All 32 agent manifests and 17 hands shipped with empty mcp_servers /
skills lists, which the kernel interprets as "no filter" — every
globally-configured MCP server's tools and every installed skill get
injected into the prompt on every LLM call. On a typical instance (9
MCP servers, ~85 MCP tools + ~82 built-in tools) that's ~50k input
tokens per turn spent on definitions the agent never uses.
Changes
-------
32 agents/*/agent.toml:
- mcp_servers: 1-4 per agent. memory wherever state persists across
turns; fetch / exa-search / brave-search only where the prompt
actually calls for web; git / github / filesystem on engineering
agents; gmail / google-calendar / linear / jira on productivity
agents whose prompts mention them.
- skills: per-role allowlist driven by what the system_prompt names
(e.g. coder → rust/python/typescript/git/shell-scripting; devops-
lead → docker/kubernetes/terraform/ansible/ci-cd/helm/prometheus/
sysadmin). Generalists (assistant) keep skills = [] (see "Open
items" below).
- skills_disabled = true on the four short-conversational agents
(hello-world, recipe-assistant, health-tracker, home-automation).
Their system prompts never instruct the LLM to consult any skill,
so loading all 60 was pure waste. They also drop the explicit
max_history_messages override and inherit the kernel default (60).
- max_history_messages tiered by workload shape:
60 short conversational (hello-world, recipe, health-tracker,
home-automation) — inherits the rising kernel default
(`DEFAULT_MAX_HISTORY_MESSAGES = 60`); no override needed.
60 single-turn task agents (writer, translator, doc-writer,
email-assistant, customer-support, sales-assistant, recruit-
er, social-media, personal-finance, tutor, travel-planner,
meeting-assistant, ops, devops-lead, planner) — explicit
override at the same value to lock the cap if the kernel
default moves again.
80 multi-step / tool-heavy (coder, debugger, architect, code-
reviewer, test-engineer, security-auditor, analyst, data-
scientist, academic-researcher, researcher, legal-assistant)
120 coordinators (assistant, orchestrator) — long multi-agent
sessions where prompt-cache continuity is critical
All values sit at or above the kernel default. Pinning lower
would thrash the prompt cache (the failure mode #91 fixed for
the creator hand by *raising* the cap, not lowering it).
17 hands/*/HAND.toml:
- hand-level mcp_servers / skills now declared on every hand, so
every [agents.*] inside inherits a sensible allowlist.
- skills_disabled = true placed on each [agents.*] inside clip and
creator (pure media pipelines that don't benefit from any skill).
HandDefinitionRaw in librefang-hands does NOT have a top-level
skills_disabled field — declaring it at the hand top level would
be silently dropped by serde, so the setting must live on the
AgentManifest of each sub-agent role.
- devteam: expand existing mcp_servers = ["github"] to include
memory / git / filesystem; populate skills with the expected
dev-team expertise (replacing the placeholder skills = []).
- wiki: replace placeholder mcp_servers = [] with [memory, fetch,
filesystem]. Hand-level skills stays [].
- lead: hand-level skills was originally [email-writer, writing-
coach, interview-prep]; interview-prep is for job-interview
preparation, not lead generation. Replaced with data-analyst
(used by the qualification-scoring step in the prompt).
schema.toml: register mcp_servers / skills / max_history_messages on
the agent field schema so machine consumers (RegistrySchema in
librefang-types) see the new top-level fields. The
max_history_messages description now points at
librefang_runtime::agent_loop::DEFAULT_MAX_HISTORY_MESSAGES (60
today) by name, so the schema doesn't go stale when the constant
moves again.
agents/README.md: example block + "Adding a New Agent" checklist
mention the allowlists; max_history_messages example is shown
commented out with a prompt-cache caveat.
Open items
----------
`assistant` (the default user-facing agent) keeps `skills = []`
deliberately. It is the generalist entry point — capping its skill
surface at a small allowlist would defeat its "delegate to any
specialist" job. The trade-off is that this single agent still pays
the full skill-definition load on every turn; operators who want a
strict allowlist for `assistant` can override it after install.
Why not adopt PR #89's approach
-------------------------------
#89 covers similar ground but with three issues this PR avoids:
1. mcp_servers = ["_none"] sentinel. #89's body explicitly notes
it's pending upstream librefang#4808 (mcp_disabled). Shipping a
magic-string today means coming back later to clean it up. This
PR uses real allowlists.
2. max_history_messages = 8 / 12 / 15 / 20. Far below today's
kernel default (60) and #91's direction for long-workflow hands
(80–120). Every turn that hits the cap invalidates the cached
prompt prefix; the cost of cache misses exceeds the saving from
shorter history. This PR uses 60–120.
3. Doubling max_llm_tokens_per_hour (coder 200k→500k, assistant
300k→500k) widens the per-agent budget — the opposite direction
from #87's "reduce per-call cost" goal. Left to the operator's
instance-specific tuning.
Refs librefang/librefang-registry#87, librefang/librefang-registry#89
LibreFang Registry
Community-maintained content registry for LibreFang — the open-source Agent Operating System.
This repository is the single source of truth for all installable content definitions. Anyone can submit a PR to add new agents, hands, MCP servers, skills, or provider models — no changes to the LibreFang binary required.
Overview
| Type | Count | Description |
|---|---|---|
| Hands | 14 | User-facing "apps" — agent + tools + settings + dashboard |
| Agents | 32 | Autonomous agent definitions with model config and tools |
| MCP Servers | 25 | MCP server connections (GitHub, Slack, DBs, etc.) |
| Providers | 46 | LLM provider & model metadata with pricing |
| Models | 232 | Individual model definitions across all providers |
| Aliases | 70 | Short names mapped to canonical model IDs |
| Plugins | 10 | Memory, guardrails, and conversation plugins |
| Skills | 2 | Reusable prompt templates and Python scripts |
| Workflows | 9 | Pre-built multi-agent workflow definitions |
| Templates | 6 | Starter templates for each content type |
Repository Structure
librefang-registry/
├── agents/ # Agent definitions (TOML manifests)
│ ├── hello-world/
│ │ └── agent.toml
│ ├── researcher/
│ │ └── agent.toml
│ └── ... (32 agents)
├── hands/ # Hand definitions (app bundles)
│ ├── browser/
│ │ ├── HAND.toml # Metadata, tools, settings, i18n (6 languages)
│ │ └── SKILL.md # Domain expert knowledge injected at runtime
│ ├── trader/
│ │ ├── HAND.toml
│ │ └── SKILL.md
│ └── ... (14 hands)
├── mcp/ # MCP server templates
│ ├── github.toml
│ ├── slack.toml
│ └── ... (25 MCP servers)
├── providers/ # LLM provider & model metadata
│ ├── anthropic.toml
│ ├── openai.toml
│ └── ... (46 providers, 232 models)
├── plugins/ # Memory, guardrails, and utility plugins
│ ├── episodic-memory/
│ ├── guardrails/
│ └── ... (10 plugins)
├── skills/ # Reusable skill definitions
│ ├── custom-skill-prompt/skill.toml
│ └── custom-skill-python/
├── workflows/ # Pre-built multi-agent workflow definitions
│ ├── code-review.toml
│ ├── research.toml
│ └── ... (9 workflows)
├── templates/ # Starter templates for each content type
│ ├── agent.toml
│ ├── HAND.toml
│ └── ... (6 templates)
├── docs/ # Additional documentation
│ └── content-guide.md # Content contribution guidelines
├── aliases.toml # Global model alias mappings (70 aliases)
├── schema.toml # Provider/model schema reference
├── scripts/
│ └── validate.py # Content validation script
├── CONTRIBUTING.md
└── LICENSE # MIT
Content Types
Hands
Hands are the user-facing "apps" in LibreFang. Each hand bundles an agent, tools, user-configurable settings, dashboard metrics, dependency checks, and i18n translations into a single deployable unit.
Every hand includes a SKILL.md — domain-specific expert knowledge that is injected into the agent's context at runtime, giving it deep expertise in its domain.
| Icon | Hand | Category | Description |
|---|---|---|---|
| 📈 | analytics | data | Data collection, analysis, visualization, dashboards, and automated reporting |
| 🔌 | apitester | development | Endpoint discovery, request validation, load testing, and regression detection |
| 🌐 | browser | productivity | Web navigation, form filling, and multi-step web tasks with user approval |
| 🎬 | clip | content | Turns long-form video into viral short clips with captions and thumbnails |
| 🔍 | collector | data | Intelligence collection, change detection, and knowledge graphs |
| 👷 | devops | development | CI/CD management, infrastructure monitoring, deployment, and incident response |
| 📊 | lead | data | Lead generation, enrichment, scoring, and scheduled delivery |
| 💼 | communication | Profile optimization, content creation, networking, and engagement | |
| 🔮 | predictor | data | Signal collection, calibrated predictions, and accuracy tracking |
| 📢 | communication | Subreddit monitoring, content posting, and engagement tracking | |
| 🧪 | researcher | productivity | Deep research, cross-referencing, fact-checking, and structured reports |
| 🎯 | strategist | productivity | Market research, competitive analysis, and strategic planning |
| 📈 | trader | data | Multi-signal analysis, adversarial reasoning, and risk management |
| 𝕏 | communication | Content creation, scheduled posting, engagement, and analytics |
HAND.toml format:
id = "browser"
name = "Browser Hand"
description = "Autonomous web browser"
category = "productivity"
icon = "🌐"
tools = ["browser_navigate", "browser_click", "browser_type"]
[routing]
aliases = ["browse", "open website"]
weak_aliases = ["web", "url"]
[[requires]]
key = "chromium"
requirement_type = "binary"
check_value = "chromium"
[[settings]]
key = "headless"
setting_type = "toggle"
default = "true"
[agent]
name = "browser-hand"
module = "builtin:chat"
system_prompt = """You are an autonomous web browser agent..."""
[dashboard]
[[dashboard.metrics]]
label = "Pages Visited"
memory_key = "pages_visited"
format = "number"
# i18n — 6 languages supported: zh, ja, ko, es, fr, de
[i18n.zh]
name = "浏览器 Hand"
description = "自主网页浏览器"
category = "生产力"
[i18n.zh.settings.headless]
label = "无头模式"
description = "在后台运行浏览器"
Agents
Agent definitions describe autonomous agents with model configuration, tools, capabilities, and routing aliases.
name = "hello-world"
description = "A friendly greeting agent"
module = "builtin:chat"
[model]
provider = "default"
model = "default"
system_prompt = "You are a helpful assistant."
[capabilities]
tools = ["web_search", "file_read"]
32 built-in agents: academic-researcher, analyst, architect, assistant, code-reviewer, coder, customer-support, data-scientist, debugger, devops-lead, doc-writer, email-assistant, health-tracker, hello-world, home-automation, legal-assistant, meeting-assistant, ops, orchestrator, personal-finance, planner, recipe-assistant, recruiter, researcher, sales-assistant, security-auditor, social-media, test-engineer, translator, travel-planner, tutor, writer
MCP Servers
MCP server templates define MCP server connections with transport configuration, required environment variables, and setup instructions.
id = "github"
name = "GitHub"
category = "devtools"
[transport]
type = "stdio"
command = "npx"
args = ["-y", "@modelcontextprotocol/server-github"]
[[required_env]]
name = "GITHUB_PERSONAL_ACCESS_TOKEN"
is_secret = true
25 MCP servers across 6 categories:
| Category | MCP Servers |
|---|---|
| DevTools | bitbucket, github, gitlab, jira, linear, sentry |
| Data | elasticsearch, mongodb, postgresql, redis, sqlite |
| Productivity | dropbox, gmail, google-calendar, google-drive, notion, todoist |
| Communication | discord, slack, teams |
| Cloud | aws, azure, gcp |
| AI Search | brave-search, exa-search |
Providers
Provider files define LLM providers and their models with pricing, context windows, and capability flags. See schema.toml for the full field reference.
49 providers including: Anthropic, OpenAI, Google Gemini, DeepSeek, Groq, Mistral, Cohere, xAI, Together, Fireworks, Ollama (local), LM Studio (local), vLLM (self-hosted), Alibaba Coding Plan, and many more.
339 models with metadata for each: pricing (input/output per token), context window size, capability flags (vision, function calling, streaming), and tier classification.
Aliases
Global model alias mappings in aliases.toml let users reference models by short names:
"sonnet" = "claude-sonnet-4-6"
"gpt4" = "gpt-4o"
"flash" = "gemini-2.5-flash"
"deepseek" = "deepseek-chat"
Models can also define aliases directly in their provider TOML files, which are auto-registered at load time.
Plugins
Plugins extend agent capabilities with memory systems, safety guardrails, and conversation utilities.
10 plugins: auto-summarizer, context-decay, conversation-logger, episodic-memory, guardrails, keyword-memory, sentiment-tracker, todo-tracker, topic-memory, user-profile
Skills
Reusable prompt templates or Python scripts that agents can invoke.
[skill]
name = "meeting-agenda"
description = "Generate a structured meeting agenda"
[runtime]
type = "promptonly"
[prompt]
template = "Create a meeting agenda for: {{topic}}"
Workflows
Pre-built multi-agent workflow definitions in workflows/<name>.toml orchestrate multiple agents for complex tasks.
9 workflows: brainstorm, code-review, content-pipeline, content-review, customer-support, data-pipeline, research, translate-polish, weekly-report
Templates
Starter templates in templates/ for creating new content. Copy a template to get started quickly:
cp templates/agent.toml agents/my-agent/agent.toml
cp templates/HAND.toml hands/my-hand/HAND.toml
6 templates: agent.toml, HAND.toml, integration.toml, plugin.toml, provider.toml, skill.toml
See also docs/content-guide.md for naming conventions and contribution guidelines.
Usage
Install from Registry
# Update all registry content
librefang catalog update
# Install a specific hand
librefang hand install browser
# Install a specific MCP server
librefang mcp install github
Custom Local Content
Create custom content locally without submitting to this registry:
# Custom agent
mkdir -p ~/.librefang/agents/my-agent
# Edit ~/.librefang/agents/my-agent/agent.toml
# Custom model aliases
# Add to ~/.librefang/model_catalog.toml
Validation
python scripts/validate.py
Validates all content files for correctness: required fields, valid types, non-negative costs, no duplicate IDs.
Contributing
- Fork this repository
- Add or edit content in the appropriate directory
- Run validation:
python scripts/validate.py - Submit a Pull Request
See CONTRIBUTING.md for detailed instructions for each content type.
License
MIT License. See LICENSE.