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Fly.io Extensions API

The Fly.io Extensions API is a provider-facing HTTP interface that enables third-party services to integrate with the Fly.io platform as extension providers. When a Fly.io user provisions an extension via the flyctl CLI, Fly.io forwards the provisioning request to the provider's API with details about the requesting organization, and the provider responds with environment variable configuration that is attached to the target application.

Fly.io Extensions API is one of 9 APIs that fly-io publishes on the APIs.io network, described by a machine-readable OpenAPI specification and an AsyncAPI event-driven specification.

Tagged areas include Extensions, Integration, Partner, Platform, and Provisioning. The published artifact set on APIs.io includes API documentation, an OpenAPI specification, and an AsyncAPI specification.

This API exposes 4 operations across 2 paths, and defines 4 schemas. It is described by OpenAPI 3.1.0, at version 1.0.

Requests are made against 2 base URLs: https://{provider_base_url}, https://api.fly.io.

4 operations 2 paths 4 schemas 1 DELETE1 GET1 PATCH1 POST

Metadata

The identity and technical contract details declared by the specification.

Specification
OpenAPI 3.1.0
API Version
1.0
Base URL
https://api.example.com
Authentication
HTTP Bearer, HTTP Bearer, API Key
Terms of Service
Resource Areas
1

Authentication & Security 3

Fly.io Extensions API declares 3 security schemes for authenticating requests. It accepts HTTP bearer tokens (flySharedSecret). It accepts HTTP bearer tokens (oauthBearerAuth). An API key is passed in the header as X-Fly-Signature (webhookHmac). By default, every request must be authenticated.

  • flySharedSecret — Shared secret provided by Fly.io to the extension provider. Fly.io includes this secret in an Authorization Bearer header on all requests to the provider's API…
  • oauthBearerAuth — Fly.io OAuth access token obtained from the token exchange endpoint.
  • webhookHmac — HMAC-SHA256 signature of the raw request body, computed using the webhook signing secret. Recipients must verify this signature before processing the payload.

Paths & Operations 4

Across 2 paths, the API surfaces 4 operations — 1 DELETE, 1 GET, 1 PATCH, 1 POST. Each is listed below with its method, path, parameters, and response codes.

Extensions 4

Operations for provisioning, retrieving, and updating extension resource instances. Fly.io calls these endpoints on the provider's server when users interact with extensions via t…

POST
/extensions
Provision an extension resource
provisionExtension body → 200400401
GET
/extensions/{extension_id}
Get extension resource details
getExtension 1 param → 200401404
PATCH
/extensions/{extension_id}
Update an extension resource
updateExtension 1 param body → 200400401404
DELETE
/extensions/{extension_id}
Delete an extension resource
deleteExtension 1 param → 200401404

Schemas 4

The contract defines 4 schemas that model the data the API accepts and returns. The most detailed are ProvisionRequest (10 properties), ProvisionResponse (4 properties), ExtensionResource (4 properties), ErrorResponse (2 properties). Each schema is shown below with its type and property counts.

ExtensionResource
object
Full details about a provisioned extension resource.
4 properties
ProvisionRequest
object
Request body sent by Fly.io to the provider when provisioning or updating an extension resource.
10 properties 7 required
ErrorResponse
object
A standard error response.
2 properties
ProvisionResponse
object
Response body returned by the provider after successfully provisioning or updating an extension resource.
4 properties 2 required

Specification

The full machine-readable OpenAPI contract behind this narrative.

Source

fly-io-extensions-api-openapi.yml Raw ↑

Other APIs fly-io publishes across the network.

Fly.io Machines API
Fly.io GraphQL API
fly-io Apps API
fly-io OAuth API
fly-io SSO API
fly-io Tokens API
fly-io Volumes API
fly-io Webhooks API