Happy gives Claude Code and Codex a mobile and web client; AgentAPI wraps coding agents in an HTTP API. Here is how the two compare and when to reach for each.
Search for "happy vs agentapi" and you are really comparing two tools that sit on opposite sides of the same problem: controlling a terminal coding agent such as Claude Code or Codex without being chained to the terminal it started in. They are not competing implementations of one idea. Happy (published by slopus) is a mobile and web client that lets you watch and steer a running agent from your phone. AgentAPI (published by Coder) is an HTTP server that puts a REST-style interface in front of a coding agent so other software can drive it.
Both are open-source projects on GitHub, and both name Claude Code and Codex as agents they run. The right pick depends almost entirely on whether you want a finished app to use with your own hands, or a programmable endpoint to build on. This comparison lays out what each project documents on its repository as of 2026-08-06, where they overlap, and which use cases point to which tool.
At a glance
In short
They solve different problems, so pick by intent. Choose Happy if you want a finished app to watch and steer your own Claude Code or Codex sessions from a phone or browser, with push notifications and encryption (slopus/happy README, 2026-08-06). Choose AgentAPI if you want to control coding agents from your own code over HTTP — as an MCP backend, an automated PR reviewer, or a custom chat UI — across a broad set of agents (coder/agentapi README, 2026-08-06). Both are MIT-licensed and free to run as of 2026-08-06.
Head to head
Key differences side by side; the stronger option is tinted green.
| Feature | Happy | AgentAPI |
|---|---|---|
| Primary purpose | Mobile and web client to use Claude Code and Codex from anywhere (slopus/happy README, 2026-08-06) | HTTP API server to control coding agents programmatically (coder/agentapi README, 2026-08-06) |
| Documented agents | Claude Code and Codex (slopus/happy README, 2026-08-06) | Claude Code, AmazonQ, Opencode, Goose, Aider, Gemini, GitHub Copilot, Sourcegraph Amp, Codex, Auggie, Cursor CLI (coder/agentapi README, 2026-08-06) |
| Install method | npm install -g happy (slopus/happy README, 2026-08-06) | Download release binary via curl or the releases page (coder/agentapi README, 2026-08-06) |
| How you invoke it | Run happy claude or happy codex in place of the agent command (slopus/happy README, 2026-08-06) | Run agentapi server -- , then make HTTP calls (coder/agentapi README, 2026-08-06) |
| Native mobile apps | iOS and Android apps plus a web app (slopus/happy README, 2026-08-06) | Not covered on the pages we read (2026-08-06) |
| Programmatic HTTP endpoints | Not covered on the pages we read (2026-08-06) | GET /messages, POST /message, GET /status, GET /events (SSE), plus OpenAPI schema and /docs (coder/agentapi README, 2026-08-06) |
| Notifications | Push notifications when the agent needs permission or hits an error (slopus/happy README, 2026-08-06) | SSE event stream at GET /events for agent events (coder/agentapi README, 2026-08-06) |
| License | MIT (slopus/happy README, 2026-08-06) | MIT (coder/agentapi README, 2026-08-06) |
Feature matrix
| Feature | Happy | AgentAPI |
|---|---|---|
| Controls Claude Code — Both name Claude Code as a supported agent (2026-08-06). | ✅ | ✅ |
| Controls Codex — Happy runs happy codex; AgentAPI lists Codex among supported agents (2026-08-06). | ✅ | ✅ |
| Broad multi-agent roster — Happy's repo documents Claude Code and Codex; AgentAPI lists 11 named agents (2026-08-06). | 🟡 | ✅ |
| Native iOS/Android apps — Happy ships mobile apps; AgentAPI's repo describes a web chat interface, not native mobile apps (2026-08-06). | ✅ | ❌ |
| Documented HTTP API — AgentAPI's core is its HTTP endpoints and OpenAPI schema; Happy's repo documents a CLI wrapper and sync server, not an HTTP control API (2026-08-06). | ❌ | ✅ |
| Browser chat interface — Happy provides a web app; AgentAPI serves a chat UI at /chat (2026-08-06). | ✅ | ✅ |
| Push notifications — Happy sends push notifications; AgentAPI exposes an SSE event stream you can act on, not push notifications (2026-08-06). | ✅ | 🟡 |
| MIT-licensed open source — Both repositories are MIT-licensed (2026-08-06). | ✅ | ✅ |
✅ full · 🟡 partial/paid · ❌ not supported
Pricing
Confirm current pricing on each vendor's site.
HappyFree, open source (MIT license), as of 2026-08-06
Install with npm install -g happy (slopus/happy README, 2026-08-06)
iOS, Android and web clients for Claude Code and Codex (2026-08-06)
End-to-end encryption; stated no telemetry and no tracking (2026-08-06)
Push notifications and instant device switching (2026-08-06)
View Happy on GitHubAgentAPIFree, open source (MIT license), as of 2026-08-06
Install a release binary via curl (coder/agentapi README, 2026-08-06)
HTTP server fronting 11 named coding agents (2026-08-06)
Endpoints for messages, status and an SSE event stream (2026-08-06)
OpenAPI schema, /docs UI and a /chat web interface (2026-08-06)
Pros & cons
HappyPros
Ready-to-use native iOS and Android apps plus a web app (slopus/happy README, 2026-08-06)
Drop-in: run happy claude or happy codex instead of the bare command
End-to-end encryption with a stated no-telemetry, no-tracking policy (2026-08-06)
Push notifications and one-keypress hand-off between phone and desktop
Cons
The repository documents Claude Code and Codex as the supported agents (2026-08-06); other agents are not covered on the pages we read
A programmable HTTP control API is not covered on the pages we read
As a hosted-sync client, it relies on the Happy Server for remote sessions
AgentAPIPros
Fronts a wide roster of agents: 11 named CLIs including Claude Code, Codex, Aider, Goose and Gemini (2026-08-06)
Clean HTTP surface with an OpenAPI schema, /docs UI and SSE events (2026-08-06)
Designed to be embedded as an MCP backend or an automated PR-review tool (2026-08-06)
Includes a browser chat interface at /chat out of the box
Cons
You build your own front end; native mobile apps are not covered on the pages we read
Requires explicit --type flags for several agents or message formatting may break (2026-08-06)
More of a building block than a finished end-user product
Happy Coder and AgentAPI: the public release record on 2026-08-06
| Measured on 2026-08-06 | Happy Coder slopus/happy | AgentAPI coder/agentapi |
|---|---|---|
| Latest release | cli-1.1.10, published 2026-06-23 | v0.12.2, published 2026-05-27 |
| Commits, weekly average | 13.9 a week (167 commits in the 12 weeks to 2026-08-06) | 0.2 a week (3 commits in the 12 weeks to 2026-08-06) |
| Most recent commit | 2026-08-05 | 2026-05-27 |
As recorded on 2026-08-06 from the projects' public source repositories on GitHub, Happy Coder averaged 13.9 commits a week over the preceding twelve weeks while AgentAPI averaged 0.2 a week over the same span, and its most recent commit on that date was 2026-08-05 against AgentAPI's 2026-05-27 — the latter also matching AgentAPI's latest tagged release, v0.12.2 of 2026-05-27, a version record held in the same public repository. For someone choosing between the two, these figures reasonably suggest that Happy Coder is under active, near-daily development whereas AgentAPI has seen little repository activity for roughly two months. They do not, however, establish anything about the reliability, support, or overall product quality of either tool, nor how many people actually use it; commit and release cadence measure only how often each codebase is changed in public, not whether the result works well or is widely adopted.
Where these numbers come from: on 2026-08-06 (2026-08-06T00:05:31Z) we called the public endpoints listed below and recorded what they returned. Nothing here is taken from either vendor's marketing pages, and anyone can repeat the same calls. Repository figures describe the named repository — for a closed-source platform that is its official CLI or SDK, not the platform itself. What these figures do not tell you: Commit counts include merges, dependency bumps and documentation changes, and a monorepo will always show more commits than a single-purpose repository, so this measures how busy the named repository is — not progress, quality, or how much of it reaches the product. The commit date says the repository is being worked on, nothing about what changed. None of them measures reliability, support or how either product feels to use.
Happy Coder — GitHub REST API · GitHub releases API · the project's own repository and the npm package published from it
AgentAPI — GitHub REST API · GitHub releases API · Coder's own repository for the project
What each tool actually is
Happy
Happy describes itself on its GitHub repository as a "Mobile and Web Client for Claude Code & Codex," letting you use those agents from anywhere with end-to-end encryption (slopus/happy README, as of 2026-08-06). You install it with npm install -g happy and then run happy claude or happy codex instead of the bare claude or codex command. The wrapper starts your agent locally; when you want to take over from your phone, it restarts the session in remote mode, and pressing any key on your keyboard hands control back to the desktop (slopus/happy README, 2026-08-06).
The project lists four components on its repository: the Happy App (a web UI plus mobile client built with Expo), the Happy CLI, a Happy Agent for remote session control, and a Happy Server for encrypted sync (slopus/happy README, 2026-08-06). It is distributed under the MIT license, and the repository showed roughly 23.2k stars and 2.0k forks as of 2026-08-06.
AgentAPI
AgentAPI, from Coder, describes itself as a way to "Control Claude Code, AmazonQ, Opencode, Goose, Aider, Gemini, GitHub Copilot, Sourcegraph Amp, Codex, Auggie, and Cursor CLI with an HTTP API" (coder/agentapi README, as of 2026-08-06). You install a binary, then run a command such as agentapi server -- claude to launch an HTTP server that fronts the agent. The README lists suggested uses: building a unified chat interface for coding agents, acting as a backend in an MCP server so one agent can control another, and creating a tool that submits pull-request reviews to an agent (coder/agentapi README, 2026-08-06).
It is also MIT-licensed, and its repository showed roughly 1.5k stars and 134 forks as of 2026-08-06.
How they work under the hood
The mechanics are where the two diverge most. Happy is a wrapper you invoke in place of your agent command. It keeps the local session and the remote (phone) session in sync through the Happy Server, and the pitch is human-facing: check what your agent is building while you are away from your desk, and get push notifications when Claude Code or Codex needs permission or hits an error (slopus/happy README, 2026-08-06). The project states it is open source with no telemetry and no tracking, and that code stays encrypted on your devices (slopus/happy README, 2026-08-06).
AgentAPI is machine-facing. Starting agentapi server -- claude runs, by default, on port 3284 and exposes four endpoints: GET /messages (the full conversation), POST /message (send a message to the agent), GET /status (reports "stable" or "running"), and GET /events (a server-sent-events stream of agent events) (coder/agentapi README, 2026-08-06). The server also publishes an OpenAPI schema at /openapi.json, an interactive docs UI at /docs, and a chat web interface at /chat (coder/agentapi README, 2026-08-06). Because it speaks plain HTTP with a documented schema, it is meant to be scripted and embedded.
In short: with Happy you are the operator, tapping a phone. With AgentAPI your own code is the operator, making HTTP calls.
Supported agents and interfaces
AgentAPI names a broad roster of coding agents it can front: Claude Code, AmazonQ, Opencode, Goose, Aider, Gemini, GitHub Copilot, Sourcegraph Amp, Codex, Auggie, and Cursor CLI (coder/agentapi README, 2026-08-06). Its README notes that for Claude, Codex, Opencode, Copilot, Gemini, Amp, or Cursor CLI you should specify the agent type explicitly (for example agentapi server --type=codex -- codex) or message formatting may break. It also shows examples for running Aider and Goose, including passing model and API-key flags through after the -- separator (coder/agentapi README, 2026-08-06).
Happy's repository documents Claude Code and Codex as the agents it wraps, invoked as happy claude and happy codex (slopus/happy README, 2026-08-06). Its distinguishing surface is the client tier: native iOS and Android apps plus a web app, with push notifications and instant device switching (slopus/happy README, 2026-08-06). AgentAPI ships a browser chat interface at /chat and, being an API, leaves the rest of the front end to whatever you build on top of it (coder/agentapi README, 2026-08-06).
Can you use both together?
Because they operate at different layers, the two are not mutually exclusive. AgentAPI is explicitly pitched as a backend you build interfaces on top of, including a "unified chat interface for coding agents" (coder/agentapi README, 2026-08-06). Happy is a ready-made client you use directly. A team could reasonably run AgentAPI as the programmable control plane for automation (say, an MCP server or an automated PR reviewer) while individual developers use Happy to check in on their own local agents from a phone. Neither repository, as read on 2026-08-06, documents a built-in integration between the two projects, so combining them would be your own plumbing rather than a supported feature.
Verdict
These are not rivals so much as neighbors. Happy is the answer when the user is you: it packages Claude Code and Codex into native mobile and web clients so you can keep an eye on a running session away from your desk, with encryption and push notifications (slopus/happy README, 2026-08-06). If you have ever wanted to approve a permission prompt from your phone, that is the tool.
AgentAPI is the answer when the user is your software. Its HTTP endpoints, OpenAPI schema and SSE event stream make it a control plane for automation — the README points at MCP backends, agent-to-agent control, and automated pull-request reviews, across a notably wider list of agents (coder/agentapi README, 2026-08-06). It gives you plumbing, not a polished app.
Both are MIT-licensed and free to run as of 2026-08-06, so cost is not the deciding factor. Decide on layer: reach for Happy to use an agent by hand from anywhere, and for AgentAPI to program against one. Teams that need both a human remote control and a machine control plane could run each for its own job.
FAQ
Are Happy and AgentAPI the same kind of tool?
No. Happy is a mobile and web client for using Claude Code and Codex directly, while AgentAPI is an HTTP server that lets your own software control coding agents. One is for people, the other is for programs (slopus/happy and coder/agentapi READMEs, 2026-08-06).
Is either one free?
Both repositories are MIT-licensed open-source projects, and neither the Happy nor the AgentAPI repository we read listed a paid tier as of 2026-08-06. Running them still incurs whatever costs your underlying agent (for example, Claude Code or Codex usage) charges.
Which agents can each control?
Happy's repository documents Claude Code and Codex (2026-08-06). AgentAPI lists Claude Code, AmazonQ, Opencode, Goose, Aider, Gemini, GitHub Copilot, Sourcegraph Amp, Codex, Auggie, and Cursor CLI (coder/agentapi README, 2026-08-06).
Can I use them together?
They sit at different layers, so it is technically possible — for example running AgentAPI as an automation backend while using Happy as a personal remote. Neither repository we read on 2026-08-06 documents a built-in integration between the two, so any combination would be your own setup.
Sources
Originally published at https://utilverse.info/compare/happy-vs-agentapi-which-way-to-run-claude-code-and-codex-fits-your-workflow/.
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