Claude Fable 5 best thing to do: a full audit of the code warehouse

Photo by Meta Alchemist

Original by Peggy, Block Beats

The editor, published on 9 June 2026 by Claude Fable 5, positioned it as a Mythos-class model that specializes in long-cycle software engineering and has stronger security features。

After the new model went online, the developers soon began exploring its use in the real engineering scene: the warehouse audit Prompt, shared by @meta alchemist, is a typical case. It allows Fable 5 to look at the code warehouse in a four-stage system, as does the senior technical officer: first combo the project structure and technology warehouse, then refine the improvement strategy and break down it into mission milestones with priority and workload estimates based on real document and line-numbered inspection architecture, security, testing, performance, dependency and documentation issues. Some users have used this to clean up technical debt, to detect security gaps and efficiency problems left out by old models, and to encounter early problems such as the unstable sandbox environment。

In general, the release of Fable 5 is not only an upgrade of model capabilities, but also a further push for AI to move from "Code Assistant" to "Project Audit and Project Improvement Collaborator"。

The following is the original text:

Did you use Claude Fable 5

One of the first things you should do is to upgrade your core project with it so that it can significantly improve everything you have been doing。

Please run the following "Audit and Project Improvement Alert" in every code repository that matters to you(Replicate paste directly):

Code warehouse audit and improvement plan

Claude Fable 5 Generates hints

You are a world-class, leading engineer-level software engineer and technical audit expert. Your task is to conduct an in-depth analysis of the code warehouse, provide an honest audit report and provide a prioritized, implementable improvement plan. Please proceed in strict accordance with the following four phases and do not jump。

All judgements must be based on a genuine document: please cite the file path and line numbers. If something cannot be verified, please specify, not guess。

Phase 1 / Discovery and Combination: Read first, judge later

Before reaching any conclusions, explore systematically the entire code warehouse:

:: Combine the catalogue structure, identifying project types, languages used, frameworks and operational objectives。

:: Identification of entry documents, core modules and the main data flow and control flow in the system。

Read the package manual, lockfile, build configuration, CI configuration, environment/configuration file, and all documents, including README, CONTRIBUBUTING, ADR, etc。

To judge the usefulness of the project: its objectives, its intended users, and its present apparent maturity — prototype, internal tools, production services, or a library。

:: Documenting practices already used by the project, including naming, modular boundaries, error-processing patterns, testing styles, etc., so that follow-up recommendations fit the existing engineering culture rather than confront it。

This stage of output: a simple "code warehouse map", including project usage, technology stacks, structure sketches, key catalogues and their description, and anything that surprises you。

Phase 2 / Audit: evidence-based and severity indicated

An audit of each of the following dimensions is requested。

For every discovery, the following is recorded:

(a) what did you find

(b) where found, in file format: line number

c) why this matter is important, i.e. the concrete consequences, not the abstract principle

(d) Critical / High / Media / Low

Structure and design

Modular boundaries, coupling/incorporation, circulatory dependence, abstract leaks, objects of God/God documents, layer violations, scalable bottlenecks。

Code quality

Repeat codes, waste codes, complex hotspots, including maximum functions, most branch functions; inconsistent models; error-processing gaps, such as abnormal osmosis, missing boundary conditions; type security loopholes。

Clear

HARD-CODED KEYS OR VOUCHERS, INJECTION OF RISK, UNSAFE INVERSE SEQUENCE, MISSING INPUT VERIFICATION, AUTHENTICATION/AUTHORIZATION WEAKNESSES, OBSOLETE RELIANCE ON KNOWN CVES, DISPROPORTIONATE CONFIGURATION。

Test

Test coverage gaps, in particular core business logic; test quality, i.e. whether the test validates behaviour or only whether the test is operational; missing test types, including unit testing, integration testing, end-to-end testing; volatile test models; and hard to test codes。

Performance

N+1 QUERY, UNNECESSARY DISTRIBUTION OR COPYING, BLOCKING CALLS IN WALKWAYS, MISSING CACHES OR INDEXES, BORDERLESS GROWTH ISSUES SUCH AS MEMORY, FILES, QUEUES。

Dependency

obsolete, unmaintained, repetitive or unnecessary heavy reliance; licence risk; lockfile maintenance。

Development experience and experience

Build/start cost, CI/CD gap, missing Lint/formating mandatory check, log and detectability quality, error reporting, deployment path。

Documentation

README ACCURACY, MANUAL PATH, UNRECORDED KEY ACTIONS, EXPIRED DOCUMENTS THAT CONTRADICT CODES。

Rule at this stage

Would rather give 15 high confidence discoveries than 50 speculative discoveries。

Distinguishing between facts and judgement. For example:

fact: "this function is not mistreated: src/api/client.ts:142"

• Adjudication: "The boundaries of this module are not clear"

And it's clear which category is which。

It also lists where this code warehouse works well. Advantages are equally important because they determine what should be retained。

This stage of output: an "audit report". Please group by dimension, sort by severity, and include a Strongs section. Let us not forget to point out those issues that are the ugliest and most in need of priority。

Phase 3 / Improvement strategy

Integrate audit findings into a set of strategies:

• To identify three to five themes that could explain most of the issues, such as the “no compulsory boundary between layers” and the “too ad hoc patchwork of mishandling”。

• Presenting the status of objectives and the principles behind each theme。

• Clarify trade-offs: which issues do you suggest not be fixed for the time being, and why not, such as the mismatch between inputs and benefits, high risk, and project maturity not needed for the time being。

• Define what is called "completed" - giving measurable signals, such as "CI will fail because of a lint error" "Core module test coverage 80%" "Critical level is zero."。

Phase 4 / Detailed mission plan

Translating the strategy into an implementation plan:

Dismantling the work into an independent task. Each mandate must include:

:: Title and a mission statement

Affected documents/regions

:: The acceptance standard, i.e., how to verify that it has been completed

WORKLOAD ESTIMATE: S = LESS THAN 2 HOURS, M = HALF DAY, L = 1-2 DAYS, XL = FURTHER DISMANTLING

:: The risk of change itself, i.e., its potential to disrupt existing functions

:: Reliance on other mandates

Please prioritize tasks by milestones:

Mirestone 0

Safety net: Matters that must be completed before the security re-engineering takes place, such as critical path testing, CI Gate, backup。

Milestone 1

Critical repairs: security and correctness issues。

Milestone 2

High leverage improvements: those that make it easier to follow up on everything。

Milestone 3

Quality and grinding: remaining middle and low priorities worth addressing。

Please indicate separately the quick wins, i.e. high impact, S workload, immediate deliverables。

For the top three tasks, please attach a summary of the realization, including methods, key steps and areas that are easy to step on。

Final delivery format

Please generate a single document containing:

Execute Summer: Not more than 10 words. Give an overall health rating A-F, with justification; list the first three risks and the first three opportunities。

Repo Map

Audit Report

Improvisation Strategy

Task Plan: including milestones, tasksheets and quick wins

Open Questions: List information that requires human decision-making, such as product intent, wasteable modules, performance targets, etc。

Constraints

No code changes will be made during this audit. Just do an analysis。

Do not fill the report. If a dimension is healthy, just one sentence, and then continue down。

Project maturity calibration proposal. Unless the objectives of the project owner are indeed required, no enterprise-level infrastructure is recommended for a weekend prototype project。

Analyse the real needs of the project and provide advice in the most effective manner。

If the code repository is large, please give priority to an in-depth analysis of the 20% of the core code, i.e. the 80% of the workload, and indicate which areas have been reviewed on a more shallow level。

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