> ## Documentation Index > Fetch the complete documentation index at: https://docs.recurso.dev/llms.txt > Use this file to discover all available pages before exploring further. # Get GSTR-3B Return > Assemble the GSTR-3B self-declared summary for a tax period from the same invoices and credit notes as GSTR-1, in readable form and in GSTN upload JSON. Builds the GSTR-3B summary return for one calendar month from the same period inputs as [GSTR-1](/api-reference/gst/gstr1) — finalized invoices and refund credit notes — so the two returns agree by construction. Table 3.1(a) outward taxable supplies are reported **net of the period's credit notes** (GSTR-3B reports net supplies; GSTR-1 lists notes separately), and Table 3.2 lists inter-state supplies to unregistered persons per place of supply. The billing engine holds no purchase-side data, so the inward reverse-charge row (3.1d) and the input-tax-credit table are emitted with zeros for schema completeness. Zero-rated (3.1b), nil/exempt (3.1c) and non-GST (3.1e) rows are also zero — the engine bills taxable supplies only. The taxpayer or their CA completes those sections before filing. As with GSTR-1 the response carries `data` (readable names, **paise**) and `gov_schema` (GSTN GSTR-3B JSON, rupees). The seller GSTIN comes from your [GST configuration](/api-reference/gst/get-config). See the [GST returns guide](/compliance/gst-returns) for the filing workflow. ## Parameters | Parameter | Type | Required | Description | | ----------- | ------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | `month` | integer | Yes | Calendar month of the tax period, `1`–`12` (query) | | `year` | integer | Yes | Year of the tax period, `2017`–`2100` (query) | | `entity_id` | string (UUID) | No | File for one legal entity's GSTIN (Multi-Entity Books). Omit to include all invoices under the tenant's primary / default GST configuration (query). See [List Entities](/api-reference/entities/list) | ## Example Request ```bash theme={null} curl "https://api.recurso.dev/v1/india/gstr3b?month=6&year=2026" \ -H "Authorization: Bearer $API_KEY" ``` ## Response The example is the same June 2026 period as the GSTR-1 page: gross outward taxable value ₹12,500 less one ₹1,000 credit note gives net ₹11,500 in 3.1(a). ```json theme={null} { "data": { "tenant_id": "2b9e1c44-7d3a-4f6b-8e21-5c0d9a7f1b33", "month": 6, "year": 2026, "outward_taxable": { "taxable_value": 1150000, "igst": 45000, "cgst": 81000, "sgst": 81000 }, "zero_rated": { "taxable_value": 0, "igst": 0, "cgst": 0, "sgst": 0 }, "nil_exempt": { "taxable_value": 0, "igst": 0, "cgst": 0, "sgst": 0 }, "inward_reverse_charge": { "taxable_value": 0, "igst": 0, "cgst": 0, "sgst": 0 }, "non_gst": { "taxable_value": 0, "igst": 0, "cgst": 0, "sgst": 0 }, "inter_state_unregistered": [ { "place_of_supply": "27", "taxable_value": 250000, "igst": 45000 } ], "invoice_count": 2, "credit_note_count": 1 }, "gov_schema": { "gstin": "29AABCT1332L1ZM", "ret_period": "062026", "sup_details": { "osup_det": { "txval": 11500, "iamt": 450, "camt": 810, "samt": 810, "csamt": 0 }, "osup_zero": { "txval": 0, "iamt": 0, "camt": 0, "samt": 0, "csamt": 0 }, "osup_nil_exmp": { "txval": 0, "iamt": 0, "camt": 0, "samt": 0, "csamt": 0 }, "isup_rev": { "txval": 0, "iamt": 0, "camt": 0, "samt": 0, "csamt": 0 }, "osup_nongst": { "txval": 0, "iamt": 0, "camt": 0, "samt": 0, "csamt": 0 } }, "inter_sup": { "unreg_details": [ { "pos": "27", "txval": 2500, "iamt": 450 } ], "comp_details": [], "uin_details": [] }, "itc_elg": { "itc_net": { "iamt": 0, "camt": 0, "samt": 0, "csamt": 0 } } } } ``` ## Fields ### `data` — readable return (minor units) Each Table 3.1 row is a values object with `taxable_value`, `igst`, `cgst`, `sgst` in paise. | Field | Type | Description | | ---------------------------- | ------------- | ------------------------------------------------------------------------------------------------------------------------------------------ | | `tenant_id` | string (UUID) | Owning tenant | | `month` / `year` | integer | The tax period | | `outward_taxable` | object | Table 3.1(a): outward taxable supplies, net of the period's credit notes | | `zero_rated` | object | Table 3.1(b): zero-rated exports / SEZ. Always zero — not modelled on invoices | | `nil_exempt` | object | Table 3.1(c): nil-rated and exempt supplies. Always zero | | `inward_reverse_charge` | object | Table 3.1(d): inward supplies liable to reverse charge. Always zero — no purchase data | | `non_gst` | object | Table 3.1(e): non-GST outward supplies. Always zero | | `inter_state_unregistered[]` | array | Table 3.2: inter-state supplies to unregistered persons, one row per `place_of_supply` with `taxable_value` and `igst`. A subset of 3.1(a) | | `invoice_count` | integer | Finalized invoices the summary was built from | | `credit_note_count` | integer | Credit notes netted into 3.1(a) | ### `gov_schema` — GSTN GSTR-3B upload JSON (rupees) | Field | Type | Description | | ------------- | ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `gstin` | string | Seller GSTIN from the GST configuration for the requested entity; empty when none is configured | | `ret_period` | string | Return period as `MMYYYY` | | `sup_details` | object | Table 3.1 rows `osup_det`, `osup_zero`, `osup_nil_exmp`, `isup_rev`, `osup_nongst`, each with `txval`, `iamt`, `camt`, `samt`, `csamt` | | `inter_sup` | object | Table 3.2: `unreg_details[]` (`pos`, `txval`, `iamt`); `comp_details[]` and `uin_details[]` are always empty arrays — the engine bills regular customers only | | `itc_elg` | object | Table 4: `itc_net` with `iamt`, `camt`, `samt`, `csamt`, all `0` — ITC is completed by the filer | Cess (`csamt`) is not modelled and is always `0`. ## Errors | Status | Code | When | Fix | | ------ | ------------------- | ---------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------- | | `400` | `validation_failed` | `month` is missing or outside `1`–`12`, `year` is missing or outside `2017`–`2100`, or `entity_id` is not a valid UUID | Pass both period parameters as integers and a valid entity UUID | | `401` | `unauthorized` | Missing or invalid API key / session | Send `Authorization: Bearer $API_KEY` | | `500` | `internal_error` | Building the summary from the period's invoices failed | Retry; contact support if it persists | | `503` | `internal_error` | GSTR-3B export is not configured on this deployment | Enable the GSTR service on the API | Errors use the standard envelope — see [Errors](/api-reference/errors). ## OpenAPI ````yaml GET /v1/india/gstr3b openapi: 3.1.0 info: title: Recurso API version: 1.0.0 description: | The Recurso billing engine REST API. Authenticate by passing your API key as a bearer token: Authorization: Bearer Obtain an API key by registering a tenant via `POST /auth/register`. All authenticated endpoints live under the `/v1` prefix. Mutating endpoints support idempotency via the `Idempotency-Key` header. license: name: MIT identifier: MIT servers: - url: https://billing.example.com description: >- Example deployment — substitute the base URL of your own Recurso deployment. security: - bearerAuth: [] tags: - name: System description: Health, version, and API metadata - name: Auth description: Tenant registration - name: Plans description: Product catalog plans - name: Customers description: Customer management - name: Subscriptions description: Subscription lifecycle - name: Invoices description: Invoices, PDFs, and Indian GST e-invoicing - name: Coupons description: Discounts - name: Usage description: Metered usage events - name: Credit Notes description: Customer credits - name: Quotes description: Quote-to-invoice lifecycle - name: Webhooks description: Webhook endpoint management and event feed - name: Analytics description: Revenue analytics - name: Checkout description: Public hosted checkout for invoices - name: Payments description: Payment order creation - name: Inbound Webhooks description: Receivers for payment-gateway callbacks (Razorpay, Stripe) - name: Customer Portal description: Customer-facing portal — magic-link auth and session-scoped data - name: Developer description: API key management - name: Account description: Tenant account settings - name: Finance description: Ledger accounts, entries, reconciliation, and revenue recognition - name: Settings description: Tax (GST) and e-invoicing (IRP) configuration - name: Consents description: Consent records for RBI-compliant recurring billing - name: Referrals description: Customer referral program - name: Gifts description: Gift subscriptions - name: Mandates description: UPI Autopay mandates - name: Offline Payments description: Virtual accounts and manually recorded payments - name: Organizations description: Multi-entity organizations grouping several tenants - name: Accounting description: QuickBooks / Xero accounting integrations - name: Churn description: Churn risk scoring and alerts - name: Cancel Flows description: Configurable retention flows shown at cancellation time - name: Dunning description: Dunning analytics and multi-channel dunning campaigns paths: /v1/india/gstr3b: get: tags: - Settings summary: GSTR-3B summary return for a tax period description: > Assembles the GSTR-3B self-declared summary from the same period inputs as GSTR-1 (finalized invoices and refund credit notes), so the two returns are consistent by construction. Table 3.1(a) outward supplies are net of the period's credit notes; Table 3.2 reports inter-state supplies to unregistered persons per place of supply. Purchase-side sections (inward reverse charge, ITC) are emitted as zeros — the billing engine holds no purchase data; the taxpayer/CA completes them before filing. Returns readable sections plus a `gov_schema` object in the GSTN GSTR-3B JSON shape (official field names, amounts in rupees). operationId: getGSTR3B parameters: - name: month in: query required: true schema: type: integer minimum: 1 maximum: 12 description: Calendar month of the tax period. - name: year in: query required: true schema: type: integer minimum: 2017 maximum: 2100 description: Year of the tax period. - $ref: '#/components/parameters/EntityIdQuery' responses: '200': description: The GSTR-3B return, readable and in government JSON shape. content: application/json: schema: type: object properties: data: type: object description: Readable GSTR-3B sections (amounts in minor units). gov_schema: type: object description: >- GSTN GSTR-3B upload JSON (official field names, amounts in rupees). '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' components: parameters: EntityIdQuery: name: entity_id in: query required: false description: >- Legal entity to scope the tax config to (Multi-Entity Books). Omit for the tenant's primary entity / default config. schema: type: string format: uuid responses: BadRequest: description: The request body or parameters are invalid. content: application/json: schema: $ref: '#/components/schemas/Error' Unauthorized: description: Missing or invalid credentials (API key or session cookie). content: application/json: schema: $ref: '#/components/schemas/Error' schemas: Error: type: object required: - error properties: error: type: object description: Structured error detail. required: - code - message properties: code: type: string description: Stable machine-readable error code. examples: - validation_failed - unauthorized - forbidden - not_found - conflict - rate_limited - internal_error - invalid_api_key - key_mode_mismatch - over_refund - invoice_not_paid - invoice_already_paid message: type: string description: Human-readable explanation. securitySchemes: bearerAuth: type: http scheme: bearer bearerFormat: API key description: >- Tenant API key obtained from `POST /auth/register` or `POST /v1/developer/keys`. ````