Create GCS Sync | Captain Docs

import requests
import json
BASE_URL = "https://api.captain.dev"
API_KEY = "your_api_key"
headers = {
    "Authorization": f"Bearer {API_KEY}",
    "Content-Type": "application/json"
}
with open("service-account.json") as f:
    sa_json = f.read()
response = requests.post(
    f"{BASE_URL}/v2/collections/company-knowledge/sync/gcs",
    headers=headers,
    json={
        "bucket": "my-bucket",
        "prefix": "docs/",
        "service_account_json": sa_json,
        "processing_type": "advanced",
        "deletion_policy": "mirror",
        "sync_interval_minutes": 15
    }
)
print(response.json())

{
  "sync_id": "sync_7e0abee6e110457db2c8",
  "collection_name": "company-knowledge",
  "bucket": "my-bucket",
  "prefix": "docs/",
  "region": "",
  "auth_method": "service_account",
  "processing_type": "advanced",
  "include_patterns": [
    "*.pdf",
    "*.docx"
  ],
  "exclude_patterns": [
    "drafts/*"
  ],
  "deletion_policy": "mirror",
  "status": "active",
  "secret_set": false,
  "sns_subscribe_url": null,
  "last_backfill_job_id": "91f2aa031d8f4e7d8877c4564eb486bd-1786120498",
  "last_reconcile_at": null,
  "sync_interval_minutes": 15,
  "next_sync_at": 1786120589056,
  "sync_state": "idle",
  "last_sync_at": null,
  "last_sync_error": null,
  "created_at": "2026-08-07T16:34:58.188233+00:00",
  "updated_at": "2026-08-07T16:34:58.612676+00:00"
}

Create a Google Cloud Storage Sync for a collection and start the initial backfill. GCS authenticates with a service-account JSON (stored in Secrets Manager, never returned), so there is no region, endpoint_url, or access-key pair. Returns the sync; indexing runs asynchronously.

Path parameters

collection_namestringRequired

Destination collection.

Request

This endpoint expects an object.

bucketstringRequired

GCS bucket to keep in sync with the collection.

service_account_jsonstringRequired

Google service-account key JSON (type=‘service_account’) with read access to the bucket (roles/storage.objectViewer). Stored securely in Secrets Manager, never returned.

processing_typeenumRequired

Parsing tier. ‘advanced’ = full document understanding; ‘basic’ = faster/cheaper.

prefixstringOptionalDefaults to

Object-name prefix to scope the sync (e.g. ‘docs/2024/’). Empty syncs the whole bucket.

include_patternslist of stringsOptional

Glob patterns; only matching object names are synced.

exclude_patternslist of stringsOptional

Glob patterns; matching object names are excluded.

deletion_policyenumOptionalDefaults to mirror

How to propagate objects removed from GCS: mirror removes them from the collection so they no longer appear in search; archive keeps the document’s content but marks it archived, excluded from search by default and surfaced with include_archived: true; ignore leaves the indexed copy in place.

metadata_mappingmap from strings to strings or nullOptional

Maps a GCS object metadata key to a Captain metadata field name.

custom_metadataobject or nullOptional

Static metadata applied to every synced document.

sync_interval_minutesinteger or nullOptional

Scheduled reconcile cadence in minutes (minimum 5; below 5 clamps to 5; null = manual).

Response

Successful Response

sync_idstringOptional

collection_namestringOptional

bucketstringOptional

prefixstringOptional

regionstringOptional

storage_typeenumOptional

The sync’s cloud storage type. Returned by the list endpoint (GET /v2/syncs) only; other sync endpoints omit this field.

auth_methodenumOptional

How the sync authenticates to the bucket: ‘iam_role’ (AWS cross-account assume-role), ‘access_key’ (S3-compatible key pair), or ‘service_account’ (GCS service-account JSON).

account_namestring or nullOptional

Azure Blob syncs only: the storage account name. Null for other providers.

endpoint_urlstring or nullOptional

S3-compatible endpoint URL (access-key syncs on non-AWS providers); null for AWS S3. Returned by the list endpoint (GET /v2/syncs) only; other sync endpoints omit this field.

processing_typeenumOptional

include_patternslist of stringsOptional

exclude_patternslist of stringsOptional

deletion_policyenumOptional

statusenumOptional

secret_setbooleanOptional

True once an event-webhook secret has been minted.

sns_subscribe_urlstring or nullOptional

SNS subscribe URL; only surfaced by the subscribe-webhook endpoint.

last_backfill_job_idstring or nullOptional

last_reconcile_atstring or nullOptional

sync_interval_minutesinteger or nullOptional

Effective (already-clamped) cadence; null = manual.

next_sync_atinteger or nullOptional

Epoch ms of the next due scheduled reconcile.

sync_stateenum or nullOptional

last_sync_atinteger or nullOptional

last_sync_errorstring or nullOptional

created_atstringOptional

updated_atstring or nullOptional

Path parameters

Headers

Request

Response