> ## Documentation Index > Fetch the complete documentation index at: https://docs.sqd.dev/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Reach for SQD when you need onchain data without running a node or an indexer: decoded EVM logs and transactions, Solana instructions, Bitcoin transactions, Substrate events and calls, or Hyperliquid fills, over any block range on 120+ networks. > To query directly, POST to https://portal.sqd.dev/datasets/{dataset}/stream. The full API is described at https://docs.sqd.dev/openapi.json, and responses to the stream endpoints are JSON Lines. > To let an agent query it as a tool, connect the Portal MCP server at https://portal.sqd.dev/mcp. > Every page on this site is available as Markdown by appending .md to its URL. # Stream Blocks > Stream available Substrate blockchain data from SQD Portal. **Real-time streaming is not supported for Substrate chains.** Only finalized historical data is available. If you need real-time Substrate data, [schedule a call with our team](https://calendly.com/t-tyrie-subsquid/30min). ## OpenAPI ````yaml en/api/catalog/substrate/openapi.yaml POST /stream openapi: 3.1.0 info: title: SQD Portal API - Substrate Dataset Endpoints description: >- API endpoints for interacting with Substrate datasets under the SQD Portal, specifically for the Polkadot dataset. version: 1.0.0 servers: - url: https://portal.sqd.dev/datasets/polkadot description: SQD Portal's endpoint for Polkadot security: [] paths: /stream: post: summary: Stream Blocks description: >- Streams a list of blocks matching the provided data query. Substrate datasets contain only finalized blocks. Required request headers: `Content-Type: application/json`; optional request headers: `Accept-Encoding: gzip`, `Content-Encoding: gzip`. operationId: streamSubstrateBlocks requestBody: description: >- Data query to filter and retrieve blocks. Request body may be gzipped (Content-Encoding: gzip). required: true content: application/json: schema: $ref: '#/components/schemas/DataQuery' examples: balances-transfer: summary: Query Balances.Transfer Events value: type: substrate fromBlock: 20000000 toBlock: 20000100 fields: block: number: true timestamp: true event: name: true args: true events: - name: - Balances.Transfer calls-with-extrinsics: summary: Query Calls with Extrinsics value: type: substrate fromBlock: 20000000 toBlock: 20000100 fields: block: number: true timestamp: true call: name: true args: true success: true extrinsic: hash: true fee: true success: true calls: - name: - Balances.transfer_keep_alive extrinsic: true evm-logs: summary: Query EVM.Log Events (Frontier) value: type: substrate fromBlock: 5000000 toBlock: 5000100 fields: block: number: true timestamp: true event: name: true args: true evmLogs: - topic0: - >- 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef responses: '200': description: >- A stream of blocks in JSON lines format, optionally gzipped. Can be empty if the data query has a bounded range and all blocks in the range have been skipped. May include X-Sqd-Finalized-Head-Number and X-Sqd-Finalized-Head-Hash headers, indicating the latest finalized block that's on the same chain as the returned blocks. headers: X-Sqd-Finalized-Head-Number: schema: type: integer format: int64 description: >- Block number of the latest finalized block. Returned blocks can be above, at, or below this block number. required: false X-Sqd-Finalized-Head-Hash: schema: type: string description: >- Hash of the latest finalized block. All returned blocks are guaranteed to belong to the same (not necessarily final) chain as this block. required: false content: application/jsonl: schema: type: array items: $ref: '#/components/schemas/Block' examples: balances-transfer-response: summary: Balances.Transfer events response value: - header: number: 20000050 hash: >- 0xabc123def456789abc123def456789abc123def456789abc123def456789abcd parentHash: >- 0x789012abc345678901234567890123456789012345678901234567890123abcd timestamp: 1700000000000 events: - index: 3 extrinsicIndex: 1 name: Balances.Transfer phase: ApplyExtrinsic args: from: 15oF4uVJwmo4TdGW7VfQxNLavjCXviqWrztPu9BFKHEtaqry to: 14E5nqKAp3oAJcg4aM6hEYyLT2JAPi6ixST1VRkNg8wAKPe amount: '10000000000' '204': description: >- No new blocks available in the requested range - the range is entirely above the current dataset head. Not an error and the response has no body; wait and retry to keep following the chain head. The portal may wait for up to 5s before returning this. headers: X-Sqd-Finalized-Head-Number: schema: type: integer format: int64 description: Block number of the latest finalized block. required: false X-Sqd-Finalized-Head-Hash: schema: type: string description: Hash of the latest finalized block. required: false '400': description: > Invalid request or query (`error.code` is `malformed_request`; `error.param` names the request field at fault when one is). Possible causes: (1) request headers or body encoding are incorrect; (2) the query is invalid - `error.message` includes an explanation; (3) fromBlock is below the dataset's start_block (see /metadata). content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: type: invalid_request_error code: malformed_request message: 'Bad request: fromBlock must be a non-negative integer' param: fromBlock '404': description: Dataset not found (`error.code` is `unknown_dataset`) content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: type: invalid_request_error code: unknown_dataset message: 'Unknown dataset: no-such-chain' '409': description: >- Parent block hash mismatch (`error.code` is `base_block_mismatch`) - the query's parentBlockHash does not match the canonical parent of the first requested block, typically after a chain reorganization. Walk the top-level previousBlocks list to find the most recent block you have already processed, roll back your data to it, then resume the stream from the next block, passing that block's hash as parentBlockHash. If nothing in the list matches your records, restart from an earlier fromBlock, again with parentBlockHash. content: application/json: schema: $ref: '#/components/schemas/ConflictResponse' '429': description: >- Rate limited (`error.type` is `rate_limit_error`). Retry after the interval in the Retry-After header; it is always present and counts seconds content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: type: rate_limit_error code: overloaded message: Service is overloaded, please try again later headers: Retry-After: schema: type: integer description: Seconds to wait before retrying (at least 1) '500': description: >- Internal server error (`error.type` is `api_error`). Do not retry; report the error together with its request_id content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: type: api_error code: internal_error message: Internal server error request_id: 0198c3f1-... '502': description: >- A data source the Portal depends on is unavailable (`error.code` is `upstream_unavailable`) - retry later. A proxied upstream failure keeps the upstream's own 5xx status content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: type: availability_error code: upstream_unavailable message: Upstream data source is unavailable, please try again later request_id: 0198c3f1-... '503': description: >- Service temporarily unavailable (`error.type` is `availability_error`, typically `no_workers` or `retries_exhausted`) - retry later. May carry Retry-After; honor it when present content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: type: availability_error code: no_workers message: No workers available for dataset request_id: 0198c3f1-... headers: Retry-After: schema: type: integer description: Seconds to wait before retrying (at least 1) '529': description: >- Overloaded (`error.code` is `overloaded`) - the Portal or a data source is at capacity. Retry after the interval in the Retry-After header; it is always present and counts seconds content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: error: type: rate_limit_error code: overloaded message: Service is overloaded, please try again later request_id: 0198c3f1-... headers: Retry-After: schema: type: integer description: Seconds to wait before retrying (at least 1) x-codeSamples: - lang: shell label: Query Balances.Transfer Events source: > curl --compressed -X POST 'https://portal.sqd.dev/datasets/polkadot/stream' \ -H 'Content-Type: application/json' \ -d '{ "type": "substrate", "fromBlock": 20000000, "toBlock": 20000100, "fields": { "block": { "number": true, "timestamp": true }, "event": { "name": true, "args": true } }, "events": [{ "name": ["Balances.Transfer"] }] }' - lang: shell label: Query Calls with Extrinsics source: > curl --compressed -X POST 'https://portal.sqd.dev/datasets/polkadot/stream' \ -H 'Content-Type: application/json' \ -d '{ "type": "substrate", "fromBlock": 20000000, "toBlock": 20000100, "fields": { "block": { "number": true, "timestamp": true }, "call": { "name": true, "args": true, "success": true }, "extrinsic": { "hash": true, "fee": true, "success": true } }, "calls": [{ "name": ["Balances.transfer_keep_alive"], "extrinsic": true }] }' - lang: shell label: Query EVM.Log Events (Frontier) source: > curl --compressed -X POST 'https://portal.sqd.dev/datasets/astar-substrate/stream' \ -H 'Content-Type: application/json' \ -d '{ "type": "substrate", "fromBlock": 5000000, "toBlock": 5000100, "fields": { "block": { "number": true, "timestamp": true }, "event": { "name": true, "args": true } }, "evmLogs": [{ "topic0": ["0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef"] }] }' - lang: python label: Query Balances.Transfer Events source: | import requests response = requests.post( "https://portal.sqd.dev/datasets/polkadot/stream", json={ "type": "substrate", "fromBlock": 20000000, "toBlock": 20000100, "fields": { "block": { "number": True, "timestamp": True }, "event": { "name": True, "args": True } }, "events": [{ "name": ["Balances.Transfer"] }] } ) data = response.json() - lang: javascript label: Query Balances.Transfer Events source: > const response = await fetch("https://portal.sqd.dev/datasets/polkadot/stream", { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ type: "substrate", fromBlock: 20000000, toBlock: 20000100, fields: { block: { number: true, timestamp: true }, event: { name: true, args: true } }, events: [{ name: ["Balances.Transfer"] }] }) }); const data = await response.json(); components: schemas: DataQuery: type: object properties: type: type: string enum: - substrate default: substrate fromBlock: type: integer format: int64 description: >- The number of the first block to fetch. If unsure how far into the past this can go consult /metadata default: 20000000 toBlock: type: integer format: int64 description: >- The block number to fetch up to (inclusive). Optional; if omitted, streams until dataset height or timeout. default: 20000100 parentBlockHash: type: string description: Expected hash of the parent of the first requested block includeAllBlocks: type: boolean description: If true, includes blocks with no matching data default: false fields: type: object description: >- Field selector. See the HTTP 200 response description for details on fields that aren't self-explanatory properties: block: type: object description: >- Field selector for block headers (the .header objects of JSON block records) properties: number: type: boolean description: Block number hash: type: boolean description: Block hash parentHash: type: boolean description: Hash of the parent block stateRoot: type: boolean description: Root hash of the state trie after this block extrinsicsRoot: type: boolean description: Root hash of the extrinsics trie for this block digest: type: boolean description: Block digest as JSON object specName: type: boolean description: Runtime spec name specVersion: type: boolean description: Runtime spec version implName: type: boolean description: Runtime implementation name implVersion: type: boolean description: Runtime implementation version validator: type: boolean description: Block validator/author address timestamp: type: boolean description: Block timestamp in milliseconds since Unix epoch extrinsic: type: object description: Field selector for extrinsics properties: index: type: boolean description: Index of the extrinsic in the block version: type: boolean description: Extrinsic format version success: type: boolean description: Whether the extrinsic executed successfully hash: type: boolean description: Extrinsic hash fee: type: boolean description: Extrinsic fee as a decimal string tip: type: boolean description: Extrinsic tip as a decimal string signature: type: boolean description: Extrinsic signature as JSON object error: type: boolean description: Extrinsic error as JSON object (if failed) call: type: object description: Field selector for calls properties: extrinsicIndex: type: boolean description: Index of the parent extrinsic in the block address: type: boolean description: >- Call address within the extrinsic call tree (array of integers) name: type: boolean description: Qualified call name (e.g. Balances.transfer_keep_alive) success: type: boolean description: Whether the call executed successfully args: type: boolean description: Call arguments as JSON origin: type: boolean description: Call origin as JSON error: type: boolean description: Call error as JSON (if failed) event: type: object description: Field selector for events properties: index: type: boolean description: Index of the event in the block extrinsicIndex: type: boolean description: Index of the parent extrinsic in the block name: type: boolean description: Qualified event name (e.g. Balances.Transfer) phase: type: boolean description: Event phase (ApplyExtrinsic, Finalization, Initialization) callAddress: type: boolean description: Address of the call that emitted this event topics: type: boolean description: Event topics as an array of hex strings args: type: boolean description: Event arguments as JSON default: block: number: true hash: true parentHash: true event: name: true call: name: true events: type: array description: >- Event data requests. An empty object matches all events; an empty array matches no events items: type: object properties: name: description: Filter by qualified event name (e.g. Balances.Transfer) type: array items: type: string extrinsic: description: Fetch parent extrinsics for matching events type: boolean call: description: Fetch the call that emitted each matching event type: boolean stack: description: >- Fetch the full call stack (all parent calls) for matching events type: boolean calls: type: array description: >- Call data requests. An empty object matches all calls; an empty array matches no calls items: type: object properties: name: description: >- Filter by qualified call name (e.g. Balances.transfer_keep_alive) type: array items: type: string subcalls: description: Fetch all child calls (subcalls) for matching calls type: boolean extrinsic: description: Fetch parent extrinsics for matching calls type: boolean stack: description: Fetch all parent calls in the call tree type: boolean events: description: Fetch all events emitted by matching calls type: boolean evmLogs: type: array description: >- EVM.Log event requests for Frontier EVM parachains (e.g. Astar). Filters on EVM.Log events specifically items: type: object properties: address: description: Filter by EVM contract address (lowercase hex) type: array items: type: string topic0: description: Filter by first topic (event signature hash) type: array items: type: string topic1: description: Filter by second topic type: array items: type: string topic2: description: Filter by third topic type: array items: type: string topic3: description: Filter by fourth topic type: array items: type: string extrinsic: description: Fetch parent extrinsics for matching events type: boolean call: description: Fetch the call that emitted each matching event type: boolean stack: description: Fetch the full call stack for matching events type: boolean ethereumTransactions: type: array description: >- Ethereum.transact call requests for Frontier EVM parachains. Filters on Ethereum.transact calls specifically items: type: object properties: to: description: Filter by destination EVM contract address (lowercase hex) type: array items: type: string sighash: description: Filter by function signature hash (4-byte hex) type: array items: type: string extrinsic: description: Fetch parent extrinsics for matching calls type: boolean stack: description: Fetch all parent calls in the call tree type: boolean events: description: Fetch all events emitted by matching calls type: boolean contractsEvents: type: array description: >- Contracts.ContractEmitted event requests for ink! smart contracts. Contract addresses must be hexadecimal (decoded from SS58) and lowercase items: type: object properties: contractAddress: description: Filter by contract address (hexadecimal, lowercase) type: array items: type: string extrinsic: description: Fetch parent extrinsics for matching events type: boolean call: description: Fetch the call that emitted each matching event type: boolean stack: description: Fetch the full call stack for matching events type: boolean gearMessagesEnqueued: type: array description: Gear.UserMessageEnqueued event requests for Gear/Vara networks items: type: object properties: programId: description: Filter by Gear program ID type: array items: type: string extrinsic: description: Fetch parent extrinsics for matching events type: boolean call: description: Fetch the call that emitted each matching event type: boolean stack: description: Fetch the full call stack for matching events type: boolean gearUserMessagesSent: type: array description: Gear.UserMessageSent event requests for Gear/Vara networks items: type: object properties: programId: description: Filter by Gear program ID type: array items: type: string extrinsic: description: Fetch parent extrinsics for matching events type: boolean call: description: Fetch the call that emitted each matching event type: boolean stack: description: Fetch the full call stack for matching events type: boolean reviveContractEmitted: type: array description: Revive.ContractEmitted event requests for Revive smart contracts items: type: object properties: contract: description: Filter by contract address type: array items: type: string topic0: description: Filter by first topic type: array items: type: string topic1: description: Filter by second topic type: array items: type: string topic2: description: Filter by third topic type: array items: type: string topic3: description: Filter by fourth topic type: array items: type: string extrinsic: description: Fetch parent extrinsics for matching events type: boolean call: description: Fetch the call that emitted each matching event type: boolean stack: description: Fetch the full call stack for matching events type: boolean required: - fromBlock Block: type: object properties: header: type: object properties: number: type: integer format: uint64 hash: type: string parentHash: type: string stateRoot: type: string extrinsicsRoot: type: string digest: type: object description: Block digest containing consensus engine data specName: type: string description: Runtime spec name specVersion: type: integer description: Runtime spec version implName: type: string description: Runtime implementation name implVersion: type: integer description: Runtime implementation version validator: type: string description: Block validator/author address timestamp: type: integer format: uint64 description: Block timestamp in milliseconds since Unix epoch extrinsics: type: array items: type: object properties: index: type: integer description: Index of the extrinsic in the block version: type: integer success: type: boolean hash: type: string description: Extrinsic hash fee: type: string description: Extrinsic fee as a decimal string tip: type: string description: Extrinsic tip as a decimal string signature: type: object description: Extrinsic signature data error: type: object description: Error data if the extrinsic failed calls: type: array items: type: object properties: extrinsicIndex: type: integer description: Index of the parent extrinsic address: type: array items: type: integer description: Call address within the extrinsic call tree name: type: string description: Qualified call name (e.g. Balances.transfer_keep_alive) success: type: boolean args: type: object description: Call arguments origin: type: object description: Call origin error: type: object description: Error data if the call failed events: type: array items: type: object properties: index: type: integer description: Index of the event in the block extrinsicIndex: type: integer description: Index of the parent extrinsic callAddress: type: array items: type: integer description: Address of the call that emitted this event name: type: string description: Qualified event name (e.g. Balances.Transfer) phase: type: string description: Event phase (ApplyExtrinsic, Finalization, Initialization) topics: type: array items: type: string args: type: object description: Event arguments required: - header ErrorResponse: type: object description: Error body shared by every failing response. properties: error: $ref: '#/components/schemas/ErrorDetail' required: - error example: error: type: invalid_request_error code: unknown_dataset message: 'Unknown dataset: no-such-chain' ConflictResponse: type: object description: >- The 409 body carries the standard error envelope plus a top-level `previousBlocks` list - a slice of the current canonical chain at and below the conflict point, in ascending block-number order. properties: error: $ref: '#/components/schemas/ErrorDetail' previousBlocks: type: array description: >- `{ number, hash }` pairs from the current canonical chain in ascending order; the last entry is the most recent block at or below the conflict point. Guaranteed to contain at least the parent of the requested fromBlock. items: type: object properties: number: type: integer format: int64 hash: type: string required: - number - hash required: - error - previousBlocks example: error: type: invalid_request_error code: base_block_mismatch message: Base block mismatch previousBlocks: - number: 21780871 hash: 0xab12cd... - number: 21780872 hash: 0xf6a96a29... ErrorDetail: type: object description: >- Machine-readable error detail. Branch on `type`; match on `code` for one specific case. properties: type: type: string description: >- Coarse category to branch on. One of `invalid_request_error`, `authentication_error`, `permission_error`, `rate_limit_error`, `availability_error`, or `api_error`. The two credential types answer 403 and appear only on a Portal that requires an API key. Treat an unknown `code` according to its `type`. example: invalid_request_error code: type: string description: >- Specific cause, stable across releases. Match on this rather than on `message`. example: base_block_mismatch message: type: string description: >- Human-readable detail. Prose, not stable; do not parse or match on it. param: type: string description: The request parameter at fault, when the error is about one. request_id: type: string description: >- Echo of the `x-request-id` response header, included in the body on 5xx errors. Quote it when reporting a problem. required: - type - code - message ```` ## Related topics - [Stream Blocks](/en/api/solana/stream.md) - [Stream Finalized Blocks](/en/api/solana/finalized-stream.md) This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.