# changelog-rss-diff

New posts from a changelog or blog RSS feed since the last successful run.

Category: Developer monitoring. Allow `blog.rust-lang.org`.

Updated 2026-10-17. HTML: https://asipipes.com/pipes-library/changelog-rss-diff

## CLI

```
pipes run examples/changelog-rss-diff.pipe.yaml
```

## MCP call

```json
{
  "name": "pipe__changelog-rss-diff",
  "arguments": {}
}
```

## Pipe file

`examples/changelog-rss-diff.pipe.yaml`

```yaml
pipes: 0
name: changelog-rss-diff
version: 0.1.0
description: New posts from a changelog or blog RSS feed since the last successful run.
permissions:
  network: [blog.rust-lang.org]
inputs:
  type: object
  properties:
    feed:
      type: string
      format: uri
      default: https://blog.rust-lang.org/feed.xml
  required: [feed]
outputs:
  type: object
  properties:
    text: { type: string }
    count: { type: integer }
  required: [text, count]
output:
  text: "${steps.format.text}"
  count: "${steps.format.count}"
steps:
  - id: fetch
    block: fetch_http
    with:
      url: "${inputs.feed}"
      max_bytes: 500000
    retry: { max: 2, backoff_ms: 500 }
    timeout_ms: 15000
  - id: entries
    block: parse_rss
    in: "${steps.fetch}"
  - id: capped
    block: limit
    in: "${steps.entries}"
    with: { n: 15 }
  - id: new
    block: diff_since_last
    in: "${steps.capped}"
    with:
      key: [id]
      compare: [id]
      emit: [added]
      first_run: all
  - id: ordered
    block: sort
    in: "${steps.new}"
    with:
      by: [{ field: published, desc: true }]
  - id: format
    block: format
    in: "${steps.ordered}"
    with:
      header: "Changelog:\n"
      item_template: "- ${item.title} (${item.published}) ${item.link}"
      separator: "\n"
  - id: print
    block: emit_stdout
    in: "${steps.format.text}"
    with: { format: text }
```