Synapse vs Tembo

At a glance

Tembo facts are from tembo.io, its pricing and docs, checked on 16 October 2026.

Terragon shut down

Terragon Labs ran Claude Code, Codex, Amp and Gemini as background agents in cloud sandboxes, with a GitHub PR workflow and bring-your-own subscriptions. It shut down. Its open-source snapshot repo carries a notice dated 16 January 2026 saying it is "an open-source snapshot of Terragon at the time of shutdown", and users asked on Hacker News for alternatives.

Tembo is the closest live product in that niche: multiple agent CLIs, cloud execution, PRs and bring-your-own subscriptions. Aggregator lists also name Codex cloud, Cursor cloud agents, Claude Code on the web and Google Jules as options. We did not re-check those. Synapse is not a Terragon replacement. It has no cloud and no background runs.

What Tembo is

Tembo describes itself as a "cloud platform for running AI agents in complete, shareable software environments". You pick a harness (Claude Code, Codex, Cursor, OpenCode, Amp, Pi or fx), and it runs in a NixOS-based sandbox VM or Docker with a terminal, files and a live desktop.

Agents start on hourly, daily or weekly schedules, on GitHub, GitLab, Sentry, Linear or Slack events, on webhooks or on @tembo mentions. They return PRs with signed commits, and a Feedback Loop turns review comments into revisions. MAX mode runs several agents on the same task so you can compare results. Tembo lists 40+ integrations, many through MCP. The company previously built a Postgres platform and moved to coding agents in 2025.

What Synapse is

Synapse puts every live coding agent on your Mac on one canvas. Drag a line from agent A to agent B, and on every prompt B gets what A has said since last time, up to 8,000 characters per link. Linked agents can message each other through six MCP tools, a CLI or a skill. It discovers agents by process scan, so there is nothing to register or relaunch.

How Tembo and Synapse handle agents talking to each other

Tembo:

• No agent-to-agent messaging or live context sharing between sessions is described in its docs. Each run is an isolated cloud job.
• Closest primitives: getAgentState and setAgentState MCP tools that persist key-value state for one configured agent across its runs, shared logs and artifacts, rule files and skills at repo level, and Slack tools for posting to humans.
• MAX mode runs several agents on one task for comparison, not collaboration.
• Hand-off happens through people: PRs, review comments and @tembo mentions.

Synapse:

• Links between live agents. A link carries the source agent's recent conversation into the receiver's next prompt, labelled as from a peer.
• Messages between any linked agents, for example Claude Code asking Codex what it found. Messages are pulled: Claude Code and Codex see them on the next prompt, other CLIs call synapse_inbox.
• Which agents: Claude Code and Codex fully, Gemini CLI with readable context, and OpenCode, Cursor Agent, Amp and Copilot CLI for messages.
• Setup: node install.mjs once. Agents already running need one restart.

Open source, accounts and privacy

Tembo is proprietary. It needs an account and a Git provider connection, and the Developer API uses API keys. Enterprise plans can self-host on AWS, GCP, Azure or Kubernetes. Your code runs in its cloud VMs, billed per second.

Synapse is MIT, has no account, keeps links and messages in ~/.synapse, and makes no network calls. Nothing leaves your machine.

Where Tembo is ahead

• Unattended work. Schedules and event triggers from Sentry, Linear, GitHub and Slack, with PRs at the end. Synapse only helps while you are at your machine.
• Cloud hardware. Many agents in parallel on VMs, not your laptop.
• Integrations. A large catalog, an MCP gateway, signed commits and review feedback loops.
• Teams. Seats on paid plans and enterprise SSO. Synapse multiplayer is in development.

One caution applies to the whole category. Terragon shut down, and hosted background-agent startups have churned in 2026, while first-party cloud agents compete on price.

Using Synapse with Tembo

1. Send overnight or ticket-driven work to Tembo, where it comes back as PRs.
2. In the morning, open Claude Code and Codex locally and link them with Synapse.
3. Have one agent review the Tembo PR while the other implements fixes, each seeing the other's recent work.

Synapse does not reach Tembo's cloud sandboxes today.

Who should pick which

• Pick Tembo if you want agents to work on tickets and alerts while you are away and send PRs, or you are replacing Terragon.
• Pick Synapse if you work interactively with several agents on your Mac and want them to share context and talk, free and local.
• Use both for background PRs plus connected local review.

FAQ

What is the best Terragon alternative?

Terragon shut down in January 2026. Tembo is the closest live product: it runs Claude Code, Codex, Cursor, OpenCode, Amp and other harnesses as cloud background agents, supports bring-your-own subscriptions and returns PRs. Aggregator lists also name Codex cloud, Cursor cloud agents, Claude Code on the web and Google Jules. Synapse is not a Terragon replacement because it runs nothing in the cloud.

Did Terragon Labs shut down?

Yes. Terragon's open-source snapshot repo has a notice dated 16 January 2026 saying it is a snapshot of Terragon at the time of shutdown.

Can Tembo agents talk to each other?

Not that we found. Tembo's docs describe per-agent state that persists across runs, shared logs and artifacts, and MAX mode for comparing agents on one task, but no agent-to-agent messaging. Synapse lets linked agents message each other and share recent conversation.

Does Tembo support my Claude or ChatGPT subscription?

Yes. Tembo lets you bring a Claude, ChatGPT or SuperGrok subscription, bring your own API key, or pay per token through Tembo Gateway.

Is Synapse a Tembo alternative?

Only if what you need is connected local agents. Synapse links agents on your Mac so they share context and message each other. It has no cloud VMs, schedules, event triggers or PR automation, which are Tembo's core.

Is Synapse free?

Yes. Synapse is free and MIT licensed, with no account and no paid tier.