# Catalog-first quickstart

## 1. Discover the chain and template

Call `inspect` with `subject: "chains"`, then `subject: "functions"`. Confirm the requested chain is configured. Select a template whose semantics match the operator's request.

For example, **if advertised**:

```json
{"tool":"inspect","arguments":{"subject":"function","function_slug":"erc20.token_balance"}}
```

Read its `params` and `row` schemas, descriptions, and defaults. The catalog's Function names are metric templates; they are not MCP tools.

## 2. Bind the scope

The following addresses and chain are placeholders. Substitute operator-supplied values, and use exactly the parameter names advertised by the selected template.

```json
{"tool":"bind","arguments":{"function_slug":"erc20.token_balance","chain_id":1,"params":{"tokens":["<TOKEN_ADDRESS>"],"owners":["<WALLET_ADDRESS>"]}}}
```

Proceed only on `outcome: "success"`. Save the returned `bound_function_id`. Binding creates an identity and scope, not an indexed dataset. `created: false` does not prove the requested window is covered.

## 3. Check coverage and choose the window

```json
{"tool":"inspect","arguments":{"subject":"bound_function","bound_function_id":"<BOUND_FUNCTION_ID>"}}
```

Read `materialized`, `materializing`, and `active_jobs`. Choose a requested half-open block interval `[from_block, to_block)` using the correct chain's `head` and the operator's intended period. The head is not a finality guarantee. Example block numbers below illustrate syntax; they do not prescribe a useful query window.

## 4. Materialize missing blocks

```json
{"tool":"materialize","arguments":{"bound_function_id":"<BOUND_FUNCTION_ID>","from_block":100,"to_block":110}}
```

If a quote is returned, inspect `outcome`, `lines`, `amount`, and `accepts`. Obtain or confirm spending authorization. Prepare the signed payload for an offered rail using the server's instructions.

```json
{"tool":"pay_quote","arguments":{"quote_id":"<QUOTE_ID>","payload":"<SIGNED_X402_JSON_TEXT>"}}
```

`payload` is JSON **text inside a string**, not a private key. It can be omitted only on a mock settlement deployment. Save the payment ID and receipt.

```json
{"tool":"materialize","arguments":{"payment_id":"<PAYMENT_ID>"}}
```

A successful accepted job can still be running. Inspect the returned `job.job_id` and the bound function's coverage before reading. Start paid execution within the quote's 120-second lifetime.

## 5. Read values

```json
{"tool":"read","arguments":{"bound_function_id":"<BOUND_FUNCTION_ID>","from_block":100,"to_block":110}}
```

Reading has its own pay gate. If it returns `payment_required`, settle that read quote, then invoke `read` with **only** its returned `payment_id`.

A successful read returns bare `values`, one row per block and key with all its attributes, typed by the Function’s `row` schema from inspect. Within fully covered blocks, absent rows follow the Function's declared emission rules; an unavailable window is not a zero balance.

## 6. Verify the source window

Use the same bound identity and exact half-open window; there is no attribute selector:

```json
{"tool":"provenance","arguments":{"bound_function_id":"<BOUND_FUNCTION_ID>","from_block":100,"to_block":110}}
```

Keep the result identity, exact window, values, source block hashes, and applicable digest together. See [provenance verification](/agents/provenance/) for limits and interpretation.