Fast GST Refund preparation APIs
63
AI ReadinessAI-Aware (B-)63/100
Official vendor OpenAPI document · agent-readyFinanceTaxoauth27 EndpointsREST
For Agents
Validate GST export-refund records, then build the Statement 3 and Annexure B JSON files for upload to the Indian GST portal. Returns every validation error with its path and a plain-language fix.
Use for: Validate my Statement 3 records before I upload them to the GST portal, Build the Annexure B JSON file for my GST export refund claim, Check whether a shipping bill and its BRC entry pass validation, Get the checklist for preparing a GST export refund application
Not supported: Does not handle source-system retrieval, eligibility decisions, or government submission. Use for preparing and validating GST refund Statement 3 and Annexure B files only.
The Fast GST Refund preparation API validates records and builds the Statement 3 and Annexure B JSON files a business uploads for a GST export refund claim in India. The validate action is open to everyone and returns each error with its JSON path and a plain-language fix, while the generate action needs a signed-in account that has paid for the specific claim. It also serves a stage-by-stage preparation checklist and lets you re-download or delete a generated file within its 24-hour window. It stops at file preparation: there is no source-system retrieval, eligibility decision, or government submission.
Install Jentic One Beta
Connect the Fast GST Refund preparation APIs to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Fast GST Refund preparation APIs, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Ffastgstrefund.com%2Ffastgstrefund" | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Ffastgstrefund.com%2Ffastgstrefund" | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with Fast GST Refund preparation APIs.
Validate Statement 3 and Annexure B records and get each error with its JSON path and a plain-language fix
Build the Statement 3 JSON file from export invoices, debit notes, and credit notes with their bank realisation rows
Build the Annexure B JSON file with ITC reversal totals and one row per input category and HSN or SAC code
Get a preparation checklist tailored to the refund stage and topic, from eligibility to answering a notice
Re-download or delete a generated refund file within its 24-hour window
Use Cases
Patterns agents use Fast GST Refund preparation APIs for, with concrete tasks.
★ Agent-prepared refund filing through Jentic
An AI agent assembles an exporter's invoices and bank realisation rows, runs them through the validate action to catch missing shipping bills or malformed GSTINs, applies the returned fixes, then builds the Statement 3 and Annexure B files ready for the GST portal. Because validation is free and open, the agent can iterate until the records are clean before the account is charged for the generate step.
Validate a Statement 3 payload for one GSTIN with two export invoices and their BRC rows, apply any returned fixes, then call the generate action to download the JSON file
Statement 3 preparation for service exporters
Service exporters reconcile export invoices against bank realisation certificates before claiming a refund. The API validates that each BRC or FIRC row is well formed and that documents and receipts tie together, returning errors keyed to the exact field path so a finance tool can surface them inline, then builds the portal-ready Statement 3 file.
Validate a Statement 3 payload whose receipts list two BRC rows against three service-export invoices and report any field-level errors
Annexure B input-tax-credit reconciliation
A refund claim needs Annexure B listing eligible input tax credit with reversal totals from GSTR-3B. The API checks that each invoice row carries a valid inward-supply type, HSN or SAC code, and tax split, flags blocked or ineligible credit, and builds the Annexure B JSON file so the claim's ITC section matches the returns.
Validate an Annexure B payload with reversal totals and five invoice rows, then build the file once validation passes
Pre-filing checklist automation
Before touching the portal, a preparer wants the records and checks for their current stage. The checklist endpoint takes a stage and a need and returns the records to gather, the checks to run, and the next step, so an assistant can walk a claimant through preparing, uploading, filing, or responding to a deficiency memo.
Fetch the checklist for the preparing stage and the statement3 need and list the records to gather
Key Endpoints
7 endpoints — the fast gst refund preparation api validates records and builds the statement 3 and annexure b json files a business uploads for a gst export refund claim in india.
METHOD
PATH
DESCRIPTION
GET
/api/generators/statement3
Statement 3 fields and where each value comes from
POST
/api/generators/statement3
Validate records or build the Statement 3 JSON file
GET
/api/generators/annexureb
Annexure B fields and where each value comes from
POST
/api/generators/annexureb
Validate records or build the Annexure B JSON file
GET
/api/checklist
Get records and checks for a refund stage and topic
GET
/api/generator-files/{id}
Re-download a generated file within 24 hours
DELETE
/api/generator-files/{id}
Delete a stored generated file before it expires
GET
/api/generators/statement3
Statement 3 fields and where each value comes from
POST
/api/generators/statement3
Validate records or build the Statement 3 JSON file
GET
/api/generators/annexureb
Annexure B fields and where each value comes from
POST
/api/generators/annexureb
Validate records or build the Annexure B JSON file
GET
/api/checklist
Get records and checks for a refund stage and topic
GET
/api/generator-files/{id}
Re-download a generated file within 24 hours
DELETE
/api/generator-files/{id}
Delete a stored generated file before it expires
Jentic AI Readiness Score
This API is usable in Jentic One now. Its AI-readiness score against Jentic's framework shows where it stands today and where improvements would make it even easier for agents to use.
F
Fast GST Refund preparation APIs
- AI-Aware (B-)63/100
100
Foundational Compliance63
Developer Experience & Jentic Compatibility54
AI-Readiness & Agent Experience94
Agent Usability90
Security29
AI DiscoverabilityPowered by JenticScoring Framework 1.0.0 | Scoring Engine 0.4.2
Show dimension breakdown
100
Foundational Compliance
Base layer of spec validity and structural soundness.
Grade: A+Signals: 4
98%
Lint Results
Aggregated quality score from linter diagnostics, weighted by severity.
100%
Resolution Completeness
Percentage of `$ref` references that resolve successfully.
100%
Specification Validity
Checks whether the API description parses successfully and conforms to its declared specification (e.g., OpenAPI).
100%
Structural Integrity
Structural correctness score based on schema issues using logarithmic dampening.
63
Developer Experience & Jentic Compatibility
Clarity, completeness, and ingestion readiness for developers and tooling.
Grade: B-Signals: 4
0%
Example Density
How richly the API is illustrated with examples.
100%
Example Validity
Percentage of examples that conform to their schemas.
50%
Response Coverage
Percentage of operations with complete response definitions (success, client error, server error).
100%
Tooling Readiness
Health of API ingestion, bundling, and resolution within Jentic pipelines.
54
AI-Readiness & Agent Experience
Semantic breadth, depth, and agent comprehension for AI systems.
Grade: CSignals: 4
56%
Description Coverage
Coverage of descriptions across API elements.
0%
Error Standardization
Coverage of RFC 9457 Problem Details for error responses.
100%
OperationId Quality
Coverage, uniqueness, and casing consistency of operationIds for AI inference.
58%
Summary Coverage
Coverage of summaries across operations/tags/info.
94
Agent Usability
Functional utility, complexity comfort, and AI orchestration readiness.
Grade: A+Signals: 1
94%
Complexity Comfort
Agent comfort level based on API operational and structural complexity.
90
Security
Trust, risk posture, and security compliance.
Grade: A+Signals: 1
90%
Authentication Strength
Average quality of security schemes based on authentication method strength (weakest link for OAuth2).
29
AI Discoverability
Findability, semantic richness, and reasoning readiness.
Grade: FSignals: 1
29%
Descriptive Richness
Clarity and depth of descriptions across API elements.
Score it yourself
Every API in the directory is allowlisted, so you can re-score it with no key required.
npx @jentic/api-scorecard-cli score <openapi-url>Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring the Fast GST Refund API by hand means handling its OAuth 2.1 authorization-code flow with PKCE, the 402 payment state for unpaid claims, and the validate-then-generate sequence yourself. Through Jentic you install once, import it from the API Directory, store the credential once, and your agent calls it.
Permission scoping
You choose which operations your agent may call, so it can validate records and build refund files while the file-delete operation stays out unless you add it. The validate action needs no account at all, so a read-only agent can check entries without any paid scope.
Credential isolation
Your Fast GST Refund account token is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'validate a Statement 3 payload' or 'build an Annexure B file', and Jentic returns the matching operation with its input schema so the agent calls the right endpoint without reading the reference docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Fast GST Refund preparation APIs through Jentic.
What authentication does the Fast GST Refund API use?
It uses OAuth 2.1 authorization-code flow with PKCE per its OpenAPI spec: a client registers, the person signs in with an emailed code, and the token carries the refund:generate scope. The requirements and checklist reads need no credential, while building or downloading a file needs a signed-in account that has paid for that claim.
Can I validate records before paying with the Fast GST Refund API?
Yes. The validate action needs no account and returns every error with its JSON path and a plain-language fix, so you can clean up an export-refund payload for free. Only the generate action, which returns the finished Statement 3 or Annexure B file, requires an account that has paid for the claim.
What are the rate limits for the Fast GST Refund API?
The checklist endpoint is limited to 60 requests per minute per IP and returns a Retry-After header on a 429 response. The OpenAPI spec does not state limits for the generator operations, so check the Fast GST Refund documentation for current limits before running large batches.
Is there a Fast GST Refund MCP server?
You don't need an MCP server to give your agent the Fast GST Refund API. Jentic connects it directly from the API Directory: import it, store your credential once, and your agent calls its validate, generate, and checklist operations on demand.
Can I limit what my agent is allowed to do with the Fast GST Refund API?
Yes. Write a rule that allows the validate and generate operations and the checklist read, and leave the file-delete operation out of the allowed set, so the agent can prepare and download refund files but cannot remove stored ones. Every call it makes is recorded in your Jentic One instance audit log.
How do I build a refund file with the Fast GST Refund API through Jentic?
Search Jentic for 'build a Statement 3 file', add the Fast GST Refund API from the directory, and store your account token once; your agent then validates the payload and calls the generate action to receive the JSON file. To run it on your own infrastructure, install Jentic One from its GitHub repo.
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