Sley / Greyforge Labs public brief / updated May 6, 2026
Sley Loom Graph profile mark

Compiler-mediated programming for agents

Sley

A structural language for agent-written, human-reviewed software where the compiler is the work surface, referee, and evidence engine.

What It Is

Sley is a new programming language from Greyforge Labs built around one hard premise: future agent-written software needs a safer control surface than blind text mutation.

Human reviewers still need readable source. Agents need typed structure, bounded inspection, deterministic checks, explicit authority, repairable diagnostics, and evidence after accepted change. Sley is the language layer designed around that loop.

agent-native human-readable compiler-mediated evidence-first
Sley Loom Graph branding image
Public release boundary: this page is intentionally detailed about purpose, posture, and safe capability classes. It does not publish the full grammar, operation payloads, schema definitions, implementation architecture, fixture corpus, or reproducible compiler internals while Sley is still private development work.

Current State

TrackPublic Status
NameSley, the language. Loom, the bootstrap compiler and strict oracle.
Development phaseActive v0 prototype. The internal surface has expanded significantly and remains in private iteration.
Evidence postureThe current internal conformance suite tracks 210 integration cases, contract fixtures, smoke manifests, schema snapshots, and local CI/contract helper surfaces.
Runtime postureHost authority is modeled explicitly. v0 host paths are deterministic test gates, not live provider, payment, shell, network, secret-store, or deployment integrations.
Public availabilityThe implementation, full specification, grammar, fixtures, and executable examples are not open source yet.
Claim boundarySley is not production-stable and should not be described as a replacement for mature general-purpose languages today.

Design Doctrine

Source Is For Review

The text projection stays compact enough for people to understand, audit, and discuss.

Structure Is For Work

Agents should operate on compiler-exposed structure instead of guessing where raw text spans begin and end.

Authority Is Explicit

Dangerous or external capabilities belong at clear task boundaries, not hidden inside incidental library calls.

Preview Before Change

Candidate edits should be inspectable and checkable before any source mutation is accepted.

Diagnostics Must Teach

The compiler should return stable, repairable feedback that helps an agent recover without private chat context.

Evidence Should Remain

Accepted changes should be able to leave provenance, verification, and handoff artifacts when the work warrants it.

Public Capability Map

Capability ClassWhat Can Be Said Publicly
Reading and normalizationSley has a compiler path for reading, normalizing, checking, and presenting supported v0 programs.
Structural inspectionThe compiler exposes bounded structural views so tools can inspect relevant program regions without treating the whole project as anonymous text.
Query and hygieneInternal reports summarize declarations, calls, authority, style, lint, and readiness surfaces for agent and CI workflows.
Planned editingThe language is being built around compiler-checked structural edit candidates rather than arbitrary textual patches.
VerificationVerification combines strict compiler checks, warning policy, deterministic runtime gates, and reproducible local package evidence.
Trace and handoffAccepted changes can be represented with provenance and content-addressed evidence suitable for later review or archival handoff.
Project scaffoldingThe private toolchain can create deterministic starter projects for pure, deploy-like, and agent-like workflows without touching live external systems.

Protected Until Source Release

Held Back

  • Complete language grammar and syntax examples.
  • Exact command recipes, flags, and invocation sequences.
  • Schema identifiers, JSON payload shapes, and fixture contents.
  • Structural edit operation inventory and acceptance rules.
  • Compiler internals, module resolution details, and repair algorithms.
  • Self-hosting ladder details and future runtime lock mechanics.

Safe To Publish

  • The problem Sley is designed to solve.
  • The agent-native and human-reviewable product thesis.
  • High-level evidence categories and current prototype status.
  • The distinction between deterministic test gates and live integrations.
  • Clear limits: private v0 work, not production-stable, not a general replacement today.
  • Branding, public roadmap shape, and links to Greyforge and ZJX.

Why It Matters

Most programming languages were designed around humans writing text and tools checking the result after the fact. That does not match the way autonomous coding agents fail. Agents lose local context, over-edit unrelated spans, repair one issue while breaking another, and need stable machine-readable surfaces to recover.

Sley tries to move the edit boundary closer to the compiler. The useful public claim is not that Sley has magic syntax. The useful claim is that language design, compiler output, diagnostics, runtime gates, and evidence artifacts can be organized around agent success rate.

Sley And ZJX

Sley and ZJX are related but distinct Greyforge systems. Sley is the programming language. ZJX is the archive and handoff lane. The public Sley page describes the language direction; the public ZJX page describes the current archive prototype.

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