# synapse

**Repository Path**: mirrors_getsentry/synapse

## Basic Information

- **Project Name**: synapse
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: Apache-2.0
- **Default Branch**: main
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2025-07-17
- **Last Updated**: 2026-02-22

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Synapse

Synapse is a set of services that supports routing for the cell-based architecture at Sentry. Its primary responsibility is to ensure incoming traffic from the public internet is correctly routed to the designated cell internally based on the organization routing key. Synapse ensures that the system appears as a single unified service to end users and other components at Sentry — they are unaware of the underlying cellular model or that multiple cells exist.


### Components

Synapse consists of 3 main components:

- **Locator**:  A read-only service that maintains the mapping of organizations to cells and synchronizes data with the control plane. The locator can operate either as a standalone service that exposes a HTTP API, or as an embedded component inside the proxy layer to make in-process decisions directly. See the [locator docs](locator/README.md).

- **Proxy**: A high-performance L7 proxy that routes incoming requests to the destination service inside a cell. It uses the locator internally to dynamically resolve the cell based on the organization. The proxy supports both traditional HTTP request/response traffic and long-lived streaming connections via server sent events. See the [proxy docs](proxy/README.md).

- **Ingest Router**: A stateless, fan-out router that sits between relay-pop and relay, which embeds cellular information inside the project config object, enabling POPs to route ingestion traffic to the correct upstream Relay for each project. See the [ingest-router docs](ingest-router/README.md).


### Metrics

Metrics emitted by Synapse are described [here](METRICS.md).


### Development

Run `make setup` once to install the pre-commit hook (runs format/lint checks before each commit).

| Task | Command |
|------|---------|
| Build | `make build` |
| Test | `make test` |
| Lint | `make lint` |
| Format | `make fmt` |
| Auto-fix | `make fix` |
| Full CI simulation | `make ci` |

`make test` manages Docker automatically (it starts a fake GCS server on port 4443 for backup route integration tests). Running `cargo test` directly will fail those GCS related tests unless the server is already running.

When adding or removing metrics, run `cargo run synapse sync-metrics` to regenerate `METRICS.md`, otherwise CI will fail.

**Running services locally** (each requires a config file — see `example_config_*.yaml`):

```sh
make run-locator
make run-proxy
make run-ingest-router
make run-mock-control-api   # mock control plane API for locator dev
make run-mock-relay-api     # mock relay API for ingest-router dev
make run-echo-server        # simple echo server for proxy dev
```