Close the feedback loop on what the agent built

This page is for anyone vibecoding, building a product primarily by prompting an AI coding agent like Cursor, Claude Code, Lovable, or Bolt, who has watched the iteration loop break the moment they tried to give structured feedback on what the agent built. The same workflow pattern shows up across the rest of the feedback for AI coding agents hub.

The feedback bottleneck in vibecoding

Prompting is fast. The agent's output arrives in seconds. Looking at the preview is fast, you see the broken hero, the misaligned form, the wrong color on the secondary button in about ten seconds.

Then you sit down to type. Eight paragraphs about UI issues, each one trying to anchor a screenshot to a description, each one re-explaining context the next paragraph also needs. Twenty minutes later the message is half-finished and you've forgotten which screenshot showed the spacing bug.

This is where vibecoding stalls. The v1 lands in an hour. The next five iterations should also take an hour. Instead they take a week, because the bottleneck moved from "writing code" to "writing up what's wrong." Typing is the slowest tool in the chain, and it's now the chain's rate-limiter.

The CobaltCapture loop

Open the agent's preview tab. Open cobaltcapture.com in a new tab. Hit Capture screen, pick the preview window, drag a box around the broken element, hit Dictate and talk through it. "The hero copy is centered on desktop but left-aligned on tablet, and the CTA below it lost its hover state since the last iteration." Repeat for each finding. Hit Publish.

You get a URL like cobaltcapture.com/r/<slug>. Paste it into the agent's next message:

Here's the design review on the last build:
https://cobaltcapture.com/r/abc12345

Apply the fixes in order, confirm each one before moving on.

Cursor's composer follows the URL and pulls the screenshots inline. Claude Code reads the markdown export from your repo. Lovable and Bolt follow the URL through their chat. The agent works against the document instead of guessing from a paragraph.

The cycle stays minutes long. Capture, dictate, publish, paste, the same length as the original prompt that produced the build. Feedback stops being the slow step.

What the loop looks like across one session

You:    "Build a pricing page with three tiers, monthly toggle, FAQ below."

Agent:  [generates v1 with hero, three tier cards, FAQ accordion]

You:    [open preview, capture cobaltcapture.com/r/k4m2p9xt]
        - cropped: pricing card on mobile, dictated "the price font
          is 60% too large, breaks the card width under 380px"
        - cropped: monthly/annual toggle, dictated "the toggle doesn't
          change color when active, can't tell which one is selected"
        - cropped: FAQ section, dictated "the chevron rotates the wrong
          way on open"

You:    "Review: https://cobaltcapture.com/r/k4m2p9xt
         Fix all three, confirm each."

Agent:  [patches each one, shows diffs]

You:    [capture again, cobaltcapture.com/r/p7n3q2vy, one finding]
        "https://cobaltcapture.com/r/p7n3q2vy, one more pass"

Agent:  [done]

Five iterations, one afternoon. The published URLs become the conversation history.

Why the loop closes faster

Dictation runs at speaking speed, four times faster than typing for descriptive prose, faster still when the description includes nuance the agent needs ("only on iOS Safari, only after scroll"). The crop carries the source URL, so the agent knows which page and which component the finding is about without you naming it.

The published URL is permanent. It becomes a record of what you asked for and when, separate from the chat. If the agent regresses a fix two iterations later, the original URL still shows what was wrong the first time.

Compare this to typing each finding into chat one by one. Each typed finding is a new message, a new context-load for the agent, and a new chance to forget the previous one. The CobaltCapture URL gives the agent everything in one shot.

Compared to typing it all

Typing is fine when there's one finding per iteration. "The button is the wrong color" is faster to type than to capture. Don't reach for a tool when a sentence will do.

The loop matters when you have three or more findings and you'd otherwise compress them into one paragraph the agent has to untangle. That's the pattern that breaks vibecoding. A walk through the preview surfaces five things; typing them up takes 20 minutes and loses two of them in the noise; the next iteration fixes three and reintroduces one. The cycle never converges.

This is also the canonical pattern behind the broader category of agent feedback, the artifact, not the conversation, is what survives the handoff. Vibecoding is where the pattern shows up first because the iteration count is highest. If you're prompting an agent ten times a day, the format of your feedback is the format of your product.