extend-agent

extend-agent is a skill for Claude Code, Codex from agno-agi/agentos-render. It costs 114 tokens per session (2,128 once invoked), scanned B, a copy of extend-agent, Apache-2.0.

A guided workflow for changing an existing agent in AgentOS, the platform described by the skill. It covers adding tools or capabilities, refining instructions, and fixing a known problem, with checks against the running agent.

In plain words
What is it for?
Use it to add an MCP tool, knowledge base, memory, sub-agent, or scheduled task; improve instructions; or fix a specific agent bug.
Why use it?
It gives developers a defined path for making agent changes and checking them in a live development setup. It also routes Studio-built components through the platform builder instead of treating them like source files.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/agno-agi/agentos-render/extend-agent
Any agent
npx skills add agno-agi/agentos-render --skill extend-agent
Clone the repo
git clone --depth 1 https://github.com/agno-agi/agentos-render

Made for: Claude Code, Codex.

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 extend-agent

README.md
[![agentmods](https://agentmods.dev/badge/skills/agno-agi/agentos-render/extend-agent.svg)](https://agentmods.dev/skills/agno-agi/agentos-render/extend-agent)
Your own site
<a href="https://agentmods.dev/skills/agno-agi/agentos-render/extend-agent"><img src="https://agentmods.dev/badge/skills/agno-agi/agentos-render/extend-agent.svg" alt="Measured on agentmods" height="20"></a>
Per session 114 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,128 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 2 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod 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 $0.00114 $0.02128
Opus 5 $0.00057 $0.01064
Sonnet 5 $0.00023 $0.00426
Haiku 4.5 $0.00011 $0.00213

Measured 4d ago against content hash 149dbec12b67, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade B, and why

extend-agent scanned grade B with 2 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 4d 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.

Sends data to an external URLmediumData exfiltration

A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.

- `curl -sSf http://localhost:8000/health` returns 200 (else ask for `docker compose up -d --build`).

Makes network callslowCapability

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

- `curl -sSf http://localhost:8000/health` returns 200 (else ask for `docker compose up -d --build`).
Origin

This is a copy

100% identical to extend-agent — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/extend-agent/SKILL.md · 113 lines

How it starts

The opening of the file, as written. The whole thing — 113 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Extend an Agent

Coding-agent workflow: run as /extend-agent or by describing the task.

The user names a change; you implement it, verify it against the live agent, and ask if there's more. Stop when they say done. The autonomous half is improve-agent — run it afterward.

The platform is on http://localhost:8000 (RUNTIME_ENV=dev); code edits hot-reload.

0. Preconditions

  • curl -sSf http://localhost:8000/health returns 200 (else ask for docker compose up -d --build).
  • The container is bound to this checkout: docker inspect agentos-api --format '{{range .Mounts}}{{.Source}}{{"\n"}}{{end}}' | grep -F "$(pwd)" prints a line. Empty → cd to the bound repo or restart compose from here.
  • Ask for the target slug. Suggest a branch: git checkout -b extend/<slug>-$(date +%Y%m%d).

1. Read the agent

Confirm the slug is code, not a Studio-built component:

curl -s http://localhost:8000/agents | jq -r '.[] | "\(.id)\tis_component=\(.is_component)"'

is_component=true has no source file — route the change through Platform Builder (edit_agent / edit_team / edit_workflow, then publish_component). Never create agents/<slug>.py under that id: code wins on resolution and silently shadows the built component.

Open the file — agents/<slug>.py, or for the reference components platform-builderagents/builder.py, platform-manageragents/manager.py, platform-engineeragents/engineer.py, agnoteams/lead.py. Capture purpose (docstring + INSTRUCTIONS), tools, pattern, and the existing levers (learning=, knowledge=, num_history_runs, model). Restate the purpose in 1–2 sentences.

2. Ask what to change

Structured choice when the harness has one, else plain text. Multi-select is fine — handle sequentially, then loop:

  • Add a tool — MCP server, agno toolkit, or function tool.
  • Add a capability — knowledge base, learning/memory, sub-agent/context provider, scheduled task.
  • Grow the registry — declare a block in app/registry.py so everything the platform builds can carry it. Offer this unprompted when the ask is plural ("agents should be able to…").
  • Refine instructions — clarify, narrow, change tone or format.
  • Fix a bug — ask for the failing prompt, the observed behavior, what they want instead.
  • Something else.

Read the full file on GitHub · 113 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. 4d ago First seen · 113 lines · 114 tokens per session scan B 149dbec12b67

Subscribe to this mod's changes

extend-agent is a skill published in the GitHub repository agno-agi/agentos-render (3 stars, last pushed 4d ago), licensed Apache-2.0. It adds 114 tokens to every session and 2,128 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it B with 2 findings (sends data to an external url, makes network calls). It is 100% identical to extend-agent, differing in 0 lines, and is treated as a copy.

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