> For the complete documentation index, see [llms.txt](https://docs.autonomi.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.autonomi.com/developers/how-to-guides/build-read-only-features.md).

# Build Read-Only Features

Retrieve existing public or private data without configuring a wallet or an upload payment flow.

This guide covers read-only retrieval through the `antd` REST API and CLI. For application code, see [SDK retrieval](/developers/sdk/retrieve-data-from-the-network.md) or [Direct Rust](/developers/direct-rust/build-directly-in-rust.md). SDK client package versions are independent of antd; follow the [language-specific installation instructions](/developers/sdk/reference/language-bindings/overview.md).

## Why this matters

Read-only features have fewer security and operational requirements than upload-enabled features.

If your application only reads data that has already been written to the Autonomi Network:

* you do not need ANT
* you do not need gas
* you do not need a wallet
* you do not need upload permissions

This keeps retrieval-only tools, dashboards, and content browsers separate from wallet keys and token approvals.

## Prerequisites

* A 64-character public address, or a hex-encoded `DataMap` for private data
* For REST: the `antd v0.14.0` binary running on `http://127.0.0.1:8082`
* For CLI: [ant installed](/developers/cli/use-the-cli.md#install-the-cli) using npm or your operating system's installer
* A known copy of the expected content if you want to verify its bytes

You do not need `AUTONOMI_WALLET_KEY`, `SECRET_KEY`, ANT, gas, or token approval for these retrieval operations.

## Steps

### 1. Retrieve public data through antd

The streaming endpoint writes the decrypted bytes directly instead of returning a base64 field inside JSON.

Set `ADDRESS` to a real public address, then run:

```bash
#!/usr/bin/env bash
set -euo pipefail

: "${ADDRESS:?Set ADDRESS to a 64-character public address}"

curl --fail --show-error \
  "http://127.0.0.1:8082/v1/data/public/${ADDRESS}/stream" \
  --output downloaded.bin

test -s downloaded.bin
printf 'Downloaded %s bytes\n' "$(wc -c < downloaded.bin)"
```

Expected output:

```
Downloaded <non-zero number> bytes
```

### 2. Retrieve private data through antd

Keep the `DataMap` private. It contains the material needed to locate and decrypt the content.

```bash
#!/usr/bin/env bash
set -euo pipefail

: "${DATA_MAP:?Set DATA_MAP to the hex-encoded DataMap}"

curl --fail --show-error \
  --request POST \
  --header "Content-Type: application/json" \
  --data "{\"data_map\":\"${DATA_MAP}\"}" \
  http://127.0.0.1:8082/v1/data/stream \
  --output downloaded-private.bin

test -s downloaded-private.bin
printf 'Downloaded %s bytes\n' "$(wc -c < downloaded-private.bin)"
```

Expected output:

```
Downloaded <non-zero number> bytes
```

The buffered endpoints, `GET /v1/data/public/{address}` and `POST /v1/data/get`, instead return JSON with the content encoded as base64 in the `data` field.

### 3. Retrieve a file with the CLI

The CLI includes built-in bootstrap peers, so no separate connection file is required for normal use. If you supply a custom `bootstrap_peers.toml` or explicit peer settings, use real network contacts rather than example IP addresses.

Public retrieval:

```bash
#!/usr/bin/env bash
set -euo pipefail

: "${ADDRESS:?Set ADDRESS to a 64-character public address}"

ant file download "$ADDRESS" --output downloaded.bin
test -s downloaded.bin
```

Private retrieval:

```bash
#!/usr/bin/env bash
set -euo pipefail

: "${DATA_MAP_FILE:?Set DATA_MAP_FILE to a local .datamap file}"

ant file download --datamap "$DATA_MAP_FILE" --output downloaded-private.bin
test -s downloaded-private.bin
```

Expected output includes `Download complete!`, the output filename, its size, and elapsed time.

### 4. Keep wallet setup out of read-only applications

If your application only reads data that has already been stored, omit:

* `AUTONOMI_WALLET_KEY`
* `SECRET_KEY`
* token approvals
* upload payment flows

Add wallet configuration only when the application also uploads.

## Verify it worked

Compare the downloaded bytes with a known copy:

```bash
#!/usr/bin/env bash
set -euo pipefail

: "${EXPECTED_FILE:?Set EXPECTED_FILE to the known original file}"

cmp "$EXPECTED_FILE" downloaded.bin
printf 'Downloaded content matches the expected file\n'
```

Expected output:

```
Downloaded content matches the expected file
```

## Common errors

**400 Bad Request**: A public address must be exactly 64 hexadecimal characters, and a private `DataMap` must be valid hex-encoded serialized data.

**404 Not Found for missing data**: `antd` returns `NOT_FOUND` when it finds no public `DataMap` at the address. Check that the address identifies stored public data. If `/health` shows no connected peers, a lookup can also report not found; restore connectivity before concluding that the data is absent.

**Connection configuration errors**: Check custom bootstrap files or explicit peer settings first. Normal CLI use does not require a separate config file; if you selected a local-development manifest, follow that environment's setup instead.

**Private retrieval without a DataMap**: Private content requires the caller-held `DataMap`, even though the storage payment has already happened.

## Next steps

* [Store and Retrieve Data with the SDKs](/developers/sdk/how-to-guides/store-and-retrieve-data.md)
* [Payment Model](/developers/core-concepts/payment-model.md)
* [Use the CLI](/developers/cli/use-the-cli.md)