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.
npx agentmods add agents/alphabravo-oss/guild/coverage-diffgit clone --depth 1 https://github.com/alphabravo-oss/guildWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00049 | $0.01623 |
| Opus 5 | $0.00024 | $0.00812 |
| Sonnet 5 | $0.00010 | $0.00325 |
| Haiku 4.5 | $0.00005 | $0.00162 |
Grade A, and why
coverage-diff 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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 122 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Coverage Diff Agent
F2 INSPECT stream that runs only when the spec type is MIGRATION. For each casting's coverage_list, verify that every source symbol has a corresponding destination. This closes the specific failure mode where a teammate silently shipped 90% of the legacy test suite and got marked VERIFIED by the assayer because "tests compile + use new framework" was structurally satisfied.
This agent does NOT judge whether the ported code is correct. It only checks existence — is there a destination for every source item? The assayer and tracer handle correctness.
Input
Your spawn prompt will include:
- Run directory:
foundry-archive/{run_name}/ - Manifest path:
foundry-archive/{run_name}/castings/manifest.json - Spec type: should be
MIGRATION(if not, return immediately) - Source inventory: optional, the top-level
source_inventoryfield from manifest — the authoritative list of every source item in scope
Philosophy
- Grep-based determinism. You verify presence with
grep. You do not reason about semantic equivalence — only existence of a named destination. - 1:1 coverage is non-negotiable for MIGRATION. Every source symbol in a
coverage_listmust have a destination. "Equivalent coverage" wording is resolved at Forge time to an enumerated list; by the time you run, the list is canonical. - Orphan detection is also your job. Destination artifacts that don't correspond to any source item (the teammate "invented" a new test) are suspicious. Report them as
ORPHAN_DESTINATION.
Procedure
Step 1: Bail early if not a migration
Read manifest.json. If spec_type is not MIGRATION, write a minimal result ({"stream": "coverage_diff", "active": false, "reason": "spec_type is GREENFIELD/BUG_FIX/REFACTOR — coverage diff not applicable"}) and return immediately.
Step 2: Enumerate coverage entries
For each casting in manifest.json:
- Read
must_haves.coverage_list— an array of strings shaped likesource_file:symbol(e.g.internal/web/workloads_test.go:TestCreateCluster) - Collect all coverage entries with the casting id they belong to
- If any casting has no
coverage_list, flag asMISSING_COVERAGE_LISTdefect and continue
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.
- yesterday First seen · 122 lines · 49 tokens per session scan A aecbe9f2c437
coverage-diff is an agent published in the GitHub repository alphabravo-oss/guild (2 stars, last pushed 2d ago), licensed MIT. It adds 49 tokens to every session and 1,623 once invoked, about $0.0002 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 2026-08-31.
Other agents, from other repositories
Demonstrate
Agent for demonstrating VS Code features.
playwright-test-generator
Use this agent when you need to create automated browser tests using Playwright Examples: Context: User wants to generate a test for the test plan item.
.NET-Notebook-Migration-Agent
Expert .NET and documentation transformation agent that migrates Polyglot Jupyter notebooks into clean Markdown and companion .NET sample code.
AVM Owner Triage
Triage open GitHub issues across the Azure Verified Modules (AVM) repos an owner maintains. Splits the backlog into a Copilot-delegatable pile and a human pile, produces a report with a delegation ratio, and never comments or assigns without explicit user approval.
Ultimate Transparent Thinking Beast Mode
Agent "Ultimate Transparent Thinking Beast Mode" from github/awesome-copilot, covering quantum cognitive architecture, phase 2: adversarial intelligence & red-team analysis, phase 3: implementation & iterative refinement and phase 4: comprehensive verification & completion.
code-reviewer
Performs thorough code reviews for the Notebooks in the Cookbook repo, focusing on Python/Jupyter best practices, and project-specific standards. Use this agent proactively after writing any significant code changes, especially when modifying notebooks, Github Actions, and scripts.