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Sweep 28 Aug 2026 · 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

Messages

api/beta/messages

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

Nearest release: v2.1.247, published under an hour 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.

api/beta/messages Changed · +206 / -44 lines

This page is larger than the 256 KiB this site keeps, so one side of the diff below stops where the stored text does.

from line 18
 
   - `string`
 
-  - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 31 more`
+  - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
 
     - `"message-batches-2024-09-24"`
from line 88
 
     - `"mid-conversation-tool-changes-2026-07-01"`
 
+    - `"compact-2026-01-12"`
+
+    - `"computer-use-2025-11-24"`
+
+    - `"mcp-tunnels-2026-06-22"`
+
+    - `"structured-outputs-2025-11-13"`
+
+    - `"task-budgets-2026-03-13"`
+
+    - `"thinking-display-updates-2026-08-18"`
+
+    - `"ce-user-management-2026-07-13"`
+
 - `"anthropic-user-profile-id": optional string`
 
   The user profile ID to attribute this request to. Use when acting on behalf of a party other than your organization. Requires the `user-profiles` beta header.
from line 1782
 
         - `type: "enabled"`
 
-        - `display: optional "summarized" or "omitted" or null`
+        - `display: optional "summarized" or "omitted" or "updates" or null`
 
           Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 1790
 
           - `"omitted"`
 
+          - `"updates"`
+
       - `BetaThinkingConfigDisabled object`
 
         - `type: "disabled"`
from line 1800
 
         - `type: "adaptive"`
 
-        - `display: optional "summarized" or "omitted" or null`
+        - `display: optional "summarized" or "omitted" or "updates" or null`
 
           Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 1808
 
           - `"omitted"`
 
+          - `"updates"`
+
   - `Default = "default"`
 
 - `inference_geo: optional string or null`
from line 5320
 
       Per-iteration token usage breakdown.
 
-      Each entry represents one sampling iteration, with its own input/output token counts and cache statistics. This allows you to:
+      Each entry represents one sampling iteration, with its own input/output token counts and cache statistics, discriminated by `type`. For `message` entries (model sampling iterations, such as the turns of a server-side tool use loop), this allows you to:
 
       - Determine which iterations exceeded long context thresholds (>=200k tokens)
-      - Calculate the true context window size from the last iteration
+      - Calculate the context window size from the last `message` entry
       - Understand token accumulation across server-side tool use loops
 
+      A `compaction` entry reports the token usage of the compaction operation itself — the server-side request that summarizes the context being closed — NOT the size of the context that was compacted away, and its token counts can be much smaller than that closed context (for example, a compaction that closes a ~200k-token context can report only a few thousand tokens). Do not derive the context window size from a `compaction` entry, even when it is the last entry. A `compaction` entry's tokens are not included in the top-level `usage` fields. When an input-token trigger is in effect (the default — 150,000 tokens unless configured otherwise), each `compaction` entry closes a context that had reached at least that threshold, though the context can exceed it by the final iteration's output and tool results.
+
       - `BetaMessageIterationUsage object`
 
         Token usage for a sampling iteration.
from line 5637
 
         Per-iteration token usage breakdown.
 
-        Each entry represents one sampling iteration, with its own input/output token counts and cache statistics. This allows you to:
+        Each entry represents one sampling iteration, with its own input/output token counts and cache statistics, discriminated by `type`. For `message` entries (model sampling iterations, such as the turns of a server-side tool use loop), this allows you to:
 
         - Determine which iterations exceeded long context thresholds (>=200k tokens)
-        - Calculate the true context window size from the last iteration
+        - Calculate the context window size from the last `message` entry
         - Understand token accumulation across server-side tool use loops
 
+        A `compaction` entry reports the token usage of the compaction operation itself — the server-side request that summarizes the context being closed — NOT the size of the context that was compacted away, and its token counts can be much smaller than that closed context (for example, a compaction that closes a ~200k-token context can report only a few thousand tokens). Do not derive the context window size from a `compaction` entry, even when it is the last entry. A `compaction` entry's tokens are not included in the top-level `usage` fields. When an input-token trigger is in effect (the default — 150,000 tokens unless configured otherwise), each `compaction` entry closes a context that had reached at least that threshold, though the context can exceed it by the final iteration's output and tool results.
+
       - `output_tokens: number`
 
         The cumulative number of output tokens which were used.
from line 5991
 
   - `string`
 
-  - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 31 more`
+  - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
 
     - `"message-batches-2024-09-24"`
from line 6061
 
     - `"mid-conversation-tool-changes-2026-07-01"`
 
+    - `"compact-2026-01-12"`
+
+    - `"computer-use-2025-11-24"`
+
+    - `"mcp-tunnels-2026-06-22"`
+
+    - `"structured-outputs-2025-11-13"`
+
+    - `"task-budgets-2026-03-13"`
+
+    - `"thinking-display-updates-2026-08-18"`
+
+    - `"ce-user-management-2026-07-13"`
+
 - `"anthropic-user-profile-id": optional string`
 
   The user profile ID to attribute this request to. Use when acting on behalf of a party other than your organization. Requires the `user-profiles` beta header.
from line 7679
 
     - `type: "enabled"`
 
-    - `display: optional "summarized" or "omitted" or null`
+    - `display: optional "summarized" or "omitted" or "updates" or null`
 
       Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 7687
 
       - `"omitted"`
 
+      - `"updates"`
+
   - `BetaThinkingConfigDisabled object`
 
     - `type: "disabled"`
from line 7697
 
     - `type: "adaptive"`
 
-    - `display: optional "summarized" or "omitted" or null`
+    - `display: optional "summarized" or "omitted" or "updates" or null`
 
       Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 7705
 
       - `"omitted"`
 
+      - `"updates"`
+
 - `tool_choice: optional BetaToolChoice`
 
   How the model should use the provided tools. The model can use a specific tool, any available tool, decide by itself, or not use tools at all.
from line 8385
 
         - `enabled: optional boolean or null`
 
-          Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.
-
-      - `screenshot: optional BetaBrowserScreenshotConfig or null`
-
-        `screenshot`'s config overrides.
-
-        - `defer_loading: optional boolean or null`
-
-          Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.
-
-        - `enabled: optional boolean or null`
-
-          Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.
-
-      - `scroll: optional BetaBrowserScrollConfig or null`
-
-        `scroll`'s config overrides.
-
-        - `defer_loading: optional boolean or null`
-
-          Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.
-
-        - `enabled: optional boolean or null`
-
-          Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.
-
-      - `scroll_to: optional BetaBrowserScrollToConfig or null`
-
-        `scroll_to`'s config overrides.
-
-        - `defer_loading: optional boolean or null`
-
-          Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.
-
-        - `enabled: optional boolean or null`
-
-          Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.
-
-      - `switch_tab: optional BetaBrowserSwitchTabConfig or null`
-
-        `switch_tab`'s config overrides.
-
-        - `defer_loading: optional boolean or null`
-
-          Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.
-
-        - `enabled: optional boolean or null`
-
-          Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enabled resolves false is withheld from the served schema.
-
-      - `triple_click: optional BetaBrowserTripleClickConfig or null`
-
-        `triple_click`'s config overrides.
-
-        - `defer_loading: optional boolean or null`
-
-          Defer loading for this member. Must resolve to the same value on every enabled member of the toolset.
-
-        - `enabled: optional boolean or null`
-
-          Whether this member is offered to the model. Default is per member, per the toolset's documentation. A member whose enab
+          Whether this member is offered to the model. Default is per member, per the