diff --git a/packages/thing-contract/src/keys.ts b/packages/thing-contract/src/keys.ts
index e87000e..ca40192 100644
--- a/packages/thing-contract/src/keys.ts
+++ b/packages/thing-contract/src/keys.ts
@@ -5,11 +5,11 @@
 import { segment, seq, version } from "./domain.js";
 
 export function surfaceKey(providerId: string, label: string): string {
-  return `thing:surface:${providerId}.${segment.decode(label)}`;
+  return `thing:surface:${providerId}.${segment.encode(label)}`;
 }
 
 export function compositionKey(publisher: string, name: string, versionNumber: number | bigint): string {
-  return `thing:composition:${publisher}.${segment.decode(name)}.v${version.decode(versionNumber)}`;
+  return `thing:composition:${publisher}.${segment.encode(name)}.v${version.encode(versionNumber)}`;
 }
 
 export function invocationKey(invocationId: string): string {
@@ -17,9 +17,9 @@ export function invocationKey(invocationId: string): string {
 }
 
 export function resultKey(invocationId: string, position: number): string {
-  return `thing:result:${invocationId}.${seq.decode(position)}`;
+  return `thing:result:${invocationId}.${seq.encode(position)}`;
 }
 
 export function assetCatalogKey(providerId: string, catalogId: string): string {
-  return `thing:asset_catalog:${providerId}.${segment.decode(catalogId)}`;
+  return `thing:asset_catalog:${providerId}.${segment.encode(catalogId)}`;
 }
diff --git a/packages/thing-contract/src/result.ts b/packages/thing-contract/src/result.ts
index ad5ed06..cdd18fd 100644
--- a/packages/thing-contract/src/result.ts
+++ b/packages/thing-contract/src/result.ts
@@ -27,7 +27,7 @@ export class CommandResult {
   private constructor(key: typeof door, invocationId: string, position: number, outcome: Outcome) {
     if (key !== door) throw new Error("a CommandResult is built by its factories");
     this.invocationId = invocationId;
-    this.seq = seq.decode(position);
+    this.seq = seq.encode(position);
     this.outcome = outcome;
     Object.freeze(this);
   }
diff --git a/packages/thing-contract/test/deep.test.ts b/packages/thing-contract/test/deep.test.ts
index 7ea7bfa..f6b8d34 100644
--- a/packages/thing-contract/test/deep.test.ts
+++ b/packages/thing-contract/test/deep.test.ts
@@ -37,7 +37,7 @@ const admits = (levels: number): boolean => {
 test("the deepest Box chain the bound admits round-trips on the default stack, and one more is refused", () => {
   let deepest = 1;
   while (admits(deepest + 1)) deepest++;
-  assert.equal(deepest, 84, "the bound admits 84 Box levels above the leaf");
+  assert.equal(deepest, 83, "the bound admits 83 Box levels above the text leaf, 84 nodes deep");
   assert.ok(!admits(deepest + 1));
 
   const value = chain(deepest);
diff --git a/packages/thing-contract/test/keys.test.ts b/packages/thing-contract/test/keys.test.ts
index 2f0423c..c228a89 100644
--- a/packages/thing-contract/test/keys.test.ts
+++ b/packages/thing-contract/test/keys.test.ts
@@ -38,6 +38,9 @@ test("a result key refuses a seq below 1 and a composition key a version below 0
   assert.throws(() => resultKey("x", 0), /Seq must be at least 1/);
   assert.throws(() => compositionKey("pub", "card", -1), /Version must be at least 0/);
   assert.equal(compositionKey("pub", "card", 0), "thing:composition:pub.card.v0");
+  assert.throws(() => compositionKey("pub", "card", 1.5), /int64/);
+  assert.throws(() => resultKey("x", 1.5), /int32/);
+  assert.throws(() => resultKey("x", 2 ** 31), /int32/);
 });
 
 test("keys are injective over their field sets", () => {