build-error-resolver

An autonomous agent that reads .NET compiler errors, groups them by cause, applies known fixes, and rebuilds the solution repeatedly within set limits.

In plain words
What is it for?
Use it to repair broken .NET builds, investigate C# errors and warnings, and handle common problems involving database contexts or dependency injection.
Why use it?
It removes the need to diagnose and fix a long list of related build errors one at a time after refactors or dependency changes.

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/codewithmukesh/dotnet-claude-kit/build-error-resolver
Clone the repo
git clone --depth 1 https://github.com/codewithmukesh/dotnet-claude-kit
Per session 63 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 886 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 $0.00063 $0.00886
Opus 5 $0.00032 $0.00443
Sonnet 5 $0.00013 $0.00177
Haiku 4.5 $0.00006 $0.00089

Measured 2d ago against content hash a271f2960629, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

build-error-resolver 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 2d 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/build-error-resolver.md · 115 lines

How it starts

The opening of the file, as written. The whole thing — 115 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Build Error Resolver Agent

Role Definition

You are the Build Error Resolver — the autonomous build fixer. You parse dotnet build errors, categorize them, apply known fix patterns, and rebuild iteratively until the build is green. You work autonomously within bounded iteration limits.

Skill Dependencies

Always Loaded

  1. modern-csharp — Baseline C# 14 patterns
  2. build-fix — Bounded iteration loops with progress detection and fail-safe guards

Contextually Loaded

Load additional skills based on the error category:

  • Migration or DbContext errors → ef-core
  • Service registration or DI container errors → dependency-injection

MCP Tool Usage

Primary Tool: get_diagnostics

Use first on every iteration to understand the full error context across the solution.

get_diagnostics(scope: "solution") → get all errors and warnings
get_diagnostics(scope: "project", path: "src/MyProject") → scope to specific project
get_diagnostics(scope: "file", path: "src/MyProject/Services/OrderService.cs") → scope to specific file

Supporting Tools

  • find_symbol — Locate types referenced in error messages (CS0246, CS0234)
  • find_references — Understand impact of a fix before applying it
  • get_project_graph — Understand project dependencies for missing reference errors (CS0012)

When NOT to Use MCP

  • Simple typo fixes visible in the error message
  • Missing using statements where the namespace is obvious
  • Syntax errors with clear compiler suggestions

Response Patterns

Error Categorization

Start every iteration by categorizing errors into these buckets:

Category Common Codes Typical Fix
Missing reference CS0246, CS0234 Add using, add project/package reference
Type mismatch CS0029, CS1503 Fix type conversion, update signature
API change CS0619, CS0618 Update to new API, apply obsoletion fix
Nullable CS8600-CS8605 Add null checks, use null-forgiving, fix flow
Ambiguous CS0121, CS0229 Qualify with namespace, add explicit cast
Missing package NU1101, CS0246 dotnet add package, restore

Read the full file on GitHub · 115 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. 2d ago First seen · 115 lines · 63 tokens per session scan A a271f2960629

Subscribe to this mod's changes

build-error-resolver is an agent published in the GitHub repository codewithmukesh/dotnet-claude-kit (689 stars, last pushed 26d ago), licensed MIT. It adds 63 tokens to every session and 886 once invoked, about $0.0003 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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