# Topl (Apparatus)

> Topl was an impact-technology company (founded 2017, Houston, Texas) that built a
> proof-of-stake blockchain for proving ethical and sustainable practices. In late 2023 it
> rebranded to Apparatus and repositioned around Thunder, a Bitcoin Layer 2. The company
> appears to have wound down: the last artifact of any kind shipped 2024-09-26, every
> documentation and API host now fails to resolve, and the topl.co domain lapsed and was
> re-registered by an unrelated owner on 2024-12-30.

This file is generated by API Evangelist from the artifacts in this repository. It is a
third-party profile, not a Topl publication. Read it as a historical record of a contract that
still exists and a service that no longer runs.

## What still exists

- The full machine-readable contract: 38 proto3 files, 6 gRPC services, 30 RPCs, 138 messages,
  saved verbatim in `grpc/` from https://buf.build/seanattopl/topl-protobuf-specs (HTTP 200,
  2026-08-30).
- First-party SDKs on Maven Central (`co.topl`, Scala), npm (`bramblts`, `topl_common`,
  `brambljs`), and pub.dev (`brambldart`, `topl_common`).
- Node and indexer container images on Docker Hub under `toplprotocol`.
- Archived developer documentation at https://github.com/Topl/Knowledge-Base (all 10 public
  Topl repositories are archived).

## What does not

- `testnet.topl.tech:443` — the documented public gRPC endpoint. NXDOMAIN.
- `docs.topl.co`, `docs.apparatus.live`, `topl.services`, `brambldart.docs.topl.co`,
  `legal.apparatus.live`, `bcarbon.topl.co` — NXDOMAIN.
- `apparatus.live` — no response.
- `topl.co` — resolves, but the domain was re-registered 2024-12-30 and now serves unrelated
  third-party content. Do not treat it as Topl.
- `github.com/Topl/Bifrost`, `/BramblJS`, `/BramblTS`, `/protobuf-specs`, `/ts_topl_common` —
  404. The source for the node and the SDKs has been removed.

## The API surface

Two gRPC surfaces, both defined in `grpc/`:

- **NodeRpc** (`co.topl.node.services`, `grpc/node/services/bifrost_rpc.proto`) — the Bifrost
  full node. `BroadcastTransaction`, `CurrentMempool`, `CurrentMempoolContains`,
  `FetchBlockHeader`, `FetchBlockBody`, `FetchTransaction`, `FetchBlockIdAtHeight`,
  `FetchBlockIdAtDepth`, `SynchronizationTraversal` (stream), `FetchNodeConfig` (stream),
  `FetchEpochData`.
- **Genus** (`co.topl.genus.services`, `grpc/genus/genus_rpc.proto`) — the indexer, split into
  `BlockService`, `TransactionService`, `NetworkMetricsService` and `TokenService`.

The node also implements the standard gRPC Health Checking Protocol (`grpc.health.v1`).

## Semantics an agent needs

- **Auth**: none at the transport. Reads are open; writes are authorized cryptographically
  inside the transaction by Quivr propositions and proofs. See
  `authentication/topl-authentication.yml`.
- **Pagination**: none. Bulk reads use gRPC server streaming.
- **Idempotency**: no idempotency key. Replay is prevented by the ledger's double-spend rule.
- **Reversibility**: `BroadcastTransaction` has no cancel, void or reverse operation and no
  published window. The only reversal in the contract is `TransactionService.dropIndex`,
  which undoes an indexer-local index. See `conventions/topl-conventions.yml`.
- **Rate limits**: never published.
- **Errors**: gRPC status codes; no error reference survives, so no error catalog is claimed.

## Artifacts in this repository

- `grpc/` — the verbatim protobuf contract, plus `grpc/topl-protobuf.yml` (index and services)
- `packages/topl-packages.yml` — every first-party distribution with its version and date
- `data-model/topl-data-model.yml` — the Brambl entity graph derived from the contract
- `conventions/topl-conventions.yml` — auth style, pagination, idempotency, reversibility
- `authentication/topl-authentication.yml` — the Quivr authorization model
- `conformance/topl-conformance.yml` — proto3, gRPC, grpc.health.v1, protoc-gen-validate
- `lifecycle/topl-lifecycle.yml` — the wind-down timeline and its evidence
- `changelog/topl-changelog.yml` — reconstructed release history
- `cli/topl-cli.yml` — brambl-cli
- `mcp/topl-mcp.yml` — a derived candidate tool list; no MCP server exists
- `well-known/topl-well-known.yml` — the .well-known probe (nothing served)
- `plans/topl-plans-pricing.yml`, `rate-limits/topl-rate-limits.yml` — honest zeros

## Corrections

If you represent Topl or Apparatus and any of this is wrong, open an issue on this repository
or email info@apievangelist.com. Corrections, re-scores and removal are free.