sandbox-agent/research/acp/old-rest-openapi-list.md

Sources

• Old OpenAPI path: docs/openapi.json at git ref 8ecd27b
• ACP v1 API path: ~/misc/acp-docs/schema/schema.json (~/misc/acp-docs/schema/schema.unstable.json for unstable methods)

Path / Schema Property	ACP Equivalent
/v1/agents	UNIMPLEMENTED
/v1/agents/{agent}/install	UNIMPLEMENTED
/v1/agents/{agent}/models	session/new.result.models.availableModels (UNSTABLE; session-scoped)
/v1/agents/{agent}/modes	session/new.result.modes.availableModes (session-scoped)
/v1/fs/entries	UNIMPLEMENTED
/v1/fs/entry	UNIMPLEMENTED
/v1/fs/file	fs/read_text_file + fs/write_text_file (text-only, agent->client direction)
/v1/fs/mkdir	UNIMPLEMENTED
/v1/fs/move	UNIMPLEMENTED
/v1/fs/stat	UNIMPLEMENTED
/v1/fs/upload-batch	UNIMPLEMENTED
/v1/health	UNIMPLEMENTED
/v1/sessions	session/list (UNSTABLE)
/v1/sessions/{session_id}	session/new | session/load | session/resume (UNSTABLE)
/v1/sessions/{session_id}/events	UNIMPLEMENTED
/v1/sessions/{session_id}/events/sse	session/update (notification stream)
/v1/sessions/{session_id}/messages	session/prompt
/v1/sessions/{session_id}/messages/stream	session/prompt + session/update notifications
/v1/sessions/{session_id}/permissions/{permission_id}/reply	session/request_permission response
/v1/sessions/{session_id}/questions/{question_id}/reject	UNIMPLEMENTED
/v1/sessions/{session_id}/questions/{question_id}/reply	UNIMPLEMENTED
/v1/sessions/{session_id}/terminate	session/cancel (turn cancellation only)
AgentCapabilities	initialize.result.agentCapabilities
AgentCapabilities.commandExecution	UNIMPLEMENTED
AgentCapabilities.errorEvents	UNIMPLEMENTED
AgentCapabilities.fileAttachments	initialize.result.agentCapabilities.promptCapabilities.embeddedContext (partial)
AgentCapabilities.fileChanges	session/update.params.update(sessionUpdate=tool_call_update).content[].type=diff
AgentCapabilities.images	initialize.result.agentCapabilities.promptCapabilities.image
AgentCapabilities.itemStarted	session/update.params.update.sessionUpdate=tool_call | *_message_chunk (no explicit item-start sentinel)
AgentCapabilities.mcpTools	initialize.result.agentCapabilities.mcpCapabilities
AgentCapabilities.permissions	session/request_permission (agent->client request)
AgentCapabilities.planMode	session/update.params.update.sessionUpdate=plan
AgentCapabilities.questions	UNIMPLEMENTED
AgentCapabilities.reasoning	session/update.params.update.sessionUpdate=agent_thought_chunk
AgentCapabilities.sessionLifecycle	session/new, session/load, session/list (UNSTABLE), session/resume (UNSTABLE), session/fork (UNSTABLE)
AgentCapabilities.sharedProcess	UNIMPLEMENTED
AgentCapabilities.status	session/update.params.update.tool_call.status | tool_call_update.status
AgentCapabilities.streamingDeltas	session/update.params.update.sessionUpdate=agent_message_chunk
AgentCapabilities.textMessages	ContentBlock.type=text
AgentCapabilities.toolCalls	session/update.params.update.sessionUpdate=tool_call
AgentCapabilities.toolResults	session/update.params.update.sessionUpdate=tool_call_update
AgentError	JSON-RPC Error
AgentError.agent	Error.data._meta["sandbox-agent/agent"] (extension)
AgentError.details	Error.data
AgentError.message	Error.message
AgentError.session_id	Error.data._meta["sandbox-agent/sessionId"] (extension)
AgentError.type	Error.code (+ Error.data._meta["sandbox-agent/errorType"] for legacy string types)
AgentError.type.$ref(ErrorType)	Error.code (+ Error.data._meta["sandbox-agent/errorType"] for legacy string types)
AgentInfo	initialize.result.agentInfo + initialize.result.agentCapabilities
AgentInfo.capabilities	initialize.result.agentCapabilities
AgentInfo.capabilities.$ref(AgentCapabilities)	initialize.result.agentCapabilities
AgentInfo.credentialsAvailable	UNIMPLEMENTED
AgentInfo.id	initialize.result.agentInfo.name
AgentInfo.installed	UNIMPLEMENTED
AgentInfo.path	UNIMPLEMENTED
AgentInfo.serverStatus	UNIMPLEMENTED
AgentInfo.serverStatus.allOf[0]	UNIMPLEMENTED
AgentInfo.serverStatus.allOf[0].$ref(ServerStatusInfo)	UNIMPLEMENTED
AgentInfo.version	initialize.result.agentInfo.version
AgentInstallRequest	UNIMPLEMENTED
AgentInstallRequest.reinstall	UNIMPLEMENTED
AgentListResponse	UNIMPLEMENTED
AgentListResponse.agents	UNIMPLEMENTED
AgentListResponse.agents[]	UNIMPLEMENTED
AgentListResponse.agents[].$ref(AgentInfo)	UNIMPLEMENTED
AgentModeInfo	SessionMode
AgentModeInfo.description	SessionMode.description
AgentModeInfo.id	SessionMode.id
AgentModeInfo.name	SessionMode.name
AgentModelInfo	ModelInfo (UNSTABLE)
AgentModelInfo.defaultVariant	UNIMPLEMENTED
AgentModelInfo.id	ModelInfo.modelId (UNSTABLE)
AgentModelInfo.name	ModelInfo.name (UNSTABLE)
AgentModelInfo.variants	UNIMPLEMENTED
AgentModelInfo.variants[]	UNIMPLEMENTED
AgentModelsResponse	SessionModelState (UNSTABLE)
AgentModelsResponse.defaultModel	SessionModelState.currentModelId (UNSTABLE)
AgentModelsResponse.models	SessionModelState.availableModels (UNSTABLE)
AgentModelsResponse.models[]	SessionModelState.availableModels[] (UNSTABLE)
AgentModelsResponse.models[].$ref(AgentModelInfo)	SessionModelState.availableModels[] -> ModelInfo (UNSTABLE)
AgentModesResponse	SessionModeState
AgentModesResponse.modes	SessionModeState.availableModes
AgentModesResponse.modes[]	SessionModeState.availableModes[]
AgentModesResponse.modes[].$ref(AgentModeInfo)	SessionModeState.availableModes[] -> SessionMode
AgentUnparsedData	session/update.params.update._meta["sandbox-agent/unparsed"] (extension)
AgentUnparsedData.error	session/update.params.update._meta["sandbox-agent/unparsed"].error (extension)
AgentUnparsedData.location	session/update.params.update._meta["sandbox-agent/unparsed"].location (extension)
AgentUnparsedData.raw_hash	session/update.params.update._meta["sandbox-agent/unparsed"].rawHash (extension)
ContentPart	ContentBlock | ToolCall | ToolCallUpdate | ToolCallContent
ContentPart.oneOf[0]	ContentBlock (type=text)
ContentPart.oneOf[0].text	ContentBlock.text
ContentPart.oneOf[0].type	ContentBlock.type="text"
ContentPart.oneOf[1]	ContentBlock (type=resource) with JSON payload
ContentPart.oneOf[1].json	EmbeddedResource.resource.text (mimeType="application/json")
ContentPart.oneOf[1].type	ContentBlock.type="resource"
ContentPart.oneOf[2]	session/update.params.update(sessionUpdate=tool_call)
ContentPart.oneOf[2].arguments	ToolCall.rawInput
ContentPart.oneOf[2].call_id	ToolCall.toolCallId
ContentPart.oneOf[2].name	ToolCall._meta["sandbox-agent/toolName"] (extension)
ContentPart.oneOf[2].type	session/update.params.update.sessionUpdate="tool_call"
ContentPart.oneOf[3]	session/update.params.update(sessionUpdate=tool_call_update)
ContentPart.oneOf[3].call_id	ToolCallUpdate.toolCallId
ContentPart.oneOf[3].output	ToolCallUpdate.rawOutput
ContentPart.oneOf[3].type	session/update.params.update.sessionUpdate="tool_call_update"
ContentPart.oneOf[4]	ToolCallContent (type=diff)
ContentPart.oneOf[4].action	ToolCall.kind (read->read, write/patch->edit)
ContentPart.oneOf[4].action.$ref(FileAction)	ToolKind (read|edit)
ContentPart.oneOf[4].diff	Diff.newText / Diff.oldText
ContentPart.oneOf[4].path	Diff.path
ContentPart.oneOf[4].type	ToolCallContent.type="diff"
ContentPart.oneOf[5]	session/update.params.update(sessionUpdate=agent_thought_chunk)
ContentPart.oneOf[5].text	ContentChunk.content.text
ContentPart.oneOf[5].type	session/update.params.update.sessionUpdate="agent_thought_chunk"
ContentPart.oneOf[5].visibility	ContentChunk.content._meta["sandbox-agent/reasoningVisibility"] (extension)
ContentPart.oneOf[5].visibility.$ref(ReasoningVisibility)	ContentChunk.content._meta["sandbox-agent/reasoningVisibility"] (extension)
ContentPart.oneOf[6]	ContentBlock (type=image)
ContentPart.oneOf[6].mime	ImageContent.mimeType
ContentPart.oneOf[6].path	ImageContent.uri
ContentPart.oneOf[6].type	ContentBlock.type="image"
ContentPart.oneOf[7]	session/update.params.update._meta["sandbox-agent/status"] (extension)
ContentPart.oneOf[7].detail	session/update.params.update._meta["sandbox-agent/status"].detail (extension)
ContentPart.oneOf[7].label	session/update.params.update._meta["sandbox-agent/status"].label (extension)
ContentPart.oneOf[7].type	session/update.params.update._meta["sandbox-agent/status"].type (extension)
CreateSessionRequest	session/new.params (+ session/set_mode, session/set_model UNSTABLE, session/set_config_option, _meta extensions)
CreateSessionRequest.agent	session/new.params._meta["sandbox-agent/agent"] (extension; agent selection is out-of-band in ACP)
CreateSessionRequest.agentMode	session/set_mode.params.modeId (or session/new.params._meta["sandbox-agent/agentMode"])
CreateSessionRequest.agentVersion	session/new.params._meta["sandbox-agent/agentVersion"] (extension)
CreateSessionRequest.directory	session/new.params.cwd
CreateSessionRequest.mcp	session/new.params.mcpServers
CreateSessionRequest.mcp.*	session/new.params.mcpServers[]
CreateSessionRequest.mcp.*.$ref(McpServerConfig)	McpServer
CreateSessionRequest.model	session/set_model.params.modelId (UNSTABLE) or session/set_config_option (category=model)
CreateSessionRequest.permissionMode	session/set_config_option.params (extension-defined option) or _meta
CreateSessionRequest.skills	session/new.params._meta["sandbox-agent/skills"] (extension)
CreateSessionRequest.skills.allOf[0]	session/new.params._meta["sandbox-agent/skills"] (extension)
CreateSessionRequest.skills.allOf[0].$ref(SkillsConfig)	session/new.params._meta["sandbox-agent/skills"] (extension)
CreateSessionRequest.title	session/new.params._meta["sandbox-agent/title"] (extension); session/update(session_info_update).title
CreateSessionRequest.variant	session/new.params._meta["sandbox-agent/variant"] (extension)
CreateSessionResponse	session/new.result
CreateSessionResponse.error	JSON-RPC error
CreateSessionResponse.error.allOf[0]	JSON-RPC error
CreateSessionResponse.error.allOf[0].$ref(AgentError)	JSON-RPC error
CreateSessionResponse.healthy	JSON-RPC success (no error)
CreateSessionResponse.nativeSessionId	session/new.result.sessionId
ErrorData	JSON-RPC Error
ErrorData.code	Error.code
ErrorData.details	Error.data
ErrorData.message	Error.message
ErrorType	Error.code (+ Error.data._meta["sandbox-agent/errorType"] for legacy string values)
EventSource	session/update.params._meta["sandbox-agent/source"] (extension)
EventsQuery	UNIMPLEMENTED
EventsQuery.includeRaw	UNIMPLEMENTED
EventsQuery.limit	UNIMPLEMENTED
EventsQuery.offset	UNIMPLEMENTED
EventsResponse	Stream of session/update notifications
EventsResponse.events	session/update notifications
EventsResponse.events[]	SessionNotification
EventsResponse.events[].$ref(UniversalEvent)	SessionNotification (+ JSON-RPC envelope)
EventsResponse.hasMore	UNIMPLEMENTED
FileAction	ToolKind (read->read, write/patch->edit)
FsActionResponse	UNIMPLEMENTED
FsActionResponse.path	UNIMPLEMENTED
FsDeleteQuery	UNIMPLEMENTED
FsDeleteQuery.path	UNIMPLEMENTED
FsDeleteQuery.recursive	UNIMPLEMENTED
FsDeleteQuery.sessionId	UNIMPLEMENTED
FsEntriesQuery	UNIMPLEMENTED
FsEntriesQuery.path	UNIMPLEMENTED
FsEntriesQuery.sessionId	UNIMPLEMENTED
FsEntry	UNIMPLEMENTED
FsEntry.entryType	UNIMPLEMENTED
FsEntry.entryType.$ref(FsEntryType)	UNIMPLEMENTED
FsEntry.modified	UNIMPLEMENTED
FsEntry.name	UNIMPLEMENTED
FsEntry.path	UNIMPLEMENTED
FsEntry.size	UNIMPLEMENTED
FsEntryType	UNIMPLEMENTED
FsMoveRequest	UNIMPLEMENTED
FsMoveRequest.from	UNIMPLEMENTED
FsMoveRequest.overwrite	UNIMPLEMENTED
FsMoveRequest.to	UNIMPLEMENTED
FsMoveResponse	UNIMPLEMENTED
FsMoveResponse.from	UNIMPLEMENTED
FsMoveResponse.to	UNIMPLEMENTED
FsPathQuery	fs/read_text_file.params | fs/write_text_file.params (partial)
FsPathQuery.path	fs/read_text_file.params.path | fs/write_text_file.params.path
FsPathQuery.sessionId	fs/read_text_file.params.sessionId | fs/write_text_file.params.sessionId
FsSessionQuery	fs/read_text_file.params | fs/write_text_file.params (partial)
FsSessionQuery.sessionId	fs/read_text_file.params.sessionId | fs/write_text_file.params.sessionId
FsStat	UNIMPLEMENTED
FsStat.entryType	UNIMPLEMENTED
FsStat.entryType.$ref(FsEntryType)	UNIMPLEMENTED
FsStat.modified	UNIMPLEMENTED
FsStat.path	UNIMPLEMENTED
FsStat.size	UNIMPLEMENTED
FsUploadBatchQuery	UNIMPLEMENTED
FsUploadBatchQuery.path	UNIMPLEMENTED
FsUploadBatchQuery.sessionId	UNIMPLEMENTED
FsUploadBatchResponse	UNIMPLEMENTED
FsUploadBatchResponse.paths	UNIMPLEMENTED
FsUploadBatchResponse.paths[]	UNIMPLEMENTED
FsUploadBatchResponse.truncated	UNIMPLEMENTED
FsWriteResponse	fs/write_text_file.result (partial)
FsWriteResponse.bytesWritten	UNIMPLEMENTED
FsWriteResponse.path	fs/write_text_file.params.path
HealthResponse	UNIMPLEMENTED
HealthResponse.status	UNIMPLEMENTED
ItemDeltaData	session/update.params.update(sessionUpdate=*message_chunk)
ItemDeltaData.delta	ContentChunk.content.text
ItemDeltaData.item_id	ContentChunk._meta["sandbox-agent/itemId"] (extension)
ItemDeltaData.native_item_id	ContentChunk._meta["sandbox-agent/nativeItemId"] (extension)
ItemEventData	session/update.params.update
ItemEventData.item	SessionUpdate (ToolCall | ToolCallUpdate | ContentChunk)
ItemEventData.item.$ref(UniversalItem)	SessionUpdate (ToolCall | ToolCallUpdate | ContentChunk)
ItemKind	SessionUpdate.sessionUpdate + ToolKind
ItemRole	Role (assistant|user) + SessionUpdate.sessionUpdate for non-message items
ItemStatus	ToolCall.status | ToolCallUpdate.status
McpCommand	McpServerStdio.command + McpServerStdio.args
McpCommand.oneOf[0]	McpServerStdio.command
McpCommand.oneOf[1]	McpServerStdio.args
McpCommand.oneOf[1][]	McpServerStdio.args[]
McpOAuthConfig	McpServer._meta["sandbox-agent/oauth"] (extension)
McpOAuthConfig.clientId	McpServer._meta["sandbox-agent/oauth"].clientId (extension)
McpOAuthConfig.clientSecret	McpServer._meta["sandbox-agent/oauth"].clientSecret (extension)
McpOAuthConfig.scope	McpServer._meta["sandbox-agent/oauth"].scope (extension)
McpOAuthConfigOrDisabled	McpServer._meta["sandbox-agent/oauth"] (extension)
McpOAuthConfigOrDisabled.oneOf[0]	McpServer._meta["sandbox-agent/oauth"] (extension)
McpOAuthConfigOrDisabled.oneOf[0].$ref(McpOAuthConfig)	McpServer._meta["sandbox-agent/oauth"] (extension)
McpOAuthConfigOrDisabled.oneOf[1]	McpServer._meta["sandbox-agent/oauthDisabled"] (extension)
McpRemoteTransport	McpServer.type ("http" | "sse")
McpServerConfig	McpServer
McpServerConfig.oneOf[0]	McpServerStdio (McpServer.type="stdio")
McpServerConfig.oneOf[0].args	McpServerStdio.args
McpServerConfig.oneOf[0].args[]	McpServerStdio.args[]
McpServerConfig.oneOf[0].command	McpServerStdio.command
McpServerConfig.oneOf[0].command.$ref(McpCommand)	McpServerStdio.command + McpServerStdio.args
McpServerConfig.oneOf[0].cwd	McpServerStdio._meta["sandbox-agent/cwd"] (extension)
McpServerConfig.oneOf[0].enabled	McpServerStdio._meta["sandbox-agent/enabled"] (extension)
McpServerConfig.oneOf[0].env	McpServerStdio.env (object -> EnvVariable[])
McpServerConfig.oneOf[0].env.*	McpServerStdio.env[].{name,value}
McpServerConfig.oneOf[0].timeoutMs	McpServerStdio._meta["sandbox-agent/timeoutMs"] (extension)
McpServerConfig.oneOf[0].type	McpServer type="stdio"
McpServerConfig.oneOf[1]	McpServerHttp | McpServerSse
McpServerConfig.oneOf[1].bearerTokenEnvVar	McpServer._meta["sandbox-agent/bearerTokenEnvVar"] (extension)
McpServerConfig.oneOf[1].enabled	McpServer._meta["sandbox-agent/enabled"] (extension)
McpServerConfig.oneOf[1].envHeaders	McpServer._meta["sandbox-agent/envHeaders"] (extension)
McpServerConfig.oneOf[1].envHeaders.*	McpServer._meta["sandbox-agent/envHeaders"] (extension)
McpServerConfig.oneOf[1].headers	McpServerHttp.headers | McpServerSse.headers (object -> HttpHeader[])
McpServerConfig.oneOf[1].headers.*	McpServerHttp.headers[].{name,value} | McpServerSse.headers[].{name,value}
McpServerConfig.oneOf[1].oauth	McpServer._meta["sandbox-agent/oauth"] (extension)
McpServerConfig.oneOf[1].oauth.allOf[0]	McpServer._meta["sandbox-agent/oauth"] (extension)
McpServerConfig.oneOf[1].oauth.allOf[0].$ref(McpOAuthConfigOrDisabled)	McpServer._meta["sandbox-agent/oauth"] (extension)
McpServerConfig.oneOf[1].timeoutMs	McpServer._meta["sandbox-agent/timeoutMs"] (extension)
McpServerConfig.oneOf[1].transport	McpServer.type ("http" | "sse")
McpServerConfig.oneOf[1].transport.allOf[0]	McpServer.type ("http" | "sse")
McpServerConfig.oneOf[1].transport.allOf[0].$ref(McpRemoteTransport)	McpServer.type ("http" | "sse")
McpServerConfig.oneOf[1].type	McpServer.type ("http" | "sse")
McpServerConfig.oneOf[1].url	McpServerHttp.url | McpServerSse.url
MessageAttachment	ContentBlock.resource_link | ContentBlock.image
MessageAttachment.filename	ResourceLink.name | ResourceLink.title
MessageAttachment.mime	ResourceLink.mimeType | ImageContent.mimeType
MessageAttachment.path	ResourceLink.uri | ImageContent.uri
MessageRequest	session/prompt.params
MessageRequest.attachments	session/prompt.params.prompt[] (non-text ContentBlock entries)
MessageRequest.attachments[]	session/prompt.params.prompt[] (resource_link/image/resource)
MessageRequest.attachments[].$ref(MessageAttachment)	ContentBlock.resource_link | ContentBlock.image
MessageRequest.message	session/prompt.params.prompt[]: ContentBlock(type=text).text
PermissionEventData	session/request_permission.params + response
PermissionEventData.action	session/request_permission.params.toolCall.title | .kind
PermissionEventData.metadata	session/request_permission.params._meta (extension)
PermissionEventData.permission_id	JSON-RPC request id of session/request_permission
PermissionEventData.status	session/request_permission lifecycle + RequestPermissionOutcome
PermissionEventData.status.$ref(PermissionStatus)	RequestPermissionOutcome + PermissionOption.kind mapping
PermissionReply	RequestPermissionOutcome.selected.optionId (mapped from chosen PermissionOption)
PermissionReplyRequest	session/request_permission response
PermissionReplyRequest.reply	RequestPermissionResponse.outcome
PermissionReplyRequest.reply.$ref(PermissionReply)	RequestPermissionResponse.outcome
PermissionStatus	RequestPermissionOutcome + PermissionOption.kind (allow_once|allow_always|reject_once|reject_always)
ProblemDetails	JSON-RPC Error (partial)
ProblemDetails.detail	Error.data.detail (or Error.message)
ProblemDetails.instance	Error.data.instance
ProblemDetails.status	Error.code
ProblemDetails.title	Error.message
ProblemDetails.type	Error.data.type
ProblemDetails.*	Error.data.*
QuestionEventData	UNIMPLEMENTED
QuestionEventData.options	UNIMPLEMENTED
QuestionEventData.options[]	UNIMPLEMENTED
QuestionEventData.prompt	UNIMPLEMENTED
QuestionEventData.question_id	UNIMPLEMENTED
QuestionEventData.response	UNIMPLEMENTED
QuestionEventData.status	UNIMPLEMENTED
QuestionEventData.status.$ref(QuestionStatus)	UNIMPLEMENTED
QuestionReplyRequest	UNIMPLEMENTED
QuestionReplyRequest.answers	UNIMPLEMENTED
QuestionReplyRequest.answers[]	UNIMPLEMENTED
QuestionReplyRequest.answers[][]	UNIMPLEMENTED
QuestionStatus	UNIMPLEMENTED
ReasoningVisibility	Content._meta["sandbox-agent/reasoningVisibility"] (extension)
ServerStatus	UNIMPLEMENTED
ServerStatusInfo	UNIMPLEMENTED
ServerStatusInfo.baseUrl	UNIMPLEMENTED
ServerStatusInfo.lastError	UNIMPLEMENTED
ServerStatusInfo.restartCount	UNIMPLEMENTED
ServerStatusInfo.status	UNIMPLEMENTED
ServerStatusInfo.status.$ref(ServerStatus)	UNIMPLEMENTED
ServerStatusInfo.uptimeMs	UNIMPLEMENTED
SessionEndedData	session/prompt.result.stopReason (+ _meta extension for process details)
SessionEndedData.exit_code	session/prompt.result._meta["sandbox-agent/sessionEnd"].exitCode (extension)
SessionEndedData.message	session/prompt.result._meta["sandbox-agent/sessionEnd"].message (extension)
SessionEndedData.reason	session/prompt.result.stopReason
SessionEndedData.reason.$ref(SessionEndReason)	session/prompt.result.stopReason
SessionEndedData.stderr	session/prompt.result._meta["sandbox-agent/sessionEnd"].stderr (extension)
SessionEndedData.stderr.allOf[0]	session/prompt.result._meta["sandbox-agent/sessionEnd"].stderr (extension)
SessionEndedData.stderr.allOf[0].$ref(StderrOutput)	session/prompt.result._meta["sandbox-agent/sessionEnd"].stderr (extension)
SessionEndedData.terminated_by	session/prompt.result._meta["sandbox-agent/sessionEnd"].terminatedBy (extension)
SessionEndedData.terminated_by.$ref(TerminatedBy)	session/prompt.result._meta["sandbox-agent/sessionEnd"].terminatedBy (extension)
SessionEndReason	StopReason (completed->end_turn, terminated->cancelled, error->JSON-RPC error or refusal)
SessionInfo	session/list.result.sessions[] (UNSTABLE) + session/update(session_info_update)
SessionInfo.agent	SessionInfo._meta["sandbox-agent/agent"] (extension)
SessionInfo.agentMode	SessionModeState.currentModeId / CurrentModeUpdate.currentModeId
SessionInfo.createdAt	SessionInfo._meta["sandbox-agent/createdAt"] (extension)
SessionInfo.directory	SessionInfo.cwd
SessionInfo.ended	SessionInfo._meta["sandbox-agent/ended"] (extension)
SessionInfo.eventCount	SessionInfo._meta["sandbox-agent/eventCount"] (extension)
SessionInfo.mcp	SessionInfo._meta["sandbox-agent/mcp"] (extension)
SessionInfo.mcp.*	SessionInfo._meta["sandbox-agent/mcp"][*] (extension)
SessionInfo.mcp.*.$ref(McpServerConfig)	SessionInfo._meta["sandbox-agent/mcp"][*] (extension)
SessionInfo.model	SessionModelState.currentModelId (UNSTABLE) or SessionInfo._meta["sandbox-agent/model"]
SessionInfo.nativeSessionId	SessionInfo._meta["sandbox-agent/nativeSessionId"] (extension)
SessionInfo.permissionMode	SessionInfo._meta["sandbox-agent/permissionMode"] (extension)
SessionInfo.sessionId	SessionInfo.sessionId
SessionInfo.skills	SessionInfo._meta["sandbox-agent/skills"] (extension)
SessionInfo.skills.allOf[0]	SessionInfo._meta["sandbox-agent/skills"] (extension)
SessionInfo.skills.allOf[0].$ref(SkillsConfig)	SessionInfo._meta["sandbox-agent/skills"] (extension)
SessionInfo.title	SessionInfo.title | SessionInfoUpdate.title
SessionInfo.updatedAt	SessionInfo.updatedAt | SessionInfoUpdate.updatedAt
SessionInfo.variant	SessionInfo._meta["sandbox-agent/variant"] (extension)
SessionListResponse	session/list.result (UNSTABLE)
SessionListResponse.sessions	session/list.result.sessions (UNSTABLE)
SessionListResponse.sessions[]	session/list.result.sessions[] (UNSTABLE)
SessionListResponse.sessions[].$ref(SessionInfo)	session/list.result.sessions[] -> SessionInfo (UNSTABLE)
SessionStartedData	session/new.result (+ _meta extensions)
SessionStartedData.metadata	session/new.result._meta (extension)
SkillsConfig	session/new.params._meta["sandbox-agent/skills"] (extension)
SkillsConfig.sources	session/new.params._meta["sandbox-agent/skills"].sources (extension)
SkillsConfig.sources[]	session/new.params._meta["sandbox-agent/skills"].sources[] (extension)
SkillsConfig.sources[].$ref(SkillSource)	session/new.params._meta["sandbox-agent/skills"].sources[] (extension)
SkillSource	session/new.params._meta["sandbox-agent/skills"].sources[] (extension)
SkillSource.ref	session/new.params._meta["sandbox-agent/skills"].sources[].ref (extension)
SkillSource.skills	session/new.params._meta["sandbox-agent/skills"].sources[].skills (extension)
SkillSource.skills[]	session/new.params._meta["sandbox-agent/skills"].sources[].skills[] (extension)
SkillSource.source	session/new.params._meta["sandbox-agent/skills"].sources[].source (extension)
SkillSource.subpath	session/new.params._meta["sandbox-agent/skills"].sources[].subpath (extension)
SkillSource.type	session/new.params._meta["sandbox-agent/skills"].sources[].type (extension)
StderrOutput	session/prompt.result._meta["sandbox-agent/sessionEnd"].stderr (extension)
StderrOutput.head	session/prompt.result._meta["sandbox-agent/sessionEnd"].stderr.head (extension)
StderrOutput.tail	session/prompt.result._meta["sandbox-agent/sessionEnd"].stderr.tail (extension)
StderrOutput.total_lines	session/prompt.result._meta["sandbox-agent/sessionEnd"].stderr.totalLines (extension)
StderrOutput.truncated	session/prompt.result._meta["sandbox-agent/sessionEnd"].stderr.truncated (extension)
TerminatedBy	session/prompt.result._meta["sandbox-agent/sessionEnd"].terminatedBy (extension)
TurnEventData	session/prompt lifecycle (request start -> response end)
TurnEventData.metadata	session/prompt.params._meta | session/prompt.result._meta
TurnEventData.phase	session/prompt lifecycle phase
TurnEventData.phase.$ref(TurnPhase)	session/prompt lifecycle phase
TurnEventData.turn_id	session/prompt.params._meta["sandbox-agent/turnId"] (extension)
TurnPhase	session/prompt lifecycle: started=request received, ended=prompt response returned
TurnStreamQuery	UNIMPLEMENTED
TurnStreamQuery.includeRaw	UNIMPLEMENTED
UniversalEvent	JSON-RPC envelope + SessionNotification(session/update) + request/response events
UniversalEvent.data	session/update.params.update
UniversalEvent.data.$ref(UniversalEventData)	SessionUpdate | JSON-RPC Error | session/request_permission
UniversalEvent.event_id	session/update.params._meta["sandbox-agent/eventId"] (extension)
UniversalEvent.native_session_id	session/update.params._meta["sandbox-agent/nativeSessionId"] (extension)
UniversalEvent.raw	session/update.params._meta["sandbox-agent/raw"] (extension)
UniversalEvent.sequence	session/update.params._meta["sandbox-agent/sequence"] (extension)
UniversalEvent.session_id	session/update.params.sessionId
UniversalEvent.source	session/update.params._meta["sandbox-agent/source"] (extension)
UniversalEvent.source.$ref(EventSource)	session/update.params._meta["sandbox-agent/source"] (extension)
UniversalEvent.synthetic	session/update.params._meta["sandbox-agent/synthetic"] (extension)
UniversalEvent.time	session/update.params._meta["sandbox-agent/time"] (extension)
UniversalEvent.type	session/update.params.update.sessionUpdate | JSON-RPC method type
UniversalEvent.type.$ref(UniversalEventType)	session/update.params.update.sessionUpdate | JSON-RPC method type
UniversalEventData	SessionUpdate | JSON-RPC Error | session/request_permission
UniversalEventData.oneOf[0]	session/prompt lifecycle (turn metadata in _meta)
UniversalEventData.oneOf[0].$ref(TurnEventData)	session/prompt lifecycle (request/response boundary)
UniversalEventData.oneOf[1]	session/new.result
UniversalEventData.oneOf[1].$ref(SessionStartedData)	session/new.result
UniversalEventData.oneOf[2]	session/prompt.result.stopReason
UniversalEventData.oneOf[2].$ref(SessionEndedData)	session/prompt.result.stopReason (+ _meta extension)
UniversalEventData.oneOf[3]	session/update.params.update
UniversalEventData.oneOf[3].$ref(ItemEventData)	SessionUpdate (tool_call/tool_call_update/content chunk)
UniversalEventData.oneOf[4]	session/update.params.update(sessionUpdate=*message_chunk)
UniversalEventData.oneOf[4].$ref(ItemDeltaData)	ContentChunk
UniversalEventData.oneOf[5]	JSON-RPC Error
UniversalEventData.oneOf[5].$ref(ErrorData)	JSON-RPC Error
UniversalEventData.oneOf[6]	session/request_permission
UniversalEventData.oneOf[6].$ref(PermissionEventData)	session/request_permission
UniversalEventData.oneOf[7]	UNIMPLEMENTED
UniversalEventData.oneOf[7].$ref(QuestionEventData)	UNIMPLEMENTED
UniversalEventData.oneOf[8]	session/update.params.update._meta["sandbox-agent/unparsed"] (extension)
UniversalEventData.oneOf[8].$ref(AgentUnparsedData)	session/update.params.update._meta["sandbox-agent/unparsed"] (extension)
UniversalEventType	session/update.sessionUpdate + JSON-RPC method categories
UniversalItem	SessionUpdate payload (ContentChunk | ToolCall | ToolCallUpdate)
UniversalItem.content	ContentChunk.content | ToolCall.content | ToolCallUpdate.content
UniversalItem.content[]	ToolCall.content[] | ToolCallUpdate.content[]
UniversalItem.content[].$ref(ContentPart)	ToolCallContent | ContentBlock
UniversalItem.item_id	ToolCall.toolCallId | ToolCallUpdate.toolCallId | _meta["sandbox-agent/itemId"]
UniversalItem.kind	SessionUpdate.sessionUpdate + ToolKind
UniversalItem.kind.$ref(ItemKind)	SessionUpdate.sessionUpdate + ToolKind
UniversalItem.native_item_id	SessionUpdate._meta["sandbox-agent/nativeItemId"] (extension)
UniversalItem.parent_id	SessionUpdate._meta["sandbox-agent/parentId"] (extension)
UniversalItem.role	Role (assistant|user) for message chunks
UniversalItem.role.allOf[0]	Role
UniversalItem.role.allOf[0].$ref(ItemRole)	Role (partial)
UniversalItem.status	ToolCall.status | ToolCallUpdate.status
UniversalItem.status.$ref(ItemStatus)	ToolCallStatus

Caveats

• UNIMPLEMENTED means there is no ACP-standard field/method with equivalent semantics in schema.unstable.json; implementation would require ACP extension methods (_...) and/or _meta payloads.
• Rows mapped to _meta[...] are ACP-compatible extensions, not standard interoperable ACP fields; both sides must agree on names and semantics.
• Legacy event polling (/v1/sessions/{session_id}/events) has no ACP equivalent; ACP is stream-first via session/update notifications over streamable HTTP.
• Session lifecycle differs: ACP has session/new, session/load, session/resume (UNSTABLE), and session/fork (UNSTABLE), but no standard explicit "close session" method.
• Permission handling is request/response (session/request_permission) tied to JSON-RPC request IDs; it does not use standalone REST reply endpoints.
• Question/answer HITL flow in the old schema has no standard ACP equivalent today (separate from permission prompts).
• Agent registry/installation/server health/status APIs are outside ACP core and require separate custom HTTP APIs or ACP extensions.
• ACP filesystem methods are client capabilities (fs/read_text_file, fs/write_text_file) and are text-only; old binary/raw filesystem REST operations remain out of scope for ACP core.
• Model and session listing mappings rely on ACP UNSTABLE methods (session/list, session/set_model, model state in session responses) and may change.
• Some old enums do not match ACP enum domains 1:1 (for example ErrorType, SessionEndReason, PermissionStatus); mappings here are best-effort normalization.