Define a bounded task and its destination
Treat each scheduled run as a historical retrieval task, not a live stream. Reddit Data Stream is independent of Reddit and provides no official affiliation, SSE, WebSocket subscription or changefeed. A recurring schedule belongs to your application. It does not establish archive refresh frequency, delivery of newly published posts or notifications about edits and deletions. Your destination file contains the records actually received in that run.
Start with https://api.redditdatastream.com/v1/posts?subreddit=apacheairflow&limit=3&page=3, the homepage example. It asks for up to three posts on page three of that query. Use X-API-Key: <key> or Authorization: Bearer <key> from the server. The Get API key page explains signup and once-only key display before payment. Keep the real key out of job logs and destination files.
Choose explicit filters and a maximum number of separate page calls for your own task. search, posts and comments allow limit and page from 1 to 100. For date windows, from and to use YYYY-MM-DD UTC on created_utc and include the entire final day, not ingestion time. Neither smaller windows nor local sorting establishes exhaustive coverage. min_score filters a threshold without sorting or checking content quality.
Validate, serialize and publish locally
Check the HTTP outcome before treating the body as data. Validate the data array and available fields, preserving missing values rather than inventing them. Records are flat; present parent_id and link_id can support local grouping, without guaranteed complete discussions. Those references are not search filters. The API returns JSON, while your code creates the JSONL destination; no server export format switch is implied.
Serialize each received record with a JSON serializer, for example json.dumps(record, ensure_ascii=False) in Python, and append one line break after that serialized value. A serializer escapes newlines inside source text, keeping one record on one physical line. Preserve the response envelope separately if your diagnostics need pagination or credits. An empty successful data array writes zero record lines; do not invent a placeholder post.
Consider writing to a temporary local destination, checking completion and only then publishing it to your downstream job. Record local progress after the intended write succeeds. These are steps in your own implementation, not an API transaction spanning retrieval and storage. A disk failure after successful retrieval remains a local failure; the remote credit can already be consumed. File naming or replacement alone does not establish exactly-once delivery.
Read pagination.total with relation: eq is an exact query total, gte a lower bound and unknown unreliable or null. An empty page after page one can return unknown rather than zero. Keep has_more and window_exhausted to describe supported boundaries and stop at page 100. Neither an exact total nor a finished local file proves that all historical matches were collected.
Retry by outcome and preserve uncertainty
Internal _doc order is not time, relevance, score or ingestion order. Do not use the last record's timestamp as proof that earlier records are complete. A local checkpoint records attempted or completed work in your own system, not a stable server cursor. A fresh retrieval of the same page may differ and can repeat records or omit previously received material without an identical-result guarantee.
Reprocessing a response you already saved locally does not call the archive. Requesting it remotely again is another retrieval and costs one credit if successful, including empty results. Invalid requests do not debit and upstream failures refund reservations. A lost client response can follow a charged success; mark that attempt as uncertain. Local validation or storage rejection does not refund a completed remote request.
Handle 400 by correcting parameters, 401 by checking key and domain, 402 by checking balance and 429 with bounded delayed retries. Public /v1/status only confirms the HTTP application and static service scope; it cannot certify search availability or reconcile a lost response. The documentation explains route constraints. Pricing is $1 per 1000 successes, a $50 paid minimum and conditional 100 trial credits, with no subscriptions.
Key regeneration requires signing into the key-page panel and confirming the password, immediately invalidating the previous key. Update scheduled workers using it. To fund work, sign in and create an invoice before transferring its exact amount using the displayed supported token and network, then submit the transaction hash for verification. Payment state and local pipeline checkpoints are separate; neither guarantees future archive availability.
