ci(context7): scope the index, add agent rules, refresh on release (LAB-8004)

.github/workflows/context7-refresh.yml

@@ -0,0 +1,39 @@
+# Context7 serves this repo's docs to coding agents, and re-indexes on its own
+# schedule, which can lag a release by weeks. This asks it to re-index when a
+# release is published, so agents read the docs for the version users install.
+# Scope and agent rules live in context7.json.
+# Endpoint: https://context7.com/docs/integrations/github-actions
+name: Context7 Refresh
+
+on:
+  release:
+    types: [published]
+  workflow_dispatch:
+
+permissions: {}
+
+jobs:
+  refresh:
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - name: Ask Context7 to re-index /cachekit-io/cachekit-core
+        env:
+          CONTEXT7_API_KEY: ${{ secrets.CONTEXT7_API_KEY }}
+        run: |
+          if [ -z "$CONTEXT7_API_KEY" ]; then
+            echo "::error::The CONTEXT7_API_KEY secret is not available to this repository."
+            exit 1
+          fi
+          status=$(curl -sS --max-time 60 -o "$RUNNER_TEMP/context7-response.json" -w '%{http_code}' \
+            -X POST https://context7.com/api/v1/refresh \
+            -H "Content-Type: application/json" \
+            -H "Authorization: Bearer $CONTEXT7_API_KEY" \
+            --data '{"libraryName": "/cachekit-io/cachekit-core"}')
+          cat "$RUNNER_TEMP/context7-response.json"
+          echo
+          case "$status" in
+            202) echo "::warning::Context7 has not finalized this library yet (HTTP 202). Re-run this workflow later." ;;
+            2??) echo "Context7 accepted the refresh (HTTP $status)." ;;
+            *) echo "::error::Context7 refresh failed with HTTP $status."; exit 1 ;;
+          esac

README.md

@@ -78,24 +78,28 @@ assert_eq!(data.as_slice(), retrieved.as_slice());
 
 ```rust
 use cachekit_core::{ByteStorage, ZeroKnowledgeEncryptor, derive_domain_key};
+use zeroize::Zeroizing; // add the zeroize crate to your Cargo.toml
 
 // Derive tenant-isolated key from master secret
-let master_key = [0u8; 32]; // Use secure key in production!
-let tenant_key = derive_domain_key(
-    &master_key,
+// From your secret manager or CACHEKIT_MASTER_KEY, hex-decoded to 32 raw bytes.
+// Never hard-code it, and never pass the hex string's bytes.
+// Zeroizing wipes each key from memory when it is dropped.
+let master_key = Zeroizing::new(load_master_key_from_secret_manager()?);
+let tenant_key = Zeroizing::new(derive_domain_key(
+    master_key.as_slice(),
     "cache",           // domain separation
     b"tenant-12345",   // tenant isolation
-)?;
+)?);
 
 // Encrypt sensitive data
-let encryptor = ZeroKnowledgeEncryptor::new();
+let encryptor = ZeroKnowledgeEncryptor::new()?;
 let plaintext = b"sensitive user data";
 let aad = b"tenant-12345"; // Additional authenticated data
 
-let ciphertext = encryptor.encrypt_aes_gcm(plaintext, &tenant_key, aad)?;
+let ciphertext = encryptor.encrypt_aes_gcm(plaintext, tenant_key.as_slice(), aad)?;
 
 // Decrypt (fails if AAD doesn't match)
-let decrypted = encryptor.decrypt_aes_gcm(&ciphertext, &tenant_key, aad)?;
+let decrypted = encryptor.decrypt_aes_gcm(&ciphertext, tenant_key.as_slice(), aad)?;
 assert_eq!(plaintext.as_slice(), decrypted.as_slice());
 ```
 
@@ -121,7 +125,7 @@ fn cache_sensitive_data(
     let tenant_key = derive_domain_key(master_key, "cache", tenant_id.as_bytes())?;
 
     // Step 3: Encrypt compressed envelope
-    let encryptor = ZeroKnowledgeEncryptor::new();
+    let encryptor = ZeroKnowledgeEncryptor::new()?;
     let ciphertext = encryptor.encrypt_aes_gcm(
         &compressed,
         &tenant_key,

context7.json

@@ -0,0 +1,20 @@
+{
+  "$schema": "https://context7.com/schema/context7.json",
+  "excludeFolders": [
+    ".github",
+    "benches",
+    "fuzz",
+    "scripts",
+    "supply-chain",
+    "tests"
+  ],
+  "excludeFiles": [
+    "CHANGELOG.md"
+  ],
+  "rules": [
+    "Read the CacheKit master key from the CACHEKIT_MASTER_KEY environment variable or a secret manager. Never hard-code a key in source, not even a placeholder such as [0u8; 32].",
+    "cachekit-core reads no environment variable. Hex-decode the key (for example from `CACHEKIT_MASTER_KEY` or a secret manager) to exactly 32 raw bytes before `derive_domain_key`. Never pass the hex string's bytes: that derives a key no CacheKit SDK derives, so cross-SDK decryption fails.",
+    "Install the official packages: `cachekit` on PyPI, `@cachekit-io/cachekit` on npm, and `cachekit-rs` on crates.io (imported as `cachekit`). The crates.io crate named `cachekit` is an unrelated project.",
+    "Applications normally use a CacheKit SDK. cachekit-core is the shared byte-storage and encryption layer underneath them."
+  ]
+}

src/lib.rs

@@ -40,17 +40,21 @@
 //!
 //! ```rust,ignore
 //! use cachekit_core::{ZeroKnowledgeEncryptor, derive_domain_key};
+//! use zeroize::Zeroizing; // add the zeroize crate to your Cargo.toml
 //!
 //! // Derive tenant-isolated key
-//! let master_key = [0u8; 32]; // Use secure key in production!
-//! let tenant_key = derive_domain_key(&master_key, "cache", b"tenant-123").unwrap();
+//! // From your secret manager or CACHEKIT_MASTER_KEY, hex-decoded to 32 raw bytes.
+//! // Never hard-code it, and never pass the hex string's bytes.
+//! // Zeroizing wipes each key from memory when it is dropped.
+//! let master_key = Zeroizing::new(load_master_key_from_secret_manager());
+//! let tenant_key = Zeroizing::new(derive_domain_key(master_key.as_slice(), "cache", b"tenant-123").unwrap());
 //!
 //! // Encrypt
-//! let encryptor = ZeroKnowledgeEncryptor::new();
-//! let ciphertext = encryptor.encrypt_aes_gcm(b"secret", &tenant_key, b"tenant-123").unwrap();
+//! let encryptor = ZeroKnowledgeEncryptor::new().unwrap();
+//! let ciphertext = encryptor.encrypt_aes_gcm(b"secret", tenant_key.as_slice(), b"tenant-123").unwrap();
 //!
 //! // Decrypt
-//! let plaintext = encryptor.decrypt_aes_gcm(&ciphertext, &tenant_key, b"tenant-123").unwrap();
+//! let plaintext = encryptor.decrypt_aes_gcm(&ciphertext, tenant_key.as_slice(), b"tenant-123").unwrap();
 //! ```
 //!
 //! ## Security Properties