> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lasso.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# First endpoint quickstart

> Create a key, make a harmless RPC call, and stage the first endpoint change

# First endpoint quickstart

This flow evaluates Lasso with a standard JSON-RPC call. Creating an external
key changes service state; an agent should ask before doing it for a user.

## 1. Check live support

```bash theme={null}
curl -sS https://lasso.sh/api/v1/agent/chains
curl -sS https://lasso.sh/api/v1/agent/pricing
```

Choose a chain and an explicit strategy. The runtime default is
`load-balanced`, but an explicit URL makes the evaluation reproducible.

## 2. Create and save a key

```bash theme={null}
curl -sS -X POST https://lasso.sh/api/v1/agent/keys
```

The response includes a full `key` and a ready-to-use endpoint. The full key is
shown once. Put it in the project's existing secret store; do not print it into
chat, logs, shell history, screenshots, or source control.

Load the key from the project's secret manager. For a one-off interactive shell,
read it without echoing it or placing the value in shell history:

```bash theme={null}
read -rsp "Lasso key: " LASSO_KEY && export LASSO_KEY && printf '\n'
```

## 3. Make a harmless call

```bash theme={null}
curl -sS -D /tmp/lasso-headers.txt \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}' \
  "https://lasso.sh/rpc/k/$LASSO_KEY/load-balanced/ethereum?include_meta=headers"
```

The body remains standard JSON-RPC. `include_meta=headers` adds a request ID and
encoded routing metadata without changing the body shape. Anonymous keys can
also receive per-request CU and USD headers. See
[Routing and usage evidence](observability) before building automation around a
header.

## 4. Install the URL

Lasso replaces the upstream URL; the client remains standard EVM JSON-RPC.

```bash theme={null}
export RPC_URL="https://lasso.sh/rpc/k/$LASSO_KEY/load-balanced/ethereum"
```

For viem:

```javascript theme={null}
import { createPublicClient, http } from "viem";
import { mainnet } from "viem/chains";

const client = createPublicClient({
  chain: mainnet,
  transport: http(
    `https://lasso.sh/rpc/k/${process.env.LASSO_KEY}/load-balanced/ethereum`,
  ),
});
```

Begin with a non-critical stateless read path. Compare results, latency, and
routing evidence before expanding traffic or adding historical, write, filter,
or subscription workloads.

## 5. Link management when useful

An anonymous key can be linked to a dashboard account without changing its RPC
URL:

```bash theme={null}
curl -sS -X POST \
  "https://lasso.sh/api/v1/agent/keys/$LASSO_KEY/claim-link"
```

Give the short-lived `claim_url` to the user. Linking adds the account management
surface; it should not be performed without the user's approval.

For exact key, funding, claim, and session-payment payloads, use
[`/openapi.json`](https://lasso.sh/openapi.json) and
[`/SKILL.md`](https://lasso.sh/SKILL.md).