Claude Platform Docs

Retrieve local session messages

GET/v1/compliance/apps/sessions/local/{local_session_id}/messages

Read one local session's transcript, oldest-first by default.

Retention is enforced read-side: turns at or before the child organization's retention boundary are never returned; a session that straddles the boundary carries one leading content_unavailable placeholder (reason: "retention_elapsed") in their place. The boundary is pinned on the walk's first page and honored for 24 hours: a cursor older than that is rejected with an explicit 400; restart the walk to read under the current boundary.

Path parameters
local_session_id: string
Query parameters
limit: optional number

Maximum results (default: 100, max: 1000)

default100
maximum1000
minimum1
order: optional "asc" or "desc"

Sort direction. asc (oldest-first, default) or desc.

defaultasc
One of the following:
"asc"
"desc"
page: optional string

Opaque pagination token from a previous response's next_page field. Pass this to retrieve the next page of results. Clients should treat this value as an opaque string and not attempt to parse or interpret its contents, as the format may change without notice.

tool_result_max_bytes: optional number

Truncate each text item inside a tool result to at most this many bytes (cut on a code-point boundary). Pass -1 to request the server maximum (approximately 1 MiB); larger values are clamped to it. 0 is not a valid value.

default10000
maximum2147483647
minimum-1
tool_use_input_max_bytes: optional number

Truncate each tool-use input to at most this many bytes (cut on a code-point boundary so the result is valid UTF-8). Pass -1 to request the server maximum (approximately 1 MiB); larger values are clamped to it. 0 is not a valid value.

default10000
maximum2147483647
minimum-1
Headers
"x-api-key": optional string
Returns
data: array of object{ id, content, created_at, 4 more }

Transcript turns for this page, in call order: oldest call first by default, newest call first with order=desc. The messages of one call carry the call's timestamp and follow each other in transcript order; a page boundary can fall between them.

id: string

Message identifier, prefixed clsm_. Stable for as long as the message's turn is retained: identifiers of retained turns do not change as older turns age out of the organization's retention period. The retention_elapsed placeholder's identifier is distinct from every retained turn's and changes only when further turns age out.

content: array of object{ text, truncated, type } or object{ id, input, name, 2 more } or object{ content, is_error, name, 3 more }

Content blocks within the message, discriminated on type (text / tool_use / tool_result: the same discriminator values as the claude.ai chat-messages endpoint; the tool variants omit integration_name and mcp_server_url, and text carries truncated). Extended-thinking content is never included. The request's system field is never included; a presence-only marker message is emitted when it was set. The request's tools[] definitions are never included as transcript messages. Project-level instructions (such as CLAUDE.md files) appear in the message stream as a user-role context block and are included. Empty when provenance.type is content_unavailable.

One of the following:
Text object{ text, truncated, type }

Text content block.

text: string

Text content from the user or the assistant

truncated: boolean

True when text was shortened by the server's fixed per-string bound (approximately 1 MiB), or when ancillary content the block carried (such as citations) was omitted, or when this block stands in for a non-text block whose content is not shown, or when it is an explanatory marker the server inserted (its text enclosed in square brackets, e.g. prefacing client-asserted history). There is no request parameter that raises the per-string bound.

defaultfalse
type: "text"
defaulttext
ToolUse object{ id, input, name, 2 more }

Tool invocation requested by the assistant.

id: string or null

Tool-use ID, e.g. 'toolu_01AbC...'

input: string

Arguments passed to the tool, as a JSON-encoded string. May be shortened (see the truncated field); a truncated value is cut mid-document and is not valid JSON.

name: string

Name of the tool invoked

truncated: boolean

True when input was shortened. Pass tool_use_input_max_bytes=-1 to request the server maximum.

defaultfalse
type: "tool_use"
defaulttool_use
ToolResult object{ content, is_error, name, 3 more }

Result returned by a tool invocation.

content: array of object{ text, type }

Text content returned by the tool. Non-text item types are omitted and signalled via truncated with an in-band item-count marker.

text: string

Text returned by the tool

type: "text"
defaulttext
is_error: boolean

True when the tool reported an error

name: string

Name of the tool that produced this result

tool_use_id: string or null

ID of the tool_use block this result responds to

truncated: boolean

True when one or more text items in content were shortened or non-text items were omitted. Pass tool_result_max_bytes=-1 to request the server maximum.

defaultfalse
type: "tool_result"
defaulttool_result
created_at: string

When the message was recorded (RFC 3339, UTC)

formatdate-time
model: string or null

The model that served this assistant turn, as reported in the model field of the underlying Messages API response. Null on user messages and on any assistant message whose provenance is set: client-asserted history and synthetic markers were not produced by a model during this session, and for unavailable content the serving model is not known.

provenance: object{ reason, type } or object{ type } or object{ type } or null

Where this turn's content came from, discriminated on type. Null (the common case) means verified content: on an assistant message, content Claude produced during this session; on a user message, content the user sent. content_unavailable: the turn's content cannot be returned and content is empty; reason says why. client_asserted: assistant content the client supplied as conversation history; content shows what the model received but its authorship is not verified; never on user-role messages. synthetic_marker: a transcript marker the endpoint generated rather than content either party sent during the session. Both client_asserted and synthetic_marker can result from normal request or client processing, not only client modification. Callers should tolerate unrecognized type values.

One of the following:
ContentUnavailable object{ reason, type }

The turn's content cannot be returned; content is empty.

reason: string

Why this turn's content cannot be returned, e.g. not_captured (the content was not captured for compliance retrieval), client_aborted (the client closed the connection or cancelled the request before the response completed, so the response was not captured for this turn; any partial output already streamed to the client is not included; assistant-role turns only), cmek_key_revoked (the content is encrypted under the organization's customer-managed key and that key is unavailable), retention_elapsed (the content lies past the organization's retention boundary; on the placeholder standing in for every pre-boundary turn), or oversize (the message exceeds the server's per-message size bound even after per-block truncation). Callers should tolerate unrecognized values. not_captured is not proof that no record was stored: content withheld by the storage layer's fail-closed access policies carries the same reason and is deliberately indistinguishable from content that was never captured.

type: "content_unavailable"
defaultcontent_unavailable
ClientAsserted object{ type }

Assistant content the client supplied as conversation history rather than produced by Claude during this session. content shows what the model received but its authorship is not verified; this can result from normal request or client processing, not only client modification. Never on user-role messages.

type: "client_asserted"
defaultclient_asserted
SyntheticMarker object{ type }

A transcript marker generated by the endpoint rather than sent by either party during the session. Marker messages indicate that the prompt history diverged from what was captured, that the request's system field was present but is not shown, or that prompt-carried history was suppressed because the session spans the child organization's retention boundary and those turns cannot be placed against it (the marker's text names the cause). Markers that report a mismatch with captured history can result from normal request or client processing, not only client modification.

type: "synthetic_marker"
defaultsynthetic_marker
role: "assistant" or "user"

Message sender (user or assistant)

One of the following:
"assistant"
"user"
type: "compliance_local_session_message"
defaultcompliance_local_session_message
next_page: string or null

Opaque pagination cursor (prefixed page_) for the next page. Null when there is no further page. Treat as an opaque string; the format may change without notice.

session: object{ id, created_at, organization_uuid, 5 more }

The local session the messages belong to. user.email_address is always null on this endpoint; the messages endpoint does not resolve email addresses.

id: string

Local session identifier, prefixed clls_. Unique within the parent organization. Treat as an opaque string; the format may change without notice.

created_at: string

Timestamp of the session's first retained inference call (RFC 3339, UTC). When a session's activity spans the child organization's retention boundary, calls older than the boundary are no longer reflected, so this value is the timestamp of the earliest retained call: always strictly after the boundary, never the boundary itself.

formatdate-time
organization_uuid: string

UUID of the child organization the session belongs to

product_surface: string or null

The product the session ran in: cowork for Cowork sessions in Claude Desktop, or claude_code for Claude Code sessions. New values appear as coverage expands; treat unrecognized values as opaque. null when the surface was not recorded.

type: "compliance_local_session"
defaultcompliance_local_session
updated_at: string

Timestamp of the session's last retained inference call (RFC 3339, UTC). Always at or after created_at. When a session's activity spans the child organization's retention boundary, calls older than the boundary are no longer reflected — but because retention removes only the oldest calls, this value (unlike created_at) is unaffected until the entire session has aged out. On the list endpoint this value is a lower bound: for a session still active at a page or created_at.lt window boundary it can momentarily lag the session's true last activity. Retrieving the session, or its messages, always reflects the exact latest retained call.

formatdate-time
user: object{ id, email_address }

The authenticated user at the time of the session. Always set; user.id is always populated. user.email_address is null when the user's account has been deleted or the user is no longer a member of an organization the key may read.

id: string

User identifier (tagged ID, prefixed user_). Always set, so attribution survives after the user's account is deleted or the user leaves the organizations the key may read.

email_address: string or null

User's email address. Null when the user's account has been deleted or the user is no longer a member of an organization the key may read. The messages endpoint does not resolve email addresses; this field is always null there.

workspace_id: string or null

Workspace identifier (tagged ID, prefixed wrkspc_). Null for sessions not attributed to a workspace.

Retrieve local session messages

cURL
curl https://api.anthropic.com/v1/compliance/apps/sessions/local/$LOCAL_SESSION_ID/messages \
    -H "Authorization: Bearer $ANTHROPIC_COMPLIANCE_API_KEY"
{
  "data": [
    {
      "id": "clsm_eyJ2IjoxLCJsIjoi…",
      "content": [
        {
          "text": "text",
          "truncated": true,
          "type": "text"
        }
      ],
      "created_at": "2025-03-12T18:22:41.123456Z",
      "model": "claude-opus-5",
      "provenance": {
        "reason": "not_captured",
        "type": "content_unavailable"
      },
      "role": "assistant",
      "type": "compliance_local_session_message"
    }
  ],
  "next_page": "page_eyJ2IjoxLCJmIjoibSIs…",
  "session": {
    "id": "clls_eyJ2IjoxLCJvIjoiOWEx…",
    "created_at": "2025-03-12T18:22:41.123456Z",
    "organization_uuid": "a1b2c3d4-e5f6-4789-a012-3456789abcde",
    "product_surface": "cowork",
    "type": "compliance_local_session",
    "updated_at": "2025-03-12T18:22:41.123456Z",
    "user": {
      "id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
      "email_address": "jane.doe@example.com"
    },
    "workspace_id": "wrkspc_01SvYKoWVRVHoEbwESNvzYdR"
  }
}
Returns Examples
{
  "data": [
    {
      "id": "clsm_eyJ2IjoxLCJsIjoi…",
      "content": [
        {
          "text": "text",
          "truncated": true,
          "type": "text"
        }
      ],
      "created_at": "2025-03-12T18:22:41.123456Z",
      "model": "claude-opus-5",
      "provenance": {
        "reason": "not_captured",
        "type": "content_unavailable"
      },
      "role": "assistant",
      "type": "compliance_local_session_message"
    }
  ],
  "next_page": "page_eyJ2IjoxLCJmIjoibSIs…",
  "session": {
    "id": "clls_eyJ2IjoxLCJvIjoiOWEx…",
    "created_at": "2025-03-12T18:22:41.123456Z",
    "organization_uuid": "a1b2c3d4-e5f6-4789-a012-3456789abcde",
    "product_surface": "cowork",
    "type": "compliance_local_session",
    "updated_at": "2025-03-12T18:22:41.123456Z",
    "user": {
      "id": "user_01WCz1FkmYMm4gnmykNKUu3Q",
      "email_address": "jane.doe@example.com"
    },
    "workspace_id": "wrkspc_01SvYKoWVRVHoEbwESNvzYdR"
  }
}