fetch

Published: March 2025 | Last updated: March 2025

fetch

Overview

The fetch RPC method allows you to retrieve files that have been stored on the Lynx blockchain. It provides a mechanism for accessing data by its unique identifier (UUID) and saving it to a specified location on your filesystem. No authentication is required prior to using this function.

Syntax

fetch <uuid> <path> [pubkeyflag]

Description

When you invoke the fetch method, the Lynx daemon searches the blockchain for the specified file and downloads it to your designated location. This method is part of the core functionality that enables Lynx to serve as a decentralized data storage solution.

Parameters

Parameter	Type	Required	Description
uuid	string	Yes	The unique identifier of the file you want to retrieve. This is a 64-character hexadecimal string (e.g., 2cf6eabc7af83152d5ad7d4ff9aeeb66f81dde70731b800bb0cd18300d9cb402).
path	string	Yes	The full filesystem path where the retrieved file should be stored (e.g., /home/username/downloads). This path must exist before calling the method.
pubkeyflag	string	No	Optional parameter that controls tenant public key inclusion in the response. Enter 0 to omit the tenant information. Default is 1 (include tenant information).

Returns

The method returns an array containing a single object with the following fields:

Field	Type	Description
result	string	Indicates whether the operation succeeded (success) or failed (failure).
message	string	Provides additional information about the result. For successful operations, returns n/a. For failures, indicates the reason (e.g., Invalid path /path/to/directory., Invalid UUID length., UUID not found.).
tenant	string/number	When authentication is active and pubkeyflag is set to 1, displays the tenant public key associated with the file. Otherwise returns n/a.

Examples

Retrieve a specific file

Retrieve the file with UUID 2cf6eabc7af83152d5ad7d4ff9aeeb66f81dde70731b800bb0cd18300d9cb402 and store it in the /home/username/downloads directory:

lynx-cli fetch 2cf6eabc7af83152d5ad7d4ff9aeeb66f81dde70731b800bb0cd18300d9cb402 /home/username/downloads

Or using JSON-RPC:

curl --user username --data-binary '{"jsonrpc": "1.0", "id": "curltest", "method": "fetch", "params": ["2cf6eabc7af83152d5ad7d4ff9aeeb66f81dde70731b800bb0cd18300d9cb402", "/home/username/downloads"]}' -H 'content-type: text/plain;' http://127.0.0.1:9332/

Retrieve a file without tenant verification

This method is significantly faster. Retrieve a file without performing tenant verification:

lynx-cli fetch 2cf6eabc7af83152d5ad7d4ff9aeeb66f81dde70731b800bb0cd18300d9cb402 /home/username/downloads 0

Error Handling

The method will return a failure result in the following scenarios:

• The specified path doesn't exist on the filesystem

• The UUID has an invalid length (must be 64 characters for a specific file)