Court Dockets

Court dockets: retrieving filings from Lex Machina, Docket Alarm and Bloomberg Law

Three commercial platforms, one job: turn a list of cases into a directory of PDFs plus a manifest you can defend. Verified end to end on 1,597 Delaware Chancery cases, 2026-08-30/31 — ~4,000 documents retrieved across all three.

Auth is the user's live browser session on CDP 9222. None of these needs a password. Read the cookie with scripts/lm_cookie.py; never log in, and never touch stored credentials unless the user explicitly says to.

Full endpoint chains, request/response shapes and per-vendor quirks: ${CLAUDE_SKILL_DIR}/references/endpoints.md — read it before writing any fetch code.

The scripts are the interface

Do not hand-roll a harvester. These are working, resumable and manifest-writing:

Copy them into the project and adapt. Rewriting from the reference doc reproduces bugs that took hours to find.

A document that is IDENTIFIED is not a document that is RETRIEVED. Never mark a substitute ok.

Every vendor names the complaint far more often than it serves the file. Measured on the same 1,597 cases: Lex identified 99.6% and served 81.0%; Docket Alarm identified 96.4% and served 81.7%. A fallback that takes "the first document that has a file" silently returns a Rule 5.1 certification, a cover letter or a verification page — and reports success.

Conflating the two overstates coverage by 15-20 points. That is not a rounding error: it is a fabricated denominator under every downstream rate, and shipping it is more harmful than returning nothing, because nobody downstream can see it happened.

Never record a document as unavailable because YOUR SELECTION RULE failed. Enumerate the docket entries and look for a later substantive version before concluding it is not public.

This is the mirror of the law above. That one catches substitutes passed off as complaints; this one catches real complaints recorded as absent — and it is the more expensive failure, because a substitute is visible in the data while an absence looks like a fact about the world.

Delaware Chancery files the complaint confidentially, then files a redacted PUBLIC VERSION days later as a SEPARATE docket entry (Ct. Ch. R. 5.1). Every vendor rule that stops at the first complaint-tagged entry sees no document and reports failure. The public version sits typically around entry 10-15, measured as deep as entry 91, on dockets running to 277 entries.

Measured 2026-08-31/09-01 on two independent Delaware populations:

Recovering them moved coverage 82.2% -> 95.3% and added 195 confirmed cases to a study population. The pre-recovery write-up asserted "~18% of complaints are not publicly retrievable — a finding about practice, not a collection defect." That sentence was wrong in both halves.

The correct statement is "~18% are filed confidentially, and ~90% of those are publicly available as a redacted version elsewhere on the same docket." Genuine unavailability is ~4%.

Two defects that bite while recovering them

• Match the public version to a COMPLAINT, not to any document mentioning one. Public Version of Answer to Verified Complaint and Motion to Extend Deadline to File Public Version of the Verified Complaint both contain "public version" and "complaint". Requiring only those two terms returned the wrong document on 10.6% (23/218) and 10.0% (7/73) of cases across two populations — a stable rate, so expect it. Exclude answer|affirmative defense|motion|letter| certificat|opposition|brief|reply|response|stipulation|notice|transcript|order.
• A resume guard keyed on filename alone silently preserves a known-bad file. After fixing the regex, the re-fetch skipped every corrected case as already_present, because the wrong document from the first pass sat on disk under the same name. Quarantine before re-fetching.

Redaction does not degrade extraction. Measured on the recovered set: misconduct_category, plaintiff_law_firm and requester_type all came back at 0% missing, identical to the unredacted baseline. Captions, parties, statutory citations, prayer for relief and signature blocks survive; body allegations may be blacked out. Carry a source flag and check the not_stated rate before using them for content coding.

Vendor facts

• Lex Machina lists the complaint with an empty files[] on ~18.7% of cases (298/1,597) — which means it was filed confidentially, NOT that it is unavailable; see the Iron Law of Absence above. The document id and title are present; only the file is withheld. That is file_withheld, a recoverable fact worth recording — not "not found", and not a reason to substitute another document.
• Docket Alarm returns HTTP 500 with a ~40 KB HTML body when it does not hold the file. It is reproducible on a fresh cookie and never recovers, so retrying it is pure waste; at a ~15% failure rate the retry backoff was the dominant cost of a run until it was removed.
• Some Docket Alarm documents never respond at all. One hanging request plus a 300 s timeout plus an ordered ThreadPoolExecutor.map is indistinguishable from a deadlocked process. Use a 45-90 s timeout.
• Bloomberg's accessToken is HttpOnly with an ~8 minute TTL, refreshed by the page's own SPA on a timer — not by your requests. The tab must stay open; a cookie snapshot into any external store authenticates for minutes, not hours.
• Bloomberg's CSV export silently truncates at 1,000 rows — no warning in the file or the UI. Always cross-check an export against the API's own remote_count and date-slice below the cap.
• Docket Alarm's search endpoint is bot-protected: HTTP 400 outside the browser, 200 via same-origin fetch() in a logged-in tab. Per-docket pages are fine outside. Do not fight it.
• ~18% of Delaware Chancery §220 complaints are unavailable from all three vendors, and they fail on the same cases — adding two vendors to the best single one bought 17 cases out of 1,597. If coverage stalls near 82%, that is the record, not your pipeline.

Finding decisions in a docket

• The docket line names the DOCUMENT, not the holding. Entries read Memorandum Opinion; the grant/deny is inside the PDF. Only ~15/152 opinion entries mention an outcome word at all.
• Chancery disposes of cases through a Magistrate's Final Report, then an order implementing it: Granted ([Proposed] Order Implementing the Court's Post-Trial Bench Ruling). Searching only for Memorandum Opinion / Letter Decision missed 34% of cases with a decision (169 found vs 257 that exist). Always include: final report, master's report, post-trial ruling, bench ruling, opinion and order, final order and judgment.
• Never search for opinions only within cases you already classified as having one. That is circular and it hides exactly the misclassifications you are trying to find. Scan the whole population.

Red Flags — STOP If You Catch Yourself: