zigrlm

zigrlm is an experimental Zig runtime for Recursive Language Model (RLM) workflows. It is directly inspired by alexzhang13/rlm, the Python reference implementation for Recursive Language Models.

Use zigrlm when you want one small CLI process to own an RLM run: the root prompt, recursive child calls, bounded local compute, parallel fanout, trace events, and usage accounting.

Install

The Python adapter is published as zigrlm:

pip install zigrlm

The Zig CLI is built from source:

git clone https://github.com/Hmbown/zigrlm.git
cd zigrlm
zig build
zig-out/bin/zigrlm --help

The Python adapter shells out to the Zig binary. After a source build it will find zig-out/bin/zigrlm automatically from this checkout. In other layouts, put the binary on PATH or set:

export ZIGRLM_BIN=/absolute/path/to/zigrlm

Relationship To RLM

The upstream RLM project is the conceptual reference:

• Upstream: https://github.com/alexzhang13/rlm
• Paper, blog, and docs are linked from that repository.
• Upstream package: rlms, imported as rlm.

zigrlm is not a fork of that Python codebase. It reimplements the core control loop in Zig and keeps the command shapes explicit:

• flat proxy commands for single model completions;
• recursive commands for RLM workflows;
• a dszig command for DSPy-style signature experiments;
• JSONL trace and metadata output for inspection.

If you want the full Python ecosystem, sandbox matrix, and upstream API, use alexzhang13/rlm. If you want a compact Zig CLI for auditable local recursive fanout, try zigrlm.

Quick Start

Run no-network checks:

zig build test
zig build run -- demo
zig build run -- echo "hello"
zig build run -- echo --trace /tmp/zigrlm-echo-trace.jsonl "hello"

Run a plain OpenAI completion through the flat proxy:

printf 'Return exactly OK.' \
  | zig-out/bin/zigrlm openai-proxy --model gpt-5.4

Run a recursive Codex workflow:

zig-out/bin/zigrlm cli-codex --timeout-ms 600000 'Solve via a child:
```repl
rlm_query child = "Answer this briefly: " + context
FINAL_VAR(child)
```'

Run parallel child calls inside one RLM process:

zig-out/bin/zigrlm cli-codex --timeout-ms 600000 'Fan out:
```repl
rlm_query_batched answers = "Task A" | "Task B" | "Task C"
FINAL_VAR(answers)
```'

Command Families

Keep flat completions and recursive workflows separate.

Rule of thumb:

single completion?       -> *-proxy
workflow with subcalls?  -> cli-<backend>, zai, or cli
parallel children?       -> rlm_query_batched inside one recursive command
custom backend?          -> cli with ZIGRLM_MAIN_CMD / ZIGRLM_RLM_CMD
DSPy-style signature?    -> dszig

The repl DSL

Recursive commands ask the root model to return fenced repl blocks:

```repl
let name = "text" + context
set name = expression
print(expression)
js name = "const n = context.length; FINAL(String(n));"
llm_query name = expression
rlm_query name = expression
llm_query_batched name = expr | expr | ...
rlm_query_batched name = expr | expr | ...
FINAL(expression)
FINAL_VAR(name)
```

Important details:

• context is the original user prompt for the current RLM frame.
• Only fences tagged exactly as repl are executed.
• llm_query is a direct child model call.
• rlm_query starts a child RLM loop, unless the depth limit has been reached.
• Batched query forms run independent calls concurrently and join responses as indexed blocks.
• A block should end with FINAL(...) or FINAL_VAR(...).

DSzig Python Adapter

The PyPI package exposes a small Python adapter:

from dszig import RLM

rlm = RLM(
    "question: str -> answer: str",
    main_cmd="python3 -c 'print(\"```python\"); print(\"SUBMIT(answer=question.upper())\"); print(\"```\")'",
    rlm_cmd="/bin/cat",
)

result = rlm(question="alpha")
assert result.answer == "ALPHA"

You can also import the same adapter through the package name:

from zigrlm import RLM

If you already have real DSPy imported and want to patch it explicitly:

import dspy
from dszig.dspy_compat import install

install(dspy)

The local python/dspy package in this repository is only a smoke-test shim. It is not the full Stanford DSPy package and is not shipped as part of the PyPI wheel.

Runtime Flags

Recursive commands support:

--file PATH
--stdin
--trace PATH
--metadata PATH
--timeout-ms N
--max-depth N
--max-iterations N
--max-concurrent-subcalls N
--max-runtime-ms N
--max-calls N
--max-input-bytes N
--max-output-bytes N
--max-consecutive-errors N
--environment script|python|docker-python
--python-bin PATH
--docker-bin PATH
--docker-image IMAGE
--docker-setup-timeout-ms N
--persistent
--compaction
--compaction-threshold-bytes N

Prefer trace paths under /tmp, for example:

--trace /tmp/zigrlm-my-run.jsonl

Traces can include prompt and model-output previews. Do not commit ad hoc traces that contain private prompts, outputs, or keys.

Configuration

Configuration is read from process environment first, then from a local .env. Do not commit .env; it normally contains live keys.

Relevant variables:

OPENAI_API_KEY
OPENAI_BASE_URL
OPENAI_MAIN_MODEL
OPENAI_RLM_MODEL

CODEX_BIN
CODEX_MAIN_MODEL
CODEX_RLM_MODEL

CLAUDE_BIN
CLAUDE_MAIN_MODEL
CLAUDE_RLM_MODEL
CLAUDE_EFFORT
CLAUDE_MAIN_EFFORT
CLAUDE_RLM_EFFORT

ZAI_CODING_API_KEY
ZAI_CODING_BASE_URL
ZAI_MAIN_MODEL
ZAI_RLM_MODEL

ZIGRLM_BIN
ZIGRLM_MAIN_CMD
ZIGRLM_RLM_CMD

Generic cli backends should read the full prompt from stdin and write only the completion text to stdout.

Project Layout

• src/main.zig: CLI commands, provider wrappers, runtime option parsing.
• src/rlm.zig: RLM loop, child calls, batching, usage, JSONL tracing.
• src/dspy_rlm.zig: DSPy-style signature runner with SUBMIT(...).
• src/env.zig: repl DSL execution and Node vm bridge.
• src/python_env.zig: Python REPL subprocess with host callbacks.
• src/docker_env.zig: Docker-backed Python REPL with host callbacks.
• python/dszig: Python adapter for zigrlm dszig.
• docs/RLM_PARITY.md: current parity notes against upstream RLM/DSPy ideas.

Development

Run the main checks:

zig build test
zig build
zig test src/dspy_rlm.zig
zig test src/python_env.zig
python3 -m py_compile scripts/compare_rlm_main.py scripts/run_oolong.py python/dszig/*.py python/dspy/*.py python/dspy/predict/*.py python/tests/*.py
PYTHONPATH=python python3 -m unittest discover -s python/tests -v

Build and validate the Python package:

python3 -m build
python3 -m twine check --strict dist/*

Safety Notes

• The JavaScript sandbox uses Node vm. Treat it as trusted local compute, not a hard security boundary.
• claude-proxy disables Claude Code tools by default. Use --allow-tools only when tool access is intentional.
• --environment docker-python runs Python in a container with --network none by default, but the host process still controls model calls and mounted state.
• --timeout-ms bounds individual subprocess calls, not the whole recursive run.

License

MIT. See LICENSE.