| --- |
| license: odc-by |
| pretty_name: "OP Stack unsafe-head observations and canonical-chain checks" |
| tags: |
| - layer-2 |
| - rollup |
| - sequencer |
| - ethereum |
| - reliability |
| - blockchain |
| - time-series |
| task_categories: |
| - time-series-forecasting |
| size_categories: |
| - 100K<n<1M |
| configs: |
| - config_name: l2_preconfirmation_checks |
| data_files: |
| - split: train |
| path: l2_preconfirmation_checks/**/*.parquet |
| default: true |
| - config_name: collection_runs |
| data_files: |
| - split: train |
| path: collection_runs/**/*.parquet |
| --- |
| |
| # L2 sequencer preconfirmation observations |
|
|
| Periodic observations of unsafe and safe heads on selected OP Stack networks, with subsequent checks of sampled unsafe block hashes against the chain reported by the endpoint. The panel records coverage and detected changes to previously observed blocks. |
|
|
| ## Contents |
|
|
| | Table | Record | |
| |---|---| |
| | `l2_preconfirmation_checks` | A heartbeat with head and check statistics, or a detected violation | |
|
|
| ## Using the data |
|
|
| `row_type` separates heartbeats from violations. Use `n_checked` and `n_failed` to assess how many checks completed before interpreting a period with no detected violations. |
|
|
| `lag_blocks` measures the reported gap between unsafe and safe heads. Use it only where `safe_tag_plausible` is true. Some endpoints have returned stale or inconsistent safe tags, which can produce implausibly large lags. |
|
|
| Compare lag with each chain's own history. Different sequencer and batch-publication policies can produce different normal levels across networks. |
|
|
| ## Limitations |
|
|
| - The configured coverage includes nine OP Stack chains. Results do not establish behaviour across other rollup architectures. |
| - Sampling can miss a block that is proposed and replaced between observations. |
| - Observations depend on public endpoint responses. A mismatch warrants investigation and is not, by itself, proof of a sequencer failure or an L1 finality failure. |
| - An unsafe head is an early chain view, not a universal transaction-level confirmation guarantee. |
| - No detected violations means none were found in completed checks; it does not establish uninterrupted reliability outside those checks. |
|
|
| ## Files and access |
|
|
| Data is stored as Parquet files under `table_name/YYYY/MM/`, with partitions for collection windows. Each measurement table has a fixed 7-day sample beginning at its configured collection start date. The sample windows in this repository span 2026-08-26 to 2026-09-01. Availability within each window depends on successful collection. The public sample dates remain fixed as additional history accumulates privately. Contact DataForge through the discussions tab to enquire about additional history. |
|
|
| ### Load a table |
|
|
| Install `datasets` and `pandas` to run this example. The `train` split contains all observations in the selected table; it is not a predefined modelling split. |
|
|
| ```python |
| from datasets import load_dataset |
| |
| data = load_dataset("dataforge-labs/l2-preconfirmation-reliability", |
| "l2_preconfirmation_checks", split="train") |
| df = data.to_pandas() |
| ``` |
|
|
| ## Coverage |
|
|
| `collection_runs` records collection windows, poll counts and failures. It is published in full and may cover dates beyond the fixed data sample. Collection gaps are not interpolated. Use this table together with measurement timestamps and error fields to assess coverage. |
|
|
| ## License and contact |
|
|
| The public sample is published under ODC-BY. Attribute it to "DataForge (dataforge-labs)". For questions about the data or access to additional history, open a discussion in this repository. |
|
|
| <details> |
| <summary>Earlier file paths</summary> |
|
|
| Each table is stored under a directory with the same descriptive name. The file contents and date partitions are unchanged. Scripts using an earlier directory name should use the corresponding table name below, or pin downloads to revision `before-folder-rename-20260915` to access the original layout. Internal collector IDs are retained in the private archive and may appear in raw coverage records. |
|
|
| | Current table and directory | Earlier directory | |
| |---|---| |
| | `l2_preconfirmation_checks` | `e14_l2_preconf/` | |
| | `collection_runs` | `e0_run_manifest/` | |
|
|
| </details> |
|
|
