{"openapi":"3.1.0","info":{"title":"Canada GST/HST Threshold Watch API","version":"0.1.0","description":"Checks quarterly taxable supplies against the GST/HST small-supplier threshold ($30,000 in a single calendar quarter or over four consecutive quarters), shows what the CRA text says about when registration takes effect, which reporting period applies by annual taxable supplies ($1.5 million and $6 million breakpoints), whether the quick method limit ($400,000) is met, the electronic filing and...\n\nEvery operation is read-only or compute-only. The same tools are available over MCP (streamable HTTP) at https://ca-gst-thresholds.connectorbay.com/mcp.\n\nDisclaimer: General information only, not legal, tax, accounting or payment advice. Canada GST/HST Threshold Watch is an independent tool: it is not affiliated with, endorsed by or operated by any government body, central bank, standards body or scheme operator. Rates, thresholds and rules change; check the cited official source and confirm with a qualified professional before you rely on a result.","contact":{"name":"Unify Dynamics LLC","email":"agent@connectorbay.com","url":"https://connectorbay.com/ca-gst-thresholds/docs"},"termsOfService":"https://connectorbay.com/ca-gst-thresholds/terms"},"servers":[{"url":"https://ca-gst-thresholds.connectorbay.com"}],"externalDocs":{"url":"https://connectorbay.com/ca-gst-thresholds/docs"},"security":[{},{"bearer":[]}],"components":{"securitySchemes":{"bearer":{"type":"http","scheme":"bearer","description":"Optional. A Pro API key raises rate limits; no credentials are required."}},"schemas":{"Error":{"type":"object","properties":{"ok":{"const":false},"error":{"type":"object"}}}}},"paths":{"/v1/tools/check_small_supplier":{"post":{"operationId":"check_small_supplier","summary":"Test quarterly taxable supplies against the 30,000 single-quarter and four-consecutive-quarter small-supplier rules and ","description":"Test quarterly taxable supplies against the 30,000 single-quarter and four-consecutive-quarter small-supplier rules and show the headroom. Use for \"My taxable sales were 9000, 11000, 12000 and 9500 in the last four quarters: am I still a small supplier?\".","tags":["tools"],"requestBody":{"required":true,"content":{"application/json":{"schema":{"properties":{"quarters":{"description":"Worldwide taxable supplies per calendar quarter (yours plus associated persons, before GST/HST, excluding financial services, capital property and goodwill), oldest first, 1 to 4 decimal strings such as \"9000.00\"","items":{"type":"string"},"title":"Quarters","type":"array"},"latest_quarter_end":{"description":"Last day of the most recent quarter in the list: 03-31, 06-30, 09-30 or 12-31, as YYYY-MM-DD","title":"Latest Quarter End","type":"string"},"public_service_body":{"default":false,"description":"true to use the 50,000 threshold that the CRA states for public service bodies (default false: 30,000)","title":"Public Service Body","type":"boolean"}},"required":["quarters","latest_quarter_end"],"title":"check_small_supplierArguments","type":"object"}}}},"responses":{"200":{"description":"Tool result. `ok: true` on success; `ok: false` with a structured `error` (provider_unavailable, upstream_error, bad_input) when the tool could not answer.","content":{"application/json":{"schema":{"type":"object","additionalProperties":true}}}},"422":{"description":"Arguments failed validation","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}},"429":{"description":"Rate limit exceeded (see Retry-After)","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}}},"x-read-only":true}},"/v1/tools/registration_deadline":{"post":{"operationId":"registration_deadline","summary":"When registration takes effect and the 29-day application window after the threshold is crossed in one quarter or over f","description":"When registration takes effect and the 29-day application window after the threshold is crossed in one quarter or over four quarters. Use for \"I passed 30,000 on 2026-08-14 in one quarter: what date must I be registered by?\".","tags":["tools"],"requestBody":{"required":true,"content":{"application/json":{"schema":{"properties":{"trigger":{"description":"single_quarter (exceeded 30,000 within one calendar quarter) or four_quarters (exceeded it over four consecutive quarters)","title":"Trigger","type":"string"},"on_date":{"description":"single_quarter: the date of the supply that took you over 30,000. four_quarters: the last day of the quarter in which the four-quarter total exceeded 30,000. YYYY-MM-DD","title":"On Date","type":"string"}},"required":["trigger","on_date"],"title":"registration_deadlineArguments","type":"object"}}}},"responses":{"200":{"description":"Tool result. `ok: true` on success; `ok: false` with a structured `error` (provider_unavailable, upstream_error, bad_input) when the tool could not answer.","content":{"application/json":{"schema":{"type":"object","additionalProperties":true}}}},"422":{"description":"Arguments failed validation","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}},"429":{"description":"Rate limit exceeded (see Retry-After)","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}}},"x-read-only":true}},"/v1/tools/assigned_reporting_period":{"post":{"operationId":"assigned_reporting_period","summary":"Annual, quarterly or monthly GST/HST reporting period by annual taxable supplies (1.5 million and 6 million breakpoints)","description":"Annual, quarterly or monthly GST/HST reporting period by annual taxable supplies (1.5 million and 6 million breakpoints), with election options and filing deadline rules. Use for \"My annual taxable supplies are 2,300,000: what GST/HST reporting period applies?\".","tags":["tools"],"requestBody":{"required":true,"content":{"application/json":{"schema":{"properties":{"annual_taxable_supplies":{"description":"Annual taxable supplies as a plain decimal string with a dot, for example 2300000.00","title":"Annual Taxable Supplies","type":"string"}},"required":["annual_taxable_supplies"],"title":"assigned_reporting_periodArguments","type":"object"}}}},"responses":{"200":{"description":"Tool result. `ok: true` on success; `ok: false` with a structured `error` (provider_unavailable, upstream_error, bad_input) when the tool could not answer.","content":{"application/json":{"schema":{"type":"object","additionalProperties":true}}}},"422":{"description":"Arguments failed validation","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}},"429":{"description":"Rate limit exceeded (see Retry-After)","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}}},"x-read-only":true}},"/v1/tools/quick_method_eligible":{"post":{"operationId":"quick_method_eligible","summary":"Check annual supplies including GST/HST against the quick method limit of 400,000 and describe the credit and election r","description":"Check annual supplies including GST/HST against the quick method limit of 400,000 and describe the credit and election routes. Use for \"My sales including HST were 385,000 last year: can I use the quick method?\".","tags":["tools"],"requestBody":{"required":true,"content":{"application/json":{"schema":{"properties":{"annual_supplies_including_tax":{"description":"Annual worldwide taxable supplies including GST/HST (yours plus associates) as a decimal string, for example 385000.00","title":"Annual Supplies Including Tax","type":"string"}},"required":["annual_supplies_including_tax"],"title":"quick_method_eligibleArguments","type":"object"}}}},"responses":{"200":{"description":"Tool result. `ok: true` on success; `ok: false` with a structured `error` (provider_unavailable, upstream_error, bad_input) when the tool could not answer.","content":{"application/json":{"schema":{"type":"object","additionalProperties":true}}}},"422":{"description":"Arguments failed validation","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}},"429":{"description":"Rate limit exceeded (see Retry-After)","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}}},"x-read-only":true}},"/v1/tools/quebec_small_supplier_check":{"post":{"operationId":"quebec_small_supplier_check","summary":"The same small-supplier test with Revenu Quebec wording for GST and QST, including activities that must register whateve","description":"The same small-supplier test with Revenu Quebec wording for GST and QST, including activities that must register whatever the sales. Use for \"I sell in Quebec: do my quarterly sales make me a small supplier for GST and QST?\".","tags":["tools"],"requestBody":{"required":true,"content":{"application/json":{"schema":{"properties":{"quarters":{"description":"Worldwide taxable supplies per calendar quarter (yours plus associates, including zero-rated, excluding GST/HST/QST, financial services and capital property), oldest first, 1 to 4 decimal strings","items":{"type":"string"},"title":"Quarters","type":"array"},"latest_quarter_end":{"description":"Last day of the most recent quarter in the list: 03-31, 06-30, 09-30 or 12-31, as YYYY-MM-DD","title":"Latest Quarter End","type":"string"}},"required":["quarters","latest_quarter_end"],"title":"quebec_small_supplier_checkArguments","type":"object"}}}},"responses":{"200":{"description":"Tool result. `ok: true` on success; `ok: false` with a structured `error` (provider_unavailable, upstream_error, bad_input) when the tool could not answer.","content":{"application/json":{"schema":{"type":"object","additionalProperties":true}}}},"422":{"description":"Arguments failed validation","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}},"429":{"description":"Rate limit exceeded (see Retry-After)","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}}},"x-read-only":true}},"/v1/tools/efile_epay_rules":{"post":{"operationId":"efile_epay_rules","summary":"Mandatory electronic filing and the 10,000 electronic payment rule for GST/HST, with a check of a payment amount. Use fo","description":"Mandatory electronic filing and the 10,000 electronic payment rule for GST/HST, with a check of a payment amount. Use for \"My GST/HST remittance is 12,400: does it have to be paid electronically?\".","tags":["tools"],"requestBody":{"required":true,"content":{"application/json":{"schema":{"properties":{"payment_amount":{"anyOf":[{"type":"string"},{"type":"null"}],"default":null,"description":"Amount of the remittance or payment to the Receiver General as a decimal string; omit to get the rules only","title":"Payment Amount"},"on_date":{"anyOf":[{"type":"string"},{"type":"null"}],"default":null,"description":"Date the rule must apply on, YYYY-MM-DD (defaults to today in UTC; modelled from 2024-01-01)","title":"On Date"}},"title":"efile_epay_rulesArguments","type":"object"}}}},"responses":{"200":{"description":"Tool result. `ok: true` on success; `ok: false` with a structured `error` (provider_unavailable, upstream_error, bad_input) when the tool could not answer.","content":{"application/json":{"schema":{"type":"object","additionalProperties":true}}}},"422":{"description":"Arguments failed validation","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}},"429":{"description":"Rate limit exceeded (see Retry-After)","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}}},"x-read-only":true}},"/v1/tools/threshold_watch_report":{"post":{"operationId":"threshold_watch_report","summary":"Weekly summary: headroom to the 30,000 lines, a run-rate projection of when a line is crossed, and what the rules say ha","description":"Weekly summary: headroom to the 30,000 lines, a run-rate projection of when a line is crossed, and what the rules say happens then. Use for \"Where am I against the 30,000 small-supplier line this quarter and when might I cross it?\".","tags":["tools"],"requestBody":{"required":true,"content":{"application/json":{"schema":{"properties":{"previous_quarters":{"description":"Taxable supplies of the completed calendar quarters just before the current one, oldest first, 0 to 3 decimal strings (empty list for a new business)","items":{"type":"string"},"title":"Previous Quarters","type":"array"},"current_quarter_to_date":{"description":"Taxable supplies so far in the current calendar quarter as a decimal string","title":"Current Quarter To Date","type":"string"},"as_of_date":{"anyOf":[{"type":"string"},{"type":"null"}],"default":null,"description":"Date the quarter-to-date figure is up to, YYYY-MM-DD (defaults to today in UTC)","title":"As Of Date"},"public_service_body":{"default":false,"description":"true to use the 50,000 public service body threshold (default false)","title":"Public Service Body","type":"boolean"}},"required":["previous_quarters","current_quarter_to_date"],"title":"threshold_watch_reportArguments","type":"object"}}}},"responses":{"200":{"description":"Tool result. `ok: true` on success; `ok: false` with a structured `error` (provider_unavailable, upstream_error, bad_input) when the tool could not answer.","content":{"application/json":{"schema":{"type":"object","additionalProperties":true}}}},"422":{"description":"Arguments failed validation","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}},"429":{"description":"Rate limit exceeded (see Retry-After)","content":{"application/json":{"schema":{"$ref":"#/components/schemas/Error"}}}}},"x-read-only":true}}}}