Content
# Drift
[](https://pypi.org/project/drift-lang/)
[](https://pypi.org/project/drift-lang/)
[](https://marketplace.visualstudio.com/items?itemName=rileyq7.drift-lang)
[](./LICENSE)
[](https://github.com/rileyq7/drift/actions/workflows/test.yml)
**An intent-based language for agentic systems.** Write your agent in English-shaped blocks, run it as async Python.
```drift
agent InboxTriage {
model: "gpt-5.4-nano"
budget: $0.10 per run
step triage(emails: list<string>) -> list<EmailAnalysis> {
let analyses = []
for each email in emails parallel {
let analysis = classify email as EmailAnalysis
analyses.add(analysis)
}
for each a in analyses {
if a.priority == "urgent" {
respond "URGENT {a.subject}: {a.summary}"
}
}
return analyses
}
}
```
A full agent: model choice, budget, parallel fan-out, structured classification, conditional output. The transpiler emits async Python that runs on Drift's thin runtime. Live against OpenAI: 5 emails, 1.82s, $0.0092, returned 5 typed dataclasses.
## Install
```bash
pip install drift-lang
```
Optional extras:
```bash
pip install "drift-lang[mcp]" # MCP tool support
pip install "drift-lang[dendric]" # Dendric memory backend
pip install "drift-lang[all]"
```
## 30 seconds to your first agent
```bash
drift new hello
cd hello
drift run hello.drift --input '{"name":"Riley"}'
```
No API key required. Drift falls back to a mock provider so you see something work immediately. Drop an `ANTHROPIC_API_KEY` or `OPENAI_API_KEY` into `.env` to use a real model.
## CLI
```
drift new <name> Scaffold a starter project
drift run <file.drift> Transpile and execute
drift check <file.drift> Validate syntax
drift transpile <file> Emit Python (use -o to write to a file)
drift lex / parse Debug tooling
```
## What's in the language
- **`agent`**: top-level unit. Has `model`, `budget`, `state`, `memory`, and `step`s.
- **`step`**: typed sub-procedure. Body is a sequence of declarative statements.
- **Intent verbs**: `summarize`, `extract`, `classify`, `translate`, `match`, `generate`, etc. Each one becomes a typed LLM call.
- **`confident<T>`**: confidence-gated branching. Run the cheap path when sure, escalate when not.
- **`model { … }`**: multi-provider routing with `prefer`, `fallback`, `upgrade when confidence < 0.7`, and `stream "fast" then "slow"`.
- **`tool name from python|mcp|rest`**: declare external tools. MCP runs against the official SDK.
- **`pipeline`**: composable flow with `->`, `=>`, `~>`, `|>` operators.
- **`for each x in xs parallel`**: `asyncio.gather` underneath.
- **`attempt / recover`**: structured error handling with retry, fail, and named arms.
- **`memory`**: short-term scratchpad or durable backend (Dendric). `remember`, `recall`, `deja_vu`, `forget`.
- **`define verb`**: extend the intent vocabulary with your own typed verbs.
- **Cross-agent calls**: `OtherAgent.step(args)` just works.
## Docs
| File | For |
|---|---|
| [`LLM.md`](./LLM.md) | Coding agents (Claude, Cursor, Copilot): complete reference for one-shot loading |
| [`docs/language.md`](./docs/language.md) | Humans learning Drift |
| [`docs/cookbook.md`](./docs/cookbook.md) | Copy-paste patterns |
| [`docs/gotchas.md`](./docs/gotchas.md) | Common mistakes |
## Examples
See [`examples/`](./examples) for working `.drift` programs and their generated Python:
- `hello.drift`: minimal agent
- `confident_demo.drift`: `confident<T>` branching
- `grant_checker.drift`: end-to-end intent + structured return
- `inbox_sorter.drift`: `for each … parallel` triage
- `inbox_triage_live.drift`: the canonical 30-line demo (real-LLM verified: 5 emails, 1.82s, $0.0092)
- `grant_checker_with_memory.drift`: Dendric-backed long-term memory
- `grant_checker_compare.drift`: citation-proof memory. Run 2's LLM reasoning cites Run 1 by name and makes side-by-side comparisons
## Status
Alpha. Language surface is stable, runtime works, 352/352 tests passing. OpenAI + Anthropic providers with strict-JSON output, MCP tools, Dendric memory, source-mapped runtime errors. Voice primitives parse but adapters aren't wired yet. Type system beyond `confident<T>` is on the roadmap.
## License
MIT
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