Compile your package

apm compile reads your instructions primitives from .apm/ (plus any unpacked under apm_modules/) and writes the per-harness root context files each agent harness reads at startup. It does not fetch packages, does not resolve dependencies, does not write the lockfile, and does not deploy other primitive types.

When you actually need it

Compile is optional for the copilot target — GitHub Copilot natively reads .github/instructions/*.instructions.md (with their applyTo: frontmatter) that apm install already deploys, so the aggregated AGENTS.md / copilot-instructions.md it produces are a nice-to-have, not a requirement.

Compile is recommended for every other target (claude, cursor, codex, gemini, antigravity, opencode, windsurf, kiro) — those harnesses load instructions through the root context file (CLAUDE.md, AGENTS.md, GEMINI.md) or a harness-specific rules folder that compile generates. Kiro receives .kiro/steering/ files; its AGENTS.md output remains the cross-harness fallback. Without compile, your instructions are on disk but the harness will not pick them up.

apm compile

Concretely, that command rolls your instructions/*.instructions.md (see Instructions) into the native rules surface each target expects:

• AGENTS.md — the cross-harness root context file. Copilot, Codex, OpenCode, and Windsurf read it directly; Kiro primarily uses the .kiro/steering/ files that compile also emits.
• CLAUDE.md — Claude Code’s root context file.
• GEMINI.md — Gemini CLI’s root context file.
• per-harness rules trees that mirror each instruction’s applyTo: glob: .github/instructions/, .claude/rules/, .cursor/rules/*.mdc, .windsurf/rules/, .kiro/steering/.

Other primitive types — prompts, skills, agents, chatmodes, hooks, commands — are NOT compiled by this command. They are deployed by apm install directly into the harness directories that consume them (.github/prompts/, .agents/skills/, .claude/commands/, etc.). For the full reach map, see Primitives and targets. For the place compile takes in the broader flow, see Lifecycle.

The authoring loop

edit .apm/instructions/  ->  apm compile  ->  inspect AGENTS.md  ->  repeat

You will run this loop while writing or refining instructions. Three flags speed it up:

apm compile --watch              # re-run on every change
apm compile --validate           # check frontmatter and structure; emit nothing
apm compile --dry-run            # print placement decisions without writing files

--validate is the fastest signal that an instruction parses. --dry-run shows you exactly which root-context tree (AGENTS.md, CLAUDE.md, …) would be written where. --watch is the tight inner loop while you edit prose.

To preview a script that wraps a .prompt.md file, use apm preview instead. apm compile builds the root context files; apm preview shows the rewritten command line your script will execute.

Pick a target

By default apm compile detects targets from your workspace (see detection cascade below). Override it with --target (-t):

apm compile --target claude
apm compile --target copilot,cursor          # comma-separated
apm compile --all                            # every canonical target

Accepted values: copilot, claude, cursor, opencode, codex, gemini, antigravity, windsurf, kiro, agent-skills, all. The agent-skills slug is a no-op for compile (skills are deployed by apm install); it is accepted in target lists for symmetry only. Unknown slugs are rejected before any work runs.

Experimental targets (hermes, openclaw, copilot-cowork, copilot-app) are also accepted once their flag is enabled via apm experimental enable <flag>, but are excluded from --all. apm compile -t hermes emits AGENTS.md (the hermes target shares the agents compile family). See Hermes Agent.

Detection cascade

When you omit --target, APM resolves which targets to build in this order:

1. Explicit --target <slug> flag.
2. The targets: field in your apm.yml.
3. Auto-detect: any harness root directory (.github/, .claude/, .cursor/, .codex/, .gemini/, .opencode/, .windsurf/, .kiro/) that already exists.
4. Fallback: minimal — writes a single AGENTS.md and skips per- harness rules folders.

Pin targets: in apm.yml if you want the same compile output on every machine. Full rules and the per-target output map live in Primitives and targets.

Where instructions land

Per target, with the rules shape on disk after compile:

Target	Root context file	Per-rule output	Compile required?
copilot	AGENTS.md	.github/instructions/<name>.instructions.md (preserves applyTo)	No — Copilot reads the per-rule files natively; deduplicates with .github/instructions/ (see below)
claude	CLAUDE.md	.claude/rules/<name>.md	Yes — deduplicates with .claude/rules/ (see below)
cursor	—	.cursor/rules/<name>.mdc	Yes — .mdc is Cursor’s rules format
codex	AGENTS.md (folded)	none — compile-only, no per-file deploy	Yes — folded into AGENTS.md
gemini	GEMINI.md (folded)	none — compile-only, no per-file deploy	Yes — folded into GEMINI.md
antigravity	AGENTS.md (folded)	.agents/rules/<name>.md	Yes — folded into AGENTS.md
opencode	AGENTS.md (folded)	none — compile-only, no per-file deploy	Yes — folded into AGENTS.md
windsurf	—	.windsurf/rules/<name>.md	Yes — compiled to Windsurf rules
kiro	AGENTS.md (fallback)	.kiro/steering/<name>.md	Yes — compiled to Kiro steering

compile vs install

You want to…	Run
Iterate on instructions in .apm/instructions/	apm compile
Deploy prompts, skills, agents, hooks, commands, MCP	apm install (see Install packages)
Add a dependency or refresh apm_modules/	apm install
Verify deployed bytes match the lockfile	apm audit

apm install runs compile internally as part of its integrate phase, so a normal apm install on a clean checkout already produces correct AGENTS.md / CLAUDE.md / GEMINI.md output. Reach for apm compile directly when you are iterating on instructions and do not want install’s side effects.

Copilot deduplication

When .github/instructions/ is already populated with .instructions.md files (deployed by apm install --target copilot), apm compile --target copilot omits AGENTS.md entirely when the only content it would carry is the instructions section — Copilot already reads .github/instructions/ directly, so an instructions-only AGENTS.md would be redundant. AGENTS.md is still written when it carries non-instruction content such as a constitution. If .github/instructions/ is later cleared, re-running apm compile restores AGENTS.md with the full instructions section.

This deduplication is target-aware: it only activates when the sole AGENTS.md consumer is Copilot. When compiling for targets that do not read .github/instructions/ (Codex, OpenCode, Windsurf, etc.), instructions are always included in AGENTS.md regardless of whether .github/instructions/ exists. To opt out of deduplication even for Copilot-only compiles, pass --no-dedup (alias: --force-instructions):

apm compile --target copilot --no-dedup

Claude Code deduplication

When .claude/rules/ is already populated with instructions, apm compile --target claude automatically omits the instructions section from CLAUDE.md to avoid duplicate content in Claude Code’s context window. The directory can be populated by either apm install --target claude or by an earlier apm compile --target claude run — both write per-file instruction rules into .claude/rules/. CLAUDE.md is still generated when it carries a constitution or dependency @import paths. If .claude/rules/ is later removed, re-running apm compile restores the instructions section to CLAUDE.md.

To opt out of the deduplication and always include the instructions section in CLAUDE.md (for debugging or when you intentionally want both copies), pass --no-dedup (alias: --force-instructions):

apm compile --target claude --no-dedup

This flag affects both the Claude and Copilot deduplication paths (see Copilot deduplication).

Managed-section mode

By default apm compile overwrites AGENTS.md entirely. If your team keeps hand-written content in AGENTS.md alongside APM-managed rules, use managed-section mode to update only the APM-owned block while leaving everything else untouched.

For the full apm.yml key reference for compilation.agents_md, see the compilation.agents_md section in the manifest schema.

1. Add markers to AGENTS.md:

<!-- apm:start -->
<!-- apm will insert content here -->
<!-- apm:end -->

2. Enable the mode in apm.yml:

compilation:
  agents_md:
    mode: managed_section
    start_marker: "<!-- apm:start -->"
    end_marker: "<!-- apm:end -->"

The default markers are <!-- apm:start --> and <!-- apm:end -->, so you can omit start_marker and end_marker if you use those verbatim.

Constraints:

• The target file must already exist: if it does not, APM raises a clear error (“does not exist yet”) instead of a confusing “markers not found”. Use mode: full for the first run to create the file, then switch to managed_section.
• Both markers must be present in the file exactly once (missing or duplicate markers raise a loud error so no content is silently lost).
• The start marker must appear before the end marker; reversed order raises a loud error.
• start_marker and end_marker must be distinct non-empty strings.
• Content outside the markers is preserved verbatim across every compile run for the root AGENTS.md; only the block between the markers is replaced.
• In distributed compile mode, subdirectory AGENTS.md files remain fully APM-owned and are overwritten on each run.

Pitfalls

• Confusing compile’s scope. Compile only handles instructions (and optionally a single chatmode to prepend). If you edit a prompt, skill, agent, hook, or command, apm compile will not redeploy it — run apm install for that.
• Forgetting --target on a clean workspace. With no harness folder present and no targets: in apm.yml, the cascade falls back to minimal and writes only AGENTS.md. The CLI prints a hint, but the easy fix is to either create the harness folder or pin targets: in your manifest.
• Stale AGENTS.md after deleting an instruction. Compile leaves previous output in place by default. Pass --clean to remove orphaned files generated by earlier runs. When compiling for the claude target, --clean also removes a stale APM-generated CLAUDE.md when deduplication suppresses CLAUDE.md entirely: all instructions already live in .claude/rules/, and no constitution or dependency content keeps CLAUDE.md active. Hand-authored CLAUDE.md files (those without the <!-- Generated by APM CLI --> marker) are never deleted.
• Hand-edited primitives skip the security scan. apm compile does not run the install-time hidden-Unicode scan. After hand-edits, run apm audit before publishing. See drift and secure-by-default.
• Zero-output success. If compile reports success but writes no files, your project either has no instructions, or every requested target was rejected. The CLI surfaces this as a warning — check targets: and the contents of .apm/instructions/.

Once your instructions compile cleanly into the harnesses you care about, package the result with apm pack and share it via a marketplace.