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.
npx agentmods add skills/softaworks/agent-toolkit/excalidrawnpx skills add softaworks/agent-toolkit --skill excalidrawgit clone --depth 1 https://github.com/softaworks/agent-toolkitWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00069 | $0.01895 |
| Opus 5 | $0.00034 | $0.00948 |
| Sonnet 5 | $0.00014 | $0.00379 |
| Haiku 4.5 | $0.00007 | $0.00189 |
Grade A, and why
excalidraw 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 3d 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.
How it starts
The opening of the file, as written. The whole thing — 222 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Excalidraw Subagent Delegation
Overview
Core principle: Main agents NEVER read Excalidraw files directly. Always delegate to subagents to isolate context consumption.
Excalidraw files are JSON with high token cost but low information density. Single files range from 4k-22k tokens (largest can exceed read tool limits). Reading multiple diagrams quickly exhausts context budget (7 files = 67k tokens = 33% of budget).
The Problem
Excalidraw JSON structure:
- Each shape has 20+ properties (x, y, width, height, strokeColor, seed, version, etc.)
- Most properties are visual metadata (positioning, styling, roughness)
- Actual content: text labels and element relationships (<10% of file)
- Signal-to-noise ratio is extremely low
Example: 14-element diagram = 596 lines, 16K, ~4k tokens. 79-element diagram = 2,916 lines, 88K, ~22k tokens (exceeds read limit).
When to Use
Trigger on ANY of these:
- File path contains
.excalidrawor.excalidraw.json - User requests: "explain/update/create diagram", "show architecture", "visualize flow"
- User mentions: "flowchart", "architecture diagram", "Excalidraw file"
- Architecture/design documentation tasks involving visual artifacts
Use delegation even for:
- "Small" files (smallest is 4k tokens - still significant)
- "Quick checks" (checking component names still loads full JSON)
- Single file operations (isolation prevents context pollution)
- Modifications (don't need full format understanding in main context)
Delegation Pattern
Main Agent Responsibilities
NEVER:
- ❌ Use Read tool on *.excalidraw files
- ❌ Parse Excalidraw JSON in main context
- ❌ Load multiple diagrams for comparison
- ❌ Inspect file to "understand the format"
ALWAYS:
- ✅ Delegate ALL Excalidraw operations to subagents
- ✅ Provide clear task description to subagent
- ✅ Request text-only summaries (not raw JSON)
- ✅ Keep diagram analysis isolated from main work
Subagent Task Templates
Read/Understand Operation
Task: Extract and explain the components in [file.excalidraw.json]
Approach:
1. Read the Excalidraw JSON
2. Extract only text elements (ignore positioning/styling)
3. Identify relationships between components
4. Summarize architecture/flow
Return:
- List of components/services with descriptions
- Connection/dependency relationships
- Key insights about the architecture
- DO NOT return raw JSON or verbose element details
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 3d ago First seen · 222 lines · 69 tokens per session scan A 561c01a2b0c7
excalidraw is a skill published in the GitHub repository softaworks/agent-toolkit (2,413 stars, last pushed 6mo ago), licensed MIT. It adds 69 tokens to every session and 1,895 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.
Other skills, from other repositories
terminal-capture
Automates terminal UI screenshot testing for CLI commands. Applies when reviewing PRs that affect CLI output, testing slash commands (/about, /context, /auth, /export), generating visual documentation, or when 'terminal screenshot', 'CLI test', 'visual test', or 'terminal-capture' is mentioned.
batch
Execute batch operations on multiple files in parallel. Automatically discovers files, splits into chunks, and processes with parallel worker agents. Use /batch followed by operation and file pattern.
fleet-manager
Use when managing, triaging, restarting, escalating, or summarizing Codewhale Pod runs and workers.
gh-assign-issues
Use to assign GitHub issues to a milestone and/or owners in bulk, verifying each.
mcp-builder
Design, build, configure, or debug Model Context Protocol servers for codewhale, including stdio and HTTP/SSE transports.
extension-creator
Create, scaffold, customize, validate, and locally test Qwen Code extensions. Use when the user wants a new Qwen Code extension, needs help choosing an extension template, wants to add QWEN.md context, commands, skills, agents, MCP servers, settings, hooks, channels, or LSP servers, or asks how to link and test an…