turbo-agent

The official Turbo Lang agent framework — written in pure Turbo source code.

Status: Placeholder

This repo is an intentional placeholder. As of 2026-04-09, the in-compiler agent { } block, tool fn modifier, Ty::Agent type, and LLM provider runtime were removed from the Turbo compiler. They will return as a sidecar library here, but only once the core language has the prerequisites it needs to host a real implementation:

• Real HTTP client in stdlib (not a curl shell-out)
• Real JSON parser + serializer in stdlib
• Generics on structs and traits
• A real trait system with impl Trait for Type
• Async / Futures that compose with I/O
• Refinement types on struct fields (for structured output validation)

When those land, this repo gets a real implementation. Until then, see DESIGN.md for the planned API.

Why a sidecar instead of a language feature

The compiler used to have soft keywords agent, tool, resource, prompt, plus a 7-pointer agent struct, hardcoded .ask / .ask_structured / .stream method dispatch in codegen, and an OpenAI/Anthropic runtime that fork()-ed curl and used strstr to scrape responses. None of it parsed real tool_use blocks. None of it tracked tokens or cost. The mock:toolloop "tool loop" was a string-matching puppet show.

That's bad compiler code, and worse, it was the wrong kind of code. Languages that ship 8-year horizons cannot bake in 2025-era domain assumptions — see PHP mysql_*, Perl CGI, every framework that went all-in on Web 2.0. Libraries age well; keywords don't.

The bigger insight: the infrastructure this library needs is exactly what Turbo needs to be a serious general-purpose language anyway. Real HTTP, real JSON, generics, traits, async. Building those for the sidecar is the same work as making Turbo a better language. So this placeholder is also a forcing function for the right kind of compiler improvements.

The pitch: "Turbo is so expressive that the official agent framework is pure-Turbo source code." Same play as Rust + tokio, Go + net/http.

Planned design (what lives here eventually)

• Provider trait with impls for Anthropic, OpenAI, Gemini, local, mock
• ToolSchema derived by the compiler from tool fn signatures and doc comments — never hand-written
• AgentEvent enum, Trace type, agent.history, agent.replay(trace)
• Usage, Cost, Budget types with runtime enforcement and typed BudgetExceeded errors
• profile blocks — reusable capability/model bundles with set algebra (tools: Researcher.tools - { exec })
• Bulk agent expansion — for p in PERSONAS { agent p.name : Profile { ... } } so 25 personas cost 25 lines
• Agents-as-tools composition — supervisors, voting, handoffs are map/reduce/spawn over agents that satisfy the tool signature. No new keywords.
• Streaming structured output — stream T yields typed Partial<T> field-by-field, not raw tokens
• @durable execution (post-1.0) — Restate-style checkpointing on top of the AgentEvent log

Consumers

• Carl Code (private) — multi-agent CLI tool, currently pinned to Turbo v0.7.2 awaiting this library. Will be the first dogfood consumer when v0.1 ships.

Versioning

This repo will follow Turbo's version cadence. The first real release will be turbo-agent v0.1.0, paired with the Turbo release that lands HTTP + JSON + generics + traits.

License

MIT (matches Turbo Lang).