Cline SDK Skill

Consolidated skill for building AI agents with the Cline SDK. Use the decision trees below to find the right entry point and API surface, then load detailed references.

Critical Rules

Follow these rules in all Cline SDK code:

1. Install with npm install @cline/sdk. The @cline/sdk package re-exports everything from @cline/core, @cline/agents, @cline/llms, and @cline/shared.
2. Requires Node.js 22 or later.
3. Use createTool() from @cline/sdk (or @cline/shared) to define tools. Tool names must be snake_case.
4. Return errors as structured data from tool execute functions. Throwing counts as a "mistake" against the agent's mistake limit.
5. Use lifecycle: { completesRun: true } on tools that should end the agent loop (e.g. a "submit answer" tool).
6. When using ClineCore, always call dispose() when done to clean up resources.
7. The standalone Agent and ClineCore have different event systems. For Agent: use agent.subscribe() to get AgentRuntimeEvent types (text streaming is "assistant-text-delta", result text is result.outputText). For ClineCore: use cline.subscribe() to get CoreSessionEvent types (text streaming is "chunk" with payload.type === "text", result text is result.text). There is no top-level onEvent field on AgentRuntimeConfig -- use agent.subscribe() or hooks.onEvent instead. Do not use event types like "content_update" or "content_start" with agent.subscribe() -- those are internal legacy types from the ClineCore adapter layer.

How to Use This Skill

Reference File Structure

The two main API surfaces (Agent and ClineCore) follow a 4-file pattern. Cross-cutting concepts are single-file guides.

Each main API surface in ./references/<api>/ contains:

File	Purpose	When to Read
REFERENCE.md	Overview, when to use, quick start	Always read first
api.md	Full API: classes, methods, config, types	Writing code
patterns.md	Common patterns, best practices	Implementation guidance
gotchas.md	Pitfalls, limitations, debugging	Troubleshooting

Cross-cutting concepts in ./references/<concept>/ have REFERENCE.md as the entry point.

Reading Order

1. Start with REFERENCE.md for your chosen API surface
2. Then read additional files relevant to your task:
   • Writing agent code -> api.md
   • Common patterns -> patterns.md
   • Creating tools -> tools/REFERENCE.md
   • Adding plugins/hooks -> plugins/REFERENCE.md
   • Configuring LLM providers -> providers/REFERENCE.md
   • Streaming events -> events/REFERENCE.md
   • Deploying to production -> production/REFERENCE.md
   • Scheduling agents -> scheduling/REFERENCE.md
   • Multi-agent orchestration -> multi-agent/REFERENCE.md
   • Debugging -> gotchas.md

Example Paths

./references/agent/REFERENCE.md           # Start here for lightweight agents
./references/clinecore/REFERENCE.md       # Start here for full runtime
./references/agent/api.md                 # Agent class, config, methods
./references/tools/REFERENCE.md           # Creating and using tools
./references/plugins/REFERENCE.md         # Plugin system
./references/providers/REFERENCE.md       # LLM provider configuration

Quick Decision Trees

"Which API surface should I use?"

Which API?
+-- I want a simple, stateless agent with custom tools
|   +-- agent/ (Agent class from @cline/agents)
+-- I need session persistence, built-in tools, config discovery
|   +-- clinecore/ (ClineCore from @cline/core)
+-- I want built-in file/shell/search/web tools
|   +-- clinecore/ (has built-in tools; Agent does not)
+-- I want scheduled or recurring agents
|   +-- clinecore/ (automation API)
+-- I need multi-process or multi-client session sharing
|   +-- clinecore/ (hub-backed runtime)
+-- I'm building a browser-compatible agent
|   +-- agent/ (no Node.js dependencies)

"I need to create tools"

Tools?
+-- Define a custom tool with schema -> tools/REFERENCE.md
+-- Use built-in tools (bash, editor, read_files) -> tools/REFERENCE.md (built-in section)
+-- Control tool approval/policies -> tools/REFERENCE.md (policies section)
+-- Tool that ends the agent loop -> tools/REFERENCE.md (completion tools)
+-- Package tools as a reusable plugin -> plugins/REFERENCE.md

"I need to handle events"

Events?
+-- Stream text/reasoning in real time -> events/REFERENCE.md
+-- Track token usage and costs -> events/REFERENCE.md
+-- Watch tool calls -> events/REFERENCE.md
+-- Detect completion/errors -> events/REFERENCE.md
+-- Hook into lifecycle stages -> plugins/REFERENCE.md

"I need to configure a model provider"

Providers?
+-- Anthropic (Claude) -> providers/REFERENCE.md
+-- OpenAI (GPT) -> providers/REFERENCE.md
+-- Google (Gemini/Vertex) -> providers/REFERENCE.md
+-- AWS Bedrock -> providers/REFERENCE.md
+-- Mistral -> providers/REFERENCE.md
+-- OpenAI-compatible (vLLM, Together, etc.) -> providers/REFERENCE.md
+-- Custom/self-hosted provider -> providers/REFERENCE.md

"I need plugins or hooks"

Plugins?
+-- Package tools + hooks together -> plugins/REFERENCE.md
+-- Observe tool calls (logging, metrics) -> plugins/REFERENCE.md
+-- Intercept lifecycle events -> plugins/REFERENCE.md
+-- Add system prompt rules -> plugins/REFERENCE.md
+-- Distribute via npm/git -> plugins/REFERENCE.md

"I need multi-agent coordination"

Multi-agent?
+-- Spawn one-off background agents -> multi-agent/REFERENCE.md (sub-agents)
+-- Persistent cross-session teams -> multi-agent/REFERENCE.md (teams)
+-- Parent-child delegation -> multi-agent/REFERENCE.md (sub-agents)
+-- Peer-to-peer task board -> multi-agent/REFERENCE.md (teams)

"I need scheduling or automation"

Scheduling?
+-- Recurring cron jobs -> scheduling/REFERENCE.md
+-- One-off scheduled tasks -> scheduling/REFERENCE.md
+-- Event-driven triggers -> scheduling/REFERENCE.md
+-- CLI schedule management -> scheduling/REFERENCE.md

"I need to go to production"

Production?
+-- Error handling and status checks -> production/REFERENCE.md
+-- Cost control and token limits -> production/REFERENCE.md
+-- Observability (OpenTelemetry) -> production/REFERENCE.md
+-- Security and sandboxing -> production/REFERENCE.md
+-- Deployment patterns -> production/REFERENCE.md

Troubleshooting Index

• Agent loop not stopping -> tools/REFERENCE.md (completion tools)
• Tool errors crashing the agent -> agent/gotchas.md or clinecore/gotchas.md
• Provider auth failures -> providers/REFERENCE.md
• Session not persisting -> clinecore/gotchas.md
• Token usage too high -> production/REFERENCE.md (cost control)
• Hub connection issues -> clinecore/gotchas.md
• Plugin not loading -> plugins/REFERENCE.md
• Events not firing -> events/REFERENCE.md

Product Index

API Surfaces

API	Entry File	Description
Agent	./references/agent/REFERENCE.md	Lightweight stateless agent loop
ClineCore	./references/clinecore/REFERENCE.md	Full runtime with sessions, persistence, built-in tools

Cross-Cutting Concepts

Concept	Entry File	Description
Tools	./references/tools/REFERENCE.md	Built-in and custom tool creation
Plugins	./references/plugins/REFERENCE.md	Extension system with hooks
Events	./references/events/REFERENCE.md	Real-time streaming events
Providers	./references/providers/REFERENCE.md	LLM provider configuration
Production	./references/production/REFERENCE.md	Deployment, security, observability
Scheduling	./references/scheduling/REFERENCE.md	Cron jobs and automation
Multi-Agent	./references/multi-agent/REFERENCE.md	Teams and sub-agents

Package Map

Package	Purpose
@cline/sdk	Everything you need, install this one
@cline/core	Sessions, persistence, built-in tools, config, hub
@cline/agents	Stateless agent loop, tool orchestration, streaming
@cline/llms	LLM provider gateway
@cline/shared	Types, tool helpers, hook engine

Resources

Repository: https://github.com/cline/cline SDK Source: https://github.com/cline/cline/tree/main/sdk Documentation: https://docs.cline.bot/sdk/overview Discord: https://discord.gg/cline