@cyanheads/bls-labor-mcp-server
Fetch US Bureau of Labor Statistics data — CPI, unemployment, wages, JOLTS, and more via MCP. STDIO or Streamable HTTP.
4 Tools by default · 6 with DataCanvas · 7 with opt-in drop
Overview
US labor statistics from the Bureau of Labor Statistics public API v2 and LABSTAT flat-file catalog. Resolve opaque SeriesIDs from natural language, fetch historical time-series or the latest observation, and query large multi-series results with SQL through an optional DataCanvas. Runs as a stdio process, a local Streamable HTTP server, or the public hosted endpoint above.
| Tool | Description |
|---|
bls_list_surveys | List BLS survey programs (CPI, CPS, CES, JOLTS, PPI, OEWS, …) with codes, descriptions, and calculation-support flags. |
bls_search_series | Search the BLS series catalog by natural language, survey, area, or keywords to resolve cryptic SeriesIDs. |
bls_get_series | Fetch time-series data for 1–50 BLS series by SeriesID, with optional year range and period-over-period calculations. |
bls_get_latest | Return the single most recent observation for one or more BLS series. |
bls_dataframe_describe | List canvas dataframes registered by bls_get_series or bls_dataframe_query — provenance, TTL, row count, column schema. Available when CANVAS_PROVIDER_TYPE=duckdb. |
bls_dataframe_query | Run a SELECT against canvas dataframes registered by bls_get_series or an earlier register_as. Supports JOINs, aggregates, window functions, CTEs. Available when CANVAS_PROVIDER_TYPE=duckdb. |
bls_dataframe_drop | Drop a canvas dataframe by name. Available when CANVAS_PROVIDER_TYPE=duckdb and BLS_DATAFRAME_DROP_ENABLED=true; TTL handles cleanup by default. |
Capability reference
- Optional
category filters survey programs by subject; returns codes, names, and calculation-support flags (allowsNetChange, allowsPercentChange, hasAnnualAverages).
- Backed by the BLS surveys API with monthly caching. Annual-average support is advisory; read
bls_get_series's annualAverageRows for the rows actually returned.
- Search by text or SeriesID, with optional
survey, area (substring of area, title, or SeriesID), and seasonal_adjustment; blank filters are omitted. limit is 1–50 (default 10), with offset pagination; without an area filter, equally matching national series rank first.
- Returns decoded SeriesIDs, titles, and
frequency. Follow nextOffset while truncated is true; capped: true makes totalCount a lower bound, and paging stops at the FTS candidate pool.
- Searches the offline LABSTAT index without using API quota; OE/OEWS is opt-in through
BLS_CATALOG_INCLUDE_OES. Unindexed surveys remain fetchable by SeriesID.
- Fetch 1–50 SeriesIDs per call, with a
start_year/end_year window of up to 20 years, optional calculations, and annual_average. A start alone resolves the end to the current year capped at start + 19; an end alone is rejected. One batch consumes one API query; calculations depend on survey support (CPI/PPI return percent change only).
- Returns observations with
available, preserves the raw - missing-value sentinel, and keeps valid series in mixed batches. Enrichment reports the applied year window, calculations, and annual-average rows.
- Large results spill to
dataset.name when CANVAS_PROVIDER_TYPE=duckdb; otherwise canvas_unavailable asks for a narrower window.
- Fetch the latest observation for up to 50 SeriesIDs (recommended ≤10). Each ID consumes one API query; use
bls_get_series for a more efficient multi-series batch.
- Returns successful
results[] beside per-series failed[] entries. latestObservation.available distinguishes a published value from BLS's missing-value sentinel.
- Optional
name describes one registered dataframe; omit it to list active dataframes for the tenant. Requires CANVAS_PROVIDER_TYPE=duckdb.
- Returns source tool, query params, row count, TTL (
created_at/expires_at), and column_schema; BLS columns are nullable. Registered-query types outside the canvas set (DECIMAL, HUGEINT, SMALLINT, lists) report as VARCHAR. Expired entries are removed when their canvas drop succeeds.
- Run one SELECT against registered tables, with JOINs, aggregates, window functions, or CTEs.
row_limit defaults to 1000 and caps at 10000; writes, external-file reads, and system catalogs are denied.
- Returns rows without consuming BLS API quota. Optional
register_as stages the result with a fresh TTL for chained analysis; requires CANVAS_PROVIDER_TYPE=duckdb.
- Required
name identifies the dataframe to drop. Available only with CANVAS_PROVIDER_TYPE=duckdb and BLS_DATAFRAME_DROP_ENABLED=true; TTL handles cleanup by default.
- Returns
dropped: false for a missing table. A failed drop returns retryable canvas_drop_failed and leaves the dataframe registered.
Features
Built on @cyanheads/mcp-ts-core: stdio and Streamable HTTP transports, pluggable auth (none / jwt / oauth), swappable storage (in-memory, filesystem, Supabase, Cloudflare KV/R2/D1), structured logging with optional OpenTelemetry tracing.
BLS-specific:
- BLS API v2 client with retry/backoff and daily quota tracking
- Offline series catalog search against LABSTAT flat files, indexed as an on-disk SQLite/FTS5 store — zero API quota for discovery; the OES/OEWS wage survey (~6M series) is opt-in via
BLS_CATALOG_INCLUDE_OES
- Typed error contracts for BLS-specific failure modes — quota exhaustion, locked database, calculations not supported
- Period-over-period net/percent-change calculations via BLS's own server-side flag, consistent with BLS's published numbers
- Optional DataCanvas spillover (DuckDB) for large multi-series result sets — schema discovery and SQL access without re-querying the API
Agent-friendly output:
- Provenance — canvas-spilled results carry a
dataset.name handle plus row count and expiry; bls_search_series echoes effectiveQuery, catalogSize, and whether the FTS candidate pool was capped
- Graceful partial failure —
bls_get_latest returns per-item failed[] (seriesId + error) alongside successful results[] instead of failing the whole batch; bls_get_series keeps valid series when another SeriesID in the same batch is invalid or empty
- Discriminated outputs — every observation carries an
available boolean for BLS's - missing-value sentinel, so callers branch on a typed field instead of parsing raw values
- Actionable notices —
enrichment.notice explains empty results, canvas spillover, and unavailable data with concrete next steps (e.g. using bls_search_series to verify a SeriesID)
Getting started
Public Hosted Instance
A public instance is available at https://bls-labor.caseyjhand.com/mcp — no installation required. Point any MCP client at it via Streamable HTTP:
{
"mcpServers": {
"bls-labor-mcp-server": {
"type": "streamable-http",
"url": "https://bls-labor.caseyjhand.com/mcp"
}
}
}
Self-Hosted / Local
Add the following to your MCP client configuration file. A free BLS API key unlocks 500 queries/day — register at bls.gov/developers. The server works without a key at 25 req/day.
{
"mcpServers": {
"bls-labor-mcp-server": {
"type": "stdio",
"command": "bunx",
"args": ["@cyanheads/bls-labor-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info",
"BLS_API_KEY": "your-key-here"
}
}
}
}
Or with npx (no Bun required):
{
"mcpServers": {
"bls-labor-mcp-server": {
"type": "stdio",
"command": "npx",
"args": ["-y", "@cyanheads/bls-labor-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info",
"BLS_API_KEY": "your-key-here"
}
}
}
}
Or with Docker:
{
"mcpServers": {
"bls-labor-mcp-server": {
"type": "stdio",
"command": "docker",
"args": ["run", "-i", "--rm", "-e", "MCP_TRANSPORT_TYPE=stdio", "-e", "BLS_API_KEY=your-key-here", "ghcr.io/cyanheads/bls-labor-mcp-server:latest"]
}
}
}
For Streamable HTTP, set the transport and start the server:
MCP_TRANSPORT_TYPE=http MCP_SESSION_MODE=stateless MCP_HTTP_PORT=3010 BLS_API_KEY=... bun run start:http
Prerequisites
- Bun v1.4.0 or higher (or Node.js v24+).
- A free BLS API v2 key — register at bls.gov/developers. Grants 500 queries/day; the server also works without a key at 25 req/day.
Installation
- Clone the repository:
git clone https://github.com/cyanheads/bls-labor-mcp-server.git
- Navigate into the directory:
- Install dependencies:
- Configure environment:
Configuration
All configuration is validated at startup via Zod schemas in src/config/server-config.ts.
| Variable | Description | Default |
|---|
BLS_API_KEY | BLS v2 API key. Optional — 25 req/day without, 500 req/day with. Register free at bls.gov/developers. | — |
BLS_BASE_URL | BLS API v2 base URL. | https://api.bls.gov/publicAPI/v2 |
BLS_CATALOG_BASE_URL | LABSTAT flat-file base URL. Override to point at a local mirror. | https://download.bls.gov/pub/time.series |
BLS_CATALOG_DB_PATH | On-disk SQLite catalog index — queried on demand and persisted across restarts. Empty uses an in-memory DB (re-harvested each boot). Mount a volume here in containers. | .cache/bls-catalog.db |
BLS_CATALOG_CACHE_TTL_HOURS | Catalog freshness window in hours — re-harvest once the index is older, checked at startup and hourly while running. | 168 (7 days) |
BLS_CATALOG_INCLUDE_OES | Include the OES/OEWS wage survey (~6M series / ~1.2 GB; multi-minute first harvest). Off by default — OES series stay fetchable by ID. | false |
BLS_OBSERVATIONS_MIRROR_ENABLED | Serve observations from a local SQLite mirror instead of the live API (requires a one-time bootstrap — see below). | false |
BLS_DATASET_TTL_SECONDS | Per-dataframe TTL for canvas-registered tables, in seconds. | 86400 (24 h) |
BLS_DATAFRAME_DROP_ENABLED | Expose bls_dataframe_drop. TTL handles cleanup by default. | false |
CANVAS_PROVIDER_TYPE | Set to duckdb to enable DataCanvas tabular spillover for large result sets. | none |
MCP_TRANSPORT_TYPE | Transport: stdio or http. | stdio |
MCP_HTTP_PORT | HTTP server port. | 3010 |
MCP_SESSION_MODE | Session mode. This server uses stateless; valid schema values are auto, stateful, and stateless. Schema-default auto resolves to stateful. | stateless |
MCP_AUTH_MODE | Auth mode: none, jwt, or oauth. | none |
MCP_LOG_LEVEL | Log level (RFC 5424). | info |
LOGS_DIR | Directory for log files (Node.js only). | <project-root>/logs |
OTEL_ENABLED | Enable OpenTelemetry instrumentation. | false |
OTEL_EXPORTER_OTLP_ENDPOINT | Base OTLP URL for traces and metrics; signal-specific endpoints override it. | — |
OTEL_EXPORTER_OTLP_LOGS_ENDPOINT | Opt-in OTLP log endpoint. The base URL never enables log export. | — |
LOG_TOOL_FAILURE_PAYLOADS | Log failed-call arguments and results, redacted by key name; secrets in free-form values remain. | false |
LOG_TOOL_FAILURE_PAYLOAD_MAX_BYTES | UTF-8 byte cap per logged failure payload. | 16384 |
See .env.example for the full list of optional overrides.
Observation mirror (optional)
For high-volume workloads, an opt-in local mirror serves bls_get_series / bls_get_latest from an embedded SQLite store instead of the BLS API — eliminating the 500/day quota cap. It is off by default. To enable:
-
Set BLS_OBSERVATIONS_MIRROR_ENABLED=true (and review the BLS_OBSERVATIONS_MIRROR_* vars in .env.example).
-
Run the one-time bootstrap out-of-band — it downloads the full LABSTAT observation set and can take a while:
node dist/services/bls-observations/subprocess.js --init
The mirror harvests every survey in the catalog's survey list — OE included, whatever BLS_CATALOG_INCLUDE_OES says — so it covers CM and CI too (about 55 MB of cm.data.* / ci.data.* files). An incremental refresh reads only files published after the mirror's last one, so a mirror bootstrapped before CM and CI joined picks each file up at its next BLS publication; until then those series come from the live API when fallback is on. Until the bootstrap completes, requests fall back to the live API (unless BLS_OBSERVATIONS_MIRROR_FALLBACK_LIVE=false). When a live fallback fails — quota exhausted, BLS unreachable — the series the mirror served are still returned, and enrichment.notice names each unserved SeriesID with the failure's reason and recovery. Mirror rows carry no BLS calculations: with calculations: true, a mirror-served series comes back without calculation fields, enrichment.calculationsApplied is false, and the notice names it. On HTTP transport, an incremental refresh runs on the BLS_OBSERVATIONS_MIRROR_REFRESH_CRON schedule. In containers, mount a persistent volume at BLS_OBSERVATIONS_MIRROR_PATH.
Upgrading an existing mirror. A mirror bootstrapped before sentinel rows were stored is missing the periods BLS publishes with its - missing-value marker. Opening such a mirror clears its sync checkpoint once, so the next refresh re-reads every LABSTAT file and fills them in — no operator action beyond letting that refresh run, and it takes as long as a full read. The mirror keeps serving throughout.
Running the server
Local development
-
Build and run:
bun run rebuild
bun run start:stdio
bun run start:http
-
Run checks and tests:
bun run devcheck
bun run test
bun run lint:mcp
Docker
docker build -t bls-labor-mcp-server .
docker run --rm -e BLS_API_KEY=your-key -e MCP_TRANSPORT_TYPE=http -p 3010:3010 bls-labor-mcp-server
The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/bls-labor-mcp-server. OpenTelemetry peer dependencies are installed by default — build with --build-arg OTEL_ENABLED=false to omit them.
Project structure
| Directory | Purpose |
|---|
src/index.ts | createApp() entry point — registers tools and initializes services. |
src/config | Server-specific environment variable parsing and validation with Zod. |
src/mcp-server/tools | Tool definitions (*.tool.ts). |
src/services/bls-api | BLS API v2 service — batch fetch, latest-value GET, surveys metadata. |
src/services/bls-catalog | LABSTAT flat-file catalog — offline series index and search. |
src/services/bls-observations | Optional LABSTAT observation mirror — embedded SQLite store, ingester, and refresh subprocess. |
src/services/bls-periods | Annual-average period semantics (M13/Q05/S03) shared by the API and mirror paths. |
src/services/canvas-bridge | DataCanvas bridge — dataframe registration, SQL gate, lifecycle management. |
docs/design.md | Full tool surface specification, service architecture, and error contracts. |
tests/ | Unit and integration tests mirroring src/. |
Development guide
See CLAUDE.md for development guidelines and architectural rules. The short version:
- Handlers throw, framework catches — no
try/catch in tool logic
- Use
ctx.log for request-scoped logging, ctx.state for tenant-scoped storage
bls_search_series is the anchor tool — design workflows to call it before the API tools
- Wrap BLS API calls: validate raw → normalize to domain type → return output schema; never fabricate missing fields
Contributing
Issues are welcome. Run checks and tests before submitting:
bun run devcheck
bun run test
License
Apache-2.0 — see LICENSE for details.