--- title: "Changes to Stream Session Thread Events" method: GET path: "/v1/sessions/{session_id}/threads/{thread_id}/stream?beta=true" --- # Changes to Stream Session Thread Events `GET /v1/sessions/{session_id}/threads/{thread_id}/stream?beta=true` > Every recorded change to this endpoint, newest first. ## Timeline Changed in 16 of 68 revisions. - **2026-09-01** `d1d189d791d1` — 2 info - **2026-08-19** `0042750ea1ee` — 8 breaking, 2 info - **2026-08-17** `d2b230555b7f` — 32 breaking, 22 info - **2026-08-06** `93d8fd7d6493` — 21 breaking, 10 info - **2026-07-24** `a97790bd7f18` — 4 info - **2026-07-22** `5e4a8830793b` — 3 info - **2026-06-30** `26335fd8487a` — 1 breaking, 1 info - **2026-06-30** `7caa9a75ddbc` — 2 info - **2026-06-09** `2336fecb081b` — 2 breaking, 2 info - **2026-06-09** `00259327305f` — 2 info - **2026-06-06** `546c704d347b` — 2 breaking, 10 info - **2026-05-28** `f9d488f9290d` — 2 info - **2026-05-19** `40e330aba8bc` — 1 breaking, 1 info - **2026-05-13** `88ef81f4f457` — 3 breaking - **2026-05-13** `80953dd6bb30` — 3 breaking, 3 info - **2026-05-06** `a4186730f56c` — 1 info ## Changes - **2026-09-01** `d1d189d791d1` — 2 info - added `subschema #2` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/anyOf[#/components/schemas/BetaManagedAgentsSessionAgent]/model/id` response property `anyOf` list for the response status `200` - added `subschema #2` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/anyOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/anyOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/oneOf[#/components/schemas/BetaManagedAgentsSessionThreadAgent]/model/id` response property `anyOf` list for the response status `200` - **2026-08-19** `0042750ea1ee` — 8 breaking, 2 info - added `#/components/schemas/BetaManagedAgentsBashToolConfig, #/components/schemas/BetaManagedAgentsEditToolConfig, #/components/schemas/BetaManagedAgentsReadToolConfig, #/components/schemas/BetaManagedAgentsWriteToolConfig, #/components/schemas/BetaManagedAgentsGlobToolConfig, #/components/schemas/BetaManagedAgentsGrepToolConfig, #/components/schemas/BetaManagedAgentsWebFetchToolConfig, #/components/schemas/BetaManagedAgentsWebSearchToolConfig` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/anyOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/anyOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/oneOf[#/components/schemas/BetaManagedAgentsSessionThreadAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsAgentToolset20260401]/configs/items/` response property `oneOf` list for the response status `200` - added `#/components/schemas/BetaManagedAgentsBashToolConfig, #/components/schemas/BetaManagedAgentsEditToolConfig, #/components/schemas/BetaManagedAgentsReadToolConfig, #/components/schemas/BetaManagedAgentsWriteToolConfig, #/components/schemas/BetaManagedAgentsGlobToolConfig, #/components/schemas/BetaManagedAgentsGrepToolConfig, #/components/schemas/BetaManagedAgentsWebFetchToolConfig, #/components/schemas/BetaManagedAgentsWebSearchToolConfig` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/anyOf[#/components/schemas/BetaManagedAgentsSessionAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsAgentToolset20260401]/configs/items/` response property `oneOf` list for the response status `200` - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/anyOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/anyOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/oneOf[#/components/schemas/BetaManagedAgentsSessionThreadAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsAgentToolset20260401]/configs/items/enabled` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/anyOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/anyOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/oneOf[#/components/schemas/BetaManagedAgentsSessionThreadAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsAgentToolset20260401]/configs/items/name` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/anyOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/anyOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/oneOf[#/components/schemas/BetaManagedAgentsSessionThreadAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsAgentToolset20260401]/configs/items/permission_policy` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/anyOf[#/components/schemas/BetaManagedAgentsSessionAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsAgentToolset20260401]/configs/items/enabled` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/anyOf[#/components/schemas/BetaManagedAgentsSessionAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsAgentToolset20260401]/configs/items/name` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/anyOf[#/components/schemas/BetaManagedAgentsSessionAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsAgentToolset20260401]/configs/items/permission_policy` from the response with the `200` status - added discriminator to `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/anyOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/anyOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/oneOf[#/components/schemas/BetaManagedAgentsSessionThreadAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsAgentToolset20260401]/configs/items/` response property for the response status `200` - added discriminator to `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/anyOf[#/components/schemas/BetaManagedAgentsSessionAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsAgentToolset20260401]/configs/items/` response property for the response status `200` - **2026-08-17** `d2b230555b7f` — 32 breaking, 22 info - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentCustomToolUseEvent]/session_thread_id` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentMcpToolResultEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/context` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentMcpToolResultEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/title` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentMcpToolResultEvent]/is_error` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentMcpToolUseEvent]/session_thread_id` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentThreadMessageReceivedEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/context` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentThreadMessageReceivedEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/title` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentThreadMessageReceivedEvent]/from_agent_name` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentThreadMessageSentEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/context` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentThreadMessageSentEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/title` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentThreadMessageSentEvent]/to_agent_name` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentToolResultEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/context` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentToolResultEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/title` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentToolResultEvent]/is_error` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsAgentToolUseEvent]/session_thread_id` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/title` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsSpanModelRequestEndEvent]/is_error` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserCustomToolResultEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/context` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserCustomToolResultEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/title` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserCustomToolResultEvent]/is_error` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserCustomToolResultEvent]/session_thread_id` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserDefineOutcomeEvent]/max_iterations` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserInterruptEvent]/session_thread_id` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserMessageEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/context` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserMessageEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/title` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserToolConfirmationEvent]/deny_message` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserToolConfirmationEvent]/session_thread_id` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserToolResultEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/context` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserToolResultEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsDocumentBlock]/title` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserToolResultEvent]/is_error` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsUserToolResultEvent]/session_thread_id` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - the `oneOf[#/components/schemas/BetaManagedAgentsUserToolConfirmationEvent]/deny_message` response property's maxLength was unset from `10000` for the response status `200` - removed `#/components/schemas/BetaManagedAgentsBudget` from the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/budget` response property `allOf` list for the response status `200` - removed `#/components/schemas/BetaManagedAgentsBudget` from the `oneOf[#/components/schemas/BetaManagedAgentsSessionUsageEvent]/budget` response property `allOf` list for the response status `200` - removed `#/components/schemas/BetaManagedAgentsSessionAgent` from the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent` response property `allOf` list for the response status `200` - removed `#/components/schemas/BetaManagedAgentsSpeed` from the `oneOf[#/components/schemas/BetaManagedAgentsSpanModelRequestEndEvent]/model_usage/allOf[#/components/schemas/BetaManagedAgentsSpanModelUsage]/speed` response property `allOf` list for the response status `200` - removed `#/components/schemas/BetaManagedAgentsSpeed` from the `oneOf[#/components/schemas/BetaManagedAgentsSpanOutcomeEvaluationEndEvent]/usage/allOf[#/components/schemas/BetaManagedAgentsSpanModelUsage]/speed` response property `allOf` list for the response status `200` - removed `#/components/schemas/BetaTimestamp` from the `oneOf[#/components/schemas/BetaManagedAgentsSystemMessageEvent]/processed_at` response property `allOf` list for the response status `200` - removed `#/components/schemas/BetaTimestamp` from the `oneOf[#/components/schemas/BetaManagedAgentsUserCustomToolResultEvent]/processed_at` response property `allOf` list for the response status `200` - removed `#/components/schemas/BetaTimestamp` from the `oneOf[#/components/schemas/BetaManagedAgentsUserInterruptEvent]/processed_at` response property `allOf` list for the response status `200` - …14 more - **2026-08-06** `93d8fd7d6493` — 21 breaking, 10 info - added `#/components/schemas/BetaManagedAgentsSessionUsageEvent` to the response body `oneOf` list for the response status `200` - added `#/components/schemas/BetaManagedAgentsRedactedBlock` to the `oneOf[#/components/schemas/BetaManagedAgentsAgentThreadMessageReceivedEvent]/content/items/` response property `oneOf` list for the response status `200` - added `#/components/schemas/BetaManagedAgentsRedactedBlock` to the `oneOf[#/components/schemas/BetaManagedAgentsAgentThreadMessageSentEvent]/content/items/` response property `oneOf` list for the response status `200` - added `#/components/schemas/BetaManagedAgentsRedactedBlock` to the `oneOf[#/components/schemas/BetaManagedAgentsUserMessageEvent]/content/items/` response property `oneOf` list for the response status `200` - added `#/components/schemas/BetaManagedAgentsSessionBudgetReached` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionStatusIdleEvent]/stop_reason` response property `oneOf` list for the response status `200` - added `#/components/schemas/BetaManagedAgentsSessionBudgetReached` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionThreadStatusIdleEvent]/stop_reason` response property `oneOf` list for the response status `200` - added `#/components/schemas/BetaManagedAgentsSessionThreadAgent, #/components/schemas/BetaManagedAgentsAdvisor` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/` response property `oneOf` list for the response status `200` - added `#/components/schemas/BetaManagedAgentsTextBlock, #/components/schemas/BetaManagedAgentsRedactedBlock` to the `oneOf[#/components/schemas/BetaManagedAgentsAgentMessageEvent]/content/items/` response property `oneOf` list for the response status `200` - the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/` response's property type changed from `object` to no type for status `200` - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsAgentMessageEvent]/content/items/text` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsAgentMessageEvent]/content/items/type` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/description` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/id` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/mcp_servers` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/model` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/name` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/skills` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/system` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/tools` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/type` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/version` from the response with the `200` status - added `session.usage` mapping keys to the response discriminator for the response status `200` - added the optional property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/model/inference_geo` to the response with the `200` status - added the optional property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/budget` to the response with the `200` status - added discriminator to `oneOf[#/components/schemas/BetaManagedAgentsAgentMessageEvent]/content/items/` response property for the response status `200` - added discriminator to `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/` response property for the response status `200` - added `budget_reached` discriminator mapping keys to the `oneOf[#/components/schemas/BetaManagedAgentsSessionStatusIdleEvent]/stop_reason` response property for the response status `200` - added `budget_reached` discriminator mapping keys to the `oneOf[#/components/schemas/BetaManagedAgentsSessionThreadStatusIdleEvent]/stop_reason` response property for the response status `200` - added `redacted` discriminator mapping keys to the `oneOf[#/components/schemas/BetaManagedAgentsAgentThreadMessageReceivedEvent]/content/items/` response property for the response status `200` - added `redacted` discriminator mapping keys to the `oneOf[#/components/schemas/BetaManagedAgentsAgentThreadMessageSentEvent]/content/items/` response property for the response status `200` - added `redacted` discriminator mapping keys to the `oneOf[#/components/schemas/BetaManagedAgentsUserMessageEvent]/content/items/` response property for the response status `200` - **2026-07-24** `a97790bd7f18` — 4 info - added `subschema #4, subschema #5, subschema #6, subschema #7, subschema #11, subschema #12` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/model/id` response property `anyOf` list for the response status `200` - added `subschema #4, subschema #5, subschema #6, subschema #7, subschema #11, subschema #12` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/model/id` response property `anyOf` list for the response status `200` - removed `subschema #4, subschema #5, subschema #6, subschema #10, subschema #11` from the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/model/id` response property `anyOf` list for the response status `200` - removed `subschema #4, subschema #5, subschema #6, subschema #10, subschema #11` from the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/model/id` response property `anyOf` list for the response status `200` - **2026-07-22** `5e4a8830793b` — 3 info - added the new optional `query` request parameter `event_deltas[]` - added the optional property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/model/effort` to the response with the `200` status - added the optional property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/model/effort` to the response with the `200` status - **2026-06-30** `26335fd8487a` — 1 breaking, 1 info - added `#/components/schemas/BetaManagedAgentsEventStartEvent, #/components/schemas/BetaManagedAgentsEventDeltaEvent` to the response body `oneOf` list for the response status `200` - added `event_start, event_delta` mapping keys to the response discriminator for the response status `200` - **2026-06-30** `7caa9a75ddbc` — 2 info - added `subschema #2` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/model/id` response property `anyOf` list for the response status `200` - added `subschema #2` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/model/id` response property `anyOf` list for the response status `200` - **2026-06-09** `2336fecb081b` — 2 breaking, 2 info - added `#/components/schemas/BetaManagedAgentsSystemMessageEvent` to the response body `oneOf` list for the response status `200` - added `#/components/schemas/BetaManagedAgentsCredentialHostUnreachableError` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionErrorEvent]/error` response property `oneOf` list for the response status `200` - added `system.message` mapping keys to the response discriminator for the response status `200` - added `credential_host_unreachable_error` discriminator mapping keys to the `oneOf[#/components/schemas/BetaManagedAgentsSessionErrorEvent]/error` response property for the response status `200` - **2026-06-09** `00259327305f` — 2 info - added `subschema #2` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/model/id` response property `anyOf` list for the response status `200` - added `subschema #2` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/model/id` response property `anyOf` list for the response status `200` - **2026-06-06** `546c704d347b` — 2 breaking, 10 info - response property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/tools/items/oneOf[#/components/schemas/BetaManagedAgentsCustomTool]/input_schema/required` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - response property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsCustomTool]/input_schema/required` list-of-types was widened by adding types `null` to media type `application/json` of response `200` - removed `#/components/schemas/BetaManagedAgentsStruct` from the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/tools/items/oneOf[#/components/schemas/BetaManagedAgentsCustomTool]/input_schema/properties` response property `allOf` list for the response status `200` - removed `#/components/schemas/BetaManagedAgentsStruct` from the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsCustomTool]/input_schema/properties` response property `allOf` list for the response status `200` - added `subschema #1, subschema #2` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/tools/items/oneOf[#/components/schemas/BetaManagedAgentsCustomTool]/input_schema/properties` response property `anyOf` list for the response status `200` - added `subschema #1, subschema #2` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsCustomTool]/input_schema/properties` response property `anyOf` list for the response status `200` - the response property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/tools/items/oneOf[#/components/schemas/BetaManagedAgentsCustomTool]/input_schema/type` became required for the status `200` - the response property `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsCustomTool]/input_schema/type` became required for the status `200` - the `type` response property const value `object` was added for the status `200` - the `type` response property const value `object` was added for the status `200` - removed the `object` enum value from the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/tools/items/oneOf[#/components/schemas/BetaManagedAgentsCustomTool]/input_schema/type` response property for the response status `200` - removed the `object` enum value from the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/tools/items/oneOf[#/components/schemas/BetaManagedAgentsCustomTool]/input_schema/type` response property for the response status `200` - **2026-05-28** `f9d488f9290d` — 2 info - added `subschema #2` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/model/id` response property `anyOf` list for the response status `200` - added `subschema #2` to the `oneOf[#/components/schemas/BetaManagedAgentsSessionUpdatedEvent]/agent/allOf[#/components/schemas/BetaManagedAgentsSessionAgent]/multiagent/allOf[#/components/schemas/BetaManagedAgentsSessionMultiagent]/oneOf[#/components/schemas/BetaManagedAgentsSessionMultiagentCoordinator]/agents/items/model/id` response property `anyOf` list for the response status `200` - **2026-05-19** `40e330aba8bc` — 1 breaking, 1 info - added `#/components/schemas/BetaManagedAgentsUserToolResultEvent, #/components/schemas/BetaManagedAgentsSessionUpdatedEvent` to the response body `oneOf` list for the response status `200` - added `user.tool_result, session.updated` mapping keys to the response discriminator for the response status `200` - **2026-05-13** `88ef81f4f457` — 3 breaking - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsAgentMcpToolResultEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsSearchResultBlock]/tool_use_id` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsAgentToolResultEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsSearchResultBlock]/tool_use_id` from the response with the `200` status - removed the required property `oneOf[#/components/schemas/BetaManagedAgentsUserCustomToolResultEvent]/content/items/oneOf[#/components/schemas/BetaManagedAgentsSearchResultBlock]/tool_use_id` from the response with the `200` status - **2026-05-13** `80953dd6bb30` — 3 breaking, 3 info - added `#/components/schemas/BetaManagedAgentsSearchResultBlock` to the `oneOf[#/components/schemas/BetaManagedAgentsAgentMcpToolResultEvent]/content/items/` response property `oneOf` list for the response status `200` - added `#/components/schemas/BetaManagedAgentsSearchResultBlock` to the `oneOf[#/components/schemas/BetaManagedAgentsAgentToolResultEvent]/content/items/` response property `oneOf` list for the response status `200` - added `#/components/schemas/BetaManagedAgentsSearchResultBlock` to the `oneOf[#/components/schemas/BetaManagedAgentsUserCustomToolResultEvent]/content/items/` response property `oneOf` list for the response status `200` - added `search_result` discriminator mapping keys to the `oneOf[#/components/schemas/BetaManagedAgentsAgentMcpToolResultEvent]/content/items/` response property for the response status `200` - added `search_result` discriminator mapping keys to the `oneOf[#/components/schemas/BetaManagedAgentsAgentToolResultEvent]/content/items/` response property for the response status `200` - added `search_result` discriminator mapping keys to the `oneOf[#/components/schemas/BetaManagedAgentsUserCustomToolResultEvent]/content/items/` response property for the response status `200` - **2026-05-06** `a4186730f56c` — 1 info - endpoint added --- [Operation](https://skmtc.dev/anthropics/apis/anthropic-api/docs/v1/sessions/:session_id/threads/:thread_id/stream?beta=true/get.md) · [API](https://skmtc.dev/anthropics/apis/anthropic-api.md) · [Page](https://skmtc.dev/anthropics/apis/anthropic-api/changes/v1/sessions/:session_id/threads/:thread_id/stream?beta=true/get)