Official agent skill

Run Apichief

Run ApiChief in the EF Core repo to emit baselines, summaries, deltas, review files, or breaking-change checks.

OfficialMITAuto-check passed

Install Run Apichief

skills CLI

$ npx skills add dotnet/efcore --skill run-apichief -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install dotnet/efcore run-apichief --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/dotnet/efcore.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/run-apichief .claude/skills/run-apichief && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "run-apichief" agent skill from https://github.com/dotnet/efcore/tree/main/.agents/skills/run-apichief into .claude/skills/run-apichief/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "run-apichief", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/dotnet/efcore/tree/main/.agents/skills/run-apichief

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add dotnet/efcore --skill run-apichief -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install dotnet/efcore run-apichief --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/dotnet/efcore.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/run-apichief .agents/skills/run-apichief && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "run-apichief" agent skill from https://github.com/dotnet/efcore/tree/main/.agents/skills/run-apichief into .agents/skills/run-apichief/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "run-apichief", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add dotnet/efcore --skill run-apichief -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install dotnet/efcore run-apichief --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/dotnet/efcore.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/run-apichief .cursor/skills/run-apichief && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "run-apichief" agent skill from https://github.com/dotnet/efcore/tree/main/.agents/skills/run-apichief into .cursor/skills/run-apichief/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "run-apichief", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/dotnet/efcore.git --path .agents/skills/run-apichief

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add dotnet/efcore --skill run-apichief -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install dotnet/efcore run-apichief --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/dotnet/efcore.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/run-apichief .gemini/skills/run-apichief && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "run-apichief" agent skill from https://github.com/dotnet/efcore/tree/main/.agents/skills/run-apichief into .gemini/skills/run-apichief/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "run-apichief", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install dotnet/efcore run-apichief

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add dotnet/efcore --skill run-apichief -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/dotnet/efcore.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/run-apichief .github/skills/run-apichief && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "run-apichief" agent skill from https://github.com/dotnet/efcore/tree/main/.agents/skills/run-apichief into .github/skills/run-apichief/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "run-apichief", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add dotnet/efcore --skill run-apichief -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install dotnet/efcore run-apichief --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/dotnet/efcore.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/run-apichief .opencode/skills/run-apichief && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "run-apichief" agent skill from https://github.com/dotnet/efcore/tree/main/.agents/skills/run-apichief into .opencode/skills/run-apichief/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "run-apichief", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: run-apichief
GitHub stars: 15k
Token cost: ~1.3k tokens
SKILL.md length: 404 words
Files: 1
Skills in repo: 17
Repo updated: Oct 8, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Run ApiChief in the EF Core repo to emit baselines, summaries, deltas, review files, or breaking-change checks.

Works in 7 steps: Identify the target project(s) → Prepare the environment → Ensure the target binaries exist → …
Refreshing .baseline.json
SKILL.md covers Commands and Workflow
Calls dotnet

What it does

Run Apichief is an agent skill from dotnet/efcore, published by the product's own GitHub organization. Run ApiChief in the EF Core repo to emit baselines, summaries, deltas, review files, or breaking-change checks. Use when refreshing .baseline.json, preparing API review artifacts, or validating API changes.

Its SKILL.md is about 1.3k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It works with .NET. The repository describes itself as: EF Core is a modern object-database mapper for .NET. It supports LINQ queries, change tracking, updates, and schema migrations. The licence is MIT.

When your agent uses it

Refreshing .baseline.json
Preparing API review artifacts
Validating API changes

Example prompts

“/run-apichief”

Workflow steps

7 steps, taken from the step headings in SKILL.md.

Identify the target project(s)
Prepare the environment
Ensure the target binaries exist
Locate the built ApiChief binary and target assembly
Run the requested ApiChief command
Review or clean up baseline changes
Report results clearly

What it can do on your machine

Read from SKILL.md and the folder at commit d2f4410. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
- dotnet
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Run Apichief loads about 1.3k tokens when it runs. Until then it costs about 56 tokens; SKILL.md has 404 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~56
When it runs · the whole SKILL.md, loaded when a task matches: ~1.3k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from dotnet/efcore at commit d2f4410, republished under its MIT licence (© dotnet). 404 words, ~1,290 tokens.

Download SKILL.mdSave it as .claude/skills/run-apichief/SKILL.md (or your agent's skills folder).

name: run-apichief
description: Run ApiChief in the EF Core repo to emit baselines, summaries, deltas, review files, or breaking-change checks. Use when refreshing `*.baseline.json`, preparing API review artifacts, or validating API changes.
user-invocable: false

Run ApiChief

Use the ApiChief tool documented at eng/Tools/ApiChief/README.md to inspect or refresh EF Core public API baselines for projects under src/.

ApiChief can run against either a compiled assembly or a previously emitted baseline JSON file. Prefer the repo-local .dotnet SDK and the checked-in build scripts in this repo.

Commands

Command	Description	Extra arguments
`emit baseline`	Emit a JSON API baseline	`-o <file>`
`emit summary`	Emit a human-readable API summary	`-o <file>`, `-x`
`emit review`	Emit API review files	`-o <dir>`, `-n`
`emit delta`	Emit a delta against an existing baseline, or markdown diff review files	`<baseline-path>`, `-o <file-or-dir>`, `--diff`
`check breaking`	Fail if breaking changes exist vs. a baseline	`<baseline-path>`

Default to emit baseline if the user only asks to "run ApiChief".

Workflow

1. Identify the target project(s)

Match user intent against project folders under src/.
Ask for clarification only if the target is ambiguous.
The checked-in baseline path convention in this repo is src/<ProjectName>/<ProjectName>.baseline.json.
If asked just to update the baselines, run EFCore.ApiBaseline.Tests tests and skip the rest of the steps below.

2. Prepare the environment

Always initialize the repo environment before building or running the tool:

powershell

.\restore.cmd
. .\activate.ps1
dotnet build .\eng\Tools\ApiChief\ApiChief.csproj --nologo --verbosity q

On Bash:

bash

./restore.sh
. ./activate.sh
dotnet build ./eng/Tools/ApiChief/ApiChief.csproj --nologo --verbosity q

3. Ensure the target binaries exist

ApiChief operates on built assemblies. If the target project has not been built yet, build it first.

Preferred options:

powershell

# Refreshes checked-in baselines after the normal build
.\build.cmd -c Debug

# Or build a single project when working narrowly
dotnet build .\src\<ProjectName>\<ProjectName>.csproj --nologo --verbosity q

Use the highest available net* TFM under artifacts/bin/<ProjectName>/<Configuration>/ by default. Avoid netstandard* and net4* targets unless the user explicitly asks for them.

Show full SKILL.md (165 more words)Show less

4. Locate the built ApiChief binary and target assembly

powershell

$dotnet = ".\\.dotnet\\dotnet"
$apiChiefProject = ".\\eng\\Tools\\ApiChief\\ApiChief.csproj"
$apiChief = (& $dotnet msbuild $apiChiefProject --getProperty:TargetPath -p:Configuration=Debug --nologo).Trim()

$name = "<ProjectName>"
$tfm = Get-ChildItem ".\\artifacts\\bin\\$name\\Debug" -Directory |
    Where-Object { $_.Name -match '^net\d+\.\d+$' } |
    Sort-Object { [version]($_.Name -replace '^net', '') } -Descending |
    Select-Object -First 1 -ExpandProperty Name

$assemblyName = (& $dotnet msbuild ".\\src\\$name\\$name.csproj" --getProperty:AssemblyName -p:Configuration=Debug --nologo).Trim()
if ([string]::IsNullOrWhiteSpace($assemblyName))
{
    $assemblyName = $name
}

$assemblyPath = ".\\artifacts\\bin\\$name\\Debug\\$tfm\\$assemblyName.dll"

Before running, report the selected TFM if it matters for the task.

5. Run the requested ApiChief command

powershell

# Emit a baseline
& $dotnet $apiChief $assemblyPath emit baseline -o ".\\src\\$name\\$name.baseline.json"

# Emit a summary
& $dotnet $apiChief $assemblyPath emit summary

# Emit a delta
& $dotnet $apiChief $assemblyPath emit delta ".\\src\\$name\\$name.baseline.json" -o ".\\artifacts\\tmp\\$name.delta.json"

# Check for breaking changes
& $dotnet $apiChief $assemblyPath check breaking ".\\src\\$name\\$name.baseline.json"

# Emit API review artifacts
& $dotnet $apiChief $assemblyPath emit review -o ".\\artifacts\\tmp\\API.$name"

# Emit GitHub-friendly markdown diff files against a baseline
& $dotnet $apiChief $assemblyPath emit delta ".\\src\\$name\\$name.baseline.json" --diff -o ".\\artifacts\\tmp\\API.$name.Diff"

emit delta also supports passing a .json file as the current input instead of a DLL.

6. Review or clean up baseline changes

After emit baseline:

preserve the original BOM and trailing newline behavior of the committed file
revert version-only diffs in the "Name" field
inspect removed // instruction comments in previous baselines and carry forward any still-needed manual edits
if those comments reference GitHub issues, check whether the underlying issue is still open before reapplying the workaround

7. Report results clearly

list the processed project(s)
show the chosen TFM(s)
report the output path(s)
for check breaking, state pass/fail
for emit delta and emit delta --diff, mention that exit code 0 means changes, 2 means no changes, and -1 means an error
prefer emit delta --diff output because it generates ready-to-post ```diff fenced markdown split across per-type .md files

Files

Just SKILL.md in .agents/skills/run-apichief of dotnet/efcore.

Open the folder on GitHubat commit d2f4410

Compare with similar skills

Run Apichief next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Run Apichief compared with similar skills
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Microsoft Skill CreatorMicrosoftDocs/mcp	1.9k	3 repos	~2.1k	Automated safety check: Pass	CC-BY-4.0	today
Speckit ConstitutionWeihanLi/WeihanLi.Common	242	11 repos	~2.1k	Automated safety check: Pass	Apache-2.0	24 days ago
Copilot Session Failure Analysisdotnet/maui	23k	—	~3.4k	Automated safety check: Pass	MIT	today
Microsoft Code ReferenceMicrosoftDocs/mcp	1.9k	4 repos	~1.1k	Automated safety check: Pass	CC-BY-4.0	today

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Questions about Run Apichief

What does Run Apichief do?

Run ApiChief in the EF Core repo to emit baselines, summaries, deltas, review files, or breaking-change checks. Run Apichief is an agent skill from dotnet/efcore, published by the product's own GitHub organization. Run ApiChief in the EF Core repo to emit baselines, summaries, deltas, review files, or breaking-change checks.

When should I use Run Apichief?

Run Apichief fits situations like: refreshing .baseline.json; preparing API review artifacts; validating API changes.

How do I install Run Apichief in Claude Code?

Run `npx skills add dotnet/efcore --skill run-apichief -a claude-code`. Or copy the skill folder (.agents/skills/run-apichief in dotnet/efcore) into .claude/skills/run-apichief in your project. Claude Code loads it when a task matches its description.

How do I install Run Apichief in Codex?

Run `npx skills add dotnet/efcore --skill run-apichief -a codex`. Or copy the skill folder (.agents/skills/run-apichief in dotnet/efcore) into .agents/skills/run-apichief in your project. Codex loads it when a task matches its description.

Can I use Run Apichief in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add dotnet/efcore --skill run-apichief -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/run-apichief, .gemini/skills/run-apichief, .github/skills/run-apichief and .opencode/skills/run-apichief in your project.

What does Run Apichief need to run?

Going by SKILL.md and its folder, Run Apichief needs the command-line tools its instructions call (dotnet).

Does Run Apichief access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Run Apichief safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Run Apichief use?

Run Apichief is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Run Apichief use?

About 1.3k tokens (SKILL.md is roughly 5.2k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Run Apichief?

Skills that share tags, products or a category with Run Apichief: Minimax DOCX (poco-ai/poco-claw, 1.4k stars), Microsoft Skill Creator (MicrosoftDocs/mcp, 1.9k stars), Speckit Constitution (WeihanLi/WeihanLi.Common, 242 stars) and Copilot Session Failure Analysis (dotnet/maui, 23k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Run Apichief?

dotnet (a GitHub organization, an official publisher) maintains it in dotnet/efcore, which has 14,800 GitHub stars. The repository holds 17 skills in this directory. The repository was last updated on October 8, 2026.

Source: dotnet/efcore on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Run Apichief

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Run ApiChief

Commands

Workflow

1. Identify the target project(s)

2. Prepare the environment

3. Ensure the target binaries exist

4. Locate the built ApiChief binary and target assembly

5. Run the requested ApiChief command

6. Review or clean up baseline changes

7. Report results clearly

Files

Compare with similar skills

Similar skills

More from dotnet/efcore

Related

Questions about Run Apichief