docs: HTTP API Status Codes

Generated with ipfs-inactive/http-api-docs#23

License: MIT
Signed-off-by: Marcin Rataj <lidel@lidel.org>

content/reference/api/http.md

@@ -9,7 +9,7 @@ menu:
 <!-- TODO: Describe how to change ports and configure the API server -->
 <!-- TODO: Structure this around command groups (dag, object, files, etc.) -->
 
-<sup>Generated on 2019-06-22, from go-ipfs v0.4.21.</sup>
+<sup>Generated on 2019-11-05, from go-ipfs v0.4.22.</sup>
 
 When an IPFS node is running as a daemon, it exposes an HTTP API that allows
 you to control the node and run the same commands you can from the command
@@ -20,17 +20,21 @@ your program — it allows you to maintain peer connections that are longer
 lived than your app and you can keep a single IPFS node running instead of
 several if your app can be launched multiple times. In fact, the `ipfs`
 CLI commands use this API when operating in [online mode]({{< relref
-"usage.md#going-online" >}}).
+"usage.md#taking-your-node-online" >}}).
 
-This document is autogenerated from go-ipfs. For issues and support, check out
-the [ipfs-http-api-docs](https://github.com/ipfs/ipfs-http-api-docs)
-repository on GitHub.
+<aside class="alert alert-info">
+  This document was autogenerated from go-ipfs.<br/>
+  For issues and support, check out
+  the <a href="https://github.com/ipfs/ipfs-http-api-docs" target="_blank">ipfs-http-api-docs&nbsp;<i class="fas fa-external-link-square-alt fa-sm"></i></a> repository on GitHub.
+</aside>
 
-## Getting started
+## Getting Started
 
 ### Alignment with CLI Commands
 
-[Every command](../commands/) usable from the CLI is also available through
+The HTTP API under `/api/v0/` is an RPC-style API over HTTP, not a REST API.
+
+[Every command]({{< relref "cli.md" >}}) usable from the CLI is also available through
 the HTTP API. For example:
 ```sh
 > ipfs swarm peers
@@ -87,6 +91,19 @@ flag is the `&encoding=json` query parameter below:
 }
 ```
 
+### HTTP Status Codes
+
+Status codes used at the RPC layer are simple:
+
+* `500` - RPC endpoint returned an error
+* `404` - RPC endpoint doesn't exist
+* `400` - Malformed RPC, argument type error, etc
+* `403` - RPC call forbidden
+
+In other words, `500` means that the function _does_ exist, it just failed internally for some reason. To know that reason, you have to look at the "application layer" error (commands lib error).
+
+## HTTP Commands
+
 ### /api/v0/add
 
 Add a file or directory to ipfs.