Introduction

Mysti is an open-source coding workspace (Apache-2.0) that brings several coding agents together inside VS Code. Instead of juggling separate terminals, you address agents in one conversation with explicit tags such as @claude and @codex, see separately attributed answers, chain work with then, and keep drafts, context and permissions in one place. It also ships a Mysti coordinator backed by a DeepMyst account, plus Brainstorm discussion strategies and Proactive context gathering.

The README describes the 2.0.0 pre-release checkout, i.e. a beta. 2.0 introduces parallel opinions, cross-agent handoffs, connected tools and Proactive context on top of the single-agent experience.

What you can do

Concurrency follows the work: independent advisory requests may overlap, while writers sharing a workspace run serially. Model, effort and Ultracode controls are shown where the selected provider supports them.

Contributor build commands

The README lists these commands for working on Mysti itself:

npm ci
npm run typecheck
npm test
npm run watch

Use the Node version in .nvmrc; press F5 to launch the extension development host. See CONTRIBUTING.md for provider contracts, browser tests and contribution expectations.

Prerequisites

• VS Code 1.86 or newer on Windows, macOS or Linux.
• A trusted local workspace to open.
• At least one configured agent. Provider families listed by the README:

• For the coordinator, connected tools and cloud responsibilities: a DeepMyst account.
• For the contributor workflow: Node (version pinned in .nvmrc), npm, and optionally a browser for Visual Test.

Permissions, data flow and limitations

• Credentials are separate. Mysti itself uses your DeepMyst account; CLI agents use their own credentials. Provider subscriptions, API access and usage charges vary by provider.
• Prompt transmission. Provider requests transmit the prompt and supplied context to the configured provider. DeepMyst features use your connected account.
• Tool connections are opt-in and scoped. Connected apps and MCP servers go through DeepMyst's Composio and Smithery catalogs; browse and authorize in DeepMyst, then manage connections from Mysti. Catalog availability and tool permissions depend on the service and your account. Local CLI access is opt-in for supported adapters. A connected app is not automatically a Proactive monitoring source.
• Proactive limits. Cloud monitoring requires DeepMyst sign-in, a supported connection and an explicitly configured responsibility. Coverage is bounded, and evidence does not prove who owns a task. Local Git watches need the editor running.
• Checkpoints are local. A checkpoint cannot undo an external action.
• Capability variance. Model availability, effort, Ultracode, attachments, native approvals and authentication are provider-specific. An adapter being included is not a claim that every provider/version/account combination has been live-tested.
• Beta status. 2.0 is a pre-release package; the Marketplace badge shows the currently published version. Review the release notes for migration and known limitations before adopting it for important work.
• Telemetry follows VS Code's telemetry setting; see .github/SECURITY.md for the security policy.
• The demo recordings in the README use shipped webviews with deterministic sample responses; they are not live provider runs or performance benchmarks.

FAQ

Do I need all 16 provider adapters configured? No. The README states you only need one configured agent to begin; more agents enable parallel opinions, handoffs and Brainstorm.

What is the difference between a second opinion and Brainstorm? A second opinion resends the original question to another configured agent so you can compare separately attributed answers. Brainstorm pairs two configured agents with a discussion strategy (Quick, Debate, Red Team, Perspectives, Delphi) and keeps individual reasoning visible alongside the synthesis.

What happens if one agent in a workflow fails? A failed participant stays visible; Mysti does not invent its answer or ask another agent to impersonate it, and a failed dependency blocks its dependent step.

Do agents run in parallel? Independent read-only assignments run concurrently within the configured limit; work that may edit a shared workspace runs serially.

Are the GIFs and video in the README live agent runs? No. They use shipped webviews with deterministic sample responses to demonstrate interaction and presentation, not live provider runs or benchmarks.

Complete upstream material

Install Mysti · Get started · 2.0 BETA release notes · Contribute

Mysti 2.0 BETA

An open-source coding workspace that brings your agents together inside VS Code.

Ask Claude Code and Codex for independent opinions. Give a specialist a specific task. Hand completed work to another agent for review. Keep their responses, context, permissions, and progress in one conversation.

Mysti connects the coding tools you choose—CLI agents, local model servers, and the DeepMyst-powered Mysti coordinator. Use one agent when that's enough; bring in more when another perspective helps.

2.0 is a beta. This checkout prepares the 2.0.0 pre-release package. The Marketplace badge shows the currently published version. See release status and limitations before adopting it for important work.

16 provider adapters + the Mysti coordinator · Parallel opinions · Cross-agent handoffs · Connected tools · Proactive context

See it work

Watch the product tour →

The recordings below use the shipped webviews with deterministic sample responses. They demonstrate interaction and presentation; they are not live provider runs or performance benchmarks. Capture details and video downloads.

Get a second opinion without rewriting the question

An answer is a starting point. On answers with a usage or session receipt, click Second opinion, choose another configured agent, and Mysti sends it the original question. Compare separately attributed answers in the same conversation; use Brainstorm when you want a discussion and synthesis.

Ask two agents. Hear from both.

@claude @codex What are your opinions on adding a cache to this API?

Explicit tags determine who does the work. Independent read-only assignments run concurrently within the configured limit. Each agent has its own live card and attributed answer—even if one of them is already your selected provider.

A failed participant stays visible. Mysti does not invent its answer or quietly ask the other agent to impersonate it.

Turn tags into a workflow

@claude Design a retry policy, then @codex review it for edge cases

Use then to make the next assignment depend on the previous result. Claude designs the policy; Codex receives that result to review. Progress cards show the current step and who runs next. A failed dependency blocks its dependent step.

Add roles such as @claude:critic or @codex:reviewer to make the perspective explicit. Independent advisory work can run in parallel; work that may edit a shared workspace runs serially. Assignment and workflow guide.

Switch agents without losing your draft

Choose from 16 registered provider adapters, plus the Mysti coordinator. Move between coding CLIs, local model servers, and API providers from the composer. Your draft stays in place, and model controls follow the selected provider's capabilities.

See all providers and setup requirements.

Keep model choices close to your work

Choose the model, adjust effort, and toggle Ultracode where the provider supports it. The model menu and action menu share the same settings. Dictation adds text to your draft for review before you send.

Bring your tools into the conversation

Connect apps and MCP servers through DeepMyst's Composio and Smithery catalogs. Bring code, team discussions, email, and calendar context within reach of your agents through the tools you authorize. Browse and authorize in DeepMyst, then manage connections from Mysti.

The recording shows sample authorized connections, not a live OAuth flow. Catalog availability and tool permissions depend on the service and your account; local CLI access is opt-in for supported adapters. A connected app is not automatically a Proactive monitoring source.

Get context before you start

Proactive brings selected local Git changes and DeepMyst-connected GitHub/Slack evidence into an inbox. The Before you start view helps you inspect relevant evidence for a responsibility, including source links and freshness information.

Cloud monitoring requires DeepMyst sign-in, a supported connection, and an explicitly configured responsibility. Coverage is bounded; evidence does not prove who owns a task. Proactive setup and limits.

Work through a decision with Brainstorm

Choose two configured agents and a discussion strategy. Quick collects independent analyses and synthesizes a response; Debate, Red Team, Perspectives and Delphi provide other ways to examine a proposal. Keep the individual reasoning visible alongside the synthesis.

Choose a Brainstorm strategy.

More ways to move the work forward

One workspace, several ways to work

Parallelism follows the work: independent advisory requests may overlap; writers share a workspace and run serially. Use then for an explicit dependency. Assignment syntax and troubleshooting.

Get started

1. Install Mysti from the VS Code Marketplace, or install the reviewed beta VSIX with Extensions → Install from VSIX. Choose the pre-release channel when 2.0 BETA is published.
2. Open a trusted local workspace. Mysti supports VS Code 1.86 or newer on Windows, macOS, and Linux. Native voice support and provider CLIs have their own host requirements.
3. Open Mysti and choose your agent. The setup screen checks installation and authentication and provides the supported install, upgrade, or sign-in action. Mysti itself uses your DeepMyst account; CLI agents use their own credentials.
4. Start with a small task. Try @claude Explain the main entry point, then add @codex for a second opinion when both are configured.

You only need one configured agent to begin. Provider subscriptions, API access, usage charges, and supported models vary. Getting started · Provider setup.

Bring your preferred agents

The UI follows each adapter's capabilities. Model availability, effort, Ultracode, attachments, native approvals, and authentication are provider-specific. An adapter being included is not a claim that every provider/version/account combination has been live-tested. Compatibility and setup.

Your context and your controls

• Context where it belongs: mention workspace files, inspect diagnostics with @problems, or add a Git summary with @git.
• Visible authority: read-only and approval modes, agent-specific tool activity, and cancellation across active assignments.
• Continuity: conversation history, context compaction, and workspace checkpoints for supported local changes.
• Explicit connections: choose the DeepMyst tools and sources used by connected features. Cloud responsibilities continue on the backend; local Git watches need the editor running.

Provider requests transmit the prompt and supplied context to the configured provider. DeepMyst features use your connected account. Telemetry follows VS Code's telemetry setting; see the security policy and feature-specific guides. A local checkpoint cannot undo an external action.

Explore the documentation

Translations: العربية · 中文 · 日本語 · 한국어 · Español · Português · Deutsch · Français · Türkçe · Русский. Community translations may describe an earlier release; this README is the current 2.0 BETA reference.

Build with us

Mysti is Apache-2.0 licensed. Useful contributions include reproducible routing bugs, native-provider compatibility checks, accessible UI improvements, and tested documentation corrections.

npm ci
npm run typecheck
npm test
npm run watch

Use the Node version in .nvmrc; press F5 to launch the extension development host. See CONTRIBUTING.md for provider contracts, browser tests, and contribution expectations.

Report a bug · Discuss an idea · View the roadmap

Contributors

Thanks to everyone who has helped make Mysti better!

Want to join them? Check out the contribution guide section below.

License

Apache License 2.0. Built by DeepMyst and the Mysti community. Provider names and trademarks belong to their respective owners.

Source and license

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