Sync Source

Starts a sync of a source now and returns the run. Poll Get Source Run with its id until state is completed, failed, or canceled.

What a sync does depends on the source type:

web: re-crawls the pages in the source’s page list and re-indexes those that changed. A source with no page list yet re-crawls the whole site and imports the pages it finds.

Documents whose page no longer comes back are deleted, unless the source’s metadata.remoteDeletionPolicy is retain.
connector: refreshes the items the source imported.
upload and object-storage: the run completes without changes.

A disabled source can be synced this way: disabled stops only scheduled syncs.

A source runs one sync, preview, or import at a time. Wait for its active run to end before starting another, and cancel a crawl preview you won’t import.

For how to start and follow a sync, see Sync and Schedule Sources.

1 min read

post/knowledge-fs/spaces/{knowledge_base_id}/sources/{source_id}/sync

Request example

curl --request POST \
  --url https://api.dify.ai/v1/knowledge-fs/spaces/{knowledge_base_id}/sources/{source_id}/sync \
  --header 'Authorization: Bearer <token>' \
  --header 'Idempotency-Key: <string>'

import requests

url = "https://api.dify.ai/v1/knowledge-fs/spaces/{knowledge_base_id}/sources/{source_id}/sync"
headers = {
    "Authorization": "Bearer <token>",
    "Idempotency-Key": "<string>",
}

response = requests.request("POST", url, headers=headers)

print(response.text)

const response = await fetch('https://api.dify.ai/v1/knowledge-fs/spaces/{knowledge_base_id}/sources/{source_id}/sync', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer <token>',
    'Idempotency-Key': '<string>'
  }
});

const data = await response.json();
console.log(data);

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => 'https://api.dify.ai/v1/knowledge-fs/spaces/{knowledge_base_id}/sources/{source_id}/sync',
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_CUSTOMREQUEST => 'POST',
  CURLOPT_HTTPHEADER => [
    'Authorization: Bearer <token>',
    'Idempotency-Key: <string>',
  ],
]);

$response = curl_exec($curl);
curl_close($curl);

echo $response;

package main

import (
	"fmt"
	"io"
	"net/http"
)

func main() {
	url := "https://api.dify.ai/v1/knowledge-fs/spaces/{knowledge_base_id}/sources/{source_id}/sync"

	req, _ := http.NewRequest("POST", url, nil)
	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Idempotency-Key", "<string>")

	res, _ := http.DefaultClient.Do(req)
	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))
}

HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://api.dify.ai/v1/knowledge-fs/spaces/{knowledge_base_id}/sources/{source_id}/sync"))
    .header("Authorization", "Bearer <token>")
    .header("Idempotency-Key", "<string>")
    .method("POST", HttpRequest.BodyPublishers.noBody())
    .build();

HttpResponse<String> response = HttpClient.newHttpClient()
    .send(request, HttpResponse.BodyHandlers.ofString());

System.out.println(response.body());

require 'uri'
require 'net/http'

url = URI('https://api.dify.ai/v1/knowledge-fs/spaces/{knowledge_base_id}/sources/{source_id}/sync')

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = url.scheme == 'https'

request = Net::HTTP::Post.new(url)
request['Authorization'] = 'Bearer <token>'
request['Idempotency-Key'] = '<string>'

response = http.request(request)
puts response.read_body

Response

{
  "canceled_at": null,
  "checkpoint": "queued",
  "completed_at": null,
  "created_at": "2026-10-20T10:00:00Z",
  "cursor": null,
  "execution_attempts": 0,
  "failure": null,
  "id": "e1f2a3b4-c5d6-4e7f-8a9b-0c1d2e3f4a5b",
  "kind": "sync",
  "knowledge_space_id": "0a9d3c2e-5b6f-4e1a-8c7d-2f3e4a5b6c7d",
  "last_error_code": null,
  "max_execution_attempts": 5,
  "progress_completed": 0,
  "progress_failed": 0,
  "progress_skipped": 0,
  "progress_total": null,
  "source_id": "6f1c2b0e-3d0b-4a5e-9f4c-1c0e6a7b8d90",
  "state": "queued",
  "updated_at": "2026-10-20T10:00:00Z"
}

{
  "code": "knowledge_fs_invalid_request",
  "message": "Agent Knowledge Base request is invalid.",
  "status": 400,
  "violations": [
    {
      "field": [
        "idempotency-key"
      ],
      "type": "string_too_short"
    }
  ]
}

{
  "code": "knowledge_fs_invalid_request",
  "message": "Agent Knowledge Base request is invalid.",
  "status": 400
}

{
  "code": "knowledge_fs_invalid_request",
  "failure": {
    "category": "validation",
    "code": "KNOWLEDGE_FS_INVALID_REQUEST",
    "message": "The Agent Knowledge Base request is invalid.",
    "retryPolicy": "never",
    "traceId": "7f3c1a90-2e64-4b7d-8a51-6c0d9e2f4b83"
  },
  "message": "The Agent Knowledge Base request is invalid.",
  "status": 400
}

{
  "code": "knowledge_fs_invalid_credential",
  "message": "Invalid Agent Knowledge Base service credential.",
  "status": 401
}

{
  "code": "unauthorized",
  "message": "Access token is invalid",
  "status": 401
}

{
  "code": "forbidden",
  "message": "Sorry, you have reached the knowledge base request rate limit of your subscription.",
  "status": 403
}

{
  "code": "knowledge_fs_access_denied",
  "message": "Agent Knowledge Base operation is not allowed.",
  "status": 403
}

{
  "code": "knowledge_fs_resource_not_found",
  "failure": {
    "category": "not_found",
    "code": "KNOWLEDGE_FS_NOT_FOUND",
    "message": "The requested Agent Knowledge Base resource was not found.",
    "retryPolicy": "never",
    "traceId": "7f3c1a90-2e64-4b7d-8a51-6c0d9e2f4b83"
  },
  "message": "The requested Agent Knowledge Base resource was not found.",
  "status": 404
}

{
  "code": "not_found",
  "message": "The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.",
  "status": 404
}

{
  "code": "knowledge_fs_upstream_unavailable",
  "failure": {
    "action": "contact_admin",
    "category": "internal",
    "code": "KNOWLEDGE_FS_INTERNAL_ERROR",
    "message": "Agent Knowledge Base could not complete the operation. Try again, or contact an administrator with the error reference.",
    "retryPolicy": "manual",
    "traceId": "5e2a9c17-3b4d-4f60-8a1b-2c3d4e5f6a7b"
  },
  "message": "Agent Knowledge Base could not complete the operation. Try again, or contact an administrator with the error reference.",
  "status": 502
}

{
  "code": "knowledge_fs_upstream_unavailable",
  "message": "Agent Knowledge Base is unavailable.",
  "status": 502
}

{
  "code": "knowledge_fs_operation_unavailable",
  "message": "Agent Knowledge Base operation is not available.",
  "status": 503
}

{
  "code": "knowledge_fs_operation_unavailable",
  "failure": {
    "action": "retry",
    "category": "dependency",
    "code": "KNOWLEDGE_FS_UNAVAILABLE",
    "message": "A service required by Agent Knowledge Base is temporarily unavailable.",
    "retryPolicy": "manual",
    "traceId": "5e2a9c17-3b4d-4f60-8a1b-2c3d4e5f6a7b"
  },
  "message": "A service required by Agent Knowledge Base is temporarily unavailable.",
  "status": 503
}

post/knowledge-fs/spaces/{knowledge_base_id}/sources/{source_id}/sync

Authorization

Authorizationstringheaderrequired#

Every request authenticates with an API key: Authorization: Bearer {API_KEY}. App endpoints take an app API key; knowledge endpoints take a knowledge base API key (Get Started).

Keep keys server-side; never embed them in client code. Requests with a missing or invalid key fail with HTTP 401 (unauthorized).

Path parameters

knowledge_base_idstringrequired#

Knowledge base ID: the last segment of the Service API endpoint shown in the knowledge base's API Access dialog (…/knowledge-fs/spaces/<knowledge base ID>), and the segment after /datasets/new/ in the address bar.

source_idstringrequired#

Source ID. From List Sources.

Headers

Idempotency-Keystringrequired#

Repeating the same key for the same source from the same API key returns the original run, in its current state, instead of starting another. Use a new key for each sync you mean to start. Use printable ASCII characters without leading or trailing whitespace.

Length: 8–255

Responses

application/json

The run, with kind: sync and state: queued.

canceled_atstring#

When the run was canceled. null unless state is canceled.

checkpointstring#

Last step the run reached: queued, provider-read, preview-staged, selection-frozen, materialized, cleanup-staging, or source-committed. Retry Source Run starts the run over whatever its checkpoint.

completed_atstring#

When the run ended (completed, zero_results, failed, or canceled), ISO 8601. null while it runs.

created_atstring#

Creation time, ISO 8601.

cursorstring#

Provider cursor the run resumes from. null when the run has not paged.

execution_attemptsinteger#

Times a worker has picked up the run, including after Retry Source Run, which does not reset it.

failureobject#

Error details when state is failed. stage is the run's checkpoint at the failure, and traceId is the run ID. null otherwise.

Show child attributes

actionstring#

Suggested next step, when there is one: configure_model, configure_parser, configure_source, contact_admin, reupload, or retry. null when not applicable; omitted from HTTP error bodies.

categorystring#

Kind of failure: authorization, canceled, configuration, conflict, dependency, internal, not_found, rate_limit, timeout, or validation.

codestring#

Stable error code in upper snake case, for example KNOWLEDGE_FS_CONFLICT or SOURCE_CREDENTIAL_TEST_FAILED.

messagestring#

Public message for the error code or failure category. Provider error details are not exposed.

parametersobject#

Up to 8 values that qualify the failure, with keys among attempt, currentRowVersion, documentCount, expectedRowVersion, fileSizeBytes, limit, maxFileSizeBytes, maxItems, modelType, providerKind, retryAfterSeconds, and status. null when there are none; omitted from HTTP error bodies.

retryPolicystring#

Whether a retry can help: automatic (the service retries on its own), manual (retry yourself), after_configuration (fix the knowledge base's setup in Dify first), or never (change the request).

stagestring#

Stage the failure belongs to, for example query_generation or credential-test. null when not applicable; omitted from HTTP error bodies.

traceIdstring#

Reference to quote when contacting an administrator. May be null in a successful response containing failure details, or omitted from an HTTP error body.

idstring#

Run ID. Pass it to Get Source Run, Cancel Source Run, or Retry Source Run.

kindstring#

What the run does:

sync: started by Sync Source, Update Source, a schedule, or Dify.
crawl-preview: started by Preview Website Crawl. It keeps this kind while Import Selected Pages imports from it.
crawl-import: started by Import Website Pages.
online-document-import, online-drive-import: started by Import Source Items.

Dify also starts previews and imports when a source is added or edited there.

knowledge_space_idstring#

Internal ID of the knowledge base. Not the knowledge base ID in the path.

last_error_codestring#

failure.code when state is failed. null otherwise.

max_execution_attemptsinteger#

Limit on execution_attempts. Once it is reached, Retry Source Run answers 409.

progress_completedinteger#

Items finished, including unchanged items a sync checked.

progress_failedinteger#

Always 0 for source runs: a failing item fails the whole run.

progress_skippedinteger#

Always 0 for source runs.

progress_totalinteger#

Items the run expects to process: the pages or items an import requested, the pages a crawl preview has staged so far, or the source's items once a sync has listed them. null until known.

While an Import Website Pages run crawls its URLs, progress_completed and progress_total both count the pages crawled so far. Once every URL is crawled, they restart at 0 of the number of URLs.

source_idstring#

Source the run belongs to.

statestring#

Progress of the run.

Live states:

queued: waiting for a worker
crawling: a crawl preview is fetching pages
preview_ready: a crawl preview is waiting for Import Selected Pages or Cancel Source Run
importing: importing and indexing items
syncing: refreshing the source's documents

Terminal states:

completed: every item was imported or refreshed, indexed, and made active
zero_results: a crawl preview found no pages
failed: see failure
canceled

After failed or canceled, Retry Source Run runs it again, and Sync Source starts a new sync.

updated_atstring#

Last change, ISO 8601.

Update Sync Policy Preview Website Crawl