H1b
H-1B MCP — US H-1B visa sponsorship & wage data from DOL Labor Condition Application (LCA)…
What can you do with H1b?
h1b_employer_sponsorship(employer, year?)— filing count, salary range,h1b_salary(job_title, employer?, city?, year?, limit?)— real disclosedh1b_top_sponsors(job_title, city?, year?, limit?)— employers ranked by
Install
Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).
claude mcp add --transport http h1b 'https://gateway.pipeworx.io/h1b/mcp'
{
"mcpServers": {
"h1b": {
"type": "http",
"url": "https://gateway.pipeworx.io/h1b/mcp"
}
}
}
Documentation
From the project's README on GitHub, refreshed weekly. Links open on GitHub.
Contents
@pipeworx/h1b
US H-1B visa sponsorship and wage data from DOL Labor Condition Application (LCA) disclosures — "does company X sponsor H-1B", "what does role Y pay at company X", "who sponsors the most data engineers in Austin".
Part of Pipeworx — an MCP gateway connecting AI agents to 1881+ live data sources. This is an independent, unofficial integration — not affiliated with, endorsed by, or published by the upstream provider.
Tools
h1b_employer_sponsorship(employer, year?)— filing count, salary range, top titles/locations for an employer.h1b_salary(job_title, employer?, city?, year?, limit?)— real disclosed base-salary stats + a sample of records for a role.h1b_top_sponsors(job_title, city?, year?, limit?)— employers ranked by filing count for a role, with median salary.
Argument names/shapes are unchanged from before fleet #2514 — only where the answer is served from changed.
Two-tier source (fleet #2514)
Primary: DOL's own LCA disclosure files for recent federal fiscal
years. Older years come from h1bdata.info. Every DOL-sourced response
carries data_as_of.
Fallback: h1bdata.info, a third-party aggregator of the same DOL data.
Used only when the requested year is outside the local mirror's loaded
window, or the DB is unreachable — this pack must never regress below its
pre-#2514 behavior while the mirror is partially backfilled. Every response
carries a source field saying which one actually answered it; the pack
never silently swaps sources without saying so.
A fallback zero is never presented as a confident "no" (fleet #3198).
If the DB read itself failed this call (no credentials, a timeout, or a
transient error — source_status: "primary_unreachable"), a zero-row
h1bdata.info answer returns sponsors_h1b: null and a message saying the
primary source was never actually consulted, not disproven. Only when the
primary source answered fine but the year is genuinely outside its loaded
window (source_status: "out_of_window") does a fallback zero stand as a
real (if third-party, lag/rename-prone) "no". dbRpc retries once
immediately on a transient failure before falling back at all, so a single
network blip doesn't by itself demote a mirror-covered query to the weaker
source. h1b_employer_sponsorship's matched_employers is also now ranked
exact-match first (then name-contains variants), each tagged name_match,
since the employer-name match is a plain substring and can legitimately
pull back more than one distinct legal name.
Why a mirror at all: the live h1bdata.info scrape caps at 20,000 raw
HTML table rows per query (fetchLcaLive's safety cap) — for any employer
or job title with more filings than that, salary stats and top_sponsors
rankings were being computed from a silently truncated, non-representative
slice. For DOL-sourced years, top_sponsors aggregates over
every matching row, with no such cap (see total_all_filings in
222_h1b_lca_disclosures.sql's h1b_top_sponsors RPC, a window-function sum
computed before the row-limit).
Fiscal year, not calendar year, on the local mirror. DOL's files are
organized by federal fiscal year (Oct 1 - Sep 30); year is passed straight
through as that fiscal year when served locally. h1bdata.info's own "year"
filter is a different, unverified semantic (most likely calendar year) — a
query answered by each path for the same year value is not guaranteed to
cover the identical 12 months. The response's note/source fields say
which happened; this is a real, disclosed difference, not papered over.
PERSONAL-DATA RULE (mandatory, local-copy rule — task #2514)
DOL's own record layout (LCA_Record_Layout_FY2024_Q4.pdf, read in full
2026-09-29) carries named-individual contact fields that are never read
into the mirror — scripts/h1b-lca-transform.py uses an ALLOWLIST of
source columns (not a blocklist), so a column DOL adds later is excluded by
default:
EMPLOYER_POC_{LAST,FIRST,MIDDLE}_NAME,EMPLOYER_POC_EMAIL,EMPLOYER_POC_PHONE— the employer's named point of contact.AGENT_ATTORNEY_{LAST,FIRST,MIDDLE}_NAME,AGENT_ATTORNEY_EMAIL_ADDRESS,AGENT_ATTORNEY_PHONE— the attorney/agent representing the employer.PREPARER_{LAST,FIRST,MIDDLE}_NAME,PREPARER_EMAIL— whoever filled out the form.
DOL's file already excludes the foreign worker's own name/address (DOL's own
cover note names only "Attorney's FEIN and Attorney's State Bar Number" as
withheld — no worker PII was ever in this dataset). Kept: EMPLOYER_NAME /
TRADE_NAME_DBA and employer address down to city/state/country (no
street), plus job/wage/worksite fields — this identifies the employer making
a mandatory public disclosure, not a private individual.
Data source
https://www.dol.gov/agencies/eta/foreign-labor/performance— DOL OFLC performance-data page, links each fiscal year's disclosure file.- Verified live 2026-09-29 (not documented by DOL, reverse-engineered from
decision_datedistributions — the record-layout PDF's cover text is WRONG about this for closed years):- The current, still-open fiscal year's latest quarterly file is
cumulative from Oct 1 of that FY through the end of the named
quarter (
FY2026_Q3.xlsxspans Oct 2025-Jun 2026). Lives athttps://www.dol.gov/media/LCA_Disclosure_Data_<label>.xlsx. Load only the single latest file for an open year. - Once a fiscal year closes, DOL's archived quarterly files for that
year are each discrete —
decision_datefalls only within that one quarter (verified:FY2025_Q3.xlsx= Apr-Jun 2025 only,FY2025_Q4.xlsx= Jul-Sep 2025 only — NOT the full year, despite the record-layout PDF literally stating "Reporting Period: October 1 ... through September 30" on its cover page). Lives athttps://www.dol.gov/sites/dolgov/files/ETA/oflc/pdfs/LCA_Disclosure_Data_<label>.xlsx. A closed year needs all four of its quarter files for full coverage; they do not overlap.
- The current, still-open fiscal year's latest quarterly file is
cumulative from Oct 1 of that FY through the end of the named
quarter (
- No auth, no rate limit observed. US federal administrative data — public domain.
Ingest harness
supabase/migrations/222_h1b_lca_disclosures.sql—h1b_lca_disclosurestable +h1b_lca_ingest_runsbookkeeping + three RPCs (h1b_lca_search,h1b_top_sponsors,h1b_lca_coverage). RLS on;anon/authenticatedhave no grants;service_roleonly.scripts/h1b-lca-transform.py— streams one.xlsxfile row-by-row viaopenpyxl(read_only=True)(never buffers a whole workbook — a full fiscal year runs 80-250MB uncompressed), allowlist-selects the non-personal columns, and computesbase_salary_annualfromWAGE_RATE_OF_PAY_FROM/WAGE_UNIT_OF_PAY(Hour×2080, Week×52, Bi-Weekly×26, Month×12, Year×1).scripts/h1b-lca-upsert.sh— per file: download (tries the current-year URL, falls back to the closed-year archive URL), transform,\copyinto a staging table, thenINSERT ... ON CONFLICT (case_number) DO UPDATE(CASE_NUMBERis DOL's own stable per-application id — no synthetic key needed)..github/workflows/h1b-lca-refresh.yml—workflow_dispatchonly (deliberately noschedule:— Bruce's "supa stagger" rule queues big Supabase loads one at a time, overnight, on purpose; GitHub'sschedule:trigger has also been unreliable fleet-wide since ~2026-09-09). Defaultfilesinput is the "latest 8 quarters" the task asked for, with verified zero overlap and zero gap:2026:FY2026_Q3(cumulative, = FY2026 Q1+Q2+Q3) +2025:FY2025_Q1,2025:FY2025_Q2,2025:FY2025_Q3,2025:FY2025_Q4(four discrete quarters) +2024:FY2024_Q4(one discrete quarter) — 6 files, Jul 2024-Jun 2026.
Observed sizes/rows (live, 2026-09-29 — proof-of-transform run, not a full load)
| File | Bytes | Real data rows |
|---|---|---|
| FY2026_Q3 (cumulative, Oct'25-Jun'26) | 251,850,891 | 437,496 |
| FY2025_Q4 (Jul-Sep'25 only) | 79,134,156 | 118,580 |
| FY2025_Q3 (Apr-Jun'25 only) | 143,867,250 | 238,425 |
| FY2025_Q2 (Jan-Mar'25 only) | 106,951,050 | not downloaded — est. ~175k by size ratio |
| FY2025_Q1 (Oct-Dec'24 only) | 87,690,398 | not downloaded — est. ~145k by size ratio |
| FY2024_Q4 (Jul-Sep'24 only) | 83,056,843 | not downloaded — est. ~120k by size ratio |
Estimated total for the default 6-file load: ~1.2-1.3M rows, ~650MB of
xlsx downloads. Every .xlsx sheet carries a large trailing block of
genuinely-empty phantom rows past the real data (e.g. FY2026_Q3's declared
sheet dimension is 1,032,736 rows for 437,496 real ones) — this is a DOL
export artifact, not a bug in the transform script; those rows are dropped
and counted as "without CASE_NUMBER".
Known source data-quality trap
DOL's raw WAGE_RATE_OF_PAY_FROM/WAGE_UNIT_OF_PAY occasionally disagree in
a way that produces an absurd base_salary_annual (an observed FY2026_Q3
row annualizes to ~$453M — almost certainly a unit-entry error by the filer,
kept verbatim rather than "corrected", same discipline as sba_loans
keeping literal duplicate/conflicting source rows). median-based stats are
resistant to this; a max in a response can occasionally show one of these
outliers — that is the source data, not a mirror defect.
Gotchas
- The live DOL
.xlsxheader spells the H-1B-dependent-employer columnH_1B_DEPENDENT(underscore) — the record-layout PDF spells itH-1B_DEPENDENT(hyphen). Trust the live file; verified againstFY2026_Q3.xlsx2026-09-29. - Do not load more than one file per still-open fiscal year, and do not load a closed year's file without all four of its quarters — see "Data source" above. Getting this wrong either duplicates rows (double-counting an overlapping cumulative + discrete file) or leaves silent gaps.
Quick Start
Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):
{
"mcpServers": {
"h1b": {
"url": "https://gateway.pipeworx.io/h1b/mcp"
}
}
}
What this endpoint actually serves
tools/list at https://gateway.pipeworx.io/h1b/mcp returns the tools in the table
above plus the shared Pipeworx meta-tools — ask_pipeworx,
discover_tools, search_within, remember/recall and the rest of the
gateway-wide set. So the tool count you see is larger than this table: a
single-pack endpoint currently lists roughly 30 shared tools alongside the
pack's own. The connection's initialize response states its exact scope, and
is the authoritative answer for a given day.
This is deliberate, not multiplexing by accident. The meta-tools are what let a
scoped connection answer a question this pack does not cover — via
ask_pipeworx, which routes across the whole catalog — without you adding a
second MCP server. There is currently no way to mount a pack endpoint without
them; if the extra schemas cost you more context than the routing is worth,
connect to the full gateway once rather than to several pack endpoints.
Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:
{
"mcpServers": {
"pipeworx": {
"url": "https://gateway.pipeworx.io/mcp"
}
}
}
Both URLs reach the same gateway and the same 1881+ data sources. The
only difference is which pack's tools are listed directly; ask_pipeworx
reaches all of them from either one.
No MCP client? Call it over HTTP
curl -X POST https://gateway.pipeworx.io/v1/tools/h1b_employer_sponsorship \
-H 'Content-Type: application/json' \
-d '{"employer":"Google","year":2024}'
No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/h1b_employer_sponsorship. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.
Standalone (no gateway account)
This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:
{
"mcpServers": {
"h1b": {
"command": "npx",
"args": ["-y", "@pipeworx/mcp-h1b"]
}
}
}
Or run it directly to confirm it starts:
npx -y @pipeworx/mcp-h1b
It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call
for only this pack's tools — none of the shared meta-tools the gateway
connection above adds. Same source, same tools, no ask_pipeworx routing.
Using with ask_pipeworx
Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:
ask_pipeworx({ question: "your question about H1b data" })
The gateway picks the right tool and fills the arguments automatically.
More
License
MIT
Frequently asked questions
What is H1b?
H-1B MCP — US H-1B visa sponsorship & wage data from DOL Labor Condition Application (LCA)…
How do I install H1b?
It runs as a remote server. In Claude Code: claude mcp add --transport http h1b 'https://gateway.pipeworx.io/h1b/mcp'. For other clients, paste the JSON configuration from this page into their MCP settings.
Does H1b need an API key?
Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.
Is H1b open source?
Yes. Its code is on GitHub under the MIT license.
Who maintains H1b?
It is published by pipeworx-io. AI.tn lists it but does not maintain or endorse it.
From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.