> ## Documentation Index
> Fetch the complete documentation index at: https://comis-feature-matrix-channel.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# Links
> How your agent understands web pages shared in messages
**Can my agent read the article I shared?** Only if you turn link
understanding on — it is **off by default**. When enabled, Comis fetches the
URL, extracts the readable content (headings + body text, no nav/ads), and
hands it to the agent alongside the user's message.
This is separate from the **client-side link previews** that Telegram,
Discord, and Slack render automatically (those are generated by the chat
platform itself and your agent cannot read them without link understanding).
WhatsApp, Signal, LINE, iMessage, IRC, and Email do not show client-side
previews at all — link understanding is the only way the agent learns what
the URL points to on those channels.
When someone shares a URL in a message, Comis can automatically fetch the web page
and extract its readable content. Your agent then sees both the original message
and a summary of what the linked page says. This gives your agent context about
shared links without the user having to copy-paste the page content.
You don't need to understand the technical details to use this feature. The configuration examples below are copy-paste ready.
## How Link Understanding Works
Comis scans incoming messages for URLs. Standard web links starting with
`http://` or `https://` are recognized. Up to 3 links per message are
processed by default (configurable).
Each URL is fetched with SSRF protection -- Comis will not fetch internal or
private network addresses. A readable extraction pulls the main content from
the page, stripping navigation menus, advertisements, sidebars, and scripts.
The result is clean, readable text.
The extracted text (up to 5,000 characters per link) is added to the message
context so your agent can reference it. Your agent sees the user's original
message plus the content of each linked page.
Link understanding is **disabled by default**. You need to explicitly enable it in
your configuration before it will process any URLs.
## When to Enable Link Understanding
Link understanding is most useful when your users regularly share web content and
expect the agent to discuss it. Common scenarios include:
* **News and research groups** -- Users share articles and want the agent to
summarize or comment on the content.
* **Support channels** -- Users share documentation links and the agent needs to
reference the linked page to answer questions.
* **Content review** -- Users share blog posts, product pages, or forum threads
for the agent to analyze.
If your agent rarely needs to understand web pages, you can leave link
understanding disabled to avoid unnecessary network requests.
## Security
Link fetching includes built-in SSRF (Server-Side Request Forgery) protection.
SSRF is an attack where a malicious user tricks a server into fetching internal
resources that should not be accessible from outside. Comis prevents this by
refusing to fetch URLs that point to:
* Private IP addresses (`10.x.x.x`, `192.168.x.x`, `127.x.x.x`)
* Internal network hostnames
* Non-HTTP/HTTPS protocols
This prevents malicious users from tricking your agent into accessing internal
services on your network. For more information on Comis security layers, see
[Defense in Depth](/security/defense-in-depth).
The SSRF protection runs automatically on every URL before any content is fetched.
You do not need to configure or maintain a blocklist -- Comis handles it for you.
## What the Agent Sees
When link understanding is enabled and a user sends a message containing a URL,
your agent receives the original message text plus the extracted page content.
The content is formatted as readable text with the page title, so the agent knows
which link each block of content came from.
If a page cannot be fetched (timeout, 404 error, blocked by the site), Comis
silently skips it. The agent still sees the original message with the URL -- it
just does not get the extracted content for that link.
## Limits
These limits control how much content is fetched and how long Comis waits for
each page to respond.
| Setting | Default | Description |
| ----------------- | --------- | ------------------------------------- |
| `maxLinks` | 3 | Maximum URLs processed per message |
| `fetchTimeoutMs` | 10,000 ms | Timeout per URL fetch |
| `maxContentChars` | 5,000 | Maximum characters extracted per link |
If a message contains more URLs than `maxLinks`, only the first URLs (in order
of appearance) are processed. The rest are ignored.
If a page's readable content exceeds `maxContentChars`, the text is truncated.
This keeps the agent's context window from being overwhelmed by very long pages.
## Configuration
```yaml theme={null}
integrations:
media:
linkUnderstanding:
enabled: false # Must be explicitly enabled
maxLinks: 3 # Max URLs per message
fetchTimeoutMs: 10000 # Timeout per fetch (10 sec)
maxContentChars: 5000 # Max chars per link
userAgentString: "Comis/1.0 (Link Understanding)" # Outbound User-Agent
```
To enable link understanding, set `enabled: true`:
```yaml theme={null}
integrations:
media:
linkUnderstanding:
enabled: true
```
All other settings are optional and have sensible defaults.
Start with the defaults and only adjust limits if you find that extracted content
is being cut off or fetches are timing out on slower sites. Increasing
`maxContentChars` gives the agent more page content to work with but uses more
of the agent's context window.
## What Happens When Disabled
When link understanding is disabled (the default), URLs in messages are passed
through to the agent as plain text. The agent sees the URL but does not know
what the page contains. Users would need to copy-paste the relevant content
from the page if they want the agent to discuss it.
## Related
Back to media overview
SSRF protection and other security layers
Full configuration reference
Image and video analysis