The right API development company in India designs the contract before writing code, plans for version two on day one, treats authorisation as a per-object question, and ships documentation that a stranger can use without a meeting. Those four habits decide whether your API stays an asset or becomes the thing nobody dares to touch.
Planning a new API, or untangling an existing one? Send us your integration map or current spec and a senior engineer will review it with you.
Why most APIs age badly
APIs rarely fail on day one. They fail slowly: a field is renamed and a mobile app that cannot be force-updated breaks; an endpoint returns every column in the table because it was quicker; a partner integration depends on an undocumented quirk; authentication is solid, yet any logged-in user can read another customer's invoice by changing an ID in the URL. Each shortcut is small. Together they make change expensive and risky.
An API is a promise to people you may never meet: your own front-end team, third-party developers, partners and future integrations. The practices below are how a disciplined team keeps that promise.
Contract-first design with OpenAPI
Contract-first means the interface is written and agreed as a machine-readable specification, usually OpenAPI for REST or a schema for GraphQL and gRPC, before implementation starts.
Why the contract comes before the code
A written contract lets front-end, mobile and partner teams start building against mock servers while the backend is still in progress. It forces early decisions about naming, pagination, error formats and required fields, while they are still easy to change. It also turns design review into a concrete conversation about a document rather than an abstract debate.
What the contract should pin down
- Consistent resource naming and HTTP method semantics.
- One pagination style (cursor-based for large or changing collections).
- A standard error body, such as RFC 9457 problem details, with stable machine-readable codes.
- Idempotency keys for operations that create payments, orders or other side effects.
- Explicit field formats: ISO 8601 timestamps with time zones, string identifiers, and minor units for monetary amounts.
Keeping code and contract honest
Specifications drift unless something enforces them. Good teams validate requests and responses against the spec in continuous integration, run contract tests between consumers and providers, and generate client SDKs from the same file so there is one source of truth.
Versioning that does not break consumers
Every successful API changes. The question is whether change is routine or a crisis.
Prefer additive change
Adding optional fields, new endpoints and new enum values (when clients were told to tolerate unknown ones) needs no new version. Removing fields, renaming them, changing types or tightening validation does.
Choose a versioning scheme and stick to it
URL path versioning
Paths such as /v1/orders are visible, cache-friendly and easy for partners to understand. They suit public and partner APIs.
Header or date-based versioning
A version header, or pinning each client to a dated API version, keeps URLs clean and allows finer-grained evolution, but demands more tooling and clear documentation.
Publish a deprecation policy
State how long old versions stay alive, announce retirements in a changelog, and signal them in responses with Deprecation and Sunset headers. Track which clients still call old versions so you can contact them directly before switching anything off.
Authentication and authorisation done properly
Authentication answers "who is calling"; authorisation answers "may they do this to this particular record". Three of the ten risks in the OWASP API Security Top 10 (2023 edition), including the top-ranked one, broken object level authorisation, are authorisation failures rather than broken logins.
- End users: OAuth 2.0 with OpenID Connect, the authorisation code flow with PKCE for browser and mobile clients, and short-lived access tokens.
- Machine-to-machine: the client credentials grant or scoped, rotatable API keys, never shared admin credentials.
- Object-level checks: every request that references an ID must verify that the caller owns or may access that object.
- Abuse controls: rate limits, request size limits and response filtering so endpoints never leak fields the caller should not see.
Documentation developers actually use
Generated reference pages are necessary but not sufficient. Useful API documentation also includes a quick-start that gets a first successful call working in minutes, a sandbox with test credentials, copy-paste examples in the languages your consumers use, a clear explanation of error codes and rate limits, and a changelog. Treat docs as part of the definition of done for every endpoint.
If you are still deciding between styles, our GraphQL vs REST decision guide walks through the trade-offs for product teams.
Evaluating an API development company in India
Ask candidates to show you a real specification they wrote (sanitised), their error model and their deprecation policy. Ask how they test authorisation rules and how they handle a breaking change requested halfway through a project. Vague answers here predict painful maintenance later.
At iJurug Soft, APIs are built by senior engineers following our Discover, Design, Build, and Launch and grow process, with fixed milestones and security and performance built in from the start. API work sits at the heart of our web, mobile, AI and cloud services, and we stay on for long-term support once your consumers depend on it. For the architectural case behind this approach, read when API-first web development makes sense.
We do not publish prices. Effort depends on the number of resources and integrations, security and compliance requirements, expected load, and whether SDKs or a developer portal are needed; we scope these with you and quote clearly.
Frequently asked questions
REST, GraphQL or gRPC: which should we use?
REST suits most public and partner APIs. GraphQL helps when many clients need different shapes of the same data. gRPC fits internal service-to-service calls where performance and strict schemas matter. Many systems combine them.
Can you take over and fix an existing API?
Yes. The usual first step is to document the API as it actually behaves, add tests around it, then fix security gaps before introducing a cleaner versioned contract.
Who owns the specification and code?
You do. Repositories, specs, cloud accounts and credentials should sit under your organisation from the first commit.
Ready to build an API your partners will enjoy integrating with? Use our contact form or write to info@ijurugsoft.com with your use case and current systems. We will review them, ask the clarifying questions and send a milestone-based proposal with a clear quote.