HTTP API

The HTTP server exposes a JSON REST API for key-value operations.

Endpoints

`GET /v1/keys/{key}`

Retrieve a value by key.

curl http://localhost:3456/v1/keys/mykey

Response 200:

{"key": "mykey", "value": "hello"}

Response 404:

{"error": "key not found"}

`PUT /v1/keys/{key}`

Store a value.

curl -X PUT http://localhost:3456/v1/keys/mykey \
  -H "Content-Type: application/json" \
  -d '{"value": "hello"}'

Response 204 (no content).

`DELETE /v1/keys/{key}`

Delete a key.

curl -X DELETE http://localhost:3456/v1/keys/mykey

Response 204 (no content).

Response 404:

{"error": "key not found"}

`GET /healthz`

Health check endpoint.

curl http://localhost:3456/healthz

Response 200 (no content).

Error Responses

All errors return a JSON body:

{"error": "description of the error"}

Status	Description
`400`	Key is missing or request body is invalid
`404`	Key not found
`405`	Method not allowed
`409`	This node is in a cluster and is not the leader, so it cannot take the write
`500`	Internal server error

A 409 names the leader in its message, so a client can be pointed at the node that will take the write:

{"error": "not the leader, 127.0.0.1:6381 is"}

During an election nobody is the leader yet and the message says so instead. Reads are unaffected: any node answers GET, though a follower’s copy may be behind the leader. See Durability and Clustering.

GET /healthz reports that this process is listening and nothing more — a node cut off from the cluster’s majority, unable to accept a single write, still answers 200.