parsimony-boc

Bank of Canada connector — Canadian exchange rates, interest/bond yields, money & credit aggregates, CPI, commodity price indices, and the data behind BoC publications, as numeric time series via the Valet API.

Part of the parsimony-connectors monorepo. Distributed standalone on PyPI as parsimony-boc.

Connectors

Discovery model

The Valet API has no native keyword search, so discovery is a built catalog (archetype A — one live full-index call lists the whole universe):

• GET /lists/series/json is the authoritative enumeration path (15,638 series, live 2026-06-09). It self-tracks BoC additions, so the catalog stays current on each rebuild.
• Groups are first-class catalog entities. Each named panel (e.g. FX_RATES_DAILY) gets its own row keyed group:NAME — the exact string boc_fetch accepts — because group descriptions carry retrieval signal no individual series has ("Month-end, Millions of dollars"). A fetch on a group: code returns the whole panel in one request.
• The per-group membership fan-out doubles as a liveness probe: ~29 retired one-off panels that 404 on every fetch path are pruned, so the catalog never offers a panel you cannot fetch.

Every series stays fetchable by name regardless of catalog coverage — the boundary is discovery, not access.

Install

pip install parsimony-boc

Pulls in a compatible parsimony automatically. Verify discovery:

python -c "from parsimony import discover; print([p.name for p in discover.iter_providers()])"

Configuration

No configuration required — the Valet API is open and unauthenticated.

boc_search reads published catalog snapshots (default root hf://parsimony-dev/boc). Override with PARSIMONY_BOC_CATALOG_URL or catalog_url= at call time; a missing snapshot is built on demand from the live list endpoints and cached in an LRU.

Observations request limit. Valet caps the /observations request URL near 4096 bytes (roughly 100–160 comma-joined series, depending on name length). boc_fetch guards this pre-call and asks you to split the request or fetch a whole panel with group:NAME. The limit is on URL length, not series count.

Quick start

from parsimony_boc import CONNECTORS

# find a series (or a whole panel) in the catalog
hits = CONNECTORS["boc_search"](query="US dollar Canadian dollar exchange rate")
code = hits.raw.iloc[0]["code"]  # e.g. "FXUSDCAD" or "group:FX_RATES_DAILY"
# fetch observations
result = CONNECTORS["boc_fetch"](series_name=code, start_date="2024-01-01")
print(result.raw.head())

For multi-plugin composition (autoloads everything installed):

from parsimony import discover

connectors = discover.load_all()

Catalog building

scripts/build_catalog.py builds the single boc catalog from the live list endpoints and saves/pushes a snapshot:

uv run python packages/boc/scripts/build_catalog.py \
  --save file:///tmp/parsimony-catalogs/boc --push hf://parsimony-dev/boc

Provider

• Homepage: https://www.bankofcanada.ca
• Valet API docs: https://www.bankofcanada.ca/valet/docs
• Terms: https://www.bankofcanada.ca/terms/ — free reuse with attribution to the Bank of Canada. Data is © Bank of Canada; this connector and its catalog are a derived index of series identifiers and titles.

License

See LICENSE.