crawlee 0.1.0

First release. A tidy, native-R, Crawlee-inspired toolkit for reproducible web crawling.

Milestone M9 — adaptive & polite streaming

• cr_stream(adaptive = TRUE, min, max) adapts the streaming pool’s in-flight target at run time (AIMD on back-pressure), like cr_autoscale() but for the continuous scheduler.
• The streaming engine now paces launches per host (delay / robots.txt Crawl-delay): a host is not hit again until its interval has elapsed, while different hosts keep running in parallel.

Milestone M8 — autoscaling & streaming

• cr_autoscale(min, max) adapts the parallel batch concurrency at run time (Crawlee autoscaled-pool style): additive-increase on clean batches, multiplicative-decrease on back-pressure (a transport failure or HTTP 429/500/502/503/504), clamped to [min, max].
• cr_stream(concurrency) adds a continuous-pool scheduler (via httr2::req_perform_promise() + /): keeps concurrency requests in flight at all times, dispatching and refilling as each finishes — avoiding the batch engine’s “wait for the slowest” stall.

Milestone M7 — parallel fetching

• cr_parallel(concurrency) enables concurrent fetching for the HTTP backend (Crawlee’s autoscaled-pool equivalent): the queue is drained in batches whose network I/O runs concurrently via httr2::req_perform_parallel(), while handlers still run sequentially in R (no shared-state hazard). robots.txt, retries, depth/request limits and queue checkpointing all still apply; delay/Crawl-delay are applied between batches.
• The engine was refactored into shared dispatch/error steps used by both the sequential and parallel loops.

Milestone M6 — persistent & resumable storage

• cr_persist() ties a crawl to a run directory: the request queue is checkpointed (queue.rds) during the run and restored on the next run, so a crawl resumes where it left off without re-fetching seen URLs.
• Persistent [Dataset] backends: cr_dataset(backend = "jsonl") (append-only, schema-flexible) and "duckdb" (SQL-ready). The RequestQueue gained save()/restore()/set_path().
• A reproducibility manifest (manifest.rds / manifest.json) records the start URLs, options snapshot and run stats.
• cr_close() releases the browser session and DuckDB connection.

Milestone M5 — RAG

• cr_chunk() splits text (a character vector or a data-frame column) into overlapping chunks, by character or word, carrying metadata per chunk.
• cr_embed() attaches an embedding list-column via a user-supplied, provider-agnostic embedding function, applied in batches. crawlee never calls an external service itself.
• cr_export() writes chunks (and embeddings) to Parquet, JSONL, CSV or DuckDB for retrieval.

Milestone M4 — headless browser

• cr_use_browser() renders JavaScript-heavy pages with a headless Chrome/Chromium via , with wait and wait_selector controls. Handlers are unchanged (ctx$page, enqueue_links()); the context gains ctx$screenshot(), saved to the [KeyValueStore].
• Fetch backends are now unified behind a normalised internal fetched object, so handlers behave identically regardless of HTTP vs browser.

Milestone M3 — documents

• Content-type aware dispatch: each response is classified (html, pdf, other) and routed to the matching default handler; explicit request labels still take precedence.
• cr_on_pdf() registers a PDF handler. Its context adds pdf_text() (per-page text via ), body_raw()/body_string() and save_body().
• KeyValueStore plus cr_store() and ctx$save_body(): persist raw responses (PDFs, images, snapshots) on disk alongside the structured dataset.

Milestone M2 — discovery

• cr_from_sitemap() enqueues URLs from a sitemap.xml, recursing into sitemap indexes, transparently handling gzipped sitemaps, with glob filters and a since filter on <lastmod> for incremental crawls.
• cr_from_rss() enqueues items from RSS and Atom feeds, carrying item title and date into the request’s user_data.
• robots.txt is now enforced when respect_robots = TRUE (the default): a native parser/matcher (User-agent grouping, */$ patterns, longest-match with Allow override, Crawl-delay), cached per host. Disallowed URLs are skipped and reported; Crawl-delay is honoured.

Milestone M1 — core

• crawler() builds a stateful, pipe-friendly crawler.
• RequestQueue: deduplicating (normalised unique_key), FIFO, resumable request queue with retry rescheduling.
• cr_options() configures concurrency, depth, delay, retries, user agent and log verbosity.
• cr_use_http() HTTP fetch backend (httr2); cr_use_browser() reserved.
• cr_on_html() registers content handlers; handler context exposes push_data() and enqueue_links() (with glob/include/exclude and same-domain filtering).
• Dataset append-only store; cr_run() drives the crawl and cr_collect() returns a tibble.
• Rich console logging via cli.