Building Plugins

Building Plugins

Plugins extend Velaclaw with new capabilities: channels, model providers, speech, realtime transcription, realtime voice, media understanding, image generation, video generation, web fetch, web search, agent tools, or any combination.

You do not need to add your plugin to the Velaclaw repository. Publish to ClawHub or npm and users install with velaclaw plugins install <package-name>. Velaclaw tries ClawHub first and falls back to npm automatically.

Prerequisites

• Node >= 22 and a package manager (npm or pnpm)
• Familiarity with TypeScript (ESM)
• For in-repo plugins: repository cloned and pnpm install done

What kind of plugin?

Channel plugin

Connect Velaclaw to a messaging platform (Discord, IRC, etc.)

Provider plugin

Add a model provider (LLM, proxy, or custom endpoint)

Tool / hook plugin

Register agent tools, event hooks, or services — continue below

If a channel plugin is optional and may not be installed when onboarding/setup runs, use createOptionalChannelSetupSurface(...) from velaclaw/plugin-sdk/channel-setup. It produces a setup adapter + wizard pair that advertises the install requirement and fails closed on real config writes until the plugin is installed.

Quick start: tool plugin

This walkthrough creates a minimal plugin that registers an agent tool. Channel and provider plugins have dedicated guides linked above.

1. Create the package and manifest

   package.json

   {
     "name": "@myorg/velaclaw-my-plugin",
     "version": "1.0.0",
     "type": "module",
     "velaclaw": {
       "extensions": ["./index.ts"],
       "compat": {
         "pluginApi": ">=2026.3.24-beta.2",
         "minGatewayVersion": "2026.3.24-beta.2"
       },
       "build": {
         "velaclawVersion": "2026.3.24-beta.2",
         "pluginSdkVersion": "2026.3.24-beta.2"
       }
     }
   }
   

   Every plugin needs a manifest, even with no config. See Manifest for the full schema. The canonical ClawHub publish snippets live in docs/snippets/plugin-publish/.

2. Write the entry point

   // index.ts
   import { definePluginEntry } from "velaclaw/plugin-sdk/plugin-entry";
   import { Type } from "@sinclair/typebox";
   
   export default definePluginEntry({
     id: "my-plugin",
     name: "My Plugin",
     description: "Adds a custom tool to Velaclaw",
     register(api) {
       api.registerTool({
         name: "my_tool",
         description: "Do a thing",
         parameters: Type.Object({ input: Type.String() }),
         async execute(_id, params) {
           return { content: [{ type: "text", text: `Got: ${params.input}` }] };
         },
       });
     },
   });
   

   definePluginEntry is for non-channel plugins. For channels, use defineChannelPluginEntry — see Channel Plugins. For full entry point options, see Entry Points.

3. Test and publish

   External plugins: validate and publish with ClawHub, then install:

   clawhub package publish your-org/your-plugin --dry-run
   clawhub package publish your-org/your-plugin
   velaclaw plugins install clawhub:@myorg/velaclaw-my-plugin
   

   Velaclaw also checks ClawHub before npm for bare package specs like @myorg/velaclaw-my-plugin.

   In-repo plugins: place under the bundled plugin workspace tree — automatically discovered.

   pnpm test -- <bundled-plugin-root>/my-plugin/
   

Plugin capabilities

A single plugin can register any number of capabilities via the api object:

Capability	Registration method	Detailed guide
Text inference (LLM)	api.registerProvider(...)	Provider Plugins
CLI inference backend	api.registerCliBackend(...)	CLI Backends
Channel / messaging	api.registerChannel(...)	Channel Plugins
Speech (TTS/STT)	api.registerSpeechProvider(...)	Provider Plugins
Realtime transcription	api.registerRealtimeTranscriptionProvider(...)	Provider Plugins
Realtime voice	api.registerRealtimeVoiceProvider(...)	Provider Plugins
Media understanding	api.registerMediaUnderstandingProvider(...)	Provider Plugins
Image generation	api.registerImageGenerationProvider(...)	Provider Plugins
Music generation	api.registerMusicGenerationProvider(...)	Provider Plugins
Video generation	api.registerVideoGenerationProvider(...)	Provider Plugins
Web fetch	api.registerWebFetchProvider(...)	Provider Plugins
Web search	api.registerWebSearchProvider(...)	Provider Plugins
Agent tools	api.registerTool(...)	Below
Custom commands	api.registerCommand(...)	Entry Points
Event hooks	api.registerHook(...)	Entry Points
HTTP routes	api.registerHttpRoute(...)	Internals
CLI subcommands	api.registerCli(...)	Entry Points

For the full registration API, see SDK Overview.

If your plugin registers custom gateway RPC methods, keep them on a plugin-specific prefix. Core admin namespaces (config.*, exec.approvals.*, wizard.*, update.*) stay reserved and always resolve to operator.admin, even if a plugin asks for a narrower scope.

Hook guard semantics to keep in mind:

• before_tool_call: { block: true } is terminal and stops lower-priority handlers.
• before_tool_call: { block: false } is treated as no decision.
• before_tool_call: { requireApproval: true } pauses agent execution and prompts the user for approval via the exec approval overlay, Telegram buttons, Discord interactions, or the /approve command on any channel.
• before_install: { block: true } is terminal and stops lower-priority handlers.
• before_install: { block: false } is treated as no decision.
• message_sending: { cancel: true } is terminal and stops lower-priority handlers.
• message_sending: { cancel: false } is treated as no decision.

The /approve command handles both exec and plugin approvals with bounded fallback: when an exec approval id is not found, Velaclaw retries the same id through plugin approvals. Plugin approval forwarding can be configured independently via approvals.plugin in config.

If custom approval plumbing needs to detect that same bounded fallback case, prefer isApprovalNotFoundError from velaclaw/plugin-sdk/error-runtime instead of matching approval-expiry strings manually.

See SDK Overview hook decision semantics for details.

Registering agent tools

Tools are typed functions the LLM can call. They can be required (always available) or optional (user opt-in):

register(api) {
  // Required tool — always available
  api.registerTool({
    name: "my_tool",
    description: "Do a thing",
    parameters: Type.Object({ input: Type.String() }),
    async execute(_id, params) {
      return { content: [{ type: "text", text: params.input }] };
    },
  });

  // Optional tool — user must add to allowlist
  api.registerTool(
    {
      name: "workflow_tool",
      description: "Run a workflow",
      parameters: Type.Object({ pipeline: Type.String() }),
      async execute(_id, params) {
        return { content: [{ type: "text", text: params.pipeline }] };
      },
    },
    { optional: true },
  );
}

Users enable optional tools in config:

{
  tools: { allow: ["workflow_tool"] },
}

• Tool names must not clash with core tools (conflicts are skipped)
• Use optional: true for tools with side effects or extra binary requirements
• Users can enable all tools from a plugin by adding the plugin id to tools.allow

Import conventions

Always import from focused velaclaw/plugin-sdk/<subpath> paths:

import { definePluginEntry } from "velaclaw/plugin-sdk/plugin-entry";
import { createPluginRuntimeStore } from "velaclaw/plugin-sdk/runtime-store";

// Wrong: monolithic root (deprecated, will be removed)
import { ... } from "velaclaw/plugin-sdk";

For the full subpath reference, see SDK Overview.

Within your plugin, use local barrel files (api.ts, runtime-api.ts) for internal imports — never import your own plugin through its SDK path.

For provider plugins, keep provider-specific helpers in those package-root barrels unless the seam is truly generic. Current bundled examples:

• Anthropic: Claude stream wrappers and service_tier / beta helpers
• OpenAI: provider builders, default-model helpers, realtime providers
• OpenRouter: provider builder plus onboarding/config helpers

If a helper is only useful inside one bundled provider package, keep it on that package-root seam instead of promoting it into velaclaw/plugin-sdk/*.

Some generated velaclaw/plugin-sdk/<bundled-id> helper seams still exist for bundled-plugin maintenance and compatibility, for example plugin-sdk/feishu-setup or plugin-sdk/zalo-setup. Treat those as reserved surfaces, not as the default pattern for new third-party plugins.

Pre-submission checklist

package.json has correct velaclaw metadata

velaclaw.plugin.json manifest is present and valid

Entry point uses defineChannelPluginEntry or definePluginEntry

All imports use focused plugin-sdk/<subpath> paths

Internal imports use local modules, not SDK self-imports

Tests pass (pnpm test -- <bundled-plugin-root>/my-plugin/)

pnpm check passes (in-repo plugins)

Beta Release Testing

1. Watch for GitHub release tags on Zavianx/velaclaw and subscribe via Watch > Releases. Beta tags look like v2026.3.N-beta.1. You can also turn on notifications for the official Velaclaw X account @velaclaw for release announcements.
2. Test your plugin against the beta tag as soon as it appears. The window before stable is typically only a few hours.
3. Post in your plugin’s thread in the plugin-forum Discord channel after testing with either all good or what broke. If you do not have a thread yet, create one.
4. If something breaks, open or update an issue titled Beta blocker: <plugin-name> - <summary> and apply the beta-blocker label. Put the issue link in your thread.
5. Open a PR to main titled fix(<plugin-id>): beta blocker - <summary> and link the issue in both the PR and your Discord thread. Contributors cannot label PRs, so the title is the PR-side signal for maintainers and automation. Blockers with a PR get merged; blockers without one might ship anyway. Maintainers watch these threads during beta testing.
6. Silence means green. If you miss the window, your fix likely lands in the next cycle.

Next steps

Channel Plugins

Build a messaging channel plugin

Provider Plugins

Build a model provider plugin

SDK Overview

Import map and registration API reference

Runtime Helpers

TTS, search, subagent via api.runtime

Testing

Test utilities and patterns

Plugin Manifest

Full manifest schema reference

Related

• Plugin Architecture — internal architecture deep dive
• SDK Overview — Plugin SDK reference
• Manifest — plugin manifest format
• Channel Plugins — building channel plugins
• Provider Plugins — building provider plugins