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Try the Sandbox

The Sandbox is a public EvidentSource server at sandbox.evidentsource.com. This page walks from nothing to a command, a read, and a look at the past.

1. The endpoints

Section titled “1. The endpoints”
  • HTTP: https://sandbox.evidentsource.com
  • gRPC: https://sandbox.evidentsource.com:50051, over TLS. Keep the https://: SDKs choose TLS from it.
  • MCP, for AI agents: see MCP for AI agents

No account or API key is needed.

2. Look around

Section titled “2. Look around”

List the databases on the server:

Terminal window
curl -H 'Accept: application/json' https://sandbox.evidentsource.com/
{"databases":["…"]}

Open the same URL in a browser for the web UI: each database, its State Views and State Changes, and its transaction log.

3. Publish an example

Section titled “3. Publish an example”

The Sandbox starts empty of applications, so bring one. Set up the TodoMVC example creates a database of your own, builds TodoMVC’s components, and publishes them. Come back here when install.sh finishes.

The rest of this page uses a database named todomvc-yourname.

4. Issue a command

Section titled “4. Issue a command”
Terminal window
curl -X POST "https://sandbox.evidentsource.com/api/v1/db/todomvc-yourname/latest/state-changes/create-todo/v1" \
  -H 'Content-Type: application/json' \
  -d '{"todoId": "3f0b5a0e-1c2d-4e5f-8a9b-0c1d2e3f4a5b", "title": "Try EvidentSource", "effectiveTimestamp": "2026-09-17T00:00:00Z"}'

The reply is the transaction the command committed, and the revision it reached. See Issuing commands.

5. Read a State View

Section titled “5. Read a State View”
Terminal window
curl -L "https://sandbox.evidentsource.com/api/v1/db/todomvc-yourname/latest/state-views/todo-list/v1"

You should see your todo in the list. See Reading state views.

6. Look at the past

Section titled “6. Look at the past”

Complete the todo:

Terminal window
curl -X POST "https://sandbox.evidentsource.com/api/v1/db/todomvc-yourname/latest/state-changes/toggle-todo/v1" \
  -H 'Content-Type: application/json' \
  -d '{"todoId": "3f0b5a0e-1c2d-4e5f-8a9b-0c1d2e3f4a5b", "effectiveTimestamp": "2026-09-17T00:05:00Z"}'

Now read the list at latest, where the todo is complete, and at the revision create-todo reported, where it isn’t yet:

Terminal window
curl -L "https://sandbox.evidentsource.com/api/v1/db/todomvc-yourname/latest/state-views/todo-list/v1"
curl "https://sandbox.evidentsource.com/api/v1/db/todomvc-yourname/1/state-views/todo-list/v1"

Nothing was overwritten. Every read runs at a revision, and every earlier revision stays readable. See Bi-temporal reads.

7. Use an SDK

Section titled “7. Use an SDK”

The SDKs give you typed clients, and the libraries for writing your own State Changes and State Views. See Connecting with an SDK.

Next steps

Section titled “Next steps”