name: add-tools
description: Create or update Sim tool configurations from service API docs, including typed params, request mapping, response transforms, outputs, and registry entries. Use when working in apps/sim/tools/{service}/ or fixing tool definitions for an integration.
Add Tools Skill
You are an expert at creating tool configurations for Sim integrations. Your job is to read API documentation and create properly structured tool files.
Your Task
When the user asks you to create tools for a service:
- Use Context7 or WebFetch to read the service's API documentation
- Create the tools directory structure
- Generate properly typed tool configurations
Hard Rule: No Guessed Response Schemas
If the docs do not clearly show the response JSON for a tool, you MUST tell the user exactly which outputs are unknown and stop short of guessing.
- Do NOT invent response field names
- Do NOT infer nested paths from nearby endpoints
- Do NOT guess array item shapes
- Do NOT write
transformResponseagainst unverified payloads
If the response shape is unknown, do one of these instead:
- Ask the user for sample responses
- Ask the user for test credentials so you can verify live responses
- Implement only the endpoints whose outputs are documented
- Leave the tool unimplemented and explicitly say why
Directory Structure
Create files in apps/sim/tools/{service}/:
tools/{service}/
├── index.ts # Barrel export
├── types.ts # Parameter & response types
└── {action}.ts # Individual tool files (one per operation)
Tool Configuration Structure
Every tool MUST follow this exact structure:
import type { {ServiceName}{Action}Params } from '@/tools/{service}/types'
import type { ToolConfig } from '@/tools/types'
interface {ServiceName}{Action}Response {
success: boolean
output: {
// Define output structure here
}
}
export const {serviceName}{Action}Tool: ToolConfig<
{ServiceName}{Action}Params,
{ServiceName}{Action}Response
> = {
id: '{service}_{action}', // snake_case, matches tool name
name: '{Service} {Action}', // Human readable
description: 'Brief description', // One sentence
version: '1.0.0',
// OAuth config (if service uses OAuth)
oauth: {
required: true,
provider: '{service}', // Must match OAuth provider ID
},
params: {
// Hidden params (system-injected, only use hidden for oauth accessToken)
accessToken: {
type: 'string',
required: true,
visibility: 'hidden',
description: 'OAuth access token',
},
// User-only params (credentials, api key, IDs user must provide)
someId: {
type: 'string',
required: true,
visibility: 'user-only',
description: 'The ID of the resource',
},
// User-or-LLM params (everything else, can be provided by user OR computed by LLM)
query: {
type: 'string',
required: false, // Use false for optional
visibility: 'user-or-llm',
description: 'Search query',
},
},
request: {
url: (params) => `https://api.service.com/v1/resource/${params.id}`,
method: 'POST',
headers: (params) => ({
Authorization: `Bearer ${params.accessToken}`,
'Content-Type': 'application/json',
}),
body: (params) => ({
// Request body - only for POST/PUT/PATCH
// Trim ID fields to prevent copy-paste whitespace errors:
// userId: params.userId?.trim(),
}),
},
transformResponse: async (response: Response) => {
const data = await response.json()
return {
success: true,
output: {
// Map API response to output
// Use ?? null for nullable fields
// Use ?? [] for optional arrays
},
}
},
outputs: {
// Define each output field
},
}
Critical Rules for Parameters
Visibility Options
'hidden'- System-injected (OAuth tokens, internal params). User never sees.'user-only'- User must provide (credentials, api keys, account-specific IDs)'user-or-llm'- User provides OR LLM can compute (search queries, content, filters, most fall into this category)
Parameter Types
'string'- Text values'number'- Numeric values'boolean'- True/false'json'- Complex objects (NOT 'object', use 'json')'file'- Single file'file[]'- Multiple files
Required vs Optional
- Always explicitly set
required: trueorrequired: false - Optional params should have
required: false
Critical Rules for Outputs
Output Types
'string','number','boolean'- Primitives'json'- Complex objects (use this, NOT 'object')'array'- Arrays withitemsproperty'object'- Objects withpropertiesproperty
Optional Outputs
Add optional: true for fields that may not exist in the response:
closedAt: {
type: 'string',
description: 'When the issue was closed',
optional: true,
},
Typed JSON Outputs
When using type: 'json' and you know the object shape in advance, always define the inner structure using properties so downstream consumers know what fields are available:
// BAD: Opaque json with no info about what's inside
metadata: {
type: 'json',
description: 'Response metadata',
},
// GOOD: Define the known properties
metadata: {
type: 'json',
description: 'Response metadata',
properties: {
id: { type: 'string', description: 'Unique ID' },
status: { type: 'string', description: 'Current status' },
count: { type: 'number', description: 'Total count' },
},
},
For arrays of objects, define the item structure:
items: {
type: 'array',
description: 'List of items',
items: {
type: 'object',
properties: {
id: { type: 'string', description: 'Item ID' },
name: { type: 'string', description: 'Item name' },
},
},
},
Only use bare type: 'json' without properties when the shape is truly dynamic or unknown.
If the response shape is unknown because the docs do not provide it, you MUST tell the user and stop. Unknown is not the same as dynamic. Never guess outputs.
Critical Rules for transformResponse
Handle Nullable Fields
ALWAYS use ?? null for fields that may be undefined:
transformResponse: async (response: Response) => {
const data = await response.json()
return {
success: true,
output: {
id: data.id,
title: data.title,
body: data.body ?? null, // May be undefined
assignee: data.assignee ?? null, // May be undefined
labels: data.labels ?? [], // Default to empty array
closedAt: data.closed_at ?? null, // May be undefined
},
}
}
Never Output Raw JSON Dumps
DON'T do this:
output: {
data: data, // BAD - raw JSON dump
}
DO this instead - extract meaningful fields:
output: {
id: data.id,
name: data.name,
status: data.status,
metadata: {
createdAt: data.created_at,
updatedAt: data.updated_at,
},
}
Types File Pattern
Create types.ts with interfaces for all params and responses:
import type { ToolResponse } from '@/tools/types'
// Parameter interfaces
export interface {Service}{Action}Params {
accessToken: string
requiredField: string
optionalField?: string
}
// Response interfaces (extend ToolResponse)
export interface {Service}{Action}Response extends ToolResponse {
output: {
field1: string
field2: number
optionalField?: string | null
}
}
Index.ts Barrel Export Pattern
// Export all tools
export { serviceTool1 } from './{action1}'
export { serviceTool2 } from './{action2}'
// Export types
export * from './types'
Registering Tools
After creating tools:
- Import tools in
apps/sim/tools/registry.ts - Add to the
toolsobject with snake_case keys (alphabetically):
import { serviceActionTool } from '@/tools/{service}'
export const tools = {
// ... existing tools ...
{service}_{action}: serviceActionTool,
}
Wiring Tools into the Block (Required)
After registering in tools/registry.ts, you MUST also update the block definition at apps/sim/blocks/blocks/{service}.ts. This is not optional — tools are only usable from the UI if they are wired into the block.
1. Add to tools.access
tools: {
access: [
// existing tools...
'service_new_action', // Add every new tool ID here
],
config: { ... }
}
2. Add operation dropdown options
If the block uses an operation dropdown, add an option for each new tool:
{
id: 'operation',
type: 'dropdown',
options: [
// existing options...
{ label: 'New Action', id: 'new_action' }, // id maps to what tools.config.tool returns
],
}
3. Add subBlocks for new tool params
For each new tool, add subBlocks covering all its required params (and optional ones where useful). Apply condition to show them only for the right operation, and mark required params with required:
// Required param for new_action
{
id: 'someParam',
title: 'Some Param',
type: 'short-input',
placeholder: 'e.g., value',
condition: { field: 'operation', value: 'new_action' },
required: { field: 'operation', value: 'new_action' },
},
// Optional param — put in advanced mode
{
id: 'optionalParam',
title: 'Optional Param',
type: 'short-input',
condition: { field: 'operation', value: 'new_action' },
mode: 'advanced',
},
4. Update tools.config.tool
Ensure the tool selector returns the correct tool ID for every new operation. The simplest pattern:
tool: (params) => `service_${params.operation}`,
// If operation dropdown IDs already match tool IDs, this requires no change.
If the dropdown IDs differ from tool IDs, add explicit mappings:
tool: (params) => {
const map: Record<string, string> = {
new_action: 'service_new_action',
// ...
}
return map[params.operation] ?? `service_${params.operation}`
},
5. Update tools.config.params
Add any type coercions needed for new params (runs at execution time, after variable resolution):
params: (params) => {
const result: Record<string, unknown> = {}
if (params.limit != null && params.limit !== '') result.limit = Number(params.limit)
if (params.newParamName) result.toolParamName = params.newParamName // rename if IDs differ
return result
},
6. Add new outputs
Add any new fields returned by the new tools to the block outputs:
outputs: {
// existing outputs...
newField: { type: 'string', description: 'Description of new field' },
}
7. Add new inputs
Add new subBlock param IDs to the block inputs section:
inputs: {
// existing inputs...
someParam: { type: 'string', description: 'Param description' },
optionalParam: { type: 'string', description: 'Optional param description' },
}
Block wiring checklist
- New tool IDs added to
tools.access - Operation dropdown has an option for each new tool
- SubBlocks cover all required params for each new tool
- SubBlocks have correct
condition(only show for the right operation) - Optional/rarely-used params set to
mode: 'advanced' -
tools.config.toolreturns correct ID for every new operation -
tools.config.paramshandles any ID remapping or type coercions - New outputs added to block
outputs - New params added to block
inputs
V2 Tool Pattern
If creating V2 tools (API-aligned outputs), use _v2 suffix:
- Tool ID:
{service}_{action}_v2 - Variable name:
{action}V2Tool - Version:
'2.0.0' - Outputs: Flat, API-aligned (no content/metadata wrapper)
Naming Convention
All tool IDs MUST use snake_case: {service}_{action} (e.g., x_create_tweet, slack_send_message). Never use camelCase or PascalCase for tool IDs.
Checklist Before Finishing
- All tool IDs use snake_case
- All params have explicit
required: trueorrequired: false - All params have appropriate
visibility - All nullable response fields use
?? null - All optional outputs have
optional: true - No raw JSON dumps in outputs
- Types file has all interfaces
- Index.ts exports all tools and re-exports types (
export * from './types') - Tools registered in
tools/registry.ts - Block wired:
tools.access, dropdown options, subBlocks,tools.config, outputs, inputs
Final Validation (Required)
After creating all tools, you MUST validate every tool before finishing:
- Read every tool file you created — do not skip any
- Cross-reference with the API docs to verify:
- All required params are marked
required: true - All optional params are marked
required: false - Param types match the API (string, number, boolean, json)
- Request URL, method, headers, and body match the API spec
transformResponseextracts the correct fields from the API response- All output fields match what the API actually returns
- No fields are missing from outputs that the API provides
- No extra fields are defined in outputs that the API doesn't return
- Every output field and JSON path is backed by docs or live-verified sample responses
- All required params are marked
- Verify consistency across tools:
- Shared types in
types.tsmatch all tools that use them - Tool IDs in the barrel export match the tool file definitions
- Error handling is consistent (error checks, meaningful messages)
- Shared types in
- If any response schema is still unknown, explicitly tell the user instead of guessing