AXIOM .axm for VS Code

Language support for .axm plans — the authoring format of AXIOM, the transactional write gate for coding agents. A plan describes a change set (files, sources, checks); AXIOM compiles it into a content-addressed manifest, runs set-level checks and applies it atomically with a journal and one-step rollback.

axiom "2"

plan add-readme {
  intent "Add a README, guarded by a secret scan"
  profile default

  artifact "README.md" {
    op create
    inline <<MD
# hello
MD
  }

  check no-secrets using content.noSecrets {}
}

Features

Diagnostics as you type — the same parser and error codes (ERR_*) as axiom compile
Completion for keywords, predicate ids after using, capabilities, mode / op / profile values
Hover documentation for keywords and predicates
Outline (document symbols) for plans, files and checks
Format Document — idempotent, only on a clean parse
Semantic highlighting on top of a TextMate grammar (heredocs, digests, embedded JSON in check / meta blocks)

The language server (@codai/axiom-axm-lsp) is bundled — nothing else to install. In a workspace that has @codai/axiom-axm-lsp in node_modules, the extension uses that version instead.

Use it with the gate

Install the CLI and wire your repository in one step:

npm install -g @codai/axiom-mcp
axiom init      # MCP server + PreToolUse hook for Copilot / Claude / Codex / Cursor / Windsurf / Gemini / Junie / Cline
axiom doctor    # checks the wiring and the gate latency
axiom compile plan.axm -o bundle.json && axiom apply bundle.json --root . --confirm <digest>

Agents can then write through the axiom_write MCP tool (preview → apply with confirmDigest) and every direct write is checked by the gate first.

Development

pnpm build                              # builds @codai/axiom-axm-lsp
pnpm --filter axiom-axm run build       # this package
pnpm --filter axiom-axm run package     # → <repo>/.copilot-tmp/axiom-axm-<version>.vsix

The .vsix carries no node_modules: dist/extension.cjs (client) and dist/server.cjs (the LSP, bundled with vscode-languageserver) are self-contained. vsce rejects pnpm's catalog: spec, so the package script writes the resolved @types/vscode version (and the release version from @codai/axiom-mcp) into package.json for the duration of the call and restores it.

Release (S-412, S-601). release.yml job vscode-extension runs on every v* tag: it packages the .vsix, attaches it to the GitHub release and publishes dragoscv.axiom-axm to the VS Code Marketplace with the Entra managed identity codai-marketplace-publisher (GitHub OIDC, environment marketplace-publish, vsce --azure-credential) — the same publisher and credential as dragoscv.codai-vscode; VSCE_PAT is only a fallback. When the repo secret OVSX_PAT exists the same .vsix goes to Open VSX under the namespace dragoscv.

AXIOM .axm — plans for the agent write gate

Dragos Catalin

AXIOM .axm for VS Code

Features

Use it with the gate

Links

Development