Agent skill

Error Handling

Error handling patterns in Celeriant. An agent skill from celeriant/celeriant-db.

Apache-2.0Auto-check passedDevelopment

Install Error Handling

skills CLI

$ npx skills add celeriant/celeriant-db --skill error-handling -a claude-code

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

GitHub CLI

$ gh skill install celeriant/celeriant-db error-handling --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/celeriant/celeriant-db.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/error-handling .claude/skills/error-handling && 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 "error-handling" agent skill from https://github.com/celeriant/celeriant-db/tree/main/.claude/skills/error-handling into .claude/skills/error-handling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "error-handling", 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/celeriant/celeriant-db/tree/main/.claude/skills/error-handling

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 celeriant/celeriant-db --skill error-handling -a codex

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

GitHub CLI

$ gh skill install celeriant/celeriant-db error-handling --agent codex

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

Manual copy

$ git clone --depth 1 https://github.com/celeriant/celeriant-db.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.claude/skills/error-handling .agents/skills/error-handling && 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 "error-handling" agent skill from https://github.com/celeriant/celeriant-db/tree/main/.claude/skills/error-handling into .agents/skills/error-handling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "error-handling", 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 celeriant/celeriant-db --skill error-handling -a cursor

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

GitHub CLI

$ gh skill install celeriant/celeriant-db error-handling --agent cursor

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

Manual copy

$ git clone --depth 1 https://github.com/celeriant/celeriant-db.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.claude/skills/error-handling .cursor/skills/error-handling && 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 "error-handling" agent skill from https://github.com/celeriant/celeriant-db/tree/main/.claude/skills/error-handling into .cursor/skills/error-handling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "error-handling", 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/celeriant/celeriant-db.git --path .claude/skills/error-handling

--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 celeriant/celeriant-db --skill error-handling -a gemini-cli

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

GitHub CLI

$ gh skill install celeriant/celeriant-db error-handling --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/celeriant/celeriant-db.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.claude/skills/error-handling .gemini/skills/error-handling && 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 "error-handling" agent skill from https://github.com/celeriant/celeriant-db/tree/main/.claude/skills/error-handling into .gemini/skills/error-handling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "error-handling", 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 celeriant/celeriant-db error-handling

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 celeriant/celeriant-db --skill error-handling -a github-copilot

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

Manual copy

$ git clone --depth 1 https://github.com/celeriant/celeriant-db.git skills-src && mkdir -p .github/skills && cp -r skills-src/.claude/skills/error-handling .github/skills/error-handling && 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 "error-handling" agent skill from https://github.com/celeriant/celeriant-db/tree/main/.claude/skills/error-handling into .github/skills/error-handling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "error-handling", 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 celeriant/celeriant-db --skill error-handling -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 celeriant/celeriant-db error-handling --agent opencode

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

Manual copy

$ git clone --depth 1 https://github.com/celeriant/celeriant-db.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.claude/skills/error-handling .opencode/skills/error-handling && 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 "error-handling" agent skill from https://github.com/celeriant/celeriant-db/tree/main/.claude/skills/error-handling into .opencode/skills/error-handling/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "error-handling", 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: error-handling
GitHub stars: 114
Token cost: ~550 tokens
SKILL.md length: 209 words
Files: 1
Skills in repo: 13
Repo updated: Sep 28, 2026
First seen: Oct 7, 2026
Licence: Apache-2.0

At a glance

Error handling patterns in Celeriant. An agent skill from celeriant/celeriant-db.

Works in 4 steps: Add a variant with typed fields to the… → Write manual From impl if it converts… → Add the mapping in error_to_response()… → …
Creating new error types
SKILL.md covers Typed Enum Variants, Not Strings, No thiserror, Conversion Chain and Client Boundary, plus 1 more section
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Error Handling is an agent skill from celeriant/celeriant-db. Error handling patterns in Celeriant. Typed enum variants over strings, manual From impls, no thiserror. Use when creating new error types, handling errors, or converting errors to client responses.

Its SKILL.md is about 550 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Development, covering Error handling. The repository describes itself as: Fast, distributed per-aggregate event log with strict ordering and optimistic concurrency control. The licence is Apache-2.0.

When your agent uses it

Creating new error types
Handling errors
Converting errors to client responses

Example prompts

“/error-handling”

Workflow steps

4 steps, taken from the first numbered list in SKILL.md.

Add a variant with typed fields to the appropriate error enum
Write manual From impl if it converts from a lower-level error
Add the mapping in error_to_response() if it can reach clients
Pick the right error code from error_codes.rs

What it can do on your machine

Read from SKILL.md and the folder at commit d071a6d. 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
No scripts in the folder and no shell commands in SKILL.md (its code samples are rust).
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

Error Handling loads about 550 tokens when it runs. Until then it costs about 53 tokens; SKILL.md has 209 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~53
When it runs · the whole SKILL.md, loaded when a task matches: ~550

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 celeriant/celeriant-db at commit d071a6d, republished under its Apache-2.0 licence (© celeriant). 209 words, ~550 tokens.

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

name: error-handling
description: Error handling patterns in Celeriant. Typed enum variants over strings, manual From impls, no thiserror. Use when creating new error types, handling errors, or converting errors to client responses.

Error Handling

Typed Enum Variants, Not Strings

Every error is a typed enum variant with typed fields carrying contextual data. Callers match on variants and use the fields to make decisions. No string parsing.

rust

// This is what errors look like here
ShardWriteError::OptimisticConcurrencyViolation {
    expected_version: u64,
    current_aggregate_version: u64,
}

Strings are acceptable for: I/O errors, catch-all infrastructure failures where you can't enumerate the cases, and wrapping errors that don't implement Clone/Send (common with glommio and io_uring error types).

No thiserror

thiserror encourages #[error("...")] string formatting at creation time, losing structured data. We use manual From implementations instead. They make error flow explicit, preserve typed data through the chain, and only convert to strings at the client boundary.

Conversion Chain

std::io::Error / GlommioError / bincode::Error
            -> RotatingLogError / WireFormatError
            -> ShardCacheError / ShardFsyncError
            -> ShardReadError / ShardWriteError
            -> ShardError
            -> ErrorResponse (to client, via error_to_response())

Only use ? (auto-From) when context is preserved. If two different calls in the same function produce the same error type, convert explicitly so you know which one failed.

Client Boundary

All errors sent to clients become ErrorResponse { correlation_id, error_code, error_message }. String formatting happens here and nowhere else. Error codes are defined in celeriant_msg/src/error_codes.rs. The conversion lives in celeriant_runtimes/src/sharded/connection_handler.rs.

Adding a New Error

Add a variant with typed fields to the appropriate error enum
Write manual From impl if it converts from a lower-level error
Add the mapping in error_to_response() if it can reach clients
Pick the right error code from error_codes.rs

Files

Just SKILL.md in .claude/skills/error-handling of celeriant/celeriant-db.

Open the folder on GitHubat commit d071a6d

Compare with similar skills

Error Handling 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.

Error Handling compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Error Handling this skillceleriant/celeriant-db	114	—	~550	Automated safety check: Pass	Apache-2.0	9 days ago
Native Data FetchingCherryHQ/cherry-studio-app	4k	6 repos	~2.9k	Automated safety check: Notes	MIT	4 days ago
Zodjasonjgardner/blockbench-mcp-plugin	488	3 repos	~1.4k	Automated safety check: Pass	GPL-3.0	6 days ago
Akka.NET Best PracticesAaronontheweb/dotnet-skills	1.2k	1 repos	~3.3k	Automated safety check: Pass	MIT	20 days ago
Windmill Rust Backend Patternswindmill-labs/windmill	18k	—	~869	Automated safety check: Pass	Custom licence	today
Rust SkillsJMBeresford/retrom	2.1k	1 repos	~9.5k	Automated safety check: Pass	MIT	3 days ago

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Questions about Error Handling

What does Error Handling do?

Error handling patterns in Celeriant. An agent skill from celeriant/celeriant-db. Error Handling is an agent skill from celeriant/celeriant-db. Error handling patterns in Celeriant.

When should I use Error Handling?

Error Handling fits situations like: creating new error types; handling errors; converting errors to client responses.

How do I install Error Handling in Claude Code?

Run `npx skills add celeriant/celeriant-db --skill error-handling -a claude-code`. Or copy the skill folder (.claude/skills/error-handling in celeriant/celeriant-db) into .claude/skills/error-handling in your project. Claude Code loads it when a task matches its description.

How do I install Error Handling in Codex?

Run `npx skills add celeriant/celeriant-db --skill error-handling -a codex`. Or copy the skill folder (.claude/skills/error-handling in celeriant/celeriant-db) into .agents/skills/error-handling in your project. Codex loads it when a task matches its description.

Can I use Error Handling 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 celeriant/celeriant-db --skill error-handling -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/error-handling, .gemini/skills/error-handling, .github/skills/error-handling and .opencode/skills/error-handling in your project.

What does Error Handling need to run?

SKILL.md names no scripts, command-line tools or credentials: Error Handling is instructions for the agent only.

Does Error Handling 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 Error Handling 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 Error Handling use?

Error Handling is published under the Apache-2.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Error Handling use?

About 550 tokens (SKILL.md is roughly 2.2k 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 Error Handling?

Skills that share tags, products or a category with Error Handling: Native Data Fetching (CherryHQ/cherry-studio-app, 4k stars), Zod (jasonjgardner/blockbench-mcp-plugin, 488 stars), Akka.NET Best Practices (Aaronontheweb/dotnet-skills, 1.2k stars) and Windmill Rust Backend Patterns (windmill-labs/windmill, 18k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Error Handling?

celeriant (a GitHub organization) maintains it in celeriant/celeriant-db, which has 114 GitHub stars. The repository holds 13 skills in this directory. The repository was last updated on September 28, 2026.

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

Error Handling

Install Error Handling

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

Error Handling

Typed Enum Variants, Not Strings

No thiserror

Conversion Chain

Client Boundary

Adding a New Error

Files

Compare with similar skills

Similar skills

Native Data Fetching

Zod

Akka.NET Best Practices

Windmill Rust Backend Patterns

Rust Skills

Rust Skills

More from celeriant/celeriant-db

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Extract A Type

Client Server Protocol

Database Architecture

Glommio Locking Patterns

Questions about Error Handling

Install Error Handling

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

Error Handling

Typed Enum Variants, Not Strings

No thiserror

Conversion Chain

Client Boundary

Adding a New Error

Files

Compare with similar skills

Similar skills

More from celeriant/celeriant-db

Related

Questions about Error Handling