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 skills add CrowdStrike/foundry-skills --skill functions-developmentgit clone --depth 1 https://github.com/CrowdStrike/foundry-skillsWrote 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.
[](https://agentmods.dev/skills/crowdstrike/foundry-skills/functions-development)<a href="https://agentmods.dev/skills/crowdstrike/foundry-skills/functions-development"><img src="https://agentmods.dev/badge/skills/crowdstrike/foundry-skills/functions-development/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/crowdstrike/foundry-skills/functions-development"><img src="https://agentmods.dev/badge/skills/crowdstrike/foundry-skills/functions-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00195 | $0.05032 |
| Opus 5.5 | $0.00078 | $0.02013 |
| Sonnet 5.5 | $0.00039 | $0.01006 |
| Haiku 4.5 | $0.00019 | $0.00503 |
Grade A, and why
functions-development scanned grade A with 1 finding 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 15d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
**CRITICAL:** If the API has a REST endpoint and an OpenAPI spec exists, you MUST use an API integration. NEVER use `os.environ` with API keys, `requests.get()` with hardcoded URLs, or localStorage for credentials when a How it starts
The opening of the file, as written. The whole thing — 417 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Foundry Functions Development
Loading this skill is NOT a command to do anything. It only equips you with function-development knowledge. Do NOT run any
foundry functionscommand (especiallyexec,test, or a deploy) just because the skill loaded — wait for the user's actual request, and if their intent isn't clear yet, ask what they'd like to do. Never execute, test, or deploy a function unprompted.When you implement or modify functions:
- Use CrowdStrike SDKs (gofalcon/falconpy) for ALL API interactions
- Implement structured JSON responses with proper status codes
- Apply input validation before processing any request
Falcon Foundry Functions are serverless handlers in Go or Python, executed inside the Foundry FaaS runtime. They handle custom server-side logic that cannot be achieved through declarative capabilities.
Functions as a Last Resort
Before writing a function, exhaust alternatives — each one avoids deployment complexity, cold start latency, and maintenance overhead:
- Collections for data storage and retrieval (CRUD without custom logic)
- Workflows for orchestrating multi-step operations
- API Integrations (HTTP Actions) for calling external APIs directly from workflows
- UI Extensions with
foundry-jsfor client-side data fetching
Credential Management — No Secrets System Exists
There is no secrets management in Falcon Foundry. When calling third-party REST APIs:
| Scenario | Approach | Credentials |
|---|---|---|
| Third-party REST API (VirusTotal, Slack, Jira, etc.) | API integration in manifest + APIIntegrations().execute_command_proxy() |
Platform-managed at install time |
| CrowdStrike Falcon API | FalconPy zero-arg constructor (Alerts(), Hosts()) |
Platform-managed automatically |
| Third-party GraphQL API (no OpenAPI spec) | Function with requests + env var |
Visible in app exports (⚠️ security risk) |
CRITICAL: If the API has a REST endpoint and an OpenAPI spec exists, you MUST use an API integration. NEVER use os.environ with API keys, requests.get() with hardcoded URLs, or localStorage for credentials when an API integration can handle it. Raw HTTP with env vars technically works, but credentials are unencrypted and visible in app exports.
What ships with it
5 files 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.
- 15d ago Changed 75e1c773a3bc
- 17d ago Changed · -4 lines 42f97d5af2d3
- 23d ago Changed · +14 lines d4723a09f990
- 25d ago Changed 54852a26893d
- 1mo ago First seen · 407 lines · 195 tokens per session scan A fff2065b0c76
functions-development is a skill published in the GitHub repository CrowdStrike/foundry-skills (35 stars, last pushed today), licensed MIT. It adds 195 tokens to every session and 5,032 once invoked, about $0.0008 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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