aleph-rlm 0.8.8

MCP server for recursive LLM reasoning—load context, iterate with search/code/think tools, converge on answers

Aleph

Aleph is an MCP server for working on large repos, logs, and documents without stuffing them into the model prompt. It keeps the working context in a Python process, then exposes tools so the model can search, peek, run code, recurse, and return small derived results.

Recommended default: install the Codex CLI, then run aleph-rlm install. Aleph still works with Claude Code, Cursor, VS Code, and other MCP clients, but Codex is the cleanest shared-session sub-query path today.

Why Aleph:

• Load context once instead of pasting it over and over.
• Compute inside Aleph memory with exec_python instead of leaking raw data back through the prompt.
• Use recursive sub-queries and recipes when a single pass is not enough.
• Save sessions and resume long investigations later.

+-----------------+    tool calls     +--------------------------+
|   LLM client    | ---------------> |  Aleph (Python process)  |
| (context budget)| <--------------- |  search / peek / exec    |
+-----------------+   small results  +--------------------------+

Quick Start

1. Install Aleph:

pip install "aleph-rlm[mcp]"

2. Configure your MCP client:

aleph-rlm install

3. Verify Aleph is reachable in your assistant:

get_status()
# or
list_contexts()

4. Run the skill flow on a real file:

/aleph /absolute/path/to/file.log
# or in Codex CLI
$aleph /absolute/path/to/file.log

The shortcut command is optional. If you want /aleph or $aleph, install docs/prompts/aleph.md in your client's command/skill folder. Exact paths are in MCP_SETUP.md.

First Workflow

Aleph is best when you load data once, do the heavy work inside Aleph, and only pull back compact answers.

load_file(path="/absolute/path/to/large_file.log", context_id="doc")
search_context(pattern="ERROR|WARN", context_id="doc")
peek_context(start=1, end=60, unit="lines", context_id="doc")
exec_python(code="""
errors = [line for line in ctx.splitlines() if "error" in line.lower()]
result = {
    "error_count": len(errors),
    "first_error": errors[0] if errors else None,
}
""", context_id="doc")
get_variable(name="result", context_id="doc")
save_session(context_id="doc", path=".aleph/doc.json")

The important habit is to compute server-side. Do not treat get_variable("ctx") as the default path. Search, filter, chunk, or summarize first, then retrieve a small result.

If you want terminal-only mode instead of MCP, use:

aleph run "Summarize this log" --provider cli --model codex --context-file app.log

Common Workloads

Scenario	What Aleph Is Good At
Large log analysis	Load big files, trace patterns, correlate events
Codebase navigation	Search symbols, inspect routes, trace behavior
Data exploration	Analyze JSON, CSV, and mixed text with Python helpers
Long document review	Load PDFs, Word docs, HTML, and compressed logs
Recursive investigations	Split work into sub-queries instead of one giant prompt
Long-running sessions	Save and resume memory packs across sessions

Core Tools

Category	Primary tools	What they do
Load context	load_context, load_file, list_contexts, diff_contexts	Put data into Aleph memory and inspect what is loaded
Navigate	search_context, semantic_search, peek_context, chunk_context, rg_search	Find the relevant slice before asking for an answer
Compute	exec_python, get_variable	Run code over the full context and retrieve only the derived result
Reason	think, evaluate_progress, get_evidence, finalize	Structure progress and close out with evidence
Orchestrate	configure, validate_recipe, estimate_recipe, run_recipe, run_recipe_code	Switch backends and automate repeated reasoning patterns
Persist	save_session, load_session	Keep long investigations outside the prompt window

Inside exec_python, Aleph also exposes helpers such as search(...), chunk(...), lines(...), sub_query(...), sub_query_batch(...), and sub_aleph(...). Recursive helpers live inside the REPL, not as top-level MCP tools.

Safety Model

Aleph is built to keep raw context out of the model window unless you explicitly pull it back:

• Tool responses are capped and truncated.
• get_variable("ctx") is policy-aware and should not be your default path.
• exec_python stdout, stderr, and return values are bounded independently.
• ALEPH_CONTEXT_POLICY=isolated adds stricter session export/import rules and more defensive defaults.

The safest pattern is always:

1. Load the large context into Aleph memory.
2. Search or compute inside Aleph.
3. Retrieve only the small result you need.

Docs Map

• MCP_SETUP.md: client-by-client MCP and skill installation.
• docs/prompts/aleph.md: the /aleph and $aleph workflow plus tool patterns.
• docs/CONFIGURATION.md: flags, env vars, limits, and safety settings.
• docs/langgraph-rlm-default.md: LangGraph integration with Aleph-style tool usage.
• examples/langgraph_rlm_repo_improver.py: repo improvement example with optional LangSmith tracing.
• CHANGELOG.md: release history.
• DEVELOPMENT.md: contributor guide.

Development

git clone https://github.com/Hmbown/aleph.git
cd aleph
pip install -e ".[dev,mcp]"
pytest tests/ -v
ruff check aleph/ tests/

References

• Zhang, A. L., Kraska, T., Khattab, O. (2025) Recursive Language Models (arXiv:2512.24601)

License

MIT