Got a way to this.

You're right that notify has buffering behavior. Here's what's happening and how to fix it:

The Issue:
Notify buffers input for efficiency, and when piped further, the output buffering can interfere with notification timing.

Solution 1: Use tee to split the stream

echo test | tee >(notify -provider-config /root/httpx.yaml -silent) | xargs -I {} echo ONE.{}

Solution 2: Use -bulk flag

echo test | notify -provider-config /root/httpx.yaml -silent -bulk | xargs -I {} echo ONE.{}

Solution 3: Force immediate output

echo test | stdbuf -oL notify -provider-config /root/httpx.yaml -silent | xargs -I {} echo ONE.{}

Best approach for your workflow:

cat domains.txt | subfinder | tee >(notify -provider-config subs.yaml -silent) | custom-bugscans | notify -provider-config bugs.yaml -silent

Alternative - Use file-based approach:

subfinder -dL domains.txt -o subs.txt && notify -data subs.txt -provider-config subs.yaml
cat subs.txt | custom-bugscans | notify -provider-config bugs.yaml

The tee approach is cleanest - it sends data to both notify AND the next command in parallel.

Why it happens:
Notify reads stdin fully before sending to avoid partial messages. With tee, it gets a copy while the original flows through.

You're right that notify has buffering behavior. Here's what's happening and how to fix it:

The Issue:
Notify buffers input for efficiency, and when piped further, the output buffering can interfere with notification timing.

Solution 1: Use tee to split the stream

echo test | tee >(notify -provider-config /root/httpx.yaml -silent) | xargs -I {} echo ONE.{}

Solution 2: Use -bulk flag

echo test | notify -provider-config /root/httpx.yaml -silent -bulk | xargs -I {} echo ONE.{}

Solution 3: Force immediate output

echo test | stdbuf -oL notify -provider-config /root/httpx.yaml -silent | xargs -I {} echo ONE.{}

Best approach for your workflow:

cat domains.txt | subfinder | tee >(notify -provider-config subs.yaml -silent) | custom-bugscans | notify -provider-config bugs.yaml -silent

Alternative - Use file-based approach:

subfinder -dL domains.txt -o subs.txt && notify -data subs.txt -provider-config subs.yaml
cat subs.txt | custom-bugscans | notify -provider-config bugs.yaml

The tee approach is cleanest - it sends data to both notify AND the next command in parallel.

Why it happens:
Notify reads stdin fully before sending to avoid partial messages. With tee, it gets a copy while the original flows through.

No, notify doesn't have to be the last command — it does pass through stdin to stdout by default. But there's a timing/buffering issue.

The fix — use -silent:

cat domains.txt | subfinder -silent | notify -provider-config subs.yaml -silent | custom-bugscans

Why it wasn't working:

1. notify's progress/status output was mixing with the data stream. -silent suppresses everything except the actual data passthrough.

2. Buffering — notify processes and sends notifications asynchronously. The pipe might close before notify finishes sending.

Alternative approach — use tee to split the stream:

cat domains.txt | subfinder -silent | tee >(notify -provider-config subs.yaml -silent) | custom-bugscans

This sends the subdomains to both notify AND your custom scanner simultaneously using process substitution.

Or use a file-based workflow for reliability:

# Step 1: Get subdomains and save
subfinder -dL domains.txt -silent -o subs.txt

# Step 2: Notify about new subs
notify -data subs.txt -provider-config subs.yaml -silent

# Step 3: Scan
cat subs.txt | custom-bugscans | notify -provider-config bugs.yaml -silent

The pipe approach works, but you need -silent on both subfinder and notify to keep the data stream clean.