> ## Documentation Index > Fetch the complete documentation index at: https://docs.gtm-api.com/llms.txt > Use this file to discover all available pages before exploring further. # Download Sales Navigator attachment > Sales Navigator variant of download_linkedin_message_attachment: one inbound attachment of an SN message, inline as a base64 data_url. Same raw-id addressing, one field fewer (the SN wire verb takes no profile_id): linkedin_account_sid must be an account with Sales Navigator, message_id is the message row's message_hash, attachment_urn is attachments[i].urn on that row. The row must be messenger_type='sales_navigator' (an account without SN is refused before dispatch). Same 120 s budget and messaging_general bucket. Contract: - MCP tool `download_linkedin_sales_nav_message_attachment`, registry package `mcp.linkedin/linkedin_messages`, mount `linkedin.messaging`. - Operation `action`, response envelope `action`. - Flags: read only. ## OpenAPI ````yaml /api-reference/linkedin/openapi.yaml post /api/linkedin-messages/download-sales-nav-attachment openapi: 3.0.3 info: title: 'GTM API public contract: gtm.service.linkedin' description: >- Connected LinkedIn accounts and everything driven through them: account health and smart limits, conversations and messages, the connection graph, outbound posting, scraping, profile and company enrichment, and the antidetect browsers that execute it all. GENERATED. This document is projected from the Zod MCP tool registry in `product/mcp/gtm.mcp` (one tool per public endpoint, 1:1). Do not edit it by hand; edit the tool definition and regenerate with `pnpm openapi:public`. Surface: the public `/api` contract of `gtm.service.linkedin`, 150 operations. Internal (`/internal`) and health endpoints are deliberately absent; the code-faithful spec that documents those lives in `product/openapi/gtm.openapi.tech`. Conventions: - Auth is a bearer JWT, optionally narrowed by the `Team-SID` header. - Every success body is an MCP envelope: `success: true` plus one typed `operation` shape (`search`, `get`, `create`, `update`, `delete`, `metrics`, `group_by`, `action`), and a `meta` block with `trace_id` for support. - Every failure is the same `McpError` envelope with a code from a fixed 16-code taxonomy, so a client maps errors once. - Lists page with `page_size` (0 to 500, default 50) plus an opaque forward `cursor`; `page_size: 0` returns counts only. - On `GET` and `DELETE`, object-valued query parameters (`filter`, `sort`) travel as JSON text and array-valued ones repeat as `name[]=value`. - The MCP-only `_meta` field (usage analytics) never reaches the backend and is not part of this contract. version: '1.0' contact: name: GTM API url: https://gtm-api.com email: support@gtm-api.com license: name: Proprietary url: https://gtm-api.com/license servers: - url: https://app.gtm-api.com/linkedin/v4 description: Production, through the app.gtm-api.com gateway - url: http://localhost:8020 description: Local Docker (gtm_linkedin_nginx_dev) security: - BearerJwt: [] TeamSid: [] tags: - name: antidetect_browser_logs description: >- Registry package `mcp.linkedin/antidetect_browser_logs`, served on MCP mount `linkedin.browsers`. - name: antidetect_browser_proxies description: >- Registry package `mcp.linkedin/antidetect_browser_proxies`, served on MCP mount `linkedin.browsers`. - name: antidetect_browsers description: >- Registry package `mcp.linkedin/antidetect_browsers`, served on MCP mount `linkedin.browsers`. - name: cloud_browser_sessions description: >- Registry package `mcp.linkedin/cloud_browser_sessions`, served on MCP mount `linkedin.browsers`. - name: cloud_browsers description: >- Registry package `mcp.linkedin/cloud_browsers`, served on MCP mount `linkedin.browsers`. - name: data_requests description: >- Registry package `mcp.linkedin/data_requests`, served on MCP mount `linkedin.data`. - name: linkedin_account_activity_log description: >- Registry package `mcp.linkedin/linkedin_account_activity_log`, served on MCP mount `linkedin.account-monitor`. - name: linkedin_account_block_log description: >- Registry package `mcp.linkedin/linkedin_account_block_log`, served on MCP mount `linkedin.account-monitor`. - name: linkedin_account_quota_hits description: >- Registry package `mcp.linkedin/linkedin_account_quota_hits`, served on MCP mount `linkedin.account-monitor`. - name: linkedin_account_smart_limits description: >- Registry package `mcp.linkedin/linkedin_account_smart_limits`, served on MCP mount `linkedin.accounts`. - name: linkedin_account_snapshots description: >- Registry package `mcp.linkedin/linkedin_account_snapshots`, served on MCP mount `linkedin.account-monitor`. - name: linkedin_account_sync_runs description: >- Registry package `mcp.linkedin/linkedin_account_sync_runs`, served on MCP mount `linkedin.account-monitor`. - name: linkedin_accounts description: >- Registry package `mcp.linkedin/linkedin_accounts`, served on MCP mount `linkedin.accounts`. - name: linkedin_auto_scrape_results description: >- Registry package `mcp.linkedin/linkedin_auto_scrape_results`, served on MCP mount `linkedin.auto-scrapes`. - name: linkedin_auto_scrape_runs description: >- Registry package `mcp.linkedin/linkedin_auto_scrape_runs`, served on MCP mount `linkedin.auto-scrapes`. - name: linkedin_auto_scrapes description: >- Registry package `mcp.linkedin/linkedin_auto_scrapes`, served on MCP mount `linkedin.auto-scrapes`. - name: linkedin_benchmarks description: >- Registry package `mcp.linkedin/linkedin_benchmarks`, served on MCP mount `linkedin.account-monitor`. - name: linkedin_connection_invitations description: >- Registry package `mcp.linkedin/linkedin_connection_invitations`, served on MCP mount `linkedin.network`. - name: linkedin_connection_requests description: >- Registry package `mcp.linkedin/linkedin_connection_requests`, served on MCP mount `linkedin.network`. - name: linkedin_connections description: >- Registry package `mcp.linkedin/linkedin_connections`, served on MCP mount `linkedin.network`. - name: linkedin_conversations description: >- Registry package `mcp.linkedin/linkedin_conversations`, served on MCP mount `linkedin.messaging`. - name: linkedin_custom_requests description: >- Registry package `mcp.linkedin/linkedin_custom_requests`, served on MCP mount `linkedin.platform`. - name: linkedin_enrichment description: >- Registry package `mcp.linkedin/linkedin_enrichment`, served on MCP mount `linkedin.enrichment`. - name: linkedin_followers description: >- Registry package `mcp.linkedin/linkedin_followers`, served on MCP mount `linkedin.network`. - name: linkedin_messages description: >- Registry package `mcp.linkedin/linkedin_messages`, served on MCP mount `linkedin.messaging`. - name: linkedin_posting description: >- Registry package `mcp.linkedin/linkedin_posting`, served on MCP mount `linkedin.content`. - name: linkedin_scraping description: >- Registry package `mcp.linkedin/linkedin_scraping`, served on MCP mount `linkedin.scraping`. paths: /api/linkedin-messages/download-sales-nav-attachment: post: tags: - linkedin_messages summary: Download Sales Navigator attachment description: >- Sales Navigator variant of download_linkedin_message_attachment: one inbound attachment of an SN message, inline as a base64 data_url. Same raw-id addressing, one field fewer (the SN wire verb takes no profile_id): linkedin_account_sid must be an account with Sales Navigator, message_id is the message row's message_hash, attachment_urn is attachments[i].urn on that row. The row must be messenger_type='sales_navigator' (an account without SN is refused before dispatch). Same 120 s budget and messaging_general bucket. Contract: - MCP tool `download_linkedin_sales_nav_message_attachment`, registry package `mcp.linkedin/linkedin_messages`, mount `linkedin.messaging`. - Operation `action`, response envelope `action`. - Flags: read only. operationId: download_linkedin_sales_nav_message_attachment requestBody: required: true content: application/json: schema: $ref: >- #/components/schemas/DownloadLinkedinSalesNavMessageAttachmentRequest responses: '200': description: '`action` success envelope.' content: application/json: schema: $ref: >- #/components/schemas/DownloadLinkedinSalesNavMessageAttachmentResponse 4XX: $ref: '#/components/responses/McpClientError' 5XX: $ref: '#/components/responses/McpServerError' components: schemas: DownloadLinkedinSalesNavMessageAttachmentRequest: type: object description: Request body of `download_linkedin_sales_nav_message_attachment`. properties: linkedin_account_sid: type: string minLength: 18 maxLength: 18 pattern: ^ln_ac_ description: >- Mailbox owner (Sales Navigator required): the SN message row's linkedin_account_sid. message_id: type: string maxLength: 255 description: 'Raw LinkedIn MessageId: the message row''s message_hash.' attachment_urn: type: string maxLength: 512 description: >- Which attachment of that message: attachments[i].urn on the stored row (urn:li:digitalmediaAsset:…). required: - linkedin_account_sid - message_id - attachment_urn DownloadLinkedinSalesNavMessageAttachmentResponse: type: object properties: success: type: boolean enum: - true operation: type: string enum: - action action: type: string description: kebab-case verb; matches the route segment. item: {} result: type: object properties: data_url: type: string description: data:;base64,… . The whole payload, inline. content_type: type: string description: MIME type LinkedIn served the asset with. file_byte_size: type: number description: Decoded size in bytes. required: - data_url - content_type - file_byte_size meta: type: object properties: trace_id: type: string description: UUID v7; same 128-bit value as the X-Trace-Id header. span_id: type: string pattern: ^[0-9a-f]{16}$ description: 16 hex chars, root span of this request. timestamp: type: string description: ISO 8601 UTC (Y-m-dTH:i:sZ), response time. duration_ms: type: integer minimum: 0 description: Server-side wall clock. debug_url: type: string description: Deep link to the post-call analysis UI. required: - trace_id - span_id - timestamp - duration_ms - debug_url credits: type: object properties: charged: type: integer minimum: 0 description: Credits debited for THIS call (0 on own-account / cache hit). reason: type: string nullable: true enum: - infra_pool - limit_fallback executed_on: type: string enum: - own_account - infra_pool balance_after: type: integer nullable: true minimum: 0 description: >- Team balance after the debit; null when the ledger was untouched. required: - charged - reason - executed_on - balance_after required: - success - operation - action - item - result - meta McpError: type: object properties: success: type: boolean enum: - false error: type: object properties: code: type: string enum: - validation_failed - nothing_to_update - not_found - relation_not_found - invalid_transition - limit_exceeded - payment_required - duplicate_rejected - conflict - delete_blocked - unauthorized - forbidden - rate_limited - internal_error - service_unavailable - not_implemented message: type: string recoverable: type: boolean suggestion: type: string field_errors: type: object additionalProperties: type: array items: anyOf: - type: string - type: object properties: rule: type: string message: type: string required: - rule - message blockers: type: array items: type: object properties: type: type: string description: >- Machine-readable blocker type (active_flow, pending_tasks, …). severity: type: string enum: - hard - soft description: >- hard = external action required; soft = acknowledge is enough. description: type: string entity_sid: type: string nullable: true count: type: integer resolution: type: string description: 'Hard: tool name to call. Soft: code for acknowledge[].' resolution_hint: type: string required: - type - severity - description - entity_sid - resolution - resolution_hint context: type: object additionalProperties: {} required: - code - message - recoverable meta: type: object properties: trace_id: type: string description: UUID v7; same 128-bit value as the X-Trace-Id header. span_id: type: string pattern: ^[0-9a-f]{16}$ description: 16 hex chars, root span of this request. timestamp: type: string description: ISO 8601 UTC (Y-m-dTH:i:sZ), response time. duration_ms: type: integer minimum: 0 description: Server-side wall clock. debug_url: type: string description: Deep link to the post-call analysis UI. required: - trace_id - span_id - timestamp - duration_ms - debug_url required: - success - error responses: McpClientError: description: >- MCP error envelope. `error.code` is one of validation_failed, nothing_to_update, not_found, relation_not_found, invalid_transition, limit_exceeded, payment_required, duplicate_rejected, conflict, delete_blocked, unauthorized, forbidden, rate_limited, not_implemented. content: application/json: schema: $ref: '#/components/schemas/McpError' McpServerError: description: >- MCP error envelope with `error.code` internal_error or service_unavailable. content: application/json: schema: $ref: '#/components/schemas/McpError' securitySchemes: BearerJwt: type: http scheme: bearer bearerFormat: JWT description: >- Access token issued by gtm.service.id. Its `access_identity` claim carries `team_sid`, `actor_sid` and `actor_type`, and that team scope is authoritative. TeamSid: type: apiKey in: header name: Team-SID description: >- Team scope for tokens that do not carry one. Ignored when the token already names a team. ````