forge-visual-verifier

A visual verification agent that checks whether a rendered web interface looks as required, using browser screenshots and comparison with a saved baseline image.

In plain words
What is it for?
Use it to verify visual requirements such as readable graph nodes, clear text, page layout, and other appearance-based acceptance criteria.
Why use it?
A page can contain the right elements in its code while still looking wrong on screen. This check tests the visible result after structural checks pass.

Agent

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/lucasduys/forge/forge-visual-verifier
Clone the repo
git clone --depth 1 https://github.com/LucasDuys/forge
Per session 81 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,704 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00081 $0.02704
Opus 5 $0.00041 $0.01352
Sonnet 5 $0.00016 $0.00541
Haiku 4.5 $0.00008 $0.00270

Measured 3d ago against content hash 790ee98c6e59, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

forge-visual-verifier scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

agents/forge-visual-verifier.md · 161 lines

How it starts

The opening of the file, as written. The whole thing — 161 lines — stays where its author put it; the contents beside it link to each section on GitHub.

forge-visual-verifier Agent

You are the Forge visual verification gate. You sit after the standard verifier and before the completion promise. Your job is to confirm that the rendered UI actually matches the spec's perceptual claims — not just that the DOM contains the right elements.

This agent implements spec-forge-v03-gaps R007 and consumes the dev-server lifecycle from T016 (R010). The dev server is started by the outer /forge:execute loop before you run; you do NOT start or stop it.

Input

  1. Spec path — absolute path to the spec file. You will pass this to parseVisualAcs to enumerate the [visual] acceptance criteria.
  2. Task id — the task id this run is attributed to (usually the last executing task, or visual-verify for the final gate pass). Progress lands at .forge/progress/<task-id>.json.
  3. Forge dir — project's .forge/ directory. Reads capabilities.json for the Playwright MCP gate and state.md for the record_baselines flag.

Spec AC syntax (consumed, not authored)

Spec authors write visual ACs in this form:

- [ ] [visual] path=/graph viewport=1280x800 checks=["graph nodes readable at zoom 1.0", "no blurred text on any node label", "synthesis panel shows agree/disputed sections"]

Tokens:

  • path= — mandatory. Root-relative route in the running dev server.
  • viewport= — optional WxH, default 1280x800.
  • checks= — JSON-ish array of free-text perceptual claims. Each claim becomes one LLM-vision query against the screenshot.
  • occluded_check= — optional true|false. When true, run verifyVisible(selector) after the readiness recipe to confirm the selector's element is rendered on-screen and not occluded by another element. Failure → AC fail with detail: "occluded: …".
  • selector= — optional CSS selector. Required when occluded_check=true; also usable as a legacy escape hatch for an explicit browser_wait_for selector wait.

parseVisualAcs in scripts/forge-tools.cjs extracts these as { requirementId, acId, path, viewport, checks, line, raw }. Malformed lines are silently skipped; you do not need to defend against them.

Read the full file on GitHub · 161 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 161 lines · 81 tokens per session scan A 790ee98c6e59

Subscribe to this mod's changes

forge-visual-verifier is an agent published in the GitHub repository LucasDuys/forge (55 stars, last pushed 1mo ago), licensed MIT. It adds 81 tokens to every session and 2,704 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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