dotnet-devcert-trust

dotnet-devcert-trust is a skill for Claude Code from Aaronontheweb/dotnet-skills. It costs 50 tokens per session (4,084 once invoked), scanned D, original, MIT.

A troubleshooting skill for making .NET development HTTPS certificates trusted on Linux. A development certificate is a local certificate used to secure connections between apps and services during development.

In plain words
What is it for?
It helps set up or repair trusted certificates for HTTPS, Redis, Aspire dashboards, gRPC connections, Ubuntu, Fedora, Arch, and WSL2.
Why use it?
It addresses localhost and service-to-service TLS errors that can occur because Linux does not automatically place the certificate in the system or browser trust stores.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the dotnet-skills plugin — 36 skills, 6 agents shipped together

Good fit It helps set up or repair trusted certificates for HTTPS, Redis, Aspire dashboards, gRPC connections, Ubuntu, Fedora, Arch, and WSL2.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/aaronontheweb/dotnet-skills/dotnet-devcert-trust
About the project

.NET Skills is an AI coding plugin that provides skills and specialized guidance for professional .NET development, covering areas such as C#, Akka.NET, Aspire, Entity Framework Core, testing, and performance. .NET developers use it with coding assistants to apply production-oriented patterns while building and maintaining applications. The catalogue contains the plugin’s skills, agents, and instructions.

Aaronontheweb/dotnet-skills · 1,143 stars · on GitHub

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.

Any agent
npx skills add Aaronontheweb/dotnet-skills --skill dotnet-devcert-trust
Clone the repo
git clone --depth 1 https://github.com/Aaronontheweb/dotnet-skills

Made for: Claude Code.

Or install dotnet-skills, the plugin that ships this one along with the rest of its 36 skills, 6 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for dotnet-devcert-trust

README.md
[![agentmods](https://agentmods.dev/badge/skills/aaronontheweb/dotnet-skills/dotnet-devcert-trust.svg)](https://agentmods.dev/skills/aaronontheweb/dotnet-skills/dotnet-devcert-trust)
Your own site
<a href="https://agentmods.dev/skills/aaronontheweb/dotnet-skills/dotnet-devcert-trust"><img src="https://agentmods.dev/badge/skills/aaronontheweb/dotnet-skills/dotnet-devcert-trust.svg" alt="Measured on agentmods" height="20"></a>
Per session 50 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,084 The whole file, excluding the scripts and references it only reads on demand.
Security scan D 3 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • Socket pass 18 Mar 2026
  • Snyk warn 16 Feb 2026
How audits are shown
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 5.1 $0.00050 $0.04084
Opus 5 $0.00025 $0.02042
Sonnet 5 $0.00010 $0.00817
Haiku 4.5 $0.00005 $0.00408

Measured 8d ago against content hash 1782921a25da, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade D, and why

dotnet-devcert-trust scanned grade D with 3 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 8d 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.

Asks for rootmediumPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

sudo rm -f /usr/local/share/ca-certificates/aspnetcore-dev.crt

Recursive force deletehighDestructive command

rm -rf with a variable or a broad path is one typo away from removing the wrong tree.

sudo rm -rf /usr/local/share/ca-certificates/aspnet/

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

This means .NET applications, OpenSSL, curl, and browsers all reject the dev certificate — even though `dotnet dev-certs https --check` reports it exists.
Origin

Copies of this mod

1 near-identical copy found in the catalogue:

skills/dotnet-devcert-trust/SKILL.md · 415 lines

How it starts

The opening of the file, as written. The whole thing — 415 lines — stays where its author put it; the contents beside it link to each section on GitHub.

.NET Dev Certificate Trust on Linux

When to Use This Skill

Use this skill when:

  • Redis TLS connections fail with UntrustedRoot or RemoteCertificateNameMismatch in Aspire
  • dotnet dev-certs https --check --trust returns exit code 7
  • HTTPS localhost connections fail with certificate validation errors
  • After running dotnet dev-certs https --clean and needing to restore trust
  • Setting up a new Linux dev machine for .NET HTTPS development
  • Aspire dashboard or inter-service gRPC calls fail with TLS errors
  • Upgrading from Aspire < 13.1.0 (which didn't use TLS on Redis by default)

The Problem

On Windows and macOS, dotnet dev-certs https --trust handles everything automatically — it generates the certificate, installs it in the user store, and adds it to the system trust store. On Linux, it does almost nothing useful. The command generates the cert and places it in the user store, but:

  1. It does not export the certificate to the system CA directory
  2. It does not run update-ca-certificates to rebuild the CA bundle
  3. It does not add the cert to browser trust stores (NSS/NSSDB)
  4. The --trust flag silently succeeds but the cert remains untrusted

This means .NET applications, OpenSSL, curl, and browsers all reject the dev certificate — even though dotnet dev-certs https --check reports it exists.

Why This Surfaces with Aspire 13.1.0+

Prior to Aspire 13.1.0, Redis connections used plaintext. Starting with 13.1.0, Aspire enables TLS on Redis by default. If your dev cert isn't trusted at the system level, Redis connections fail immediately with:

System.Security.Authentication.AuthenticationException:
  The remote certificate is invalid because of errors in the certificate chain: UntrustedRoot

How Linux Certificate Trust Works

Understanding the architecture prevents cargo-cult debugging:

┌─────────────────────────────────────────────────────┐
│ Application (.NET, curl, OpenSSL)                   │
│   reads: /etc/ssl/certs/ca-certificates.crt         │
│          (consolidated CA bundle)                    │
└──────────────────────┬──────────────────────────────┘
                       │ built by
┌──────────────────────▼──────────────────────────────┐
│ update-ca-certificates                              │
│   reads from:                                        │
│     /usr/share/ca-certificates/      (distro CAs)   │
│     /usr/local/share/ca-certificates/ (local CAs)   │
│   writes to:                                         │
│     /etc/ssl/certs/ca-certificates.crt (bundle)     │
│     /etc/ssl/certs/*.pem (individual symlinks)      │
└─────────────────────────────────────────────────────┘

Read the full file on GitHub · 415 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. 8d ago First seen · 415 lines · 50 tokens per session scan D 1782921a25da

Subscribe to this mod's changes

dotnet-devcert-trust is a skill published in the GitHub repository Aaronontheweb/dotnet-skills (1,143 stars, last pushed 1mo ago), licensed MIT. It adds 50 tokens to every session and 4,084 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it D with 3 findings (asks for root, recursive force delete, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories

dotnet-reverse

A guide for analyzing compiled .NET and C# programs, including managed Windows executables and libraries. Reverse engineering means studying compiled software to understand how it works, and decompiling turns it back into readable approximate source code.

zhaoxuya520/reverse-skill · 144 tokens

check-bin-obj-clash

Detects MSBuild projects with conflicting OutputPath or IntermediateOutputPath. USE FOR: builds failing with 'Cannot create a file when that file already exists', 'The process cannot access the file because it is being used by another process', intermittent build failures that succeed on retry, or missing/overwritten…

dotnet/skills · 160 tokens

build-perf-diagnostics

Diagnose MSBuild build performance bottlenecks using binary log analysis. USE FOR: identifying why builds are slow by analyzing binlog performance summaries, detecting ResolveAssemblyReference (RAR) taking >5s, Roslyn analyzers consuming >30% of Csc time, single targets dominating >50% of build time, node utilization…

dotnet/skills · 160 tokens

dump-collect

Configure and collect crash dumps for modern .NET applications. USE FOR: enabling automatic crash dumps for CoreCLR or NativeAOT, capturing dumps from running .NET processes, setting up dump collection in Docker or Kubernetes, using dotnet-dump collect or createdump. DO NOT USE FOR: analyzing or debugging dumps…

dotnet/skills · 96 tokens

binlog-generation

Generate MSBuild binary logs (binlogs) for build diagnostics and analysis. USE FOR: adding /bl:{} to any dotnet build, test, pack, publish, or restore command to capture a full build execution trace, prerequisite for binlog-failure-analysis and build-perf-diagnostics skills, enabling post-build investigation of errors…

dotnet/skills · 133 tokens

binlog-failure-analysis

Analyze MSBuild binary logs to diagnose build failures. USE FOR: build errors that are unclear from console output, diagnosing cascading failures across multi-project builds, tracing MSBuild target execution order, and generally any MSBuild build issues. Requires an existing .binlog file. DO NOT USE FOR: generating…

dotnet/skills · 79 tokens