Sim vs StackAI (2026)

More than 1,000 native integrations span communication (Gmail, Slack, Teams, Telegram, WhatsApp), productivity (Notion, Google Workspace, Airtable), development (GitHub, Jira, Linear), CRM and revenue (Salesforce, HubSpot, Attio, Gong), data and search (PostgreSQL, BigQuery, Pinecone, Perplexity, Exa) and security and IT (CrowdStrike, Okta, AWS IAM), exposed to agents as tools inside workflows. Anything not built in connects through MCP.

Sourcedocs.sim.ai/introductionread 2026-09-29

Roughly ninety app nodes each come with their actions, inputs, configurations and outputs spelled out.

Classes represented include CRM and sales with Salesforce, HubSpot and Outreach, ERP with SAP, NetSuite and Oracle, ITSM and ticketing with ServiceNow, Jira, Linear, ClickUp and Zendesk, HR with Workday, data warehouses and databases with Snowflake, Databricks, BigQuery, Azure SQL, Synapse, MongoDB, MySQL and PostgreSQL, vector stores with Pinecone and Weaviate, storage and documents with SharePoint, Box, OneDrive, Egnyte, Google Docs and Excel, communications with Slack, Teams, Gmail, Outlook and Missive, financial data with SEC EDGAR, Pitchbook, Crunchbase, Fred and Yahoo Finance, plus Docusign, Stripe, Miro, Notion, Airtable, Smartsheet, Coda and a Custom API node. An MCP node connects to any Model Context Protocol server.

Sourcedocs.stackai.com apps treeread 2026-08-31

A visual workflow builder offers built in control blocks including Router, Condition, Loop, Parallel and a Workflow block for composing sub workflows. Agents reason inside Agent blocks and act through tools, and Mothership, the natural language control plane, scaffolds and edits workflows, tables and knowledge bases across the workspace, with API and SDK build paths running alongside the canvas.

Sourcedocs.sim.ai/introductionread 2026-09-29

In the AI Agent node, Subflow Tools let an agent call another flow as a tool with its own tools, knowledge sources, main and advanced settings. Logic nodes cover AI Routing for branching the model decides, If/Else for deterministic branching, Loop Subflow for iteration, and Code and Python Code for custom logic, with a Delay node for pacing and a StackAI Project Node for invoking another project. StackAI also gives guidance on orchestrating AI agents, common architectures, handling errors and fallback, detecting the first run, and skipping or replacing a node.

Sourcedocs.stackai.com core nodes, logic and guides treesread 2026-08-31

Six core triggers, Start, Schedule, Webhook, RSS Feed, Table and Sim Workspace Events, start workflows, and deployments expose any workflow to the outside world as an API, a chat interface or an MCP server.

Sourcedocs.sim.ai/introductionread 2026-09-29

Trigger Nodes start automated workflows in two ways.

Event based triggers run the moment something happens, such as a new Gmail or Outlook email, a Typeform submission, a Stripe payment, a new Zendesk ticket or another StackAI workflow finishing, with filters on conditions such as sender, label or attachments, and time based triggers run once at a set date and time or recur hourly, daily or weekly.

Both start the workflow without a person initiating it. End-user interfaces add Form, Chat Assistant, Website Chatbot, Slack App, Microsoft Teams, WhatsApp and SMS through Twilio, Batch Run and API.

Sourcedocs.stackai.com Trigger Node page and end-user interfaces treeread 2026-09-29

Knowledge bases are a workspace resource of their own, with connectors, tag based filtering, chunking strategies and retrieval debugging, and agents retrieve relevant passages from customer documents to ground answers.

Sourcedocs.sim.ai/tools/knowledgeread 2026-09-29

Knowledge bases can be created and used by an AI agent in two ways, through knowledge base nodes and tools, with a Knowledge Base app node for search and retrieval over indexed documents and a Knowledge Bases REST endpoint. Connection and Knowledge Base Permissions restrict access independently of workflow access. A Dynamic Vector Store node builds retrieval at runtime, Search Connected Apps grounds against live systems, and Pinecone and Weaviate nodes query customer-managed vector databases. Chunking and embeddings are configurable, and Reducto and VLM nodes handle document parsing.

Sourcedocs.stackai.com knowledge bases, apps and core concepts treesread 2026-08-31

Memory on the Agent block needs a conversation ID to persist across runs, and the agent can be set to one of four memory modes. None sends independent requests, Conversation holds the full history keyed by a conversation ID, Sliding Window by messages keeps the N most recent, and Sliding Window by tokens keeps messages up to a token limit.

The Mem0 integration lets agents keep persistent memory across workflow executions, recalling past conversations, remembering user preferences and building on previous interactions, with add, semantic search and retrieve operations, and Zep ships as a second external memory option. Tables hold durable structured rows that workflows read and write, and Variables carry in-run state.

Sourcedocs.sim.ai agent block, Mem0 tool and workflow documentationread 2026-08-31

The Shared Memory node passes conversational context from one LLM node to another, with the builder choosing how many past interactions to forward, and StackAI warns that passing too many will overwhelm the receiving model's context window. That context is passed within a run, and no memory kept across sessions or learned over time is described. Browser session state that persists across runs and Canvas version history for each conversation belong to the browser and document features.

Sourcedocs.stackai.com Shared Memory node and complete documentation indexread 2026-08-31

Human in the Loop and Guardrails ship as core workflow blocks alongside Condition and Wait, and enterprise access control enforces which blocks and model providers each permission group can use, both in the UI and at execution time.

Sourcedocs.sim.ai/introductionread 2026-09-29

Human in the Loop is one of StackAI's core nodes, and the first of its building challenges is constructing a procurement intake assistant that gathers missing details with HITL and confirms the final request before sending. Approval requests can be delivered in Slack with approve and disapprove controls, bringing human oversight into critical decision points. Workflow Notifications are available, and Project Controls lock workflows when in production. Feature Access lets an admin enforce governance standards over what builders may use.

Sourcedocs.stackai.com human-in-the-loop node, building challenges and security tree, stackai.comread 2026-08-31

Sim's Trust Center at trust.sim.ai lists SOC 2 Type II, ISO 27001 and GDPR, and SOC 2 compliance is among the Enterprise features. Access controls include SAML 2.0 and OIDC SSO across Okta, Entra ID, Google Workspace and ADFS, workspace roles and permission groups enforced at execution time, verified domains, session policies with maximum lifetime, idle timeout and sign out of all members, dedicated outbound IPs, secrets management and configurable data retention.

Sourcesim.ai homepage and pricing page, docs.sim.ai enterprise Security pageread 2026-09-29

Security and governance controls cover Security and Privacy, AI Governance, Role-Based Access Controls and Groups, Workspace and Folder Access, Project Controls, Feature Access for admin enforcement of governance standards, Connection and Knowledge Base Permissions, Authentication and MFA, an Agentic Development Lifecycle, and SCIM provisioning from the customer's identity provider with dedicated Okta and Entra guides.

Environment Variables store encrypted secrets outside the workflow and resolve stage-specific values at runtime. StackAI holds SOC 2 Type II, ISO 27001, HIPAA and GDPR certification, with a Trust Center at trust.stackai.com, a SOC 2 report request form, published OpenAI and Anthropic data processing addenda, and a BAA signing route.

Sourcedocs.stackai.com security tree and stackai.com certificationsread 2026-08-31

Logs record every run block by block as a workspace resource of their own, with logging and alerts, cost visibility for each run, enterprise audit logs tracking configuration and security relevant actions, and data drains that stream workflow logs, audit logs and Mothership data to a customer owned S3 bucket or HTTPS webhook on a schedule.

Sourcedocs.sim.ai/introductionread 2026-09-29

The Analytics page gives node level information to follow the data flowing through a workflow, trace any actions taken at each step and find the node where an error originated, a record of the agent's run step by step. It also shows runs, users, errors and token usage over a time range, with an admin only switch to disable logs for sensitive workflows, the Manager view shows every conversation between users and agents, and an Analytics REST endpoint is available.

Sourcedocs.stackai.com Troubleshooting a Workflow, Analytics and Manager pagesread 2026-09-29

Sim runs cloud hosted at sim.ai or self hosted through Docker Compose and Kubernetes, including a fully offline setup with local models through Ollama, and self hosted deployments unlock the entire enterprise feature set through environment configuration, so the customer can control hosting entirely.

Sourcedocs.sim.ai/introductionread 2026-09-29

StackAI can run on premises, and the StackAI Auto CLI, an enterprise command line tool, deploys and manages StackAI on customer infrastructure, with engineering standards, a getting started guide, migration from a legacy Docker deployment and a storage-api CVE upgrade plan. Government deployments come with guidance for provisioning Azure OpenAI in Azure Government. StackAI offers multi tenant, VPC and on premise deployment with Kubernetes, and the workflow builder supports local LLM hosting and LLMs hosted on Azure and AWS Bedrock so inference can stay inside the customer's own cloud account.

Sourcedocs.stackai.com on-premise, government deployments and Auto CLI trees, stackai.com deploy anywhere sectionread 2026-08-31

Agent skills provide reusable packaged capabilities and Mothership scaffolds complete systems from a natural language description, and Sim does not describe a template gallery, prebuilt agent library or marketplace.

Sourcedocs.sim.ai/introductionread 2026-09-29

Templates are offered in the workflow builder and on the product site. StackAI Computer users can open the Templates section and search for the Content Writer template, a pre-built agent with a structured system prompt that demonstrates document generation from start to finish. Skills are reusable instruction packs that AI Agents load on demand, a Prompt Library holds saved prompts and instructions, and common architectures give reusable workflow patterns. Fourteen tutorial agents can be built as examples, including compliance, IT support, policy, Salesforce and web research agents.

Sourcedocs.stackai.com templates, skills, prompt library and tutorials treesread 2026-08-31

More than fifteen providers are supported, including OpenAI, Anthropic, Google Gemini, Groq, Cerebras, DeepSeek, Mistral, xAI and OpenRouter, with bring your own key at base provider pricing and no markup, and local models run through Ollama or VLLM at no API cost. Enterprise permission groups can restrict which providers are allowed.

Sourcedocs.sim.ai/blocks/agentread 2026-09-29

StackAI supports multiple LLMs, models hosted on Azure and AWS Bedrock in the customer's own account, and local LLMs on the customer's own infrastructure, and LLM Provider Governance controls which LLMs the organization has access to and where information is sent and stored. Guidance covers using multiple LLMs and improving LLM performance, a Cerebras node adds a dedicated inference provider, and StackAI is LLM agnostic, naming Anthropic, Meta, OpenAI, Google Gemini and Mistral. A public LLM Leaderboard is published on its site.

Sourcedocs.stackai.com LLM hosting and governance tree, stackai.comread 2026-08-31

Sim is open source under Apache 2.0 with the full source on GitHub, a public API and SDKs, a Function block for custom JavaScript, custom tools, and MCP in both directions, so agents consume MCP tools and any workflow deploys as an MCP server, with enterprise custom blocks on top.

Sourcedocs.sim.ai/introductionread 2026-09-29

An API Reference covers Run Flow, Knowledge Bases and Analytics endpoints, and a StackAI MCP Server exposes the platform to MCP clients. The StackAI Auto CLI is an enterprise command line tool for deploying and managing the platform. Within workflows, a Custom API node calls arbitrary external endpoints, a Code Node and Python Code node run custom logic, and Exporting and Importing Projects plus Sharing Projects and Backup make agent definitions portable. An interface can be deployed as an API, alongside Exposed Inputs and signed URL generation.

Sourcedocs.stackai.com API reference, MCP reference, utils and interface treesread 2026-08-31

The Evaluator block is a core block that uses AI to score and assess content quality against metrics the customer defines, each with a name, description and numeric range, with accuracy, clarity and relevance on one to five scales as worked examples.

The block generates a JSON Schema response format from those metrics and enforces strict mode so the model returns only numeric scores, and it supports quality control and A/B testing, including comparing several AI generated responses and assessing Agent block outputs to create feedback loops. A published pattern chains Agent to Evaluator to Condition against a threshold.

Guardrails, knowledge base retrieval debugging, block-by-block run traces and per-run cost visibility help with debugging. Sim does not describe keeping test sets, stored expected outputs or a regression history across versions.

Sourcedocs.sim.ai evaluator block and core blocks documentationread 2026-08-31

An Evaluator in the Observability section scores an agent's performance with an LLM as a judge, alongside Analytics and Manager. StackAI covers an Agentic Development Lifecycle, the workflow editor shows version control, a pull request and a prompt diff, and Project Controls track versions during workflow development and lock workflows in production. Guides cover troubleshooting a workflow and handling errors and fallback, and a Prompt Library stores saved prompts and instructions.

Sourcedocs.stackai.com Observability and Security in StackAI treesread 2026-08-31

Browser Use and Stagehand ship as workflow tools in the integrations catalog alongside Apify and Bright Data, letting workflows drive real browsers against interfaces that expose no programmatic API, with Stagehand performing natural language navigation and action on live pages. These are third party browser engines wired in as catalog integrations, not a hosted or local browser or desktop session Sim runs itself.

Sourcedocs.sim.ai tools catalogread 2026-08-31

Browser Navigation Replay persists browser state including cookies, sessions and local storage across runs. A session is recorded through a bundled browser extension in a sandboxed browser and replayed later on a schedule or trigger, and if the recording was captured while logged into a web application, that session state is preserved between runs so re-authentication is not needed.

Each replay returns a step-by-step result payload plus a stream URL for watching execution in real time. Browser Navigation is the choice when the agent must reason its way through an unfamiliar or dynamic task, and a separate HyperBrowser node automates browser tasks. The Terminal sandbox and Canvas actions on the same provider handle code execution and document editing.

Sourcedocs.stackai.com StackAI Computer and HyperBrowser nodesread 2026-08-31