Harness
One slim tool surface
Every harness sees discovery, batched execution, and secret refs instead of a giant static tool list into context.
open source · cross-harness AI runtime
Cross-harness runtime for serious AI work.
MCPlexer gives Claude Code, Codex, OpenCode, Cursor, Grok, Pi, Gemini, and other MCP clients the same operating layer: delegations, workers, tasks, memory, browser control, approvals, audit, workspaces, sandboxing, and routed MCP servers.
$ one slim surface · mcpx__search_tools + mcpx__execute_code + secret refs
Built for the harnesses and tools agents actually use
Full feature list
The important part is not a single dashboard. It is that the same primitives are available across harnesses: work can be delegated, remembered, audited, approved, routed, restricted, and continued.
Harness
Every harness sees discovery, batched execution, and secret refs instead of a giant static tool list into context.
Delegations
Delegate between models and harnesses with ease: keep the parent strategic while workers inspect files, run tests, draft changes, and return for scored review.
Workers
Manual, scheduled, mesh-triggered, and delegation-backed workers with model profiles, caps, approvals, and live run output.
Tasks
A work ledger designed for LLMs: stable IDs, leases, status events, offers, assignments, context packets, and attachments.
Memory
Persistent facts and notes survive model swaps, client swaps, and machines, with consolidation, invalidation, and sharing.
Browser
Drive visible Chrome, Playwright sessions, and desktop surfaces through the same routed MCP layer, including worker and peer workflows.
Workspaces
The real working directory decides which servers, tools, auth scopes, routes, and approval policies are available.
Restrictions
Capability presets, allowlists, deny rules, shell guard, sanitizer guard, schedule guard, sandbox guard, and downstream sandboxing.
Approvals
Sensitive calls for review in another session or the dashboard, with OS notifications and a worker approval queue.
Audit
Tool calls, worker dispatches, model sends, denials, approvals, mesh triggers, memory events, and route decisions are searchable.
Servers
GitHub, Linear, Slack, Gmail, Calendar, Postgres, Vercel, WordPress, WooCommerce, Reddit, Telegram, browsers, and custom servers.
Secrets
OAuth and API keys are encrypted at rest, injected only into matching routes, and kept out of transcripts through secret refs.
Mesh
Agents discover peers, exchange findings, offer tasks, send targeted questions, and coordinate across paired machines.
Skills
Search, install, publish, compose, and sync skills so agents load only the guidance they need for the current job.
Models
Capacity routing, provider profiles, cost dashboards, review scores, and leaderboards show which cheap models actually work.
Dashboard
PWA dashboard for approvals, audit, live signals, workspaces, routes, servers, model providers, backups, and recovery.
Plan
Frontier sessions define architecture, scope, and acceptance criteria. Workers do broad inspection, implementation, test loops, and log triage in bounded contexts.
Run
Tasks, memory, skills, and mesh give agents durable coordination primitives instead of making every chat rediscover the same project state.
Control
Workspace routing, approvals, audit, tool restrictions, sandboxing, and encrypted auth scopes make powerful MCP servers usable in real repos.
Browser control
A browser tied to one chat helps that chat. MCPlexer achieves browser control with brw — a real, visible Chrome window for agents — exposed as routed infrastructure, so the capability works across any harness, durable workers, and paired machines while staying auditable.
MCP server fabric
Downstream servers sit behind routes, auth scopes, workspace policy, approvals, and audit. Agents discover what they need when they need it.
AI-native setup
Inside ~/.mcplexer
, the agent can provision servers, import OpenAPI specs, write routes, set auth scopes, inspect audit, and manage approvals. In ordinary project repos, it only sees the slim universal surface.
example prompt
Wire GitHub, Linear, Gmail, Calendar, Postgres, browser control, and a cheap worker model into this workspace. Require approval for write tools and give Codex the same surface Claude Code gets.
Power with boundaries
MCPlexer is open source infrastructure for people pushing past one model, one chat, and one tool list.