docs: convert ascii art sequence diagram into mermaid diagrams

1 files changed, 42 insertions, 0 deletions

diff --git a/share/man/ENVOY.md b/share/man/ENVOY.md
index 1bdeee2..1f4dd51 100644
--- a/share/man/ENVOY.md
+++ b/share/man/ENVOY.md
@@ -102,6 +102,25 @@ boarding pass, bus ticket from trusted and reputable authorities.
    |<--- deny access --|
 ```
 
+```mermaid
+sequenceDiagram
+    participant P as Passenger
+    participant BD as Bus Driver
+    participant B as Bus
+
+    P->>BD: request access
+    BD->>P: request ticket
+    P->>BD: present ticket
+    Note over BD: authorize (bus #, expiration, fake/legit?)
+
+    alt Valid ticket
+        BD->>P: grant access
+        P->>B: board bus
+    else Invalid ticket
+        BD->>P: deny access
+    end
+```
+
 The Bus # indicates the canonical identifier for the resource and
 this is similar to accessing a resource exposed via a REST/GraphQL
 API. The expiration check ensures that the same token cannot be re-used
@@ -139,6 +158,29 @@ warrant the need for authentication and only requires authorization.
    |--- board plane  ------------------------------------------------->|
 ```
 
+```mermaid
+sequenceDiagram
+    participant P as Passenger
+    participant SA as Security Agent
+    participant BA as Boarding Agent
+    participant Plane as Plane
+
+    P->>SA: request access to gate
+    SA->>P: request boarding pass
+    P->>SA: present boarding pass
+    SA->>SA: validate pass
+    SA->>P: allow access to gate
+
+    P->>BA: request access to board plane
+    BA->>P: request passport
+    P->>BA: present passport
+    BA->>P: request boarding pass
+    P->>BA: present boarding pass
+    BA->>P: allow access to board plane
+
+    P->>Plane: board plane
+```
+
 To board a plane you must pass through more security checks before you can
 access the airplane. That is because flying in an airplane is a high security
 context that requires additional checks to ensure the safety of everyone and the