Slack Overview

Slack Web API replica for agent testing

Overview

Agent Diff provides a high-fidelity replica of the Slack Web API. Your agent can post messages, manage channels, add reactions, and more - all in an isolated environment.

Getting Started

from agent_diff import AgentDiff

client = AgentDiff()

# Create Slack environment
env = client.init_env(
    templateService="slack",
    templateName="slack_default",
    impersonateUserId="U01AGENBOT9"  # User your agent acts as
)

# API base URL
print(env.environmentUrl)
# Output: http://localhost:8000/api/env/{id}/services/slack

Making API Calls

Direct HTTP

import requests

# List channels
response = requests.get(f"{env.environmentUrl}/conversations.list")
channels = response.json()["channels"]

# Post message
response = requests.post(f"{env.environmentUrl}/chat.postMessage", json={
    "channel": "C01GENERAL99",
    "text": "Hello from my agent!"
})

Using Code Executor

from agent_diff import PythonExecutorProxy

executor = PythonExecutorProxy(env.environmentId, client.base_url)

# Agent code uses production URLs - they get transformed automatically
result = executor.execute("""
import requests

response = requests.post('https://slack.com/api/chat.postMessage', json={
    'channel': 'C01GENERAL99',
    'text': 'Hello!'
})
print(response.json())
""")

Available Templates

Template	Description	Seed Data
slack_default	Basic workspace	3 users, 2 channels, 3 messages
slack_bench_default	Benchmark suite	Extended data for evaluations
slack_base	Minimal	Users and channels only

Response Format

All responses follow the Slack Web API format:

{
  "ok": true,
  "channel": "C01GENERAL99",
  "ts": "1732645891.000200",
  "message": {
    "type": "message",
    "user": "U01AGENBOT9",
    "text": "Hello!",
    "ts": "1732645891.000200"
  }
}

Error Handling

Errors match Slack’s error codes:

{
  "ok": false,
  "error": "channel_not_found"
}

Common error codes:

• channel_not_found - Invalid channel ID
• not_in_channel - User not a member
• message_not_found - Invalid message timestamp
• is_archived - Channel is archived

Authentication

In Agent Diff, authentication is mocked. The impersonateUserId you specify when creating the environment determines which user the agent acts as.

env = client.init_env(
    templateService="slack",
    templateName="slack_default",
    impersonateUserId="U01AGENBOT9"  # Agent's identity
)

# All API calls are made as U01AGENBOT9

Seed Data Structure

{
  "users": [
    {
      "user_id": "U01AGENBOT9",
      "username": "agent_bot",
      "display_name": "Agent Bot"
    }
  ],
  "channels": [
    {
      "channel_id": "C01GENERAL99",
      "name": "general",
      "is_private": false
    }
  ],
  "channel_members": [
    {"channel_id": "C01GENERAL99", "user_id": "U01AGENBOT9"}
  ],
  "messages": [
    {
      "message_id": "1732645800.000100",
      "channel_id": "C01GENERAL99",
      "user_id": "U01AGENBOT9",
      "message_text": "Welcome!"
    }
  ]
}

Next Steps

Supported Methods

Full API method reference

Seed Files

Create custom seed data