Building plugins
Tool plugins
defineToolPlugin builds a plugin that only adds agent-callable tools: no
channel, model provider, hook, service, or setup backend. It generates the
manifest metadata OpenClaw needs to discover tools without loading plugin
runtime code.
For provider, channel, hook, service, or mixed-capability plugins, start with Building plugins, Channel Plugins, or Provider Plugins instead.
Requirements
- Node 24.16+ or Node 26.1+.
- TypeScript ESM package output.
typeboxindependencies(not justdevDependencies- the generated plugin imports it at runtime).openclaw >=2026.5.17, the first version that exportsopenclaw/plugin-sdk/tool-plugin.- A package root that ships
dist/,openclaw.plugin.json, andpackage.json.
Quickstart
openclaw plugins init stock-quotes --name "Stock Quotes"cd stock-quotesnpm installnpm run plugin:buildnpm run plugin:validatenpm testplugins init scaffolds:
| File | Purpose |
|---|---|
src/index.ts |
defineToolPlugin entry with one echo tool |
src/index.test.ts |
Metadata test asserting the tool list |
tsconfig.json |
NodeNext TypeScript output to dist/ |
vitest.config.ts |
Vitest config for src/**/*.test.ts |
package.json |
Scripts, runtime deps, openclaw.extensions: ["./dist/index.js"] |
openclaw.plugin.json |
Generated manifest metadata for the initial tool |
npm run plugin:build runs npm run build (tsc) then
openclaw plugins build --entry ./dist/index.js. npm run plugin:validate
rebuilds and runs openclaw plugins validate --entry ./dist/index.js.
Successful validation prints:
Plugin stock-quotes is valid.openclaw plugins init <id> options:
| Flag | Default | Effect |
|---|---|---|
--directory <path> |
<id> |
Output directory |
--name <name> |
Title-cased <id> |
Display name |
--type <type> |
tool |
Scaffold type: tool or provider |
--force |
off | Overwrite an existing output directory |
Write a tool
defineToolPlugin takes plugin identity, an optional config schema, and a
static list of tools. Parameter and config types are inferred from the
TypeBox schemas.
import { Type } from "typebox";import { defineToolPlugin } from "openclaw/plugin-sdk/tool-plugin"; export default defineToolPlugin({ id: "stock-quotes", name: "Stock Quotes", description: "Fetch stock quote snapshots.", configSchema: Type.Object({ apiKey: Type.Optional(Type.String({ description: "Quote API key." })), baseUrl: Type.Optional(Type.String({ description: "Quote API base URL." })), }), tools: (tool) => [ tool({ name: "stock_quote", label: "Stock Quote", description: "Fetch a stock quote snapshot.", parameters: Type.Object({ symbol: Type.String({ description: "Ticker symbol, for example OPEN." }), }), outputSchema: Type.Object( { symbol: Type.String(), configured: Type.Boolean(), baseUrl: Type.String(), }, { additionalProperties: false }, ), async execute({ symbol }, config, context) { context.signal?.throwIfAborted(); return { symbol: symbol.toUpperCase(), configured: Boolean(config.apiKey), baseUrl: config.baseUrl ?? "https://api.example.com", }; }, }), ],});Tool names are the stable API. Pick names that are unique, lowercase, and specific enough to avoid collisions with core tools or other plugins.
Optional and factory tools
Set optional: true when users should explicitly allowlist the tool before it
is sent to a model. openclaw plugins build writes the matching
toolMetadata.<tool>.optional manifest entry, so OpenClaw can see that the
tool is optional without loading plugin runtime code.
tool({ name: "workflow_run", description: "Run an external workflow.", parameters: Type.Object({ goal: Type.String() }), optional: true, execute: ({ goal }) => ({ queued: true, goal }),});Use factory when a tool needs the runtime tool context before it can be
created - to opt out for a specific run, inspect sandbox state, or bind
runtime helpers. Metadata stays static even though the concrete tool is built
at runtime.
tool({ name: "local_workflow", description: "Run a local workflow outside sandboxed sessions.", parameters: Type.Object({ goal: Type.String() }), optional: true, factory({ api, toolContext }) { if (toolContext.sandboxed) { return null; } return createLocalWorkflowTool(api); },});Factories can use toolContext.delivery?.send({ text, mediaUrl }) for outbound
messages in the active conversation. The host chooses the destination,
account, thread, and local-media policy; plugins cannot retarget this helper,
and retained copies stop working after the turn closes. The helper is unavailable
for channels whose delivery is owned by a Gateway transport.
A factory may return a core AgentTool, an array of them, or null or
undefined to opt out, as the example above does. When it returns a concrete
tool, that tool uses the core runtime signature
execute(toolCallId, params, signal?, onUpdate?) with the tool call ID first.
That is the opposite argument order from the declarative
execute(params, config, context) shown above, and it matches the
api.registerTool examples in Building Plugins.
Reading params from the first argument of a factory tool returns the tool
call ID string instead.
Concrete tools can provide prepareArguments(args) to normalize input before
schema validation. The native agent loop also honors
executionMode: "sequential" when tool calls must run one at a time. These
runtime properties, schemas, and display metadata come from the current factory
context whenever tools are assembled. Argument preparation and execution use the
same instance. Retained tools stop working when their owning plugin registry is
retired.
Set hideFromChannelProgress: true on the concrete factory tool to keep its
transient activity out of channel progress drafts. Lifecycle events and the
final tool result still flow normally. OpenClaw preserves the current factory's
flag when normalizing its schema; omitted or false leaves normal progress
behavior in place. See Progress drafts.
Factories still declare a fixed tool name up front. Use definePluginEntry
directly when the plugin computes tool names dynamically or combines tools
with hooks, services, providers, or commands.
Return values
defineToolPlugin wraps plain return values into the OpenClaw tool-result
format:
- Return a string when the model should see that exact text.
- Return a JSON-compatible value when you want the model to see formatted JSON
and OpenClaw to keep the original value in
details.
tool({ name: "echo_text", description: "Echo input text.", parameters: Type.Object({ input: Type.String(), }), execute: ({ input }) => input,});tool({ name: "echo_json", description: "Echo input as structured JSON.", parameters: Type.Object({ input: Type.String(), }), execute: ({ input }) => ({ input, length: input.length }),});Use a factory tool when you need a custom AgentToolResult or want to reuse an
existing api.registerTool implementation.
Output contracts
Add outputSchema when a tool returns stable JSON-compatible data. It describes
the original value stored in AgentToolResult.details, not the formatted text
in content:
tool({ name: "shipment_list", description: "List shipments.", parameters: Type.Object({ buyer: Type.Optional(Type.String()), }), outputSchema: Type.Array( Type.Object( { id: Type.String(), buyer: Type.String(), paid: Type.Boolean(), tons: Type.Number(), }, { additionalProperties: false }, ), ), execute: ({ buyer }) => listShipments(buyer),});Code Mode and Tool Search turn this schema into a bounded TypeScript-style output hint. That lets a model call and transform a known result in one program instead of spending another model turn observing its shape.
OpenClaw compiles the schema before executing a catalog call, then validates the
final details value after tool hooks before returning it through the bridge.
An invalid schema cannot run the tool; a result mismatch fails the completed
call. Include every non-throwing result variant, including structured error
variants, or omit the schema when the result is not stable. Do not put secrets
or sensitive values in schema descriptions because trusted output metadata can
become model-visible.
Use { additionalProperties: false } on object layers when you want a complete
compact output hint; open or truncated schemas remain available through
the callable catalog handle's describe() but are not advertised as complete
quick-index contracts.
Factory tools declare outputSchema on the concrete AnyAgentTool they
return. The static tool({ factory }) declaration does not accept a separate
output schema because it could drift from the runtime tool.
OpenClaw also grades the call outcome from details, so status, ok,
success, error, timedOut, and exitCode are reserved names. A status
of blocked, denied, invalid, cancelled, or any other failure value
marks the call failed unless ok or success is explicitly true, even when
execute returned normally. Domain data that
uses one of those names belongs under a wrapper key, such as { card },
instead of at the top level of details.
Configuration
configSchema is optional. Omit it and OpenClaw applies a strict empty object
schema; the generated manifest still includes configSchema.
export default defineToolPlugin({ id: "no-config-tools", name: "No Config Tools", description: "Adds tools that do not need configuration.", tools: () => [],});With a configSchema, the second execute argument is typed from it:
const configSchema = Type.Object({ apiKey: Type.String(),}); export default defineToolPlugin({ id: "configured-tools", name: "Configured Tools", description: "Adds configured tools.", configSchema, tools: (tool) => [ tool({ name: "configured_ping", description: "Check whether configuration is available.", parameters: Type.Object({}), execute: (_params, config) => ({ hasKey: config.apiKey.length > 0 }), }), ],});OpenClaw reads plugin config from the plugin's entry in the Gateway config. Do not hard-code secrets in source or docs examples; use config, environment variables, or SecretRefs per the plugin's security model.
Generated metadata
OpenClaw must read the plugin manifest before importing plugin runtime code.
defineToolPlugin exposes static metadata for this, and
openclaw plugins build writes it into the package. Rerun the generator after
changing plugin id, name, description, config schema, activation, or tool
names:
npm run buildopenclaw plugins build --entry ./dist/index.jsGenerated manifest for a one-tool plugin:
{ "id": "stock-quotes", "name": "Stock Quotes", "description": "Fetch stock quote snapshots.", "version": "0.1.0", "configSchema": { "type": "object", "additionalProperties": false, "properties": {} }, "activation": { "onStartup": true }, "contracts": { "tools": ["stock_quote"] }}contracts.tools is the important discovery contract: it tells OpenClaw which
plugin owns each tool without loading every installed plugin's runtime. A
stale manifest means a tool can go missing from discovery, or a registration
error gets blamed on the wrong plugin.
Package metadata
openclaw plugins build also aligns package.json to the selected runtime
entry:
{ "type": "module", "files": ["dist", "openclaw.plugin.json", "README.md"], "dependencies": { "typebox": "^1.1.38" }, "peerDependencies": { "openclaw": ">=2026.5.17" }, "openclaw": { "extensions": ["./dist/index.js"] }}Ship built JavaScript (./dist/index.js), not a TypeScript source entry.
Source entries only work for workspace-local development.
Validate in CI
plugins build --check fails without rewriting files when generated metadata
is stale:
npm run buildopenclaw plugins build --entry ./dist/index.js --checkopenclaw plugins validate --entry ./dist/index.jsnpm testOpenClaw SDK compatibility fields carry TypeScript @deprecated annotations,
which editors surface as migration warnings. To enforce them in CI, enable a
type-aware rule such as
@typescript-eslint/no-deprecated.
Oxlint is not type-aware, so it cannot enforce these annotations. The generated
plugins init scaffold therefore does not add a deprecation lint config.
plugins validate checks that:
openclaw.plugin.jsonexists and passes the normal manifest loader.- The current entry exports
defineToolPluginmetadata. - Generated manifest fields match the entry metadata.
contracts.toolsmatches the declared tool names.package.jsonpointsopenclaw.extensionsat the selected runtime entry.
Install and inspect locally
From a separate OpenClaw checkout or installed CLI, install the package path:
openclaw plugins install ./stock-quotesopenclaw plugins inspect stock-quotes --runtimeFor a packaged smoke test, pack first and install the tarball:
npm packopenclaw plugins install npm-pack:./openclaw-plugin-stock-quotes-0.1.0.tgzopenclaw plugins inspect stock-quotes --runtime --jsonAfter installing, restart or reload the Gateway and ask the agent to use the tool. If the tool is not visible, inspect the plugin runtime and the effective tool catalog before changing code (see Troubleshooting).
Publish
Publish through ClawHub once the package is ready. clawhub package publish
takes a source: a local folder, a GitHub repo (owner/repo[@ref]), or a
tarball URL.
clawhub package publish ./stock-quotes --dry-runclawhub package publish ./stock-quotesInstall with an explicit ClawHub locator:
openclaw plugins install clawhub:your-org/stock-quotesBare npm package specs install from npm, but ClawHub is the preferred discovery and distribution surface for OpenClaw plugins. See ClawHub publishing for owner scope and release review.
Troubleshooting
plugin entry not found: ./dist/index.js
The selected entry file does not exist. Run npm run build, then rerun
openclaw plugins build --entry ./dist/index.js or
openclaw plugins validate --entry ./dist/index.js.
plugin entry does not expose defineToolPlugin metadata
The entry did not export a value created by defineToolPlugin. Confirm the
module's default export is the defineToolPlugin(...) result, or pass the
correct entry with --entry.
openclaw.plugin.json generated metadata is stale
The manifest no longer matches the entry metadata. Run:
npm run buildopenclaw plugins build --entry ./dist/index.jsCommit both openclaw.plugin.json and package.json changes.
package.json openclaw.extensions must include ./dist/index.js
The package metadata points at a different runtime entry. Run
openclaw plugins build --entry ./dist/index.js so the generator aligns
package metadata with the entry you intend to ship.
Cannot find package 'typebox'
The built plugin imports typebox at runtime. Keep it in dependencies,
reinstall, rebuild, and rerun validation.
Tool does not appear after install
Check these in order:
openclaw plugins inspect <plugin-id> --runtimeopenclaw plugins validate --root <plugin-root> --entry ./dist/index.jsopenclaw.plugin.jsonhascontracts.toolswith the expected tool names.package.jsonhasopenclaw.extensions: ["./dist/index.js"].- The Gateway was restarted or reloaded after installing the plugin.