api/beta/messages / documentation change

### Beta Compaction Config ### Beta Input Transformation ### Beta Summarize Compaction ### Beta Thinking Mismatch Allowed Input Transformation ### Beta Web Fetch URL Source All ### Beta Web Fetch URL Source Except ### Beta Web Fetch URL Source None ### Beta Web Fetch URL Source Only ### Beta Web Fetch URL Source Tool Reference ### Beta Web Fetch URL Sources

The whole hunk

from line 23, old and new numbered

lines

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from line 23

2323

2424 - `string`

2525

26 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 42 more`

26 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 43 more`

2727

2828 - `"message-batches-2024-09-24"`

2929

from line 114

114114 - `"thinking-binding-controls-2026-08-01"`

115115

116116 - `"mid-conversation-system-clear-at-2026-08-21"`

117

118 - `"compact-2026-09-04"`

117119

118120- `"anthropic-user-profile-id": optional string`

119121

from line 1286

12841286 - `encrypted_content: optional string or null`

12851287

12861288 Opaque metadata from prior compaction, to be round-tripped verbatim

1289

1290 - `signature: optional string or null`

1291

1292 The block's signature as returned, to be sent back verbatim

12871293

12881294 - `BetaRequestToolAdditionBlock object`

12891295

from line 1530

15241530- `cache_control: optional BetaCacheControlEphemeral or null`

15251531

15261532 Top-level cache control automatically applies a cache_control marker to the last cacheable block in the request.

1533

1534- `compaction: optional BetaCompactionConfig or null`

1535

1536 Compact the whole conversation and return a signed `compaction` block,

1537 alone, that a later request sends back first in `messages`, in place of

1538 the messages it summarizes. There is no trigger and no pause flag: sending

1539 the parameter compacts, and nothing is sampled after the block.

1540

1541 The summarization prompt is the server's own unless `instructions` are

1542 given, which then replace it for this request; a value that is empty or

1543 only whitespace counts as absent.

1544

1545 - `type: "summarize"`

1546

1547 - `instructions: optional string or null`

1548

1549 Replaces the server's default summarization prompt for this request. An empty or whitespace-only value counts as absent.

1550

1551 maxLength: 16384

15271552

15281553- `container: optional BetaContainerParams or string or null`

15291554

from line 3468

34433468

34443469 When true, guarantees schema validation on tool names and inputs

34453470

3471 - `url_sources: optional BetaWebFetchURLSources or null`

3472

3473 Which sources contribute to the set of URLs web fetch may fetch.

3474

3475 Each key is a tagged variant: `user_input` is `all` or `none`; the

3476 two tool filters are `all`, `none`, `only` (only the named tools'

3477 results) or `except` (every result but the named tools'). A named tool

3478 must be declared in this request's `tools[]`.

3479

3480 - `client_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

3481

3482 Which client tools' results contribute fetchable URLs: "all", "none", or an only or except list of client tool names from tools[].

3483

3484 - `BetaWebFetchURLSourceAll object`

3485

3486 The `url_sources` variant under which a source contributes in

3487 full: every result of the tool filter's source, or all user input.

3488

3489 - `type: "all"`

3490

3491 - `BetaWebFetchURLSourceNone object`

3492

3493 The `url_sources` variant under which a source contributes nothing:

3494 no result of the tool filter's source, or no user input.

3495

3496 - `type: "none"`

3497

3498 - `BetaWebFetchURLSourceOnly object`

3499

3500 The tool filter variant under which only the named tools' results

3501 contribute.

3502

3503 - `type: "only"`

3504

3505 - `tools: array of BetaWebFetchURLSourceToolReference`

3506

3507 - `type: "tool_reference"`

3508

3509 - `name: string`

3510

3511 - `BetaWebFetchURLSourceExcept object`

3512

3513 The tool filter variant under which every result but the named

3514 tools' contributes.

3515

3516 - `type: "except"`

3517

3518 - `tools: array of BetaWebFetchURLSourceToolReference`

3519

3520 - `type: "tool_reference"`

3521

3522 - `name: string`

3523

3524 - `server_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

3525

3526 Which server tools' results contribute fetchable URLs: "all", "none", or an only or except list of server tool names from tools[]; only web_search and web_fetch results ever contribute.

3527

3528 - `BetaWebFetchURLSourceAll object`

3529

3530 The `url_sources` variant under which a source contributes in

3531 full: every result of the tool filter's source, or all user input.

3532

3533 - `BetaWebFetchURLSourceNone object`

3534

3535 The `url_sources` variant under which a source contributes nothing:

3536 no result of the tool filter's source, or no user input.

3537

3538 - `BetaWebFetchURLSourceOnly object`

3539

3540 The tool filter variant under which only the named tools' results

3541 contribute.

3542

3543 - `BetaWebFetchURLSourceExcept object`

3544

3545 The tool filter variant under which every result but the named

3546 tools' contributes.

3547

3548 - `user_input: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone`

3549

3550 Whether URLs in user messages are fetchable: "all" or "none".

3551

3552 - `BetaWebFetchURLSourceAll object`

3553

3554 The `url_sources` variant under which a source contributes in

3555 full: every result of the tool filter's source, or all user input.

3556

3557 - `BetaWebFetchURLSourceNone object`

3558

3559 The `url_sources` variant under which a source contributes nothing:

3560 no result of the tool filter's source, or no user input.

3561

34463562 - `BetaWebSearchTool20260209 object`

34473563

34483564 - `type: "web_search_20260209"`

from line 3665

35493665

35503666 When true, guarantees schema validation on tool names and inputs

35513667

3668 - `url_sources: optional BetaWebFetchURLSources or null`

3669

3670 Which sources contribute to the set of URLs web fetch may fetch.

3671

3672 Each key is a tagged variant: `user_input` is `all` or `none`; the

3673 two tool filters are `all`, `none`, `only` (only the named tools'

3674 results) or `except` (every result but the named tools'). A named tool

3675 must be declared in this request's `tools[]`.

3676

35523677 - `BetaWebFetchTool20260309 object`

35533678

35543679 Web fetch tool with use_cache parameter for bypassing cached content.

from line 3732

36073732

36083733 When true, guarantees schema validation on tool names and inputs

36093734

3735 - `url_sources: optional BetaWebFetchURLSources or null`

3736

3737 Which sources contribute to the set of URLs web fetch may fetch.

3738

3739 Each key is a tagged variant: `user_input` is `all` or `none`; the

3740 two tool filters are `all`, `none`, `only` (only the named tools'

3741 results) or `except` (every result but the named tools'). A named tool

3742 must be declared in this request's `tools[]`.

3743

36103744 - `use_cache: optional boolean`

36113745

36123746 Whether to use cached content. Set to false to bypass the cache and fetch fresh content. Only set to false when the user explicitly requests fresh content or when fetching rapidly-changing sources.

from line 3866

37323866 - `strict: optional boolean`

37333867

37343868 When true, guarantees schema validation on tool names and inputs

3869

3870 - `url_sources: optional BetaWebFetchURLSources or null`

3871

3872 Which sources contribute to the set of URLs web fetch may fetch.

3873

3874 Each key is a tagged variant: `user_input` is `all` or `none`; the

3875 two tool filters are `all`, `none`, `only` (only the named tools'

3876 results) or `except` (every result but the named tools'). A named tool

3877 must be declared in this request's `tools[]`.

37353878

37363879 - `use_cache: optional boolean`

37373880

from line 4985

48424985 - `encrypted_content: string or null`

48434986

48444987 Opaque metadata from prior compaction, to be round-tripped verbatim

4988

4989 - `signature: optional string or null`

4990

4991 Signature over the summary, to be sent back with the block verbatim

48454992

48464993 - `BetaFallbackBlock object`

48474994

from line 5753

56065753

56075754 - `"fast"`

56085755

5609 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`

5610

5611 Changes the API made to the request's input before showing it to the model:

5612 one entry per change, in request order. Today the only entry type is

5613 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`

5614 block from the request's `messages` that was removed from the prompt instead

5615 of being shown to the model because it failed a binding check. More entry

5616 types may be added over time; ignore types you do not recognize.

5756 - `input_transformations: optional array of BetaInputTransformation or null`

5757

5758 Changes the API made to the request's input before showing it to the model,

5759 and blocks that failed a binding check but were left unchanged: one entry per

5760 block, in request order. Two entry types today. `thinking_dropped` — a

5761 `thinking`, `redacted_thinking` or `connector_text` block from the request's

5762 `messages` that was removed from the prompt instead of being shown to the

5763 model because it failed a binding check. `thinking_mismatch_allowed` — a

5764 `thinking` or `redacted_thinking` block that failed the conversation check

5765 (the conversation before it differs from the one it was created in, or it

5766 carries no record of one on a model that requires it) and was shown to the

5767 model all the same, because that check is not enforced for this request.

5768 More entry types may be added over time; ignore types you do not recognize.

56175769

56185770 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on

56195771 every such response from a model that supports extended thinking, as `[]`

5620 when nothing was changed; without the beta, blocks are removed all the same

5621 but nothing is reported. Removed blocks contribute nothing to

5622 `usage.input_tokens`. When streaming, the array is final in `message_start`;

5623 the final `message_delta` event carries it only when a server-side model

5624 fallback happened mid-stream, in which case it holds the serving model's

5625 entries and replaces the one in `message_start`.

5626

5627 - `type: "thinking_dropped"`

5628

5629 Always `thinking_dropped` for this entry type.

5630

5631 default: thinking_dropped

5632

5633 - `path: string`

5634

5635 Where the removed block was in your request, as `messages.{i}.content.{j}`:

5636 `i` indexes the `messages` array you sent and `j` that message's `content`

5637 array — the same form error messages use.

5638

5639 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

5640

5641 Which binding check removed the block: `model_binding_mismatch` — it was

5642 created by a model whose reasoning the requested model may not read;

5643 `prefix_binding_mismatch` — the conversation before it differs from the

5644 conversation it was created in (the rest of that turn's consecutive thinking

5645 blocks are removed with it, each with this reason);

5646 `organization_binding_mismatch` — it was created under a different

5647 organization (an Anthropic organization, AWS account or Google Cloud project)

5648 and this organization is not one of its additional organizations;

5649 `end_user_binding_mismatch` — it was created for a different end user, or

5650 was removed by the consumer-organization binding. A block that would fail

5651 several checks reports one reason, in this order of precedence:

5652 `organization_binding_mismatch`, `end_user_binding_mismatch`,

5653 `model_binding_mismatch`, `prefix_binding_mismatch`.

5654

5655 - `"model_binding_mismatch"`

5656

5657 - `"prefix_binding_mismatch"`

5658

5659 - `"organization_binding_mismatch"`

5660

5661 - `"end_user_binding_mismatch"`

5662

5663- `BetaRawMessageStreamEvent = BetaRawMessageStartEvent or BetaRawMessageDeltaEvent or BetaRawMessageStopEvent or 3 more`

5664

5665 - `BetaRawMessageStartEvent object`

5666

5667 - `type: "message_start"`

5668

5669 default: message_start

5670

5671 - `message: BetaMessage`

5672

5673 - `BetaRawMessageDeltaEvent object`

5674

5675 - `type: "message_delta"`

5676

5677 default: message_delta

5678

5679 - `context_management: BetaContextManagementResponse or null`

5680

5681 Information about context management strategies applied during the request

5682

5683 - `delta: object`

5684

5685 - `container: BetaContainer or null`

5686

5687 Information about the container used in the request (for the code execution tool)

5688

5689 - `stop_details: BetaRefusalStopDetails or null`

5690

5691 Structured information about a refusal.

5692

5693 - `stop_reason: BetaStopReason or null`

5694

5695 - `stop_sequence: string or null`

5696

5697 - `usage: BetaMessageDeltaUsage`

5698

5699 Billing and rate-limit usage.

5700

5701 Anthropic's API bills and rate-limits by token counts, as tokens represent the underlying cost to our systems.

5702

5703 Under the hood, the API transforms requests into a format suitable for the model. The model's output then goes through a parsing stage before becoming an API response. As a result, the token counts in `usage` will not match one-to-one with the exact visible content of an API request or response.

5704

5705 For example, `output_tokens` will be non-zero, even for an empty string response from Claude.

5706

5707 Total input tokens in a request is the summation of `input_tokens`, `cache_creation_input_tokens`, and `cache_read_input_tokens`.

5708

5709 - `cache_creation_input_tokens: number or null`

5710

5711 The cumulative number of input tokens used to create the cache entry.

5712

5713 minimum: 0

5714

5715 - `cache_read_input_tokens: number or null`

5716

5717 The cumulative number of input tokens read from the cache.

5718

5719 minimum: 0

5720

5721 - `fallback_credit: BetaFallbackCreditUsage or null`

5722

5723 Outcome of the `fallback_credit_token` presented on this request.

5724

5725 - `input_tokens: number or null`

5726

5727 The cumulative number of input tokens which were used.

5728

5729 minimum: 0

5730

5731 - `iterations: BetaIterationsUsage or null`

5732

5733 Per-iteration token usage breakdown.

5734

5735 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:

5736

5737 - Determine which iterations exceeded long context thresholds (>=200k tokens)

5738 - Calculate the context window size from the last `message` entry

5739 - Understand token accumulation across server-side tool use loops

5740

5741 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.

5742

5743 - `output_tokens: number`

5744

5745 The cumulative number of output tokens which were used.

5746

5747 - `output_tokens_details: BetaOutputTokensDetails or null`

5748

5749 Breakdown of output tokens by category.

5750

5751 `output_tokens` remains the inclusive, authoritative total used for billing.

5752 This object provides a read-only decomposition for observability — for example,

5753 how many of the billed output tokens were spent on internal reasoning that may

5754 have been summarized before being returned to you.

5755

5756 - `server_tool_use: BetaServerToolUsage or null`

5757

5758 The number of server tool requests.

5759

5760 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`

5761

5762 Changes the API made to the request's input before showing it to the model:

5763 one entry per change, in request order. Today the only entry type is

5764 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`

5765 block from the request's `messages` that was removed from the prompt instead

5766 of being shown to the model because it failed a binding check. More entry

5767 types may be added over time; ignore types you do not recognize.

5768

5769 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on

5770 every such response from a model that supports extended thinking, as `[]`

5771 when nothing was changed; without the beta, blocks are removed all the same

5772 but nothing is reported. Removed blocks contribute nothing to

5773 `usage.input_tokens`. When streaming, the array is final in `message_start`;

5774 the final `message_delta` event carries it only when a server-side model

5775 fallback happened mid-stream, in which case it holds the serving model's

5776 entries and replaces the one in `message_start`.

5772 when there is no entry to report; without the beta, blocks are removed or

5773 left in place all the same but nothing is reported. Removed blocks contribute

5774 nothing to `usage.input_tokens`; blocks left in place count as sent. When

5775 streaming, the array is final in `message_start`; the final `message_delta`

5776 event carries it only when a server-side model fallback happened mid-stream,

5777 in which case it holds the serving model's entries and replaces the one in

5778 `message_start`.

5779

5780 - `BetaThinkingDroppedInputTransformation object`

57775781

57785782 - `type: "thinking_dropped"`

57795783

from line 5806

58025806 several checks reports one reason, in this order of precedence:

58035807 `organization_binding_mismatch`, `end_user_binding_mismatch`,

58045808 `model_binding_mismatch`, `prefix_binding_mismatch`.

5809

5810 - `"model_binding_mismatch"`

5811

5812 - `"prefix_binding_mismatch"`

5813

5814 - `"organization_binding_mismatch"`

5815

5816 - `"end_user_binding_mismatch"`

5817

5818 - `BetaThinkingMismatchAllowedInputTransformation object`

5819

5820 - `type: "thinking_mismatch_allowed"`

5821

5822 Always `thinking_mismatch_allowed` for this entry type.

5823

5824 default: thinking_mismatch_allowed

5825

5826 - `path: string`

5827

5828 Where the block is in your request, as `messages.{i}.content.{j}`:

5829 `i` indexes the `messages` array you sent and `j` that message's `content`

5830 array — the same form error messages use.

5831

5832 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

5833

5834 Which binding check the block failed; the block was shown to the model all

5835 the same. Always `prefix_binding_mismatch` today — the conversation before

5836 the block differs from the conversation it was created in, or the block

5837 carries no record of one on a model that requires it. Were the check

5838 enforced for this request, the block would have been removed or the request

5839 rejected (`thinking.block_binding.prefix_mismatch_behavior`). A removal also

5840 takes the rest of that turn's consecutive thinking blocks, whereas here each

5841 block is checked on its own, so `thinking_mismatch_allowed` entries are a

5842 lower bound on what enforcement would remove.

5843

5844 - `"model_binding_mismatch"`

5845

5846 - `"prefix_binding_mismatch"`

5847

5848 - `"organization_binding_mismatch"`

5849

5850 - `"end_user_binding_mismatch"`

5851

5852- `BetaRawMessageStreamEvent = BetaRawMessageStartEvent or BetaRawMessageDeltaEvent or BetaRawMessageStopEvent or 3 more`

5853

5854 - `BetaRawMessageStartEvent object`

5855

5856 - `type: "message_start"`

5857

5858 default: message_start

5859

5860 - `message: BetaMessage`

5861

5862 - `BetaRawMessageDeltaEvent object`

5863

5864 - `type: "message_delta"`

5865

5866 default: message_delta

5867

5868 - `context_management: BetaContextManagementResponse or null`

5869

5870 Information about context management strategies applied during the request

5871

5872 - `delta: object`

5873

5874 - `container: BetaContainer or null`

5875

5876 Information about the container used in the request (for the code execution tool)

5877

5878 - `stop_details: BetaRefusalStopDetails or null`

5879

5880 Structured information about a refusal.

5881

5882 - `stop_reason: BetaStopReason or null`

5883

5884 - `stop_sequence: string or null`

5885

5886 - `usage: BetaMessageDeltaUsage`

5887

5888 Billing and rate-limit usage.

5889

5890 Anthropic's API bills and rate-limits by token counts, as tokens represent the underlying cost to our systems.

5891

5892 Under the hood, the API transforms requests into a format suitable for the model. The model's output then goes through a parsing stage before becoming an API response. As a result, the token counts in `usage` will not match one-to-one with the exact visible content of an API request or response.

5893

5894 For example, `output_tokens` will be non-zero, even for an empty string response from Claude.

5895

5896 Total input tokens in a request is the summation of `input_tokens`, `cache_creation_input_tokens`, and `cache_read_input_tokens`.

5897

5898 - `cache_creation_input_tokens: number or null`

5899

5900 The cumulative number of input tokens used to create the cache entry.

5901

5902 minimum: 0

5903

5904 - `cache_read_input_tokens: number or null`

5905

5906 The cumulative number of input tokens read from the cache.

5907

5908 minimum: 0

5909

5910 - `fallback_credit: BetaFallbackCreditUsage or null`

5911

5912 Outcome of the `fallback_credit_token` presented on this request.

5913

5914 - `input_tokens: number or null`

5915

5916 The cumulative number of input tokens which were used.

5917

5918 minimum: 0

5919

5920 - `iterations: BetaIterationsUsage or null`

5921

5922 Per-iteration token usage breakdown.

5923

5924 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:

5925

5926 - Determine which iterations exceeded long context thresholds (>=200k tokens)

5927 - Calculate the context window size from the last `message` entry

5928 - Understand token accumulation across server-side tool use loops

5929

5930 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.

5931

5932 - `output_tokens: number`

5933

5934 The cumulative number of output tokens which were used.

5935

5936 - `output_tokens_details: BetaOutputTokensDetails or null`

5937

5938 Breakdown of output tokens by category.

5939

5940 `output_tokens` remains the inclusive, authoritative total used for billing.

5941 This object provides a read-only decomposition for observability — for example,

5942 how many of the billed output tokens were spent on internal reasoning that may

5943 have been summarized before being returned to you.

5944

5945 - `server_tool_use: BetaServerToolUsage or null`

5946

5947 The number of server tool requests.

5948

5949 - `input_transformations: optional array of BetaInputTransformation or null`

5950

5951 Changes the API made to the request's input before showing it to the model,

5952 and blocks that failed a binding check but were left unchanged: one entry per

5953 block, in request order. Two entry types today. `thinking_dropped` — a

5954 `thinking`, `redacted_thinking` or `connector_text` block from the request's

5955 `messages` that was removed from the prompt instead of being shown to the

5956 model because it failed a binding check. `thinking_mismatch_allowed` — a

5957 `thinking` or `redacted_thinking` block that failed the conversation check

5958 (the conversation before it differs from the one it was created in, or it

5959 carries no record of one on a model that requires it) and was shown to the

5960 model all the same, because that check is not enforced for this request.

5961 More entry types may be added over time; ignore types you do not recognize.

5962

5963 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on

5964 every such response from a model that supports extended thinking, as `[]`

5965 when there is no entry to report; without the beta, blocks are removed or

5966 left in place all the same but nothing is reported. Removed blocks contribute

5967 nothing to `usage.input_tokens`; blocks left in place count as sent. When

5968 streaming, the array is final in `message_start`; the final `message_delta`

5969 event carries it only when a server-side model fallback happened mid-stream,

5970 in which case it holds the serving model's entries and replaces the one in

5971 `message_start`.

5972

5973 - `BetaThinkingDroppedInputTransformation object`

5974

5975 - `BetaThinkingMismatchAllowedInputTransformation object`

58055976

58065977 - `BetaRawMessageStopEvent object`

58075978

from line 6308

61376308

61386309 - `string`

61396310

6140 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 42 more`

6311 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 43 more`

61416312

61426313 - `"message-batches-2024-09-24"`

61436314

from line 6399

62286399 - `"thinking-binding-controls-2026-08-01"`

62296400

62306401 - `"mid-conversation-system-clear-at-2026-08-21"`

6402

6403 - `"compact-2026-09-04"`

62316404

62326405- `"anthropic-user-profile-id": optional string`

62336406

from line 7559

73867559 - `encrypted_content: optional string or null`

73877560

73887561 Opaque metadata from prior compaction, to be round-tripped verbatim

7562

7563 - `signature: optional string or null`

7564

7565 The block's signature as returned, to be sent back verbatim

73897566

73907567 - `BetaRequestToolAdditionBlock object`

73917568

from line 7803

76267803- `cache_control: optional BetaCacheControlEphemeral or null`

76277804

76287805 Top-level cache control automatically applies a cache_control marker to the last cacheable block in the request.

7806

7807- `compaction: optional BetaCompactionConfig or null`

7808

7809 Compact the whole conversation and return a signed `compaction` block,

7810 alone, that a later request sends back first in `messages`, in place of

7811 the messages it summarizes. There is no trigger and no pause flag: sending

7812 the parameter compacts, and nothing is sampled after the block.

7813

7814 The summarization prompt is the server's own unless `instructions` are

7815 given, which then replace it for this request; a value that is empty or

7816 only whitespace counts as absent.

7817

7818 - `type: "summarize"`

7819

7820 - `instructions: optional string or null`

7821

7822 Replaces the server's default summarization prompt for this request. An empty or whitespace-only value counts as absent.

7823

7824 maxLength: 16384

76297825

76307826- `context_management: optional BetaContextManagementConfig or null`

76317827

from line 9567

93719567

93729568 When true, guarantees schema validation on tool names and inputs

93739569

9570 - `url_sources: optional BetaWebFetchURLSources or null`

9571

9572 Which sources contribute to the set of URLs web fetch may fetch.

9573

9574 Each key is a tagged variant: `user_input` is `all` or `none`; the

9575 two tool filters are `all`, `none`, `only` (only the named tools'

9576 results) or `except` (every result but the named tools'). A named tool

9577 must be declared in this request's `tools[]`.

9578

9579 - `client_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

9580

9581 Which client tools' results contribute fetchable URLs: "all", "none", or an only or except list of client tool names from tools[].

9582

9583 - `BetaWebFetchURLSourceAll object`

9584

9585 The `url_sources` variant under which a source contributes in

9586 full: every result of the tool filter's source, or all user input.

9587

9588 - `type: "all"`

9589

9590 - `BetaWebFetchURLSourceNone object`

9591

9592 The `url_sources` variant under which a source contributes nothing:

9593 no result of the tool filter's source, or no user input.

9594

9595 - `type: "none"`

9596

9597 - `BetaWebFetchURLSourceOnly object`

9598

9599 The tool filter variant under which only the named tools' results

9600 contribute.

9601

9602 - `type: "only"`

9603

9604 - `tools: array of BetaWebFetchURLSourceToolReference`

9605

9606 - `type: "tool_reference"`

9607

9608 - `name: string`

9609

9610 - `BetaWebFetchURLSourceExcept object`

9611

9612 The tool filter variant under which every result but the named

9613 tools' contributes.

9614

9615 - `type: "except"`

9616

9617 - `tools: array of BetaWebFetchURLSourceToolReference`

9618

9619 - `type: "tool_reference"`

9620

9621 - `name: string`

9622

9623 - `server_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

9624

9625 Which server tools' results contribute fetchable URLs: "all", "none", or an only or except list of server tool names from tools[]; only web_search and web_fetch results ever contribute.

9626

9627 - `BetaWebFetchURLSourceAll object`

9628

9629 The `url_sources` variant under which a source contributes in

9630 full: every result of the tool filter's source, or all user input.

9631

9632 - `BetaWebFetchURLSourceNone object`

9633

9634 The `url_sources` variant under which a source contributes nothing:

9635 no result of the tool filter's source, or no user input.

9636

9637 - `BetaWebFetchURLSourceOnly object`

9638

9639 The tool filter variant under which only the named tools' results

9640 contribute.

9641

9642 - `BetaWebFetchURLSourceExcept object`

9643

9644 The tool filter variant under which every result but the named

9645 tools' contributes.

9646

9647 - `user_input: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone`

9648

9649 Whether URLs in user messages are fetchable: "all" or "none".

9650

9651 - `BetaWebFetchURLSourceAll object`

9652

9653 The `url_sources` variant under which a source contributes in

9654 full: every result of the tool filter's source, or all user input.

9655

9656 - `BetaWebFetchURLSourceNone object`

9657

9658 The `url_sources` variant under which a source contributes nothing:

9659 no result of the tool filter's source, or no user input.

9660

93749661 - `BetaWebSearchTool20260209 object`

93759662

93769663 - `type: "web_search_20260209"`

from line 9764

94779764

94789765 When true, guarantees schema validation on tool names and inputs

94799766

9767 - `url_sources: optional BetaWebFetchURLSources or null`

9768

9769 Which sources contribute to the set of URLs web fetch may fetch.

9770

9771 Each key is a tagged variant: `user_input` is `all` or `none`; the

9772 two tool filters are `all`, `none`, `only` (only the named tools'

9773 results) or `except` (every result but the named tools'). A named tool

9774 must be declared in this request's `tools[]`.

9775

94809776 - `BetaWebFetchTool20260309 object`

94819777

94829778 Web fetch tool with use_cache parameter for bypassing cached content.

from line 9831

95359831

95369832 When true, guarantees schema validation on tool names and inputs

95379833

9834 - `url_sources: optional BetaWebFetchURLSources or null`

9835

9836 Which sources contribute to the set of URLs web fetch may fetch.

9837

9838 Each key is a tagged variant: `user_input` is `all` or `none`; the

9839 two tool filters are `all`, `none`, `only` (only the named tools'

9840 results) or `except` (every result but the named tools'). A named tool

9841 must be declared in this request's `tools[]`.

9842

95389843 - `use_cache: optional boolean`

95399844

95409845 Whether to use cached content. Set to false to bypass the cache and fetch fresh content. Only set to false when the user explicitly requests fresh content or when fetching rapidly-changing sources.

from line 9965

96609965 - `strict: optional boolean`

96619966

96629967 When true, guarantees schema validation on tool names and inputs

9968

9969 - `url_sources: optional BetaWebFetchURLSources or null`

9970

9971 Which sources contribute to the set of URLs web fetch may fetch.

9972

9973 Each key is a tagged variant: `user_input` is `all` or `none`; the

9974 two tool filters are `all`, `none`, `only` (only the named tools'

9975 results) or `except` (every result but the named tools'). A named tool

9976 must be declared in this request's `tools[]`.

96639977

96649978 - `use_cache: optional boolean`

96659979

from line 13883

1356913883

1357013884 Opaque metadata from prior compaction, to be round-tripped verbatim

1357113885

13886 - `signature: optional string or null`

13887

13888 Signature over the summary, to be sent back with the block verbatim

13889

1357213890### Beta Compaction Block Param

1357313891

1357413892- `BetaCompactionBlockParam object`

from line 13929

1361113929 - `encrypted_content: optional string or null`

1361213930

1361313931 Opaque metadata from prior compaction, to be round-tripped verbatim

13932

13933 - `signature: optional string or null`

13934

13935 The block's signature as returned, to be sent back verbatim

13936

13937### Beta Compaction Config

13938

13939- `BetaCompactionConfig object`

13940

13941 Compact the whole conversation and return a signed `compaction` block,

13942 alone, that a later request sends back first in `messages`, in place of

13943 the messages it summarizes. There is no trigger and no pause flag: sending

13944 the parameter compacts, and nothing is sampled after the block.

13945

13946 The summarization prompt is the server's own unless `instructions` are

13947 given, which then replace it for this request; a value that is empty or

13948 only whitespace counts as absent.

13949

13950 - `type: "summarize"`

13951

13952 - `instructions: optional string or null`

13953

13954 Replaces the server's default summarization prompt for this request. An empty or whitespace-only value counts as absent.

13955

13956 maxLength: 16384

1361413957

1361513958### Beta Compaction Content Block Delta

1361613959

from line 15689

1534615689

1534715690 Opaque metadata from prior compaction, to be round-tripped verbatim

1534815691

15692 - `signature: optional string or null`

15693

15694 Signature over the summary, to be sent back with the block verbatim

15695

1534915696 - `BetaFallbackBlock object`

1535015697

1535115698 Marks the point in `content` where one model's output gives way to the next.

from line 16929

1658216929 - `encrypted_content: optional string or null`

1658316930

1658416931 Opaque metadata from prior compaction, to be round-tripped verbatim

16932

16933 - `signature: optional string or null`

16934

16935 The block's signature as returned, to be sent back verbatim

1658516936

1658616937 - `BetaRequestToolAdditionBlock object`

1658716938

from line 19212

1886119212

1886219213 minimum: 1

1886319214

19215### Beta Input Transformation

19216

19217- `BetaInputTransformation = BetaThinkingDroppedInputTransformation or BetaThinkingMismatchAllowedInputTransformation`

19218

19219 One entry of `input_transformations`: either a change the API made to the

19220 request's input before showing it to the model, or a block that failed a

19221 binding check and was still shown to the model unchanged. The `type` field

19222 says which.

19223

19224 - `BetaThinkingDroppedInputTransformation object`

19225

19226 - `type: "thinking_dropped"`

19227

19228 Always `thinking_dropped` for this entry type.

19229

19230 default: thinking_dropped

19231

19232 - `path: string`

19233

19234 Where the removed block was in your request, as `messages.{i}.content.{j}`:

19235 `i` indexes the `messages` array you sent and `j` that message's `content`

19236 array — the same form error messages use.

19237

19238 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

19239

19240 Which binding check removed the block: `model_binding_mismatch` — it was

19241 created by a model whose reasoning the requested model may not read;

19242 `prefix_binding_mismatch` — the conversation before it differs from the

19243 conversation it was created in (the rest of that turn's consecutive thinking

19244 blocks are removed with it, each with this reason);

19245 `organization_binding_mismatch` — it was created under a different

19246 organization (an Anthropic organization, AWS account or Google Cloud project)

19247 and this organization is not one of its additional organizations;

19248 `end_user_binding_mismatch` — it was created for a different end user, or

19249 was removed by the consumer-organization binding. A block that would fail

19250 several checks reports one reason, in this order of precedence:

19251 `organization_binding_mismatch`, `end_user_binding_mismatch`,

19252 `model_binding_mismatch`, `prefix_binding_mismatch`.

19253

19254 - `"model_binding_mismatch"`

19255

19256 - `"prefix_binding_mismatch"`

19257

19258 - `"organization_binding_mismatch"`

19259

19260 - `"end_user_binding_mismatch"`

19261

19262 - `BetaThinkingMismatchAllowedInputTransformation object`

19263

19264 - `type: "thinking_mismatch_allowed"`

19265

19266 Always `thinking_mismatch_allowed` for this entry type.

19267

19268 default: thinking_mismatch_allowed

19269

19270 - `path: string`

19271

19272 Where the block is in your request, as `messages.{i}.content.{j}`:

19273 `i` indexes the `messages` array you sent and `j` that message's `content`

19274 array — the same form error messages use.

19275

19276 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

19277

19278 Which binding check the block failed; the block was shown to the model all

19279 the same. Always `prefix_binding_mismatch` today — the conversation before

19280 the block differs from the conversation it was created in, or the block

19281 carries no record of one on a model that requires it. Were the check

19282 enforced for this request, the block would have been removed or the request

19283 rejected (`thinking.block_binding.prefix_mismatch_behavior`). A removal also

19284 takes the rest of that turn's consecutive thinking blocks, whereas here each

19285 block is checked on its own, so `thinking_mismatch_allowed` entries are a

19286 lower bound on what enforcement would remove.

19287

19288 - `"model_binding_mismatch"`

19289

19290 - `"prefix_binding_mismatch"`

19291

19292 - `"organization_binding_mismatch"`

19293

19294 - `"end_user_binding_mismatch"`

19295

1886419296### Beta Iterations Usage

1886519297

1886619298- `BetaIterationsUsage = array of BetaMessageIterationUsage or BetaCompactionIterationUsage or BetaAdvisorMessageIterationUsage or BetaFallbackMessageIterationUsage`

from line 21058

2062621058 - `encrypted_content: string or null`

2062721059

2062821060 Opaque metadata from prior compaction, to be round-tripped verbatim

21061

21062 - `signature: optional string or null`

21063

21064 Signature over the summary, to be sent back with the block verbatim

2062921065

2063021066 - `BetaFallbackBlock object`

2063121067

from line 21826

2139021826

2139121827 - `"fast"`

2139221828

21393 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`

21394

21395 Changes the API made to the request's input before showing it to the model:

21396 one entry per change, in request order. Today the only entry type is

21397 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`

21398 block from the request's `messages` that was removed from the prompt instead

21399 of being shown to the model because it failed a binding check. More entry

21400 types may be added over time; ignore types you do not recognize.

21829 - `input_transformations: optional array of BetaInputTransformation or null`

21830

21831 Changes the API made to the request's input before showing it to the model,

21832 and blocks that failed a binding check but were left unchanged: one entry per

21833 block, in request order. Two entry types today. `thinking_dropped` — a

21834 `thinking`, `redacted_thinking` or `connector_text` block from the request's

21835 `messages` that was removed from the prompt instead of being shown to the

21836 model because it failed a binding check. `thinking_mismatch_allowed` — a

21837 `thinking` or `redacted_thinking` block that failed the conversation check

21838 (the conversation before it differs from the one it was created in, or it

21839 carries no record of one on a model that requires it) and was shown to the

21840 model all the same, because that check is not enforced for this request.

21841 More entry types may be added over time; ignore types you do not recognize.

2140121842

2140221843 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on

2140321844 every such response from a model that supports extended thinking, as `[]`

21404 when nothing was changed; without the beta, blocks are removed all the same

21405 but nothing is reported. Removed blocks contribute nothing to

21406 `usage.input_tokens`. When streaming, the array is final in `message_start`;

21407 the final `message_delta` event carries it only when a server-side model

21408 fallback happened mid-stream, in which case it holds the serving model's

21409 entries and replaces the one in `message_start`.

21410

21411 - `type: "thinking_dropped"`

21412

21413 Always `thinking_dropped` for this entry type.

21414

21415 default: thinking_dropped

21416

21417 - `path: string`

21418

21419 Where the removed block was in your request, as `messages.{i}.content.{j}`:

21420 `i` indexes the `messages` array you sent and `j` that message's `content`

21421 array — the same form error messages use.

21422

21423 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

21424

21425 Which binding check removed the block: `model_binding_mismatch` — it was

21426 created by a model whose reasoning the requested model may not read;

21427 `prefix_binding_mismatch` — the conversation before it differs from the

21428 conversation it was created in (the rest of that turn's consecutive thinking

21429 blocks are removed with it, each with this reason);

21430 `organization_binding_mismatch` — it was created under a different

21431 organization (an Anthropic organization, AWS account or Google Cloud project)

21432 and this organization is not one of its additional organizations;

21433 `end_user_binding_mismatch` — it was created for a different end user, or

21434 was removed by the consumer-organization binding. A block that would fail

21435 several checks reports one reason, in this order of precedence:

21436 `organization_binding_mismatch`, `end_user_binding_mismatch`,

21437 `model_binding_mismatch`, `prefix_binding_mismatch`.

21438

21439 - `"model_binding_mismatch"`

21440

21441 - `"prefix_binding_mismatch"`

21442

21443 - `"organization_binding_mismatch"`

21444

21445 - `"end_user_binding_mismatch"`

21845 when there is no entry to report; without the beta, blocks are removed or

21846 left in place all the same but nothing is reported. Removed blocks contribute

21847 nothing to `usage.input_tokens`; blocks left in place count as sent. When

21848 streaming, the array is final in `message_start`; the final `message_delta`

21849 event carries it only when a server-side model fallback happened mid-stream,

21850 in which case it holds the serving model's entries and replaces the one in

21851 `message_start`.

21852

21853 - `BetaThinkingDroppedInputTransformation object`

21854

21855 - `type: "thinking_dropped"`

21856

21857 Always `thinking_dropped` for this entry type.

21858

21859 default: thinking_dropped

21860

21861 - `path: string`

21862

21863 Where the removed block was in your request, as `messages.{i}.content.{j}`:

21864 `i` indexes the `messages` array you sent and `j` that message's `content`

21865 array — the same form error messages use.

21866

21867 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

21868

21869 Which binding check removed the block: `model_binding_mismatch` — it was

21870 created by a model whose reasoning the requested model may not read;

21871 `prefix_binding_mismatch` — the conversation before it differs from the

21872 conversation it was created in (the rest of that turn's consecutive thinking

21873 blocks are removed with it, each with this reason);

21874 `organization_binding_mismatch` — it was created under a different

21875 organization (an Anthropic organization, AWS account or Google Cloud project)

21876 and this organization is not one of its additional organizations;

21877 `end_user_binding_mismatch` — it was created for a different end user, or

21878 was removed by the consumer-organization binding. A block that would fail

21879 several checks reports one reason, in this order of precedence:

21880 `organization_binding_mismatch`, `end_user_binding_mismatch`,

21881 `model_binding_mismatch`, `prefix_binding_mismatch`.

21882

21883 - `"model_binding_mismatch"`

21884

21885 - `"prefix_binding_mismatch"`

21886

21887 - `"organization_binding_mismatch"`

21888

21889 - `"end_user_binding_mismatch"`

21890

21891 - `BetaThinkingMismatchAllowedInputTransformation object`

21892

21893 - `type: "thinking_mismatch_allowed"`

21894

21895 Always `thinking_mismatch_allowed` for this entry type.

21896

21897 default: thinking_mismatch_allowed

21898

21899 - `path: string`

21900

21901 Where the block is in your request, as `messages.{i}.content.{j}`:

21902 `i` indexes the `messages` array you sent and `j` that message's `content`

21903 array — the same form error messages use.

21904

21905 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

21906

21907 Which binding check the block failed; the block was shown to the model all

21908 the same. Always `prefix_binding_mismatch` today — the conversation before

21909 the block differs from the conversation it was created in, or the block

21910 carries no record of one on a model that requires it. Were the check

21911 enforced for this request, the block would have been removed or the request

21912 rejected (`thinking.block_binding.prefix_mismatch_behavior`). A removal also

21913 takes the rest of that turn's consecutive thinking blocks, whereas here each

21914 block is checked on its own, so `thinking_mismatch_allowed` entries are a

21915 lower bound on what enforcement would remove.

21916

21917 - `"model_binding_mismatch"`

21918

21919 - `"prefix_binding_mismatch"`

21920

21921 - `"organization_binding_mismatch"`

21922

21923 - `"end_user_binding_mismatch"`

2144621924

2144721925### Beta Message Delta Usage

2144821926

from line 23571

2309323571 - `encrypted_content: optional string or null`

2309423572

2309523573 Opaque metadata from prior compaction, to be round-tripped verbatim

23574

23575 - `signature: optional string or null`

23576

23577 The block's signature as returned, to be sent back verbatim

2309623578

2309723579 - `BetaRequestToolAdditionBlock object`

2309823580

from line 25126

2464425126 - `encrypted_content: string or null`

2464525127

2464625128 Opaque metadata from prior compaction, to be round-tripped verbatim

25129

25130 - `signature: optional string or null`

25131

25132 Signature over the summary, to be sent back with the block verbatim

2464725133

2464825134 - `BetaFallbackBlock object`

2464925135

from line 25907

2542125907

2542225908 default: 0, minimum: 0

2542325909

25424 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`

25425

25426 Changes the API made to the request's input before showing it to the model:

25427 one entry per change, in request order. Today the only entry type is

25428 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`

25429 block from the request's `messages` that was removed from the prompt instead

25430 of being shown to the model because it failed a binding check. More entry

25431 types may be added over time; ignore types you do not recognize.

25910 - `input_transformations: optional array of BetaInputTransformation or null`

25911

25912 Changes the API made to the request's input before showing it to the model,

25913 and blocks that failed a binding check but were left unchanged: one entry per

25914 block, in request order. Two entry types today. `thinking_dropped` — a

25915 `thinking`, `redacted_thinking` or `connector_text` block from the request's

25916 `messages` that was removed from the prompt instead of being shown to the

25917 model because it failed a binding check. `thinking_mismatch_allowed` — a

25918 `thinking` or `redacted_thinking` block that failed the conversation check

25919 (the conversation before it differs from the one it was created in, or it

25920 carries no record of one on a model that requires it) and was shown to the

25921 model all the same, because that check is not enforced for this request.

25922 More entry types may be added over time; ignore types you do not recognize.

2543225923

2543325924 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on

2543425925 every such response from a model that supports extended thinking, as `[]`

25435 when nothing was changed; without the beta, blocks are removed all the same

25436 but nothing is reported. Removed blocks contribute nothing to

25437 `usage.input_tokens`. When streaming, the array is final in `message_start`;

25438 the final `message_delta` event carries it only when a server-side model

25439 fallback happened mid-stream, in which case it holds the serving model's

25440 entries and replaces the one in `message_start`.

25441

25442 - `type: "thinking_dropped"`

25443

25444 Always `thinking_dropped` for this entry type.

25445

25446 default: thinking_dropped

25447

25448 - `path: string`

25449

25450 Where the removed block was in your request, as `messages.{i}.content.{j}`:

25451 `i` indexes the `messages` array you sent and `j` that message's `content`

25452 array — the same form error messages use.

25453

25454 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

25455

25456 Which binding check removed the block: `model_binding_mismatch` — it was

25457 created by a model whose reasoning the requested model may not read;

25458 `prefix_binding_mismatch` — the conversation before it differs from the

25459 conversation it was created in (the rest of that turn's consecutive thinking

25460 blocks are removed with it, each with this reason);

25461 `organization_binding_mismatch` — it was created under a different

25462 organization (an Anthropic organization, AWS account or Google Cloud project)

25463 and this organization is not one of its additional organizations;

25464 `end_user_binding_mismatch` — it was created for a different end user, or

25465 was removed by the consumer-organization binding. A block that would fail

25466 several checks reports one reason, in this order of precedence:

25467 `organization_binding_mismatch`, `end_user_binding_mismatch`,

25468 `model_binding_mismatch`, `prefix_binding_mismatch`.

25469

25470 - `"model_binding_mismatch"`

25471

25472 - `"prefix_binding_mismatch"`

25473

25474 - `"organization_binding_mismatch"`

25475

25476 - `"end_user_binding_mismatch"`

25926 when there is no entry to report; without the beta, blocks are removed or

25927 left in place all the same but nothing is reported. Removed blocks contribute

25928 nothing to `usage.input_tokens`; blocks left in place count as sent. When

25929 streaming, the array is final in `message_start`; the final `message_delta`

25930 event carries it only when a server-side model fallback happened mid-stream,

25931 in which case it holds the serving model's entries and replaces the one in

25932 `message_start`.

25933

25934 - `BetaThinkingDroppedInputTransformation object`

25935

25936 - `type: "thinking_dropped"`

25937

25938 Always `thinking_dropped` for this entry type.

25939

25940 default: thinking_dropped

25941

25942 - `path: string`

25943

25944 Where the removed block was in your request, as `messages.{i}.content.{j}`:

25945 `i` indexes the `messages` array you sent and `j` that message's `content`

25946 array — the same form error messages use.

25947

25948 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

25949

25950 Which binding check removed the block: `model_binding_mismatch` — it was

25951 created by a model whose reasoning the requested model may not read;

25952 `prefix_binding_mismatch` — the conversation before it differs from the

25953 conversation it was created in (the rest of that turn's consecutive thinking

25954 blocks are removed with it, each with this reason);

25955 `organization_binding_mismatch` — it was created under a different

25956 organization (an Anthropic organization, AWS account or Google Cloud project)

25957 and this organization is not one of its additional organizations;

25958 `end_user_binding_mismatch` — it was created for a different end user, or

25959 was removed by the consumer-organization binding. A block that would fail

25960 several checks reports one reason, in this order of precedence:

25961 `organization_binding_mismatch`, `end_user_binding_mismatch`,

25962 `model_binding_mismatch`, `prefix_binding_mismatch`.

25963

25964 - `"model_binding_mismatch"`

25965

25966 - `"prefix_binding_mismatch"`

25967

25968 - `"organization_binding_mismatch"`

25969

25970 - `"end_user_binding_mismatch"`

25971

25972 - `BetaThinkingMismatchAllowedInputTransformation object`

25973

25974 - `type: "thinking_mismatch_allowed"`

25975

25976 Always `thinking_mismatch_allowed` for this entry type.

25977

25978 default: thinking_mismatch_allowed

25979

25980 - `path: string`

25981

25982 Where the block is in your request, as `messages.{i}.content.{j}`:

25983 `i` indexes the `messages` array you sent and `j` that message's `content`

25984 array — the same form error messages use.

25985

25986 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

25987

25988 Which binding check the block failed; the block was shown to the model all

25989 the same. Always `prefix_binding_mismatch` today — the conversation before

25990 the block differs from the conversation it was created in, or the block

25991 carries no record of one on a model that requires it. Were the check

25992 enforced for this request, the block would have been removed or the request

25993 rejected (`thinking.block_binding.prefix_mismatch_behavior`). A removal also

25994 takes the rest of that turn's consecutive thinking blocks, whereas here each

25995 block is checked on its own, so `thinking_mismatch_allowed` entries are a

25996 lower bound on what enforcement would remove.

25997

25998 - `"model_binding_mismatch"`

25999

26000 - `"prefix_binding_mismatch"`

26001

26002 - `"organization_binding_mismatch"`

26003

26004 - `"end_user_binding_mismatch"`

2547726005

2547826006### Beta Raw Message Start Event

2547926007

from line 26909

2638126909 - `encrypted_content: string or null`

2638226910

2638326911 Opaque metadata from prior compaction, to be round-tripped verbatim

26912

26913 - `signature: optional string or null`

26914

26915 Signature over the summary, to be sent back with the block verbatim

2638426916

2638526917 - `BetaFallbackBlock object`

2638626918

from line 27677

2714527677

2714627678 - `"fast"`

2714727679

27148 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`

27149

27150 Changes the API made to the request's input before showing it to the model:

27151 one entry per change, in request order. Today the only entry type is

27152 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`

27153 block from the request's `messages` that was removed from the prompt instead

27154 of being shown to the model because it failed a binding check. More entry

27155 types may be added over time; ignore types you do not recognize.

27680 - `input_transformations: optional array of BetaInputTransformation or null`

27681

27682 Changes the API made to the request's input before showing it to the model,

27683 and blocks that failed a binding check but were left unchanged: one entry per

27684 block, in request order. Two entry types today. `thinking_dropped` — a

27685 `thinking`, `redacted_thinking` or `connector_text` block from the request's

27686 `messages` that was removed from the prompt instead of being shown to the

27687 model because it failed a binding check. `thinking_mismatch_allowed` — a

27688 `thinking` or `redacted_thinking` block that failed the conversation check

27689 (the conversation before it differs from the one it was created in, or it

27690 carries no record of one on a model that requires it) and was shown to the

27691 model all the same, because that check is not enforced for this request.

27692 More entry types may be added over time; ignore types you do not recognize.

2715627693

2715727694 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on

2715827695 every such response from a model that supports extended thinking, as `[]`

27159 when nothing was changed; without the beta, blocks are removed all the same

27160 but nothing is reported. Removed blocks contribute nothing to

27161 `usage.input_tokens`. When streaming, the array is final in `message_start`;

27162 the final `message_delta` event carries it only when a server-side model

27163 fallback happened mid-stream, in which case it holds the serving model's

27164 entries and replaces the one in `message_start`.

27165

27166 - `type: "thinking_dropped"`

27167

27168 Always `thinking_dropped` for this entry type.

27169

27170 default: thinking_dropped

27171

27172 - `path: string`

27173

27174 Where the removed block was in your request, as `messages.{i}.content.{j}`:

27175 `i` indexes the `messages` array you sent and `j` that message's `content`

27176 array — the same form error messages use.

27177

27178 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

27179

27180 Which binding check removed the block: `model_binding_mismatch` — it was

27181 created by a model whose reasoning the requested model may not read;

27182 `prefix_binding_mismatch` — the conversation before it differs from the

27183 conversation it was created in (the rest of that turn's consecutive thinking

27184 blocks are removed with it, each with this reason);

27185 `organization_binding_mismatch` — it was created under a different

27186 organization (an Anthropic organization, AWS account or Google Cloud project)

27187 and this organization is not one of its additional organizations;

27188 `end_user_binding_mismatch` — it was created for a different end user, or

27189 was removed by the consumer-organization binding. A block that would fail

27190 several checks reports one reason, in this order of precedence:

27191 `organization_binding_mismatch`, `end_user_binding_mismatch`,

27192 `model_binding_mismatch`, `prefix_binding_mismatch`.

27193

27194 - `"model_binding_mismatch"`

27195

27196 - `"prefix_binding_mismatch"`

27197

27198 - `"organization_binding_mismatch"`

27199

27200 - `"end_user_binding_mismatch"`

27696 when there is no entry to report; without the beta, blocks are removed or

27697 left in place all the same but nothing is reported. Removed blocks contribute

27698 nothing to `usage.input_tokens`; blocks left in place count as sent. When

27699 streaming, the array is final in `message_start`; the final `message_delta`

27700 event carries it only when a server-side model fallback happened mid-stream,

27701 in which case it holds the serving model's entries and replaces the one in

27702 `message_start`.

27703

27704 - `BetaThinkingDroppedInputTransformation object`

27705

27706 - `type: "thinking_dropped"`

27707

27708 Always `thinking_dropped` for this entry type.

27709

27710 default: thinking_dropped

27711

27712 - `path: string`

27713

27714 Where the removed block was in your request, as `messages.{i}.content.{j}`:

27715 `i` indexes the `messages` array you sent and `j` that message's `content`

27716 array — the same form error messages use.

27717

27718 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

27719

27720 Which binding check removed the block: `model_binding_mismatch` — it was

27721 created by a model whose reasoning the requested model may not read;

27722 `prefix_binding_mismatch` — the conversation before it differs from the

27723 conversation it was created in (the rest of that turn's consecutive thinking

27724 blocks are removed with it, each with this reason);

27725 `organization_binding_mismatch` — it was created under a different

27726 organization (an Anthropic organization, AWS account or Google Cloud project)

27727 and this organization is not one of its additional organizations;

27728 `end_user_binding_mismatch` — it was created for a different end user, or

27729 was removed by the consumer-organization binding. A block that would fail

27730 several checks reports one reason, in this order of precedence:

27731 `organization_binding_mismatch`, `end_user_binding_mismatch`,

27732 `model_binding_mismatch`, `prefix_binding_mismatch`.

27733

27734 - `"model_binding_mismatch"`

27735

27736 - `"prefix_binding_mismatch"`

27737

27738 - `"organization_binding_mismatch"`

27739

27740 - `"end_user_binding_mismatch"`

27741

27742 - `BetaThinkingMismatchAllowedInputTransformation object`

27743

27744 - `type: "thinking_mismatch_allowed"`

27745

27746 Always `thinking_mismatch_allowed` for this entry type.

27747

27748 default: thinking_mismatch_allowed

27749

27750 - `path: string`

27751

27752 Where the block is in your request, as `messages.{i}.content.{j}`:

27753 `i` indexes the `messages` array you sent and `j` that message's `content`

27754 array — the same form error messages use.

27755

27756 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

27757

27758 Which binding check the block failed; the block was shown to the model all

27759 the same. Always `prefix_binding_mismatch` today — the conversation before

27760 the block differs from the conversation it was created in, or the block

27761 carries no record of one on a model that requires it. Were the check

27762 enforced for this request, the block would have been removed or the request

27763 rejected (`thinking.block_binding.prefix_mismatch_behavior`). A removal also

27764 takes the rest of that turn's consecutive thinking blocks, whereas here each

27765 block is checked on its own, so `thinking_mismatch_allowed` entries are a

27766 lower bound on what enforcement would remove.

27767

27768 - `"model_binding_mismatch"`

27769

27770 - `"prefix_binding_mismatch"`

27771

27772 - `"organization_binding_mismatch"`

27773

27774 - `"end_user_binding_mismatch"`

2720127775

2720227776### Beta Raw Message Stop Event

2720327777

from line 28689

2811528689 - `encrypted_content: string or null`

2811628690

2811728691 Opaque metadata from prior compaction, to be round-tripped verbatim

28692

28693 - `signature: optional string or null`

28694

28695 Signature over the summary, to be sent back with the block verbatim

2811828696

2811928697 - `BetaFallbackBlock object`

2812028698

from line 29457

2887929457

2888029458 - `"fast"`

2888129459

28882 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`

28883

28884 Changes the API made to the request's input before showing it to the model:

28885 one entry per change, in request order. Today the only entry type is

28886 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`

28887 block from the request's `messages` that was removed from the prompt instead

28888 of being shown to the model because it failed a binding check. More entry

28889 types may be added over time; ignore types you do not recognize.

29460 - `input_transformations: optional array of BetaInputTransformation or null`

29461

29462 Changes the API made to the request's input before showing it to the model,

29463 and blocks that failed a binding check but were left unchanged: one entry per

29464 block, in request order. Two entry types today. `thinking_dropped` — a

29465 `thinking`, `redacted_thinking` or `connector_text` block from the request's

29466 `messages` that was removed from the prompt instead of being shown to the

29467 model because it failed a binding check. `thinking_mismatch_allowed` — a

29468 `thinking` or `redacted_thinking` block that failed the conversation check

29469 (the conversation before it differs from the one it was created in, or it

29470 carries no record of one on a model that requires it) and was shown to the

29471 model all the same, because that check is not enforced for this request.

29472 More entry types may be added over time; ignore types you do not recognize.

2889029473

2889129474 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on

2889229475 every such response from a model that supports extended thinking, as `[]`

28893 when nothing was changed; without the beta, blocks are removed all the same

28894 but nothing is reported. Removed blocks contribute nothing to

28895 `usage.input_tokens`. When streaming, the array is final in `message_start`;

28896 the final `message_delta` event carries it only when a server-side model

28897 fallback happened mid-stream, in which case it holds the serving model's

28898 entries and replaces the one in `message_start`.

28899

28900 - `type: "thinking_dropped"`

28901

28902 Always `thinking_dropped` for this entry type.

28903

28904 default: thinking_dropped

28905

28906 - `path: string`

28907

28908 Where the removed block was in your request, as `messages.{i}.content.{j}`:

28909 `i` indexes the `messages` array you sent and `j` that message's `content`

28910 array — the same form error messages use.

28911

28912 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

28913

28914 Which binding check removed the block: `model_binding_mismatch` — it was

28915 created by a model whose reasoning the requested model may not read;

28916 `prefix_binding_mismatch` — the conversation before it differs from the

28917 conversation it was created in (the rest of that turn's consecutive thinking

28918 blocks are removed with it, each with this reason);

28919 `organization_binding_mismatch` — it was created under a different

28920 organization (an Anthropic organization, AWS account or Google Cloud project)

28921 and this organization is not one of its additional organizations;

28922 `end_user_binding_mismatch` — it was created for a different end user, or

28923 was removed by the consumer-organization binding. A block that would fail

28924 several checks reports one reason, in this order of precedence:

28925 `organization_binding_mismatch`, `end_user_binding_mismatch`,

28926 `model_binding_mismatch`, `prefix_binding_mismatch`.

28927

28928 - `"model_binding_mismatch"`

28929

28930 - `"prefix_binding_mismatch"`

28931

28932 - `"organization_binding_mismatch"`

28933

28934 - `"end_user_binding_mismatch"`

29476 when there is no entry to report; without the beta, blocks are removed or

29477 left in place all the same but nothing is reported. Removed blocks contribute

29478 nothing to `usage.input_tokens`; blocks left in place count as sent. When

29479 streaming, the array is final in `message_start`; the final `message_delta`

29480 event carries it only when a server-side model fallback happened mid-stream,

29481 in which case it holds the serving model's entries and replaces the one in

29482 `message_start`.

29483

29484 - `BetaThinkingDroppedInputTransformation object`

29485

29486 - `type: "thinking_dropped"`

29487

29488 Always `thinking_dropped` for this entry type.

29489

29490 default: thinking_dropped

29491

29492 - `path: string`

29493

29494 Where the removed block was in your request, as `messages.{i}.content.{j}`:

29495 `i` indexes the `messages` array you sent and `j` that message's `content`

29496 array — the same form error messages use.

29497

29498 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

29499

29500 Which binding check removed the block: `model_binding_mismatch` — it was

29501 created by a model whose reasoning the requested model may not read;

29502 `prefix_binding_mismatch` — the conversation before it differs from the

29503 conversation it was created in (the rest of that turn's consecutive thinking

29504 blocks are removed with it, each with this reason);

29505 `organization_binding_mismatch` — it was created under a different

29506 organization (an Anthropic organization, AWS account or Google Cloud project)

29507 and this organization is not one of its additional organizations;

29508 `end_user_binding_mismatch` — it was created for a different end user, or

29509 was removed by the consumer-organization binding. A block that would fail

29510 several checks reports one reason, in this order of precedence:

29511 `organization_binding_mismatch`, `end_user_binding_mismatch`,

29512 `model_binding_mismatch`, `prefix_binding_mismatch`.

29513

29514 - `"model_binding_mismatch"`

29515

29516 - `"prefix_binding_mismatch"`

29517

29518 - `"organization_binding_mismatch"`

29519

29520 - `"end_user_binding_mismatch"`

29521

29522 - `BetaThinkingMismatchAllowedInputTransformation object`

29523

29524 - `type: "thinking_mismatch_allowed"`

29525

29526 Always `thinking_mismatch_allowed` for this entry type.

29527

29528 default: thinking_mismatch_allowed

29529

29530 - `path: string`

29531

29532 Where the block is in your request, as `messages.{i}.content.{j}`:

29533 `i` indexes the `messages` array you sent and `j` that message's `content`

29534 array — the same form error messages use.

29535

29536 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

29537

29538 Which binding check the block failed; the block was shown to the model all

29539 the same. Always `prefix_binding_mismatch` today — the conversation before

29540 the block differs from the conversation it was created in, or the block

29541 carries no record of one on a model that requires it. Were the check

29542 enforced for this request, the block would have been removed or the request

29543 rejected (`thinking.block_binding.prefix_mismatch_behavior`). A removal also

29544 takes the rest of that turn's consecutive thinking blocks, whereas here each

29545 block is checked on its own, so `thinking_mismatch_allowed` entries are a

29546 lower bound on what enforcement would remove.

29547

29548 - `"model_binding_mismatch"`

29549

29550 - `"prefix_binding_mismatch"`

29551

29552 - `"organization_binding_mismatch"`

29553

29554 - `"end_user_binding_mismatch"`

2893529555

2893629556 - `BetaRawMessageDeltaEvent object`

2893729557

from line 29640

2902029640

2902129641 The number of server tool requests.

2902229642

29023 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`

29024

29025 Changes the API made to the request's input before showing it to the model:

29026 one entry per change, in request order. Today the only entry type is

29027 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`

29028 block from the request's `messages` that was removed from the prompt instead

29029 of being shown to the model because it failed a binding check. More entry

29030 types may be added over time; ignore types you do not recognize.

29643 - `input_transformations: optional array of BetaInputTransformation or null`

29644

29645 Changes the API made to the request's input before showing it to the model,

29646 and blocks that failed a binding check but were left unchanged: one entry per

29647 block, in request order. Two entry types today. `thinking_dropped` — a

29648 `thinking`, `redacted_thinking` or `connector_text` block from the request's

29649 `messages` that was removed from the prompt instead of being shown to the

29650 model because it failed a binding check. `thinking_mismatch_allowed` — a

29651 `thinking` or `redacted_thinking` block that failed the conversation check

29652 (the conversation before it differs from the one it was created in, or it

29653 carries no record of one on a model that requires it) and was shown to the

29654 model all the same, because that check is not enforced for this request.

29655 More entry types may be added over time; ignore types you do not recognize.

2903129656

2903229657 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on

2903329658 every such response from a model that supports extended thinking, as `[]`

29034 when nothing was changed; without the beta, blocks are removed all the same

29035 but nothing is reported. Removed blocks contribute nothing to

29036 `usage.input_tokens`. When streaming, the array is final in `message_start`;

29037 the final `message_delta` event carries it only when a server-side model

29038 fallback happened mid-stream, in which case it holds the serving model's

29039 entries and replaces the one in `message_start`.

29040

29041 - `type: "thinking_dropped"`

29042

29043 Always `thinking_dropped` for this entry type.

29044

29045 default: thinking_dropped

29046

29047 - `path: string`

29048

29049 Where the removed block was in your request, as `messages.{i}.content.{j}`:

29050 `i` indexes the `messages` array you sent and `j` that message's `content`

29051 array — the same form error messages use.

29052

29053 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

29054

29055 Which binding check removed the block: `model_binding_mismatch` — it was

29056 created by a model whose reasoning the requested model may not read;

29057 `prefix_binding_mismatch` — the conversation before it differs from the

29058 conversation it was created in (the rest of that turn's consecutive thinking

29059 blocks are removed with it, each with this reason);

29060 `organization_binding_mismatch` — it was created under a different

29061 organization (an Anthropic organization, AWS account or Google Cloud project)

29062 and this organization is not one of its additional organizations;

29063 `end_user_binding_mismatch` — it was created for a different end user, or

29064 was removed by the consumer-organization binding. A block that would fail

29065 several checks reports one reason, in this order of precedence:

29066 `organization_binding_mismatch`, `end_user_binding_mismatch`,

29067 `model_binding_mismatch`, `prefix_binding_mismatch`.

29659 when there is no entry to report; without the beta, blocks are removed or

29660 left in place all the same but nothing is reported. Removed blocks contribute

29661 nothing to `usage.input_tokens`; blocks left in place count as sent. When

29662 streaming, the array is final in `message_start`; the final `message_delta`

29663 event carries it only when a server-side model fallback happened mid-stream,

29664 in which case it holds the serving model's entries and replaces the one in

29665 `message_start`.

29666

29667 - `BetaThinkingDroppedInputTransformation object`

29668

29669 - `BetaThinkingMismatchAllowedInputTransformation object`

2906829670

2906929671 - `BetaRawMessageStopEvent object`

2907029672

from line 30939

3033730939

3033830940 - `"model_context_window_exceeded"`

3033930941

30942### Beta Summarize Compaction

30943

30944- `BetaSummarizeCompaction object`

30945

30946 Compact the whole conversation and return a signed `compaction` block,

30947 alone, that a later request sends back first in `messages`, in place of

30948 the messages it summarizes. There is no trigger and no pause flag: sending

30949 the parameter compacts, and nothing is sampled after the block.

30950

30951 The summarization prompt is the server's own unless `instructions` are

30952 given, which then replace it for this request; a value that is empty or

30953 only whitespace counts as absent.

30954

30955 - `type: "summarize"`

30956

30957 - `instructions: optional string or null`

30958

30959 Replaces the server's default summarization prompt for this request. An empty or whitespace-only value counts as absent.

30960

30961 maxLength: 16384

30962

3034030963### Beta System Message Output Config

3034130964

3034230965- `BetaSystemMessageOutputConfig object`

from line 32132

3150932132

3151032133 - `"end_user_binding_mismatch"`

3151132134

32135### Beta Thinking Mismatch Allowed Input Transformation

32136

32137- `BetaThinkingMismatchAllowedInputTransformation object`

32138

32139 - `type: "thinking_mismatch_allowed"`

32140

32141 Always `thinking_mismatch_allowed` for this entry type.

32142

32143 default: thinking_mismatch_allowed

32144

32145 - `path: string`

32146

32147 Where the block is in your request, as `messages.{i}.content.{j}`:

32148 `i` indexes the `messages` array you sent and `j` that message's `content`

32149 array — the same form error messages use.

32150

32151 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

32152

32153 Which binding check the block failed; the block was shown to the model all

32154 the same. Always `prefix_binding_mismatch` today — the conversation before

32155 the block differs from the conversation it was created in, or the block

32156 carries no record of one on a model that requires it. Were the check

32157 enforced for this request, the block would have been removed or the request

32158 rejected (`thinking.block_binding.prefix_mismatch_behavior`). A removal also

32159 takes the rest of that turn's consecutive thinking blocks, whereas here each

32160 block is checked on its own, so `thinking_mismatch_allowed` entries are a

32161 lower bound on what enforcement would remove.

32162

32163 - `"model_binding_mismatch"`

32164

32165 - `"prefix_binding_mismatch"`

32166

32167 - `"organization_binding_mismatch"`

32168

32169 - `"end_user_binding_mismatch"`

32170

3151232171### Beta Thinking Prefix Mismatch Behavior

3151332172

3151432173- `BetaThinkingPrefixMismatchBehavior = "error" or "drop_block"`

from line 35190

3453135190

3453235191 When true, guarantees schema validation on tool names and inputs

3453335192

35193 - `url_sources: optional BetaWebFetchURLSources or null`

35194

35195 Which sources contribute to the set of URLs web fetch may fetch.

35196

35197 Each key is a tagged variant: `user_input` is `all` or `none`; the

35198 two tool filters are `all`, `none`, `only` (only the named tools'

35199 results) or `except` (every result but the named tools'). A named tool

35200 must be declared in this request's `tools[]`.

35201

35202 - `client_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

35203

35204 Which client tools' results contribute fetchable URLs: "all", "none", or an only or except list of client tool names from tools[].

35205

35206 - `BetaWebFetchURLSourceAll object`

35207

35208 The `url_sources` variant under which a source contributes in

35209 full: every result of the tool filter's source, or all user input.

35210

35211 - `type: "all"`

35212

35213 - `BetaWebFetchURLSourceNone object`

35214

35215 The `url_sources` variant under which a source contributes nothing:

35216 no result of the tool filter's source, or no user input.

35217

35218 - `type: "none"`

35219

35220 - `BetaWebFetchURLSourceOnly object`

35221

35222 The tool filter variant under which only the named tools' results

35223 contribute.

35224

35225 - `type: "only"`

35226

35227 - `tools: array of BetaWebFetchURLSourceToolReference`

35228

35229 - `type: "tool_reference"`

35230

35231 - `name: string`

35232

35233 - `BetaWebFetchURLSourceExcept object`

35234

35235 The tool filter variant under which every result but the named

35236 tools' contributes.

35237

35238 - `type: "except"`

35239

35240 - `tools: array of BetaWebFetchURLSourceToolReference`

35241

35242 - `type: "tool_reference"`

35243

35244 - `name: string`

35245

35246 - `server_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

35247

35248 Which server tools' results contribute fetchable URLs: "all", "none", or an only or except list of server tool names from tools[]; only web_search and web_fetch results ever contribute.

35249

35250 - `BetaWebFetchURLSourceAll object`

35251

35252 The `url_sources` variant under which a source contributes in

35253 full: every result of the tool filter's source, or all user input.

35254

35255 - `BetaWebFetchURLSourceNone object`

35256

35257 The `url_sources` variant under which a source contributes nothing:

35258 no result of the tool filter's source, or no user input.

35259

35260 - `BetaWebFetchURLSourceOnly object`

35261

35262 The tool filter variant under which only the named tools' results

35263 contribute.

35264

35265 - `BetaWebFetchURLSourceExcept object`

35266

35267 The tool filter variant under which every result but the named

35268 tools' contributes.

35269

35270 - `user_input: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone`

35271

35272 Whether URLs in user messages are fetchable: "all" or "none".

35273

35274 - `BetaWebFetchURLSourceAll object`

35275

35276 The `url_sources` variant under which a source contributes in

35277 full: every result of the tool filter's source, or all user input.

35278

35279 - `BetaWebFetchURLSourceNone object`

35280

35281 The `url_sources` variant under which a source contributes nothing:

35282 no result of the tool filter's source, or no user input.

35283

3453435284 - `BetaWebSearchTool20260209 object`

3453535285

3453635286 - `type: "web_search_20260209"`

from line 35387

3463735387

3463835388 When true, guarantees schema validation on tool names and inputs

3463935389

35390 - `url_sources: optional BetaWebFetchURLSources or null`

35391

35392 Which sources contribute to the set of URLs web fetch may fetch.

35393

35394 Each key is a tagged variant: `user_input` is `all` or `none`; the

35395 two tool filters are `all`, `none`, `only` (only the named tools'

35396 results) or `except` (every result but the named tools'). A named tool

35397 must be declared in this request's `tools[]`.

35398

3464035399 - `BetaWebFetchTool20260309 object`

3464135400

3464235401 Web fetch tool with use_cache parameter for bypassing cached content.

from line 35454

3469535454

3469635455 When true, guarantees schema validation on tool names and inputs

3469735456

35457 - `url_sources: optional BetaWebFetchURLSources or null`

35458

35459 Which sources contribute to the set of URLs web fetch may fetch.

35460

35461 Each key is a tagged variant: `user_input` is `all` or `none`; the

35462 two tool filters are `all`, `none`, `only` (only the named tools'

35463 results) or `except` (every result but the named tools'). A named tool

35464 must be declared in this request's `tools[]`.

35465

3469835466 - `use_cache: optional boolean`

3469935467

3470035468 Whether to use cached content. Set to false to bypass the cache and fetch fresh content. Only set to false when the user explicitly requests fresh content or when fetching rapidly-changing sources.

from line 35588

3482035588 - `strict: optional boolean`

3482135589

3482235590 When true, guarantees schema validation on tool names and inputs

35591

35592 - `url_sources: optional BetaWebFetchURLSources or null`

35593

35594 Which sources contribute to the set of URLs web fetch may fetch.

35595

35596 Each key is a tagged variant: `user_input` is `all` or `none`; the

35597 two tool filters are `all`, `none`, `only` (only the named tools'

35598 results) or `except` (every result but the named tools'). A named tool

35599 must be declared in this request's `tools[]`.

3482335600

3482435601 - `use_cache: optional boolean`

3482535602

from line 36875

3609836875

3609936876 When true, guarantees schema validation on tool names and inputs

3610036877

36878 - `url_sources: optional BetaWebFetchURLSources or null`

36879

36880 Which sources contribute to the set of URLs web fetch may fetch.

36881

36882 Each key is a tagged variant: `user_input` is `all` or `none`; the

36883 two tool filters are `all`, `none`, `only` (only the named tools'

36884 results) or `except` (every result but the named tools'). A named tool

36885 must be declared in this request's `tools[]`.

36886

36887 - `client_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

36888

36889 Which client tools' results contribute fetchable URLs: "all", "none", or an only or except list of client tool names from tools[].

36890

36891 - `BetaWebFetchURLSourceAll object`

36892

36893 The `url_sources` variant under which a source contributes in

36894 full: every result of the tool filter's source, or all user input.

36895

36896 - `type: "all"`

36897

36898 - `BetaWebFetchURLSourceNone object`

36899

36900 The `url_sources` variant under which a source contributes nothing:

36901 no result of the tool filter's source, or no user input.

36902

36903 - `type: "none"`

36904

36905 - `BetaWebFetchURLSourceOnly object`

36906

36907 The tool filter variant under which only the named tools' results

36908 contribute.

36909

36910 - `type: "only"`

36911

36912 - `tools: array of BetaWebFetchURLSourceToolReference`

36913

36914 - `type: "tool_reference"`

36915

36916 - `name: string`

36917

36918 - `BetaWebFetchURLSourceExcept object`

36919

36920 The tool filter variant under which every result but the named

36921 tools' contributes.

36922

36923 - `type: "except"`

36924

36925 - `tools: array of BetaWebFetchURLSourceToolReference`

36926

36927 - `type: "tool_reference"`

36928

36929 - `name: string`

36930

36931 - `server_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

36932

36933 Which server tools' results contribute fetchable URLs: "all", "none", or an only or except list of server tool names from tools[]; only web_search and web_fetch results ever contribute.

36934

36935 - `BetaWebFetchURLSourceAll object`

36936

36937 The `url_sources` variant under which a source contributes in

36938 full: every result of the tool filter's source, or all user input.

36939

36940 - `BetaWebFetchURLSourceNone object`

36941

36942 The `url_sources` variant under which a source contributes nothing:

36943 no result of the tool filter's source, or no user input.

36944

36945 - `BetaWebFetchURLSourceOnly object`

36946

36947 The tool filter variant under which only the named tools' results

36948 contribute.

36949

36950 - `BetaWebFetchURLSourceExcept object`

36951

36952 The tool filter variant under which every result but the named

36953 tools' contributes.

36954

36955 - `user_input: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone`

36956

36957 Whether URLs in user messages are fetchable: "all" or "none".

36958

36959 - `BetaWebFetchURLSourceAll object`

36960

36961 The `url_sources` variant under which a source contributes in

36962 full: every result of the tool filter's source, or all user input.

36963

36964 - `BetaWebFetchURLSourceNone object`

36965

36966 The `url_sources` variant under which a source contributes nothing:

36967 no result of the tool filter's source, or no user input.

36968

3610136969### Beta Web Fetch Tool 20260209

3610236970

3610336971- `BetaWebFetchTool20260209 object`

from line 37043

3617537043

3617637044 When true, guarantees schema validation on tool names and inputs

3617737045

37046 - `url_sources: optional BetaWebFetchURLSources or null`

37047

37048 Which sources contribute to the set of URLs web fetch may fetch.

37049

37050 Each key is a tagged variant: `user_input` is `all` or `none`; the

37051 two tool filters are `all`, `none`, `only` (only the named tools'

37052 results) or `except` (every result but the named tools'). A named tool

37053 must be declared in this request's `tools[]`.

37054

37055 - `client_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

37056

37057 Which client tools' results contribute fetchable URLs: "all", "none", or an only or except list of client tool names from tools[].

37058

37059 - `BetaWebFetchURLSourceAll object`

37060

37061 The `url_sources` variant under which a source contributes in

37062 full: every result of the tool filter's source, or all user input.

37063

37064 - `type: "all"`

37065

37066 - `BetaWebFetchURLSourceNone object`

37067

37068 The `url_sources` variant under which a source contributes nothing:

37069 no result of the tool filter's source, or no user input.

37070

37071 - `type: "none"`

37072

37073 - `BetaWebFetchURLSourceOnly object`

37074

37075 The tool filter variant under which only the named tools' results

37076 contribute.

37077

37078 - `type: "only"`

37079

37080 - `tools: array of BetaWebFetchURLSourceToolReference`

37081

37082 - `type: "tool_reference"`

37083

37084 - `name: string`

37085

37086 - `BetaWebFetchURLSourceExcept object`

37087

37088 The tool filter variant under which every result but the named

37089 tools' contributes.

37090

37091 - `type: "except"`

37092

37093 - `tools: array of BetaWebFetchURLSourceToolReference`

37094

37095 - `type: "tool_reference"`

37096

37097 - `name: string`

37098

37099 - `server_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

37100

37101 Which server tools' results contribute fetchable URLs: "all", "none", or an only or except list of server tool names from tools[]; only web_search and web_fetch results ever contribute.

37102

37103 - `BetaWebFetchURLSourceAll object`

37104

37105 The `url_sources` variant under which a source contributes in

37106 full: every result of the tool filter's source, or all user input.

37107

37108 - `BetaWebFetchURLSourceNone object`

37109

37110 The `url_sources` variant under which a source contributes nothing:

37111 no result of the tool filter's source, or no user input.

37112

37113 - `BetaWebFetchURLSourceOnly object`

37114

37115 The tool filter variant under which only the named tools' results

37116 contribute.

37117

37118 - `BetaWebFetchURLSourceExcept object`

37119

37120 The tool filter variant under which every result but the named

37121 tools' contributes.

37122

37123 - `user_input: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone`

37124

37125 Whether URLs in user messages are fetchable: "all" or "none".

37126

37127 - `BetaWebFetchURLSourceAll object`

37128

37129 The `url_sources` variant under which a source contributes in

37130 full: every result of the tool filter's source, or all user input.

37131

37132 - `BetaWebFetchURLSourceNone object`

37133

37134 The `url_sources` variant under which a source contributes nothing:

37135 no result of the tool filter's source, or no user input.

37136

3617837137### Beta Web Fetch Tool 20260309

3617937138

3618037139- `BetaWebFetchTool20260309 object`

from line 37213

3625437213

3625537214 When true, guarantees schema validation on tool names and inputs

3625637215

37216 - `url_sources: optional BetaWebFetchURLSources or null`

37217

37218 Which sources contribute to the set of URLs web fetch may fetch.

37219

37220 Each key is a tagged variant: `user_input` is `all` or `none`; the

37221 two tool filters are `all`, `none`, `only` (only the named tools'

37222 results) or `except` (every result but the named tools'). A named tool

37223 must be declared in this request's `tools[]`.

37224

37225 - `client_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

37226

37227 Which client tools' results contribute fetchable URLs: "all", "none", or an only or except list of client tool names from tools[].

37228

37229 - `BetaWebFetchURLSourceAll object`

37230

37231 The `url_sources` variant under which a source contributes in

37232 full: every result of the tool filter's source, or all user input.

37233

37234 - `type: "all"`

37235

37236 - `BetaWebFetchURLSourceNone object`

37237

37238 The `url_sources` variant under which a source contributes nothing:

37239 no result of the tool filter's source, or no user input.

37240

37241 - `type: "none"`

37242

37243 - `BetaWebFetchURLSourceOnly object`

37244

37245 The tool filter variant under which only the named tools' results

37246 contribute.

37247

37248 - `type: "only"`

37249

37250 - `tools: array of BetaWebFetchURLSourceToolReference`

37251

37252 - `type: "tool_reference"`

37253

37254 - `name: string`

37255

37256 - `BetaWebFetchURLSourceExcept object`

37257

37258 The tool filter variant under which every result but the named

37259 tools' contributes.

37260

37261 - `type: "except"`

37262

37263 - `tools: array of BetaWebFetchURLSourceToolReference`

37264

37265 - `type: "tool_reference"`

37266

37267 - `name: string`

37268

37269 - `server_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

37270

37271 Which server tools' results contribute fetchable URLs: "all", "none", or an only or except list of server tool names from tools[]; only web_search and web_fetch results ever contribute.

37272

37273 - `BetaWebFetchURLSourceAll object`

37274

37275 The `url_sources` variant under which a source contributes in

37276 full: every result of the tool filter's source, or all user input.

37277

37278 - `BetaWebFetchURLSourceNone object`

37279

37280 The `url_sources` variant under which a source contributes nothing:

37281 no result of the tool filter's source, or no user input.

37282

37283 - `BetaWebFetchURLSourceOnly object`

37284

37285 The tool filter variant under which only the named tools' results

37286 contribute.

37287

37288 - `BetaWebFetchURLSourceExcept object`

37289

37290 The tool filter variant under which every result but the named

37291 tools' contributes.

37292

37293 - `user_input: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone`

37294

37295 Whether URLs in user messages are fetchable: "all" or "none".

37296

37297 - `BetaWebFetchURLSourceAll object`

37298

37299 The `url_sources` variant under which a source contributes in

37300 full: every result of the tool filter's source, or all user input.

37301

37302 - `BetaWebFetchURLSourceNone object`

37303

37304 The `url_sources` variant under which a source contributes nothing:

37305 no result of the tool filter's source, or no user input.

37306

3625737307 - `use_cache: optional boolean`

3625837308

3625937309 Whether to use cached content. Set to false to bypass the cache and fetch fresh content. Only set to false when the user explicitly requests fresh content or when fetching rapidly-changing sources.

from line 37393

3634337393

3634437394 When true, guarantees schema validation on tool names and inputs

3634537395

37396 - `url_sources: optional BetaWebFetchURLSources or null`

37397

37398 Which sources contribute to the set of URLs web fetch may fetch.

37399

37400 Each key is a tagged variant: `user_input` is `all` or `none`; the

37401 two tool filters are `all`, `none`, `only` (only the named tools'

37402 results) or `except` (every result but the named tools'). A named tool

37403 must be declared in this request's `tools[]`.

37404

37405 - `client_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

37406

37407 Which client tools' results contribute fetchable URLs: "all", "none", or an only or except list of client tool names from tools[].

37408

37409 - `BetaWebFetchURLSourceAll object`

37410

37411 The `url_sources` variant under which a source contributes in

37412 full: every result of the tool filter's source, or all user input.

37413

37414 - `type: "all"`

37415

37416 - `BetaWebFetchURLSourceNone object`

37417

37418 The `url_sources` variant under which a source contributes nothing:

37419 no result of the tool filter's source, or no user input.

37420

37421 - `type: "none"`

37422

37423 - `BetaWebFetchURLSourceOnly object`

37424

37425 The tool filter variant under which only the named tools' results

37426 contribute.

37427

37428 - `type: "only"`

37429

37430 - `tools: array of BetaWebFetchURLSourceToolReference`

37431

37432 - `type: "tool_reference"`

37433

37434 - `name: string`

37435

37436 - `BetaWebFetchURLSourceExcept object`

37437

37438 The tool filter variant under which every result but the named

37439 tools' contributes.

37440

37441 - `type: "except"`

37442

37443 - `tools: array of BetaWebFetchURLSourceToolReference`

37444

37445 - `type: "tool_reference"`

37446

37447 - `name: string`

37448

37449 - `server_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

37450

37451 Which server tools' results contribute fetchable URLs: "all", "none", or an only or except list of server tool names from tools[]; only web_search and web_fetch results ever contribute.

37452

37453 - `BetaWebFetchURLSourceAll object`

37454

37455 The `url_sources` variant under which a source contributes in

37456 full: every result of the tool filter's source, or all user input.

37457

37458 - `BetaWebFetchURLSourceNone object`

37459

37460 The `url_sources` variant under which a source contributes nothing:

37461 no result of the tool filter's source, or no user input.

37462

37463 - `BetaWebFetchURLSourceOnly object`

37464

37465 The tool filter variant under which only the named tools' results

37466 contribute.

37467

37468 - `BetaWebFetchURLSourceExcept object`

37469

37470 The tool filter variant under which every result but the named

37471 tools' contributes.

37472

37473 - `user_input: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone`

37474

37475 Whether URLs in user messages are fetchable: "all" or "none".

37476

37477 - `BetaWebFetchURLSourceAll object`

37478

37479 The `url_sources` variant under which a source contributes in

37480 full: every result of the tool filter's source, or all user input.

37481

37482 - `BetaWebFetchURLSourceNone object`

37483

37484 The `url_sources` variant under which a source contributes nothing:

37485 no result of the tool filter's source, or no user input.

37486

3634637487 - `use_cache: optional boolean`

3634737488

3634837489 Whether to use cached content. Set to false to bypass the cache and fetch fresh content. Only set to false when the user explicitly requests fresh content or when fetching rapidly-changing sources.

from line 38035

3689438035

3689538036 - `"content_too_large"`

3689638037

38038### Beta Web Fetch URL Source All

38039

38040- `BetaWebFetchURLSourceAll object`

38041

38042 The `url_sources` variant under which a source contributes in

38043 full: every result of the tool filter's source, or all user input.

38044

38045 - `type: "all"`

38046

38047### Beta Web Fetch URL Source Except

38048

38049- `BetaWebFetchURLSourceExcept object`

38050

38051 The tool filter variant under which every result but the named

38052 tools' contributes.

38053

38054 - `type: "except"`

38055

38056 - `tools: array of BetaWebFetchURLSourceToolReference`

38057

38058 - `type: "tool_reference"`

38059

38060 - `name: string`

38061

38062### Beta Web Fetch URL Source None

38063

38064- `BetaWebFetchURLSourceNone object`

38065

38066 The `url_sources` variant under which a source contributes nothing:

38067 no result of the tool filter's source, or no user input.

38068

38069 - `type: "none"`

38070

38071### Beta Web Fetch URL Source Only

38072

38073- `BetaWebFetchURLSourceOnly object`

38074

38075 The tool filter variant under which only the named tools' results

38076 contribute.

38077

38078 - `type: "only"`

38079

38080 - `tools: array of BetaWebFetchURLSourceToolReference`

38081

38082 - `type: "tool_reference"`

38083

38084 - `name: string`

38085

38086### Beta Web Fetch URL Source Tool Reference

38087

38088- `BetaWebFetchURLSourceToolReference object`

38089

38090 One entry of a tool filter's `tools`: it must name a tool declared

38091 in this request's `tools[]`.

38092

38093 - `type: "tool_reference"`

38094

38095 - `name: string`

38096

38097### Beta Web Fetch URL Sources

38098

38099- `BetaWebFetchURLSources object`

38100

38101 Which sources contribute to the set of URLs web fetch may fetch.

38102

38103 Each key is a tagged variant: `user_input` is `all` or `none`; the

38104 two tool filters are `all`, `none`, `only` (only the named tools'

38105 results) or `except` (every result but the named tools'). A named tool

38106 must be declared in this request's `tools[]`.

38107

38108 - `client_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

38109

38110 Which client tools' results contribute fetchable URLs: "all", "none", or an only or except list of client tool names from tools[].

38111

38112 - `BetaWebFetchURLSourceAll object`

38113

38114 The `url_sources` variant under which a source contributes in

38115 full: every result of the tool filter's source, or all user input.

38116

38117 - `type: "all"`

38118

38119 - `BetaWebFetchURLSourceNone object`

38120

38121 The `url_sources` variant under which a source contributes nothing:

38122 no result of the tool filter's source, or no user input.

38123

38124 - `type: "none"`

38125

38126 - `BetaWebFetchURLSourceOnly object`

38127

38128 The tool filter variant under which only the named tools' results

38129 contribute.

38130

38131 - `type: "only"`

38132

38133 - `tools: array of BetaWebFetchURLSourceToolReference`

38134

38135 - `type: "tool_reference"`

38136

38137 - `name: string`

38138

38139 - `BetaWebFetchURLSourceExcept object`

38140

38141 The tool filter variant under which every result but the named

38142 tools' contributes.

38143

38144 - `type: "except"`

38145

38146 - `tools: array of BetaWebFetchURLSourceToolReference`

38147

38148 - `type: "tool_reference"`

38149

38150 - `name: string`

38151

38152 - `server_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

38153

38154 Which server tools' results contribute fetchable URLs: "all", "none", or an only or except list of server tool names from tools[]; only web_search and web_fetch results ever contribute.

38155

38156 - `BetaWebFetchURLSourceAll object`

38157

38158 The `url_sources` variant under which a source contributes in

38159 full: every result of the tool filter's source, or all user input.

38160

38161 - `BetaWebFetchURLSourceNone object`

38162

38163 The `url_sources` variant under which a source contributes nothing:

38164 no result of the tool filter's source, or no user input.

38165

38166 - `BetaWebFetchURLSourceOnly object`

38167

38168 The tool filter variant under which only the named tools' results

38169 contribute.

38170

38171 - `BetaWebFetchURLSourceExcept object`

38172

38173 The tool filter variant under which every result but the named

38174 tools' contributes.

38175

38176 - `user_input: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone`

38177

38178 Whether URLs in user messages are fetchable: "all" or "none".

38179

38180 - `BetaWebFetchURLSourceAll object`

38181

38182 The `url_sources` variant under which a source contributes in

38183 full: every result of the tool filter's source, or all user input.

38184

38185 - `BetaWebFetchURLSourceNone object`

38186

38187 The `url_sources` variant under which a source contributes nothing:

38188 no result of the tool filter's source, or no user input.

38189

3689738190### Beta Web Search Result Block

3689838191

3689938192- `BetaWebSearchResultBlock object`

from line 38823

3753038823

3753138824 - `string`

3753238825

37533 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 42 more`

38826 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 43 more`

3753438827

3753538828 - `"message-batches-2024-09-24"`

3753638829

from line 38914

3762138914 - `"thinking-binding-controls-2026-08-01"`

3762238915

3762338916 - `"mid-conversation-system-clear-at-2026-08-21"`

38917

38918 - `"compact-2026-09-04"`

3762438919

3762538920- `"anthropic-user-profile-id": optional string`

3762638921

from line 40106

3881140106 - `encrypted_content: optional string or null`

3881240107

3881340108 Opaque metadata from prior compaction, to be round-tripped verbatim

40109

40110 - `signature: optional string or null`

40111

40112 The block's signature as returned, to be sent back verbatim

3881440113

3881540114 - `BetaRequestToolAdditionBlock object`

3881640115

from line 40350

3905140350 - `cache_control: optional BetaCacheControlEphemeral or null`

3905240351

3905340352 Top-level cache control automatically applies a cache_control marker to the last cacheable block in the request.

40353

40354 - `compaction: optional BetaCompactionConfig or null`

40355

40356 Compact the whole conversation and return a signed `compaction` block,

40357 alone, that a later request sends back first in `messages`, in place of

40358 the messages it summarizes. There is no trigger and no pause flag: sending

40359 the parameter compacts, and nothing is sampled after the block.

40360

40361 The summarization prompt is the server's own unless `instructions` are

40362 given, which then replace it for this request; a value that is empty or

40363 only whitespace counts as absent.

40364

40365 - `type: "summarize"`

40366

40367 - `instructions: optional string or null`

40368

40369 Replaces the server's default summarization prompt for this request. An empty or whitespace-only value counts as absent.

40370

40371 maxLength: 16384

3905440372

3905540373 - `container: optional BetaContainerParams or string or null`

3905640374

from line 42288

4097042288

4097142289 When true, guarantees schema validation on tool names and inputs

4097242290

42291 - `url_sources: optional BetaWebFetchURLSources or null`

42292

42293 Which sources contribute to the set of URLs web fetch may fetch.

42294

42295 Each key is a tagged variant: `user_input` is `all` or `none`; the

42296 two tool filters are `all`, `none`, `only` (only the named tools'

42297 results) or `except` (every result but the named tools'). A named tool

42298 must be declared in this request's `tools[]`.

42299

42300 - `client_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

42301

42302 Which client tools' results contribute fetchable URLs: "all", "none", or an only or except list of client tool names from tools[].

42303

42304 - `BetaWebFetchURLSourceAll object`

42305

42306 The `url_sources` variant under which a source contributes in

42307 full: every result of the tool filter's source, or all user input.

42308

42309 - `type: "all"`

42310

42311 - `BetaWebFetchURLSourceNone object`

42312

42313 The `url_sources` variant under which a source contributes nothing:

42314 no result of the tool filter's source, or no user input.

42315

42316 - `type: "none"`

42317

42318 - `BetaWebFetchURLSourceOnly object`

42319

42320 The tool filter variant under which only the named tools' results

42321 contribute.

42322

42323 - `type: "only"`

42324

42325 - `tools: array of BetaWebFetchURLSourceToolReference`

42326

42327 - `type: "tool_reference"`

42328

42329 - `name: string`

42330

42331 - `BetaWebFetchURLSourceExcept object`

42332

42333 The tool filter variant under which every result but the named

42334 tools' contributes.

42335

42336 - `type: "except"`

42337

42338 - `tools: array of BetaWebFetchURLSourceToolReference`

42339

42340 - `type: "tool_reference"`

42341

42342 - `name: string`

42343

42344 - `server_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`

42345

42346 Which server tools' results contribute fetchable URLs: "all", "none", or an only or except list of server tool names from tools[]; only web_search and web_fetch results ever contribute.

42347

42348 - `BetaWebFetchURLSourceAll object`

42349

42350 The `url_sources` variant under which a source contributes in

42351 full: every result of the tool filter's source, or all user input.

42352

42353 - `BetaWebFetchURLSourceNone object`

42354

42355 The `url_sources` variant under which a source contributes nothing:

42356 no result of the tool filter's source, or no user input.

42357

42358 - `BetaWebFetchURLSourceOnly object`

42359

42360 The tool filter variant under which only the named tools' results

42361 contribute.

42362

42363 - `BetaWebFetchURLSourceExcept object`

42364

42365 The tool filter variant under which every result but the named

42366 tools' contributes.

42367

42368 - `user_input: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone`

42369

42370 Whether URLs in user messages are fetchable: "all" or "none".

42371

42372 - `BetaWebFetchURLSourceAll object`

42373

42374 The `url_sources` variant under which a source contributes in

42375 full: every result of the tool filter's source, or all user input.

42376

42377 - `BetaWebFetchURLSourceNone object`

42378

42379 The `url_sources` variant under which a source contributes nothing:

42380 no result of the tool filter's source, or no user input.

42381

4097342382 - `BetaWebSearchTool20260209 object`

4097442383

4097542384 - `type: "web_search_20260209"`

from line 42485

4107642485

4107742486 When true, guarantees schema validation on tool names and inputs

4107842487

42488 - `url_sources: optional BetaWebFetchURLSources or null`

42489

42490 Which sources contribute to the set of URLs web fetch may fetch.

42491

42492 Each key is a tagged variant: `user_input` is `all` or `none`; the

42493 two tool filters are `all`, `none`, `only` (only the named tools'

42494 results) or `except` (every result but the named tools'). A named tool

42495 must be declared in this request's `tools[]`.

42496

4107942497 - `BetaWebFetchTool20260309 object`

4108042498

4108142499 Web fetch tool with use_cache parameter for bypassing cached content.

from line 42552

4113442552

4113542553 When true, guarantees schema validation on tool names and inputs

4113642554

42555 - `url_sources: optional BetaWebFetchURLSources or null`

42556

42557 Which sources contribute to the set of URLs web fetch may fetch.

42558

42559 Each key is a tagged variant: `user_input` is `all` or `none`; the

42560 two tool filters are `all`, `none`, `only` (only the named tools'

42561 results) or `except` (every result but the named tools'). A named tool

42562 must be declared in this request's `tools[]`.

42563

4113742564 - `use_cache: optional boolean`

4113842565

4113942566 Whether to use cached content. Set to false to bypass the cache and fetch fresh content. Only set to false when the user explicitly requests fresh content or when fetching rapidly-changing sources.

from line 42686

4125942686 - `strict: optional boolean`

4126042687

4126142688 When true, guarantees schema validation on tool names and inputs

42689

42690 - `url_sources: optional BetaWebFetchURLSources or null`

42691

42692 Which sources contribute to the set of URLs web fetch may fetch.

42693

42694 Each key is a tagged variant: `user_input` is `all` or `none`; the

42695 two tool filters are `all`, `none`, `only` (only the named tools'

42696 results) or `except` (every result but the named tools'). A named tool

42697 must be declared in this request's `tools[]`.

4126242698

4126342699 - `use_cache: optional boolean`

4126442700

from line 43087

4165143087

4165243088 - `string`

4165343089

41654 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 42 more`

43090 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 43 more`

4165543091

4165643092 - `"message-batches-2024-09-24"`

4165743093

from line 43178

4174243178 - `"thinking-binding-controls-2026-08-01"`

4174343179

4174443180 - `"mid-conversation-system-clear-at-2026-08-21"`

43181

43182 - `"compact-2026-09-04"`

4174543183

4174643184- `"anthropic-workspace-id": optional string`

4174743185

from line 43359

4192143359

4192243360 - `string`

4192343361

41924 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 42 more`

43362 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 43 more`

4192543363

4192643364 - `"message-batches-2024-09-24"`

4192743365

from line 43450

4201243450 - `"thinking-binding-controls-2026-08-01"`

4201343451

4201443452 - `"mid-conversation-system-clear-at-2026-08-21"`

43453

43454 - `"compact-2026-09-04"`

4201543455

4201643456- `"anthropic-workspace-id": optional string`

4201743457

from line 43640

4220043640

4220143641 - `string`

4220243642

42203 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 42 more`

43643 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 43 more`

4220443644

4220543645 - `"message-batches-2024-09-24"`

4220643646

from line 43731

4229143731 - `"thinking-binding-controls-2026-08-01"`

4229243732

4229343733 - `"mid-conversation-system-clear-at-2026-08-21"`

43734

43735 - `"compact-2026-09-04"`

4229443736

4229543737- `"anthropic-workspace-id": optional string`

4229643738

from line 43903

4246143903

4246243904 - `string`

4246343905

42464 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 42 more`

43906 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 43 more`

4246543907

4246643908 - `"message-batches-2024-09-24"`

4246743909

from line 43994

4255243994 - `"thinking-binding-controls-2026-08-01"`

4255343995

4255443996 - `"mid-conversation-system-clear-at-2026-08-21"`

43997

43998 - `"compact-2026-09-04"`

4255543999

4255644000- `"anthropic-workspace-id": optional string`

4255744001

from line 44058

4261444058

4261544059 - `string`

4261644060

42617 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 42 more`

44061 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 43 more`

4261844062

4261944063 - `"message-batches-2024-09-24"`

4262044064

from line 44149

4270544149 - `"thinking-binding-controls-2026-08-01"`

4270644150

4270744151 - `"mid-conversation-system-clear-at-2026-08-21"`

44152

44153 - `"compact-2026-09-04"`

4270844154

4270944155- `"anthropic-workspace-id": optional string`

4271044156

from line 45076

4363045076 - `encrypted_content: string or null`

4363145077

4363245078 Opaque metadata from prior compaction, to be round-tripped verbatim

45079

45080 - `signature: optional string or null`

45081

45082 Signature over the summary, to be sent back with the block verbatim

4363345083

4363445084 - `BetaFallbackBlock object`

4363545085

from line 45844

4439445844

4439545845 - `"fast"`

4439645846

44397 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`

44398

44399 Changes the API made to the request's input before showing it to the model:

44400 one entry per change, in request order. Today the only entry type is

44401 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`

44402 block from the request's `messages` that was removed from the prompt instead

44403 of being shown to the model because it failed a binding check. More entry

44404 types may be added over time; ignore types you do not recognize.

45847 - `input_transformations: optional array of BetaInputTransformation or null`

45848

45849 Changes the API made to the request's input before showing it to the model,

45850 and blocks that failed a binding check but were left unchanged: one entry per

45851 block, in request order. Two entry types today. `thinking_dropped` — a

45852 `thinking`, `redacted_thinking` or `connector_text` block from the request's

45853 `messages` that was removed from the prompt instead of being shown to the

45854 model because it failed a binding check. `thinking_mismatch_allowed` — a

45855 `thinking` or `redacted_thinking` block that failed the conversation check

45856 (the conversation before it differs from the one it was created in, or it

45857 carries no record of one on a model that requires it) and was shown to the

45858 model all the same, because that check is not enforced for this request.

45859 More entry types may be added over time; ignore types you do not recognize.

4440545860

4440645861 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on

4440745862 every such response from a model that supports extended thinking, as `[]`

44408 when nothing was changed; without the beta, blocks are removed all the same

44409 but nothing is reported. Removed blocks contribute nothing to

44410 `usage.input_tokens`. When streaming, the array is final in `message_start`;

44411 the final `message_delta` event carries it only when a server-side model

44412 fallback happened mid-stream, in which case it holds the serving model's

44413 entries and replaces the one in `message_start`.

44414

44415 - `type: "thinking_dropped"`

44416

44417 Always `thinking_dropped` for this entry type.

44418

44419 default: thinking_dropped

44420

44421 - `path: string`

44422

44423 Where the removed block was in your request, as `messages.{i}.content.{j}`:

44424 `i` indexes the `messages` array you sent and `j` that message's `content`

44425 array — the same form error messages use.

44426

44427 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

44428

44429 Which binding check removed the block: `model_binding_mismatch` — it was

44430 created by a model whose reasoning the requested model may not read;

44431 `prefix_binding_mismatch` — the conversation before it differs from the

44432 conversation it was created in (the rest of that turn's consecutive thinking

44433 blocks are removed with it, each with this reason);

44434 `organization_binding_mismatch` — it was created under a different

44435 organization (an Anthropic organization, AWS account or Google Cloud project)

44436 and this organization is not one of its additional organizations;

44437 `end_user_binding_mismatch` — it was created for a different end user, or

44438 was removed by the consumer-organization binding. A block that would fail

44439 several checks reports one reason, in this order of precedence:

44440 `organization_binding_mismatch`, `end_user_binding_mismatch`,

44441 `model_binding_mismatch`, `prefix_binding_mismatch`.

44442

44443 - `"model_binding_mismatch"`

44444

44445 - `"prefix_binding_mismatch"`

44446

44447 - `"organization_binding_mismatch"`

44448

44449 - `"end_user_binding_mismatch"`

45863 when there is no entry to report; without the beta, blocks are removed or

45864 left in place all the same but nothing is reported. Removed blocks contribute

45865 nothing to `usage.input_tokens`; blocks left in place count as sent. When

45866 streaming, the array is final in `message_start`; the final `message_delta`

45867 event carries it only when a server-side model fallback happened mid-stream,

45868 in which case it holds the serving model's entries and replaces the one in

45869 `message_start`.

45870

45871 - `BetaThinkingDroppedInputTransformation object`

45872

45873 - `type: "thinking_dropped"`

45874

45875 Always `thinking_dropped` for this entry type.

45876

45877 default: thinking_dropped

45878

45879 - `path: string`

45880

45881 Where the removed block was in your request, as `messages.{i}.content.{j}`:

45882 `i` indexes the `messages` array you sent and `j` that message's `content`

45883 array — the same form error messages use.

45884

45885 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

45886

45887 Which binding check removed the block: `model_binding_mismatch` — it was

45888 created by a model whose reasoning the requested model may not read;

45889 `prefix_binding_mismatch` — the conversation before it differs from the

45890 conversation it was created in (the rest of that turn's consecutive thinking

45891 blocks are removed with it, each with this reason);

45892 `organization_binding_mismatch` — it was created under a different

45893 organization (an Anthropic organization, AWS account or Google Cloud project)

45894 and this organization is not one of its additional organizations;

45895 `end_user_binding_mismatch` — it was created for a different end user, or

45896 was removed by the consumer-organization binding. A block that would fail

45897 several checks reports one reason, in this order of precedence:

45898 `organization_binding_mismatch`, `end_user_binding_mismatch`,

45899 `model_binding_mismatch`, `prefix_binding_mismatch`.

45900

45901 - `"model_binding_mismatch"`

45902

45903 - `"prefix_binding_mismatch"`

45904

45905 - `"organization_binding_mismatch"`

45906

45907 - `"end_user_binding_mismatch"`

45908

45909 - `BetaThinkingMismatchAllowedInputTransformation object`

45910

45911 - `type: "thinking_mismatch_allowed"`

45912

45913 Always `thinking_mismatch_allowed` for this entry type.

45914

45915 default: thinking_mismatch_allowed

45916

45917 - `path: string`

45918

45919 Where the block is in your request, as `messages.{i}.content.{j}`:

45920 `i` indexes the `messages` array you sent and `j` that message's `content`

45921 array — the same form error messages use.

45922

45923 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`

45924

45925 Which binding check the block failed; the block was shown to the model all

45926 the same. Always `prefix_binding_mismatch` today — the conversation before

45927 the block differs from the conversation it was created in, or the block

45928 carries no record of one on a model that requires it. Were the check

45929 enforced for this request, the block would have been removed or the request

45930 rejected (`thinking.block_binding.prefix_mismatch_behavior`). A removal also

45931 takes the rest of that turn's consecutive thinking blocks, whereas here each

45932 block is checked on its own, so `thinking_mismatch_allowed` entries are a

45933 lower bound on what enforcement would remove.

45934

45935 - `"model_binding_mismatch"`

45936

45937 - `"prefix_binding_mismatch"`

45938

45939 - `"organization_binding_mismatch"`

45940

45941 - `"end_user_binding_mismatch"`

4445045942

4445145943 - `BetaMessageBatchErroredResult object`

4445245944

4445345945

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