> ## Documentation Index > Fetch the complete documentation index at: https://docs.goldsky.com/llms.txt > Use this file to discover all available pages before exploring further. # Add chains to a sync > Start syncing more chains. With the sync's `backfill` on, the added chains' history is backfilled for every watched wallet, and the other chains are not read again; this answers 409 while a backfill job is still running. ## OpenAPI ````yaml https://api.goldsky.com/api/v1/docs/openapi.json post /feeds/{theme}/{dataset}/syncs/{name}/chains openapi: 3.1.0 info: title: Goldsky API description: >- REST API for managing Goldsky resources — pipelines, subgraphs, Edge endpoints, and Feeds keys and usage. Create, deploy, monitor, and manage them programmatically. For guides and reference, see the [Goldsky documentation](https://docs.goldsky.com) — including [Subgraphs](https://docs.goldsky.com/subgraphs/introduction) and [Pipelines](https://docs.goldsky.com/mirror/introduction). ## Authentication Every request carries an API token as a bearer token: ``` Authorization: Bearer ``` Create one on the [API Keys page](https://app.goldsky.com/dashboard/settings/api-keys) of the Goldsky dashboard. A token is scoped to the project it was created in, so the project is never part of a request path. Read operations need the Viewer role; writes need Editor. The Feeds data itself — wallet transfers and balances — is served from `https://edge.goldsky.com/data` with a Data API key, and documented in its own reference: [edge.goldsky.com/data/openapi.json](https://edge.goldsky.com/data/openapi.json). ## Errors Errors are [RFC 9457 problem details](https://www.rfc-editor.org/rfc/rfc9457) served as `application/problem+json`: ```json { "type": "https://api.goldsky.com/api/errors/subgraph-not-found", "title": "Subgraph not found", "status": 404, "detail": "No subgraph named 'my-subgraph' exists in this project.", "instance": "/api/v1/subgraphs/my-subgraph" } ``` Branch on `type`, not on `title` or `detail` — the URI is stable, the prose is not. Every `type` dereferences to a human-readable page describing the cause and the fix; the full list lives at [api.goldsky.com/api/errors](https://api.goldsky.com/api/errors). Validation failures (400) add an `errors` array naming each offending field. ## Pagination List endpoints that can return unbounded results — pipelines and subgraphs — page with `page_size` and `page_token`: ``` GET /api/v1/subgraphs?page_size=50 GET /api/v1/subgraphs?page_size=50&page_token= ``` Keep following `pagination.next_page_token` until it comes back `null`. A page can hold fewer than `page_size` items and still have a next page, so treat a short page as "keep going", not as the end. version: 1.6.0 contact: name: Goldsky Support email: support@goldsky.com url: https://docs.goldsky.com servers: - url: /api/v1 description: Current environment security: - BearerAuth: [] tags: - name: Pipelines x-displayName: Create & manage description: >- Create, read, and delete pipelines. A pipeline is identified by its name within the project. - name: Pipeline Authoring x-displayName: Validate & preview description: >- Check a pipeline definition and see what it would produce, before creating anything. Neither endpoint touches an existing pipeline. - name: Pipeline Lifecycle x-displayName: Lifecycle description: Pause, resume, and restart a running pipeline. - name: Pipeline Status x-displayName: Status description: Query pipeline runtime status and per-source progress state. - name: Pipeline Logs x-displayName: Logs description: Retrieve pipeline execution logs and error counts. - name: Subgraphs x-displayName: Browse description: >- Read subgraphs and their versions. A subgraph is identified by `name`/`version`. - name: Subgraph Deployments x-displayName: Deployments description: >- Deploy a compiled subgraph bundle as a new version, or remove a deployed one. - name: Subgraph Tags x-displayName: Tags description: >- Point a stable alias — `production`, say — at a specific version, so consumers keep one URL across deploys. - name: Subgraph Lifecycle x-displayName: Lifecycle description: Pause and resume indexing, and update the settings of a deployed version. - name: Subgraph Logs x-displayName: Logs description: Retrieve subgraph indexing logs. - name: Subgraph Webhooks x-displayName: Webhooks description: >- Stream row-level changes to a subgraph entity out to a URL. Webhooks are project-scoped and each one targets a single entity of a single subgraph version. - name: Edge Endpoints x-displayName: Create & manage description: >- Create and manage Edge endpoints — RPC and Data — including rate limits and allowed domains. - name: Edge Lifecycle x-displayName: Lifecycle description: >- Pause and resume an endpoint. A paused endpoint rejects traffic but keeps its configuration and key. - name: Edge API Keys x-displayName: API keys description: Reveal the API key an Edge endpoint serves traffic under. - name: Edge Metrics x-displayName: Metrics description: Request volume and error rates for an Edge endpoint. - name: Boost x-displayName: Endpoint description: >- Read and update the project's Boost: a cache-first proxy for EVM JSON-RPC reads, backed by your own provider upstreams. One Boost per project. Free for verified organizations: a team with a member on a business email domain (not a free mailbox provider) qualifies automatically. - name: Boost Lifecycle x-displayName: Lifecycle description: >- Enable and disable the project's Boost. A disabled Boost refuses traffic but keeps its chains, upstreams, and key. - name: Boost API Keys x-displayName: API key description: Reveal the API key the Boost serves traffic under. - name: Boost Chains x-displayName: Chains description: >- List the chains Boost can cache, and switch a chain on or off or override its timeouts on this Boost. - name: Boost Providers x-displayName: Provider accounts description: >- Connect a provider account (Alchemy or QuickNode) and let Boost create and register its endpoints for you, instead of pasting URLs one chain at a time. - name: Boost Upstreams x-displayName: Upstreams description: >- The provider URLs Boost forwards to, one active per chain with fallbacks. Validate a URL, add or remove an upstream, replace its URL, fail over to another, or tune its settings. Upstreams are addressed by `{chain, id}` in the request body. - name: Boost Metrics x-displayName: Metrics description: >- Cache hit rate, latency, provider calls, credit savings, and the per-request history for a Boost. - name: Feed Catalog x-displayName: Catalog & API key description: >- List the feeds Goldsky offers and when the project first used each, and get or create the project's Feeds key (a Data API key named `feeds`) every feed authenticates with; rotate it with `POST /api/v1/feeds/key/rotate`. - name: Feed Syncs x-displayName: Syncs description: >- Stream a wallet feed into your own database or webhook: create a sync, add and remove the wallets, tokens and chains it covers, backfill history, follow its status, and delete it. Syncs exist for `wallets/balances` and `wallets/transfers`. - name: Feed Logs x-displayName: Request logs description: >- Every request the project sent a feed: when, which path, whether it succeeded, and how long it took. Kept for 30 days. - name: Catalogs x-displayName: Catalogs description: >- What Goldsky supports: chains you can index a subgraph on, and the networks and datasets an Edge endpoint can be pointed at. Unauthenticated-safe reads that never change per project. paths: /feeds/{theme}/{dataset}/syncs/{name}/chains: post: tags: - Feed Syncs summary: Add chains to a sync description: >- Start syncing more chains. With the sync's `backfill` on, the added chains' history is backfilled for every watched wallet, and the other chains are not read again; this answers 409 while a backfill job is still running. operationId: addFeedSyncChains parameters: - schema: type: string in: path name: theme required: true description: The feed's theme, e.g. `wallets`. - schema: type: string in: path name: dataset required: true description: The feed's dataset, e.g. `balances` or `transfers`. - schema: minLength: 1 type: string in: path name: name required: true description: The sync's name. requestBody: content: application/json: schema: additionalProperties: false type: object properties: chains: minItems: 1 description: Goldsky chain slugs or dataset prefixes. type: array items: minLength: 1 type: string required: - chains required: true responses: '202': description: Default Response content: application/json: schema: type: object properties: name: type: string theme: type: string dataset: type: string chains: description: The chains the sync covers, by Goldsky chain slug. type: array items: type: string backfill: description: >- Whether each wallet's history is backfilled when it is added, and an added chain's history for every wallet. type: boolean secret_name: anyOf: - description: >- The secret holding the destination database's credentials, or a webhook's auth headers. type: string - type: 'null' compose_app_name: anyOf: - description: >- The compose app holding the sync's watched wallets and tokens, and running its tasks. type: string - type: 'null' pipeline_name: anyOf: - description: The pipeline that streams new rows. type: string - type: 'null' backfill_pipeline_name: anyOf: - description: >- The job that backfills history, once the sync has backfilled at least once. type: string - type: 'null' created_at: format: date-time type: string required: - name - theme - dataset - chains - backfill - secret_name - compose_app_name - pipeline_name - backfill_pipeline_name - created_at components: securitySchemes: BearerAuth: type: http scheme: bearer description: >- API token generated from the [Goldsky Dashboard](https://app.goldsky.com/dashboard/settings/api-keys). Pass as: Authorization: Bearer ```` ## Related topics - [Remove a chain from a sync](https://docs.goldsky.com/api-reference/feed-syncs/remove-a-chain-from-a-sync.md) - [Add wallets to a sync](https://docs.goldsky.com/api-reference/feed-syncs/add-wallets-to-a-sync.md) - [Add a token to a sync's filter](https://docs.goldsky.com/api-reference/feed-syncs/add-a-token-to-a-syncs-filter.md) - [List the chains a sync can cover](https://docs.goldsky.com/api-reference/feed-syncs/list-the-chains-a-sync-can-cover.md) - [Build a multi-chain NAV oracle](https://docs.goldsky.com/compose/guides/build-a-nav-oracle.md)