ ( "accessToken", Maybe.map E.string context.accessToken )
+        , ( "baseUrl", Maybe.map E.string context.baseUrl )
+        , ( "password", Maybe.map E.string context.password )
+        , ( "refreshToken", Maybe.map E.string context.refreshToken )
+        , ( "username", Maybe.map E.string context.username )
+        , ( "transaction", Maybe.map E.string context.transaction )
+        , ( "versions", Maybe.map (E.list E.string) context.versions )
+        ]
+
+
+{-| A basic, untouched version of the Context, containing no information.
+-}
+init : Context
+init =
+    { accessToken = Nothing
+    , baseUrl = Nothing
+    , refreshToken = Nothing
+    , password = Nothing
+    , username = Nothing
+    , transaction = Nothing
+    , versions = Nothing
+    }
+
+
+{-| Get an inserted access token.
+-}
+getAccessToken : APIContext { a | accessToken : () } -> String
+getAccessToken (APIContext c) =
+    c.accessToken
+
+
+{-| Insert an access token into the APIContext.
+-}
+setAccessToken : String -> APIContext a -> APIContext { a | accessToken : () }
+setAccessToken value (APIContext c) =
+    APIContext { c | accessToken = value }
+
+
+{-| Get an inserted base URL.
+-}
+getBaseUrl : APIContext { a | baseUrl : () } -> String
+getBaseUrl (APIContext c) =
+    c.baseUrl
+
+
+{-| Insert a base URL into the APIContext.
+-}
+setBaseUrl : String -> APIContext a -> APIContext { a | baseUrl : () }
+setBaseUrl value (APIContext c) =
+    APIContext { c | baseUrl = value }
+
+
+{-| Get an inserted transaction id.
+-}
+getTransaction : APIContext { a | transaction : () } -> String
+getTransaction (APIContext c) =
+    c.transaction
+
+
+{-| Insert a transaction id into the APIContext.
+-}
+setTransaction : String -> APIContext a -> APIContext { a | transaction : () }
+setTransaction value (APIContext c) =
+    APIContext { c | transaction = value }
+
+
+{-| Get an inserted versions list.
+-}
+getVersions : APIContext { a | versions : () } -> List String
+getVersions (APIContext c) =
+    c.versions
+
+
+{-| Insert a versions list into the APIContext.
+-}
+setVersions : List String -> APIContext a -> APIContext { a | versions : () }
+setVersions value (APIContext c) =
+    APIContext { c | versions = value }