Comment on project activity

POST/v1/projects/{projectId}/activity/{eventId}/comments

Add a durable comment to a project timeline event and dispatch validated human or agent mentions.

How to call this endpoint

Every ACP API request uses bearer authentication. The examples here show the actual request path, auth header, and body shape that the platform expects.

Path, query, and header parameters

These parameters control which ACP object the endpoint acts on and how the request is processed.

Path parameters
NameLocationTypeRequiredDescription
projectIdpathstringYesProject ID
eventIdpathstringYes
Query parameters
None.

Body schema

Content type: application/json · Required

FieldTypeRequiredDescription
bodystringYes
idempotencyKeystringNo
mentionsobject[]No
mentions[].kindhuman | agentYes
mentions[].idstringYesUnique identifier.
mentions[].labelstringYes

What the API returns

Each response code below includes the documented payload shape for the ACP API.

201Project activity comment createdapplication/json
FieldTypeRequiredDescription
commentobjectNo
comment.idstringYesUnique identifier.
comment.parentCommentIdstringNo
comment.bodystringYes
comment.attachmentsobject[]Yes
comment.attachments[].idstringNoUnique identifier.
comment.attachments[].filenamestringYes
comment.attachments[].mimeTypestringNo
comment.attachments[].sizeintegerNo
comment.attachments[].urlstringNo
comment.attachments[].previewUrlstringNo
comment.attachments[].workspacePathstringNo
comment.attachments[].sourcePathstringNoWorkspace-relative file path.
comment.attachments[].environmentIdstringNoComputer ID.
comment.repliesobject[]YesDirect replies to this top-level update comment.
comment.replies[].idstringYesUnique identifier.
comment.replies[].parentCommentIdstringNo
comment.replies[].bodystringYes
comment.replies[].attachmentsobject[]Yes
comment.replies[].attachments[].idstringNoUnique identifier.
comment.replies[].attachments[].filenamestringYes
comment.replies[].attachments[].mimeTypestringNo
comment.replies[].attachments[].sizeintegerNo
comment.replies[].attachments[].urlstringNo
comment.replies[].attachments[].previewUrlstringNo
comment.replies[].attachments[].workspacePathstringNo
comment.replies[].attachments[].sourcePathstringNoWorkspace-relative file path.
comment.replies[].attachments[].environmentIdstringNoComputer ID.
comment.replies[].repliesobject[]YesDirect replies to this top-level update comment.
comment.replies[].replies[].idstringYesUnique identifier.
comment.replies[].replies[].parentCommentIdstringNo
comment.replies[].replies[].bodystringYes
comment.replies[].replies[].attachmentsobject[]Yes
comment.replies[].replies[].attachments[].idstringNoUnique identifier.
comment.replies[].replies[].attachments[].filenamestringYes
comment.replies[].replies[].attachments[].mimeTypestringNo
comment.replies[].replies[].attachments[].sizeintegerNo
comment.replies[].replies[].attachments[].urlstringNo
comment.replies[].replies[].attachments[].previewUrlstringNo
comment.replies[].replies[].attachments[].workspacePathstringNo
comment.replies[].replies[].attachments[].sourcePathstringNoWorkspace-relative file path.
comment.replies[].replies[].attachments[].environmentIdstringNoComputer ID.
comment.replies[].replies[].repliesobject[]YesDirect replies to this top-level update comment.
comment.replies[].replies[].replies[].idstringYesUnique identifier.
comment.replies[].replies[].replies[].parentCommentIdstringNo
comment.replies[].replies[].replies[].bodystringYes
comment.replies[].replies[].replies[].attachmentsobject[]Yes
comment.replies[].replies[].replies[].attachments[].idstringNoUnique identifier.
comment.replies[].replies[].replies[].attachments[].filenamestringYes
comment.replies[].replies[].replies[].attachments[].mimeTypestringNo
comment.replies[].replies[].replies[].attachments[].sizeintegerNo
comment.replies[].replies[].replies[].attachments[].urlstringNo
comment.replies[].replies[].replies[].attachments[].previewUrlstringNo
comment.replies[].replies[].replies[].attachments[].workspacePathstringNo
comment.replies[].replies[].replies[].attachments[].sourcePathstringNoWorkspace-relative file path.
comment.replies[].replies[].replies[].attachments[].environmentIdstringNoComputer ID.
comment.replies[].replies[].replies[].repliesobject[]YesDirect replies to this top-level update comment.
comment.replies[].replies[].replies[].replies[].idstringYesUnique identifier.
comment.replies[].replies[].replies[].replies[].parentCommentIdstringNo
comment.replies[].replies[].replies[].replies[].bodystringYes
comment.replies[].replies[].replies[].replies[].attachmentsobject[]Yes
comment.replies[].replies[].replies[].replies[].attachments[].idstringNoUnique identifier.
comment.replies[].replies[].replies[].replies[].attachments[].filenamestringYes
comment.replies[].replies[].replies[].replies[].attachments[].mimeTypestringNo
comment.replies[].replies[].replies[].replies[].attachments[].sizeintegerNo
comment.replies[].replies[].replies[].replies[].attachments[].urlstringNo
comment.replies[].replies[].replies[].replies[].attachments[].previewUrlstringNo
comment.replies[].replies[].replies[].replies[].attachments[].workspacePathstringNo
comment.replies[].replies[].replies[].replies[].attachments[].sourcePathstringNoWorkspace-relative file path.
comment.replies[].replies[].replies[].replies[].attachments[].environmentIdstringNoComputer ID.
comment.replies[].replies[].replies[].replies[].repliesobject[]YesDirect replies to this top-level update comment.
comment.replies[].replies[].replies[].replies[].replies[].idstringYesUnique identifier.
comment.replies[].replies[].replies[].replies[].replies[].parentCommentIdstringNo
comment.replies[].replies[].replies[].replies[].replies[].bodystringYes
comment.replies[].replies[].replies[].replies[].replies[].attachmentsobject[]Yes
comment.replies[].replies[].replies[].replies[].replies[].attachments[].idstringNoUnique identifier.
comment.replies[].replies[].replies[].replies[].replies[].attachments[].filenamestringYes
comment.replies[].replies[].replies[].replies[].replies[].attachments[].mimeTypestringNo
comment.replies[].replies[].replies[].replies[].replies[].attachments[].sizeintegerNo
comment.replies[].replies[].replies[].replies[].replies[].attachments[].urlstringNo
comment.replies[].replies[].replies[].replies[].replies[].attachments[].previewUrlstringNo
comment.replies[].replies[].replies[].replies[].replies[].attachments[].workspacePathstringNo
comment.replies[].replies[].replies[].replies[].replies[].attachments[].sourcePathstringNoWorkspace-relative file path.
comment.replies[].replies[].replies[].replies[].replies[].attachments[].environmentIdstringNoComputer ID.
comment.replies[].replies[].replies[].replies[].replies[].repliesobject[]YesDirect replies to this top-level update comment.
comment.replies[].replies[].replies[].replies[].replies[].replies[].idstringYesUnique identifier.
comment.replies[].replies[].replies[].replies[].replies[].replies[].parentCommentIdstringNo
comment.replies[].replies[].replies[].replies[].replies[].replies[].bodystringYes
comment.replies[].replies[].replies[].replies[].replies[].replies[].attachmentsobject[]Yes
comment.replies[].replies[].replies[].replies[].replies[].replies[].attachments[].idstringNoUnique identifier.
comment.replies[].replies[].replies[].replies[].replies[].replies[].attachments[].filenamestringYes
comment.replies[].replies[].replies[].replies[].replies[].replies[].attachments[].mimeTypestringNo
comment.replies[].replies[].replies[].replies[].replies[].replies[].attachments[].sizeintegerNo
comment.replies[].replies[].replies[].replies[].replies[].replies[].attachments[].urlstringNo
comment.replies[].replies[].replies[].replies[].replies[].replies[].attachments[].previewUrlstringNo
comment.replies[].replies[].replies[].replies[].replies[].replies[].attachments[].workspacePathstringNo
comment.replies[].replies[].replies[].replies[].replies[].replies[].attachments[].sourcePathstringNoWorkspace-relative file path.
comment.replies[].replies[].replies[].replies[].replies[].replies[].attachments[].environmentIdstringNoComputer ID.
comment.replies[].replies[].replies[].replies[].replies[].replies[].repliesobject[]YesDirect replies to this top-level update comment.
comment.replies[].replies[].replies[].replies[].replies[].replies[].replies[].idstringYesUnique identifier.
comment.replies[].replies[].replies[].replies[].replies[].replies[].replies[].parentCommentIdstringNo
comment.replies[].replies[].replies[].replies[].replies[].replies[].replies[].bodystringYes
comment.replies[].replies[].replies[].replies[].replies[].replies[].replies[].attachmentsobject[]Yes
comment.replies[].replies[].replies[].replies[].replies[].replies[].replies[].repliesobject[]YesDirect replies to this top-level update comment.
comment.replies[].replies[].replies[].replies[].replies[].replies[].replies[].authorobjectYes
comment.replies[].replies[].replies[].replies[].replies[].replies[].replies[].createdAtstringYesISO 8601 timestamp.
comment.replies[].replies[].replies[].replies[].replies[].replies[].replies[].updatedAtstringYesISO 8601 timestamp.
comment.replies[].replies[].replies[].replies[].replies[].replies[].authorobjectYes
comment.replies[].replies[].replies[].replies[].replies[].replies[].author.userIdstringYesUser ID.
comment.replies[].replies[].replies[].replies[].replies[].replies[].author.namestringYesHuman-readable name.
comment.replies[].replies[].replies[].replies[].replies[].replies[].author.emailstringNo
comment.replies[].replies[].replies[].replies[].replies[].replies[].author.avatarUrlstringNo
comment.replies[].replies[].replies[].replies[].replies[].replies[].createdAtstringYesISO 8601 timestamp.
comment.replies[].replies[].replies[].replies[].replies[].replies[].updatedAtstringYesISO 8601 timestamp.
comment.replies[].replies[].replies[].replies[].replies[].authorobjectYes
comment.replies[].replies[].replies[].replies[].replies[].author.userIdstringYesUser ID.
comment.replies[].replies[].replies[].replies[].replies[].author.namestringYesHuman-readable name.
comment.replies[].replies[].replies[].replies[].replies[].author.emailstringNo
comment.replies[].replies[].replies[].replies[].replies[].author.avatarUrlstringNo
comment.replies[].replies[].replies[].replies[].replies[].createdAtstringYesISO 8601 timestamp.
comment.replies[].replies[].replies[].replies[].replies[].updatedAtstringYesISO 8601 timestamp.
comment.replies[].replies[].replies[].replies[].authorobjectYes
comment.replies[].replies[].replies[].replies[].author.userIdstringYesUser ID.
comment.replies[].replies[].replies[].replies[].author.namestringYesHuman-readable name.
comment.replies[].replies[].replies[].replies[].author.emailstringNo
comment.replies[].replies[].replies[].replies[].author.avatarUrlstringNo
comment.replies[].replies[].replies[].replies[].createdAtstringYesISO 8601 timestamp.
comment.replies[].replies[].replies[].replies[].updatedAtstringYesISO 8601 timestamp.
comment.replies[].replies[].replies[].authorobjectYes
comment.replies[].replies[].replies[].author.userIdstringYesUser ID.
comment.replies[].replies[].replies[].author.namestringYesHuman-readable name.
comment.replies[].replies[].replies[].author.emailstringNo
comment.replies[].replies[].replies[].author.avatarUrlstringNo
comment.replies[].replies[].replies[].createdAtstringYesISO 8601 timestamp.
comment.replies[].replies[].replies[].updatedAtstringYesISO 8601 timestamp.
comment.replies[].replies[].authorobjectYes
comment.replies[].replies[].author.userIdstringYesUser ID.
comment.replies[].replies[].author.namestringYesHuman-readable name.
comment.replies[].replies[].author.emailstringNo
comment.replies[].replies[].author.avatarUrlstringNo
comment.replies[].replies[].createdAtstringYesISO 8601 timestamp.
comment.replies[].replies[].updatedAtstringYesISO 8601 timestamp.
comment.replies[].authorobjectYes
comment.replies[].author.userIdstringYesUser ID.
comment.replies[].author.namestringYesHuman-readable name.
comment.replies[].author.emailstringNo
comment.replies[].author.avatarUrlstringNo
comment.replies[].createdAtstringYesISO 8601 timestamp.
comment.replies[].updatedAtstringYesISO 8601 timestamp.
comment.authorobjectYes
comment.author.userIdstringYesUser ID.
comment.author.namestringYesHuman-readable name.
comment.author.emailstringNo
comment.author.avatarUrlstringNo
comment.createdAtstringYesISO 8601 timestamp.
comment.updatedAtstringYesISO 8601 timestamp.
projectobjectNo
project.objectproject | project.overviewNo
project.isOverviewRecordbooleanNo
project.idstringYesUnique identifier.
project.userIdstringYesUser ID.
project.ownerUserIdstringNo
project.ownerNamestringNo
project.ownerEmailstringNo
project.ownerAvatarUrlstringNo
project.ownerobjectNo
project.owner.userIdstringYesUser ID.
project.owner.namestringYesHuman-readable name.
project.owner.emailstringNo
project.owner.avatarUrlstringNo
project.canTransferOwnershipbooleanNo
project.organizationIdstringNo
project.createdByUserIdstringNo
project.createdByNamestringNo
project.createdByEmailstringNo
project.createdByAvatarUrlstringNo
project.createdByobjectNo
project.createdBy.userIdstringYesUser ID.
project.createdBy.namestringYesHuman-readable name.
project.createdBy.emailstringNo
project.createdBy.avatarUrlstringNo
project.namestringYesHuman-readable name.
project.descriptionstringYesHuman-readable description.
project.typelocal | cloud | syncedNo
project.primarySourcestringNo
project.sourcesobject[]No
project.colorstringYes
project.defaultEnvironmentIdstringYes
project.environmentIdsstring[]No
project.permissionSetobjectNoAgent permission policy. The shape is intentionally subject-typed so it can also be reused for human users and teams later.
project.permissionSet.version1No
project.permissionSet.subjectTypeagent | human_user | team | project | security_repositoryNo
project.permissionSet.defaultAccessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.ringsobjectNo
project.permissionSet.actionsobjectNo
project.permissionSet.resourcesobjectNo
project.permissionSet.resources.agentsobjectNo
project.permissionSet.resources.agents.defaultAccessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.agents.rulesobject[]No
project.permissionSet.resources.agents.rules[].idstringNoOptional stable rule ID.
project.permissionSet.resources.agents.rules[].targetIdstringNoOptional resource identifier for agent, skill, server, computer, or project rules.
project.permissionSet.resources.agents.rules[].pathstringNoOptional file or directory path for path-scoped rules.
project.permissionSet.resources.agents.rules[].accessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.agents.rules[].notestringNoOptional human-readable note for the rule.
project.permissionSet.resources.skillsobjectNo
project.permissionSet.resources.skills.defaultAccessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.skills.rulesobject[]No
project.permissionSet.resources.skills.rules[].idstringNoOptional stable rule ID.
project.permissionSet.resources.skills.rules[].targetIdstringNoOptional resource identifier for agent, skill, server, computer, or project rules.
project.permissionSet.resources.skills.rules[].pathstringNoOptional file or directory path for path-scoped rules.
project.permissionSet.resources.skills.rules[].accessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.skills.rules[].notestringNoOptional human-readable note for the rule.
project.permissionSet.resources.serversobjectNo
project.permissionSet.resources.servers.defaultAccessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.servers.rulesobject[]No
project.permissionSet.resources.servers.rules[].idstringNoOptional stable rule ID.
project.permissionSet.resources.servers.rules[].targetIdstringNoOptional resource identifier for agent, skill, server, computer, or project rules.
project.permissionSet.resources.servers.rules[].pathstringNoOptional file or directory path for path-scoped rules.
project.permissionSet.resources.servers.rules[].accessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.servers.rules[].notestringNoOptional human-readable note for the rule.
project.permissionSet.resources.computersobjectNo
project.permissionSet.resources.computers.defaultAccessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.computers.rulesobject[]No
project.permissionSet.resources.computers.rules[].idstringNoOptional stable rule ID.
project.permissionSet.resources.computers.rules[].targetIdstringNoOptional resource identifier for agent, skill, server, computer, or project rules.
project.permissionSet.resources.computers.rules[].pathstringNoOptional file or directory path for path-scoped rules.
project.permissionSet.resources.computers.rules[].accessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.computers.rules[].notestringNoOptional human-readable note for the rule.
project.permissionSet.resources.filesobjectNo
project.permissionSet.resources.files.defaultAccessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.files.rulesobject[]No
project.permissionSet.resources.files.rules[].idstringNoOptional stable rule ID.
project.permissionSet.resources.files.rules[].targetIdstringNoOptional resource identifier for agent, skill, server, computer, or project rules.
project.permissionSet.resources.files.rules[].pathstringNoOptional file or directory path for path-scoped rules.
project.permissionSet.resources.files.rules[].accessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.files.rules[].notestringNoOptional human-readable note for the rule.
project.permissionSet.resources.directoriesobjectNo
project.permissionSet.resources.directories.defaultAccessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.directories.rulesobject[]No
project.permissionSet.resources.directories.rules[].idstringNoOptional stable rule ID.
project.permissionSet.resources.directories.rules[].targetIdstringNoOptional resource identifier for agent, skill, server, computer, or project rules.
project.permissionSet.resources.directories.rules[].pathstringNoOptional file or directory path for path-scoped rules.
project.permissionSet.resources.directories.rules[].accessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.directories.rules[].notestringNoOptional human-readable note for the rule.
project.permissionSet.resources.projectsobjectNo
project.permissionSet.resources.projects.defaultAccessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.projects.rulesobject[]No
project.permissionSet.resources.projects.rules[].idstringNoOptional stable rule ID.
project.permissionSet.resources.projects.rules[].targetIdstringNoOptional resource identifier for agent, skill, server, computer, or project rules.
project.permissionSet.resources.projects.rules[].pathstringNoOptional file or directory path for path-scoped rules.
project.permissionSet.resources.projects.rules[].accessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.projects.rules[].notestringNoOptional human-readable note for the rule.
project.permissionSet.resources.security_repositoriesobjectNo
project.permissionSet.resources.security_repositories.defaultAccessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.security_repositories.rulesobject[]No
project.permissionSet.resources.security_repositories.rules[].idstringNoOptional stable rule ID.
project.permissionSet.resources.security_repositories.rules[].targetIdstringNoOptional resource identifier for agent, skill, server, computer, or project rules.
project.permissionSet.resources.security_repositories.rules[].pathstringNoOptional file or directory path for path-scoped rules.
project.permissionSet.resources.security_repositories.rules[].accessfull_access | ask_for_permission | read_only | no_accessNoAccess level for a resource category. `full_access` allows viewing and actions, `ask_for_permission` allows proposed actions that require approval, `read_only` allows viewing without mutation, and `no_access` blocks view and action access.
project.permissionSet.resources.security_repositories.rules[].notestringNoOptional human-readable note for the rule.
project.metadataobjectYesFree-form metadata object.
project.sharedWithMebooleanNo
project.isSharedbooleanNo
project.teamSharedbooleanNo
project.teamShareIdstringNo
project.teamIdstringNo
project.teamNamestringNo
project.teamAccessLeveluse | edit | manageNo
project.teamShareSourceresource_share | project_settingsNo
project.summaryobjectNo
project.createdAtstringYesISO 8601 timestamp.
project.updatedAtstringYesISO 8601 timestamp.
400Invalid comment
None.
404Resource not foundapplication/json
FieldTypeRequiredDescription
errorstringNo
Comment on project activity
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Response 201
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