For developers and engineering teams

Formation is a few API calls away

A clean REST API, official SDKs, a full sandbox, and signed webhooks let you build entity formation, registered agent, and compliance right into your product. Skip standing up a fifty-state filing operation and ship the feature in an afternoon.

REST and SDKs Full sandbox Signed webhooks
The filing platform, built for developers REST API and SDKs Idempotency and retries 4.9 from 8,200+ reviews SOC 2 Type II
4 SDKs
Node, Python, Ruby, and Go, typed and tested
Sandbox
Full test environment, no state fees
Webhooks
Signed, retried, and idempotent by event id
Versioned
Pinned by date, you upgrade on your schedule
What you would otherwise build

Formation looks like a feature. Then you scope it

Adding entity formation to your product sounds like a weekend project until you list what it needs: an integration with every secretary of state, a registered agent in fifty states, retries when a filing bounces, deadline tracking per entity, and a support path when a state kicks something back. That is an operations company, and it competes for the roadmap you would rather ship.

The API gives you all of it behind a handful of endpoints. You call create, subscribe to a webhook, and File.Business runs the filing, the agent network, and the compliance tracking underneath your product.

Building it yourself
  • An integration per secretary of state
  • A fifty-state agent network to run
  • Retry and reconciliation logic
  • Deadline tracking per entity
  • Months off your own roadmap
On the File.Business API
  • One endpoint to form an entity
  • The agent network already there
  • Idempotency and retries built in
  • Compliance events by webhook
  • Your team stays on your product
Your language, a few lines

Form an entity, in the SDK you already use

The same call in every official SDK. Switch languages to see it in yours.

create-entity.jsPOST /v1/entities

One call forms the entity, sets the registered agent, and returns an id you track by webhook. Run it against the sandbox with test keys, no state fees.

How you integrate

From sandbox key to filing in production

Five steps, in the right order. Select one to see the detail.

Step 1

Generate sandbox keys

Sign up and issue sandbox keys in a click. The sandbox mirrors production, so everything you build against it works the same when you switch to live.

Keys in a click, no fees.
Sandbox keys: ISSUED
Mirrors production
Ready to call
Step 2

Install the SDK

Add the SDK for your stack, drop in your key, and you have a typed client with retries and pagination handled. Or call the REST API directly from anything that speaks JSON.

One install, a typed client.
SDK: INSTALLED
Client configured
Ready to build
Step 3

Call create

One call forms the entity, sets the registered agent, and returns an id and a status. Pass an idempotency key so a retry never doubles a filing.

Create the entity in a few lines. API reference.
create: 201
Idempotency key set
Entity id returned
Step 4

Handle webhooks

Subscribe to events like filing.completed and compliance.due, verify the signature, and update your app. Events are retried with backoff and carry an id for idempotent handling.

Signed events, retried, idempotent.
Webhook: VERIFIED
Retried with backoff
App in sync
Step 5

Swap to live keys and go

When it works in sandbox, switch to live keys and your same code files real entities. Version pinning means future changes never break the integration you shipped.

Same code, live filings. Read the docs.
Live: ENABLED
Version pinned
Filing for real
How this compares for a builder

Built as a platform, not a form with a hook

Most options make you build the reliability yourself. Here is the difference.

CapabilityFile.BusinessBuild in-houseScrape state portalsBasic filer API
Official typed SDKsNoNoSome
Sandbox without state feesNoNoVaries
Signed, retried webhooksYou build itNoBasic
Idempotency on writesYou build itNoNo
Fifty-state agent behind one callNoNoAdd-on
Transparent, published pricingInternal costFragilePer call

The honest version. This is infrastructure, not legal advice, and complex structures still involve your customers' own counsel. What File.Business provides is a reliable formation, registered agent, and compliance API so you build the feature instead of the plumbing. Compare on the comparison hub.

BosAI for developers

An operator who knows the integration playbook

Ask in plain English. BosAI knows the endpoints, the events, and the reliability model.

BosAIDeveloper workspace, Northwind

If my create call times out and I retry, do I get two LLCs?

No, as long as you send the same idempotency key on the retry. The API recognizes it and returns the original result instead of filing again, so a timeout plus a retry never doubles a state filing. The SDKs set and reuse the key for you by default.

How do I know when a filing actually clears the state?

Subscribe to the filing.completed webhook. We send a signed payload when the state confirms, retried with backoff if your endpoint is down, and every event has an id so you can dedupe. You update your app off the event rather than polling.

Will an API change break what I ship today?

No. The API is versioned by date, and your integration stays pinned to the version you built on. Breaking changes ship under a new version with a changelog, and you upgrade when you choose. See the API docs.
From an engineer

A feature we scoped in quarters, shipped in days

We priced out building formation ourselves and it was a fifty-state integration plus an agent network plus a filing support team, easily a quarter of roadmap. We integrated the File.Business API in a sprint instead. The idempotency and signed webhooks meant we could trust it against real filings, and version pinning means it will not break under us. Our users form entities inside our app and never know there is anything behind it.
Staff engineer
Fintech platform
One sprint
to a working integration
Idempotent
safe against real filings
Pinned
will not break under us

Representative composite based on developer outcomes. Nothing here is legal or tax advice; consult your professionals for your situation.

For the questions developers actually ask

Straight answers on SDKs, webhooks, and reliability

What can I build with the API?
Entity formation, EINs, registered agent setup, annual reports, foreign qualification, amendments, dissolutions, and compliance status, all as REST endpoints. If it is a filing File.Business performs, it is available programmatically, so you can offer formation and compliance natively inside your product. See the API docs.
Which SDKs do you offer?
Official SDKs for Node, Python, Ruby, and Go, with typed models, automatic retries, and pagination handled for you. If your stack is not listed, the REST API is standard JSON over HTTPS and works from any language.
Is there a sandbox?
Yes. A full sandbox environment lets you create test entities, trigger filing state changes, and receive webhooks without touching production or paying state fees. When you are ready, switching to live is a key change.
How do webhooks work?
You subscribe to events like entity.formed, filing.submitted, filing.completed, and compliance.due, and we send signed payloads to your endpoint. Webhooks are retried with backoff, and every event carries an id so you can make handling idempotent.
How do you handle idempotency and retries?
Write endpoints accept an idempotency key, so a retried request never creates a duplicate filing, and the SDKs retry transient failures automatically. Combined with signed, retried webhooks, that makes integrations safe to build against real state filings.
How is the API versioned?
The API is versioned by date, and breaking changes ship under a new version while your integration stays pinned to the one you built on. You upgrade on your own schedule, and changelogs describe exactly what changed.
How do you keep it secure?
API keys with scoped permissions, signed webhooks, TLS everywhere, and SOC 2 Type II controls. You can issue separate keys for sandbox and live and rotate them without downtime.
How do I get access?
Sign up and generate sandbox keys, or talk to us about production and volume terms. If you would rather not build the front end, the same platform is available as white-label. Pricing is published and transparent. Talk to us.
SDKs, sandbox, and webhooks, ready

Build formation in an afternoon

Generate sandbox keys, install the SDK for your stack, and form your first entity today. Read the docs, or talk with our team about production and volume.

SOC 2 Type II · Not a law firm · State fees passed through at cost