diff --git a/Makefile b/Makefile
index 7f5186ec..8ff9d89b 100644
--- a/Makefile
+++ b/Makefile
@@ -30,9 +30,9 @@ clean:: # Clean-up project resources (main) @Operations
 # (cd src/server && make clean)
 
 guard-%:
-	@ if [ "${${*}}" = "" ]; then \
+	@if [ -z "$${$*}" ]; then \
 		echo "Variable $* not set"; \
-		echo "Usage: make <target> APIM_ENV=<env>"
+		echo "Usage: make <target> $*=<env>"; \
 		exit 1; \
 	fi
 serve:
@@ -59,6 +59,9 @@ set-security: guard-APIM_ENV
 	@ SECURITY=security-$$APIM_ENV.yml \
 	envsubst '$${SECURITY}' \
 	< specification/api/components/security/security-template.yml > specification/api/components/security/security.yml
+	@ SECURITY_SCHEMES=security-schemes-$$APIM_ENV.yml \
+	envsubst '$${SECURITY_SCHEMES}' \
+	< specification/api/components/security-schemes/security-schemes-template.yml > specification/api/components/security-schemes/security-schemes.yml
 
 construct-spec: guard-APIM_ENV
 	$(MAKE) set-target APIM_ENV=$$APIM_ENV
diff --git a/internal/datastore/src/cli/diagrams.ts b/internal/datastore/src/cli/diagrams.ts
index c9e8ad3c..d7667f6a 100644
--- a/internal/datastore/src/cli/diagrams.ts
+++ b/internal/datastore/src/cli/diagrams.ts
@@ -1,25 +1,39 @@
-import {LetterSchema, MISchema, SupplierSchema} from '../types';
-import { generateMermaidDiagram } from 'zod-mermaid';
-import * as fs from 'node:fs';
+import { generateMermaidDiagram } from "zod-mermaid";
+import * as fs from "node:fs";
+import {
+  LetterSchema,
+  MISchema,
+  SupplierSchema,
+} from "internal/datastore/src/types";
 
-const out = fs.openSync('src/types.md', 'w');
+const out = fs.openSync("src/types.md", "w");
 
-fs.writeSync(out, `# Data Store Schemas
+fs.writeSync(
+  out,
+  `# Data Store Schemas
 
 This document contains the mermaid diagrams for the data store schemas used in the application.
 
 The schemas are generated from Zod definitions and provide a visual representation of the data structure.
-`);
+`,
+);
 
-for (const [name, schema] of Object.entries({ Letter: [LetterSchema], MI: [MISchema], Supplier: [SupplierSchema] })) {
+for (const [name, schema] of Object.entries({
+  Letter: [LetterSchema],
+  MI: [MISchema],
+  Supplier: [SupplierSchema],
+})) {
   const mermaid = generateMermaidDiagram(schema);
-  fs.writeSync(out, `
+  fs.writeSync(
+    out,
+    `
 ## ${name} schema
 
 \`\`\`mermaid
 ${mermaid}
 \`\`\`
-`);
+`,
+  );
 }
 
 fs.closeSync(out);
diff --git a/specification/api/components/security-schemes/security-schemes-int.yml b/specification/api/components/security-schemes/security-schemes-int.yml
new file mode 100644
index 00000000..80a446d6
--- /dev/null
+++ b/specification/api/components/security-schemes/security-schemes-int.yml
@@ -0,0 +1 @@
+$ref: './security-schemes-ptl.yml'
diff --git a/specification/api/components/security-schemes/security-schemes-internal-dev-pr.yml b/specification/api/components/security-schemes/security-schemes-internal-dev-pr.yml
new file mode 100644
index 00000000..80a446d6
--- /dev/null
+++ b/specification/api/components/security-schemes/security-schemes-internal-dev-pr.yml
@@ -0,0 +1 @@
+$ref: './security-schemes-ptl.yml'
diff --git a/specification/api/components/security-schemes/security-schemes-internal-dev.yml b/specification/api/components/security-schemes/security-schemes-internal-dev.yml
new file mode 100644
index 00000000..80a446d6
--- /dev/null
+++ b/specification/api/components/security-schemes/security-schemes-internal-dev.yml
@@ -0,0 +1 @@
+$ref: './security-schemes-ptl.yml'
diff --git a/specification/api/components/security-schemes/security-schemes-prod.yml b/specification/api/components/security-schemes/security-schemes-prod.yml
new file mode 100644
index 00000000..53ade6bd
--- /dev/null
+++ b/specification/api/components/security-schemes/security-schemes-prod.yml
@@ -0,0 +1,4 @@
+app-level3:
+  $ref: https://proxygen.prod.api.platform.nhs.uk/components/securitySchemes/app-level3
+app-level0:
+  $ref: https://proxygen.prod.api.platform.nhs.uk/components/securitySchemes/app-level0
diff --git a/specification/api/components/security-schemes/security-schemes-ptl.yml b/specification/api/components/security-schemes/security-schemes-ptl.yml
new file mode 100644
index 00000000..91763ecc
--- /dev/null
+++ b/specification/api/components/security-schemes/security-schemes-ptl.yml
@@ -0,0 +1,4 @@
+app-level3:
+  $ref: https://proxygen.ptl.api.platform.nhs.uk/components/securitySchemes/app-level3
+app-level0:
+  $ref: https://proxygen.ptl.api.platform.nhs.uk/components/securitySchemes/app-level0
diff --git a/specification/api/components/security-schemes/security-schemes-ref.yml b/specification/api/components/security-schemes/security-schemes-ref.yml
new file mode 100644
index 00000000..80a446d6
--- /dev/null
+++ b/specification/api/components/security-schemes/security-schemes-ref.yml
@@ -0,0 +1 @@
+$ref: './security-schemes-ptl.yml'
diff --git a/specification/api/components/security-schemes/security-schemes-sandbox.yml b/specification/api/components/security-schemes/security-schemes-sandbox.yml
new file mode 100644
index 00000000..80a446d6
--- /dev/null
+++ b/specification/api/components/security-schemes/security-schemes-sandbox.yml
@@ -0,0 +1 @@
+$ref: './security-schemes-ptl.yml'
diff --git a/specification/api/components/security-schemes/security-schemes-template.yml b/specification/api/components/security-schemes/security-schemes-template.yml
new file mode 100644
index 00000000..f15a14a3
--- /dev/null
+++ b/specification/api/components/security-schemes/security-schemes-template.yml
@@ -0,0 +1 @@
+$ref: $SECURITY_SCHEMES
diff --git a/specification/api/components/security-schemes/security-schemes.yml b/specification/api/components/security-schemes/security-schemes.yml
new file mode 100644
index 00000000..78a3ea0e
--- /dev/null
+++ b/specification/api/components/security-schemes/security-schemes.yml
@@ -0,0 +1 @@
+$ref: security-schemes-prod.yml
diff --git a/specification/api/notify-supplier-phase1.yml b/specification/api/notify-supplier-phase1.yml
index 4062bf09..589c18af 100644
--- a/specification/api/notify-supplier-phase1.yml
+++ b/specification/api/notify-supplier-phase1.yml
@@ -49,10 +49,7 @@ paths:
       summary: Health check
 components:
   securitySchemes:
-    app-level3:
-      $ref: https://proxygen.ptl.api.platform.nhs.uk/components/securitySchemes/app-level3
-    app-level0:
-      $ref: https://proxygen.ptl.api.platform.nhs.uk/components/securitySchemes/app-level0
+    $ref: ./components/security-schemes/security-schemes.yml
 
 tags:
   - name: letter