@atlante/opencode

OpenCode host adapter for Atlante. It ships the build-time native materializer that atlante build runs to write host-native agent and skill files directly into the project — no runtime plugin, no persisted payload tree. Requires Node.js 22 or later.

Published package

The adapter package is published to npm as @atlante/opencode. It ships as a self-contained Bun-bundled artifact (the dist/ output of bun run build at the repository root) with a single entry, @atlante/opencode, exporting:

• materializeOpenCode(projectRoot, prepared) — deterministic native materialization of a prepared project
• readOpenCodeNative(projectRoot) — verifies and reads the manifest-backed native outputs for local consumers such as eval
• openCodeMaterializer — the builder-facing adapter ({ host, materialize(projectRoot, prepared) }) the CLI passes to buildProject; failures map to MaterializationDiagnostic values
• OpenCodeMaterializationError and its OpenCodeMaterializationErrorCode (invalid-input, invalid-id, invalid-manifest, unsafe-path, collision, drift, filesystem, publication-failed)
• the ownership-manifest types (OpenCodeOwnershipManifest, OpenCodeOwnedFile), verified-native-output types (OpenCodeNativeProject, OpenCodeNativeFile), prepared-project types (OpenCodePreparedProject, OpenCodePreparedAgent, OpenCodePreparedSkill), and adapter types (OPENCODE_HOST_TARGET, MaterializationDiagnostic, OpenCodeMaterializerPrepared, HostMaterializationOutcome)

What a build materializes

atlante build renders the source configuration into a prepared project and the materializer writes, deterministically:

• .opencode/agents/<id>.md — frontmatter description plus the agent prompt
• .opencode/skills/<id>/SKILL.md — frontmatter name/description plus the skill content
• .atlante/opencode-native.json — the ownership manifest: format, version, and one files entry (kind, id, path, sha256) per generated file

The manifest is bookkeeping state, not a trust boundary: it never stores prompt or skill payloads, only identity and digests. Generated outputs and the manifest are ignored by git by default (atlante init enforces .opencode/agents/, .opencode/skills/, and .atlante/ in .gitignore) because rendered content can carry sensitive interpolated values.

Safety invariants

Materialization is fail-closed and staged:

• Collisions — an unowned file at a target path is never overwritten; the build fails with a repair action instead.
• Drift — an owned file whose recorded hash no longer matches is never replaced; repair is intentional (restore or delete the drifted file).
• Stale outputs — owned files no longer produced by the configuration are removed only when the manifest still accounts for them.
• Rollback — publication stages first and rolls back on failure, preserving the previous valid generated set.
• ID rules — IDs must be lowercase kebab-case ASCII, at most 64 characters; invalid IDs fail the build rather than being renamed.

Rebuilds are idempotent: unchanged content is not rewritten.

Migration from the runtime plugin

Older versions exposed a runtime OpenCode plugin registered as "plugin": ["@atlante/opencode"] in opencode.jsonc/opencode.json. The plugin no longer exists: a stale registration is inert (the host silently drops packages that expose no plugin target), and atlante init removes the Atlante-written entry from the configuration. The harmless "plugin": [] residue it may leave behind requires no action.