diff --git a/README.md b/README.md
index 46c8563d..b9c72a3c 100644
--- a/README.md
+++ b/README.md
@@ -200,7 +200,7 @@ Note that the Invocation MUST include the Signature envelope. An [Invocation Pay
 ## Type Tag
 [Type Tag]: #type-tag
  
-The UCAN envelope's payload tag MUST be `ucan/inv@1.0.0-rc.1`.
+The UCAN envelope's [payload tag] MUST be `ucan/inv@1.0.0-rc.1`.
 
 ## Invocation Payload
 [Invocation Payload]: #invocation-payload
@@ -568,5 +568,6 @@ Thanks to [Rod Vagg] for the clarifications on IPLD Schema implicits and the gen
 [designation without authorization]: https://srl.cs.jhu.edu/pubs/SRL2003-02.pdf
 [distributed promise pipelines]: http://erights.org/elib/distrib/pipeline.html
 [eRights]: https://erights.org
+[payload tag]: https://github.com/ucan-wg/spec/blob/main/README.md#envelope
 [principle of least authority]: https://en.wikipedia.org/wiki/Principle_of_least_privilege
 [ucanto RPC]: https://github.com/web3-storage/ucanto
diff --git a/invocation.ipldsch b/invocation.ipldsch
index 6deda743..6cb44d6a 100644
--- a/invocation.ipldsch
+++ b/invocation.ipldsch
@@ -5,17 +5,15 @@ type Invocation struct {
 
 type SignaturePayload {
   h VarsigHeader
-  i Invocation
+  i InvocationV1Payload
 }
 
-type InvocationPayload struct {
-  uiv SemVer
-
+type InvocationV1Payload struct {
   iss DID
   sub DID
   aud optional DID
 
-  do Command
+  cmd Command
   args {String : Any}
   nonce String
 
diff --git a/receipt.ipldsch b/receipt.ipldsch
deleted file mode 100644
index 27c5f539..00000000
--- a/receipt.ipldsch
+++ /dev/null
@@ -1,28 +0,0 @@
-type Receipt {
-  s Signature
-  p SignaturePayload
-}
-
-type SignaturePayload {
-  h VarsigHeader
-  r ReceiptPayload
-}
-
-type ReceiptPayload struct {
-  iss DID
-  ran &Invocation
-
-  enq [&Task]
-  out Result
-
-  iat Integer
-  mta {String : Any}
-
-  prf [&Delegation]
-  rec &Receipt
-}
-
-type Result union {
-  | any "ok"
-  | any "error"
-} representation keyed
diff --git a/signature.ipldsch b/signature.ipldsch
deleted file mode 100644
index fc4e7118..00000000
--- a/signature.ipldsch
+++ /dev/null
@@ -1,9 +0,0 @@
-type Signature union {
-  | inline Bytes
-  | batch  &BatchSignature
-}
-
-type BatchSignature struct {
-  scp [&Any]
-  sig Bytes
-}