SimTX API v24/Account service

The SimTX account service is the HTTPS JSON API at https://auth.simtx.net. It signs users in, issues credentials, lists the game servers that are online, and exchanges a credential for the single-use game ticket that a game server accepts during the handshake. It also serves a small set of public, unauthenticated endpoints.

A client that only receives does not need the account service at all, apart from discovering a server address. A client that transmits or publishes to the extension catalog does.

Endpoint summary

Method	Path	Authentication	Purpose
POST	/api/v1/device/authorizations	None	Start a device login
POST	/api/v1/device/token	None	Poll for credentials
POST	/api/v1/device/refresh	None	Rotate the credential pair
GET	/api/v1/servers	Bearer	List online game servers
POST	/api/v1/game-tickets	Bearer	Obtain a game ticket
GET	/api/v1/status	None	Service status
GET	/api/v1/profiles	None	Search public profiles
GET	/api/v1/profiles/{handle}	None	Read one public profile
GET	/api/v1/releases	None	Published transmitter releases
GET	/downloads/transmitter-update.properties	None	Update manifest
GET	/downloads/{filename}	None	Release download
GET	/api/v1/network-test/ping	None	Latency probe
POST	/api/v1/network-test/upload	None	Upload probe

Endpoints under /api/v1/me/, /api/v1/auth/ and the device approval endpoints (/api/v1/device/verify, /api/v1/device/deny, GET /api/v1/device/authorizations/{userCode}) belong to the account website. They require a browser session cookie and a CSRF token and do not accept bearer credentials. Administrative and internal endpoints are not part of the public API and are not documented here.

Conventions

• Transport. HTTPS only. Request and response bodies are application/json (UTF-8) unless stated otherwise. Timestamps are ISO-8601 strings in UTC, for example 2026-10-24T12:00:00Z.
• Field names are camelCase. Unknown response fields may be added in future and must be ignored by clients.
• Caching. Every /api/ response carries Cache-Control: no-store.
• Timeouts. The official client uses a 5 second connect timeout and a 10 second request timeout. Those values are a sensible default.
• Request IDs. A client may send an X-Request-ID header matching [A-Za-z0-9._-]{8,64}. The service echoes it in the response header and in error bodies. Without one, the service generates a UUID. Quote it when reporting a problem.

Authentication

Authenticated endpoints read a bearer credential from the Authorization header. The header must begin with exactly Bearer (capital B, one space).

GET /api/v1/servers HTTP/1.1
Host: auth.simtx.net
Authorization: Bearer stx_at1_0f3c…

Two kinds of credential are accepted as a bearer:

• an access credential obtained through device login, or
• a personal credential created by the user on the account website. It is intended for bots, scripts and other headless software. The user chooses its scopes and expiry, and the secret is displayed once.

Credential formats

All SimTX credentials are opaque strings: a fixed prefix followed by 64 lowercase hexadecimal characters (32 random bytes). They are not JWTs and contain no readable data. A client must store them as given and must never parse them.

Prefix	Credential	Lifetime	Used for
stx_dc1_	Device code	10 minutes	Polling /api/v1/device/token
stx_at1_	Access credential	10 minutes	Bearer for authenticated endpoints
stx_rt1_	Refresh credential	30 days idle, 180 days absolute; rotates on every use	/api/v1/device/refresh
stx_pc1_	Personal credential	Chosen by the user, at most 1 year	Bearer for authenticated endpoints
stx_gt1_	Game ticket	60 seconds, single use	The game server handshake

A user code (shown to the person signing in) has the form ABCD-EF23: eight characters from the alphabet ABCDEFGHJKLMNPQRSTUVWXYZ23456789, with a hyphen after the fourth. The alphabet omits I, O, 0 and 1, so nobody has to wonder which one they are looking at.

Storing credentials

• Keep the access credential in memory only. It expires after ten minutes in any case.
• Persist the refresh credential (or a personal credential) in the operating system's credential store, such as Keychain, Windows Credential Manager or Secret Service.
• There is no client-side logout endpoint. Signing out means deleting the stored refresh credential. Users revoke devices and personal credentials on the account website.
• Never send an access, refresh or personal credential to a game server. Game servers only ever see game tickets.

Errors

Every error response has the same JSON body:

{
  "code": "credential_invalid",
  "message": "The access credential is invalid or expired",
  "fieldErrors": {},
  "requestId": "3d7f0c1e-5b2a-4a8e-9a77-1f0f6f5d2b10"
}

Field	Type	Description
code	string	Stable, machine-readable error code. Branch on this.
message	string	Human-readable English text. May change; do not parse.
fieldErrors	object	Additional string values keyed by name. For example, device polling reports the required poll interval as fieldErrors.interval.
requestId	string	The request ID. See Conventions.

Common error codes

HTTP	code	Meaning
401	credential_missing	No Authorization header, or it does not start with Bearer .
401	credential_invalid	The bearer credential is unknown, expired, revoked, or belongs to an account that is not active. Refresh once and retry; if that fails, sign in again.
400	scope_invalid	A requested scope is not a known permission.
400	ticket_request_invalid	See Game tickets.
400	authorization_pending, slow_down, expired_token, access_denied, invalid_grant	Device polling states. See Device login.
401	invalid_grant, refresh_reuse_detected	Refresh failures. See Device login.
404	profile_not_found, release_artifact_not_found, release_manifest_unavailable	The requested public resource does not exist.
429	rate_limited	A rate-limit bucket is exhausted. See below.
500	internal_error	Unexpected server failure. Retry later with backoff.

Rate limits

Rate limits are counted per client IP address, per bucket, in fixed one-minute windows aligned to the UTC minute. A request over the limit receives 429 with code rate_limited. No Retry-After header is sent, so wait for the next minute boundary.

Bucket	Endpoint(s)	Requests per minute
device-create	POST /api/v1/device/authorizations	20
device-poll	POST /api/v1/device/token	120
device-refresh	POST /api/v1/device/refresh	120
server-directory	GET /api/v1/servers	120
game-ticket	POST /api/v1/game-tickets	120
public-directory	GET /api/v1/profiles	60
public-profile	GET /api/v1/profiles/{handle}	120
public-releases	GET /api/v1/releases	120
release-manifest	GET /downloads/transmitter-update.properties	240
release-download	GET /downloads/{filename}	240
network-test-ping	GET /api/v1/network-test/ping	60
network-test-upload	POST /api/v1/network-test/upload	144

GET /api/v1/status is not rate limited.

See also

• SimTX API v24/Device login: the sign-in flow for desktop and command-line software.
• SimTX API v24/Game tickets: how a credential becomes a game server connection.
• SimTX API v24/Permissions: scopes and numeric capabilities.