Source Intelligence
Sweep 28 Aug 2026 ยท 00:00Z Build v2.1.250 478 read Stable v2.1.236 Latest v2.1.250 Next v2.1.250 Feeds RSS JSON llms.txt

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

One change

cache-diagnostics

build-with-claude/cache-diagnostics

first seen The page's own history The capture it came from

Nearest release: v2.1.239, published 2 hours before this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.

build-with-claude/cache-diagnostics Changed · +16 / -16 lines

from line 30
   ```bash cURL
   # Turn 1: establish the cache and opt in to diagnostics
   response=$(curl -sS --fail-with-body https://api.anthropic.com/v1/messages \
-    --header "x-api-key: $ANTHROPIC_API_KEY" \
-    --header "anthropic-version: 2023-06-01" \
-    --header "anthropic-beta: cache-diagnosis-2026-04-07" \
-    --header "content-type: application/json" \
-    --data '{
+    -H "x-api-key: $ANTHROPIC_API_KEY" \
+    -H "anthropic-version: 2023-06-01" \
+    -H "anthropic-beta: cache-diagnosis-2026-04-07" \
+    -H "content-type: application/json" \
+    -d '{
       "model": "claude-opus-5",
       "max_tokens": 1024,
       "cache_control": {"type": "ephemeral"},
from line 47
 
   # Turn 2: reference the previous turn so the API can compare prefixes
   curl -sS --fail-with-body https://api.anthropic.com/v1/messages \
-    --header "x-api-key: $ANTHROPIC_API_KEY" \
-    --header "anthropic-version: 2023-06-01" \
-    --header "anthropic-beta: cache-diagnosis-2026-04-07" \
-    --header "content-type: application/json" \
-    --data @- <<EOF | jq '{id, diagnostics}'  # diagnostics: null means no divergence was found
+    -H "x-api-key: $ANTHROPIC_API_KEY" \
+    -H "anthropic-version: 2023-06-01" \
+    -H "anthropic-beta: cache-diagnosis-2026-04-07" \
+    -H "content-type: application/json" \
+    -d @- <<EOF | jq '{id, diagnostics}'  # diagnostics: null means no divergence was found
   {
     "model": "claude-opus-5",
     "max_tokens": 1024,
from line 427
   # Turn 2: stream the response. diagnostics arrives on the message_start event;
   # a null value means no divergence was found.
   curl -sS --fail-with-body https://api.anthropic.com/v1/messages \
-    --header "x-api-key: $ANTHROPIC_API_KEY" \
-    --header "anthropic-version: 2023-06-01" \
-    --header "anthropic-beta: cache-diagnosis-2026-04-07" \
-    --header "content-type: application/json" \
-    --data @- <<EOF | jq -R 'select(startswith("data: ")) | ltrimstr("data: ") | fromjson | select(.type == "message_start") | .message.diagnostics'
+    -H "x-api-key: $ANTHROPIC_API_KEY" \
+    -H "anthropic-version: 2023-06-01" \
+    -H "anthropic-beta: cache-diagnosis-2026-04-07" \
+    -H "content-type: application/json" \
+    -d @- <<EOF | jq -R 'select(startswith("data: ")) | ltrimstr("data: ") | fromjson | select(.type == "message_start") | .message.diagnostics'
   {
     "model": "claude-opus-5",
     "max_tokens": 1024,
from line 1078
 
 ## Limitations
 
-* **Beta:** Field names and semantics may change before general availability.
+* **Beta:** Field names and semantics may change while this feature is in beta.
 * **Claude API only:** Not available on Amazon Bedrock or Google Cloud.
 * **Limited retention:** Fingerprints for `previous_message_id` lookup expire after a short period. Run diagnostic comparisons between closely spaced requests.
 * **Same workspace:** The previous request must have been made with an API key from the same organization and workspace. To check, compare the `anthropic-workspace-id` [response header](https://platform.claude.com/docs/en/api/overview#response-headers) on the two responses.