Architecture

This page is for contributors changing pm-cli internals. Users should start with Quickstart. Agents should start with Agent Guide.

Agent Quick Context

• CLI wiring lives in src/cli/.
• Domain behavior lives in src/core/.
• Public SDK exports live in src/sdk/.
• Items are stored as TOON by default; history is append-only JSONL.
• pm contracts is the machine-readable runtime contract source.

Tracked documentation work: pm-u9d0.

System Overview

pm-cli is a TypeScript ESM CLI for Node.js 22.18+. It is file-backed, git-native, deterministic, and designed for concurrent human plus agent workflows.

High-level flow:

1. Commander parses CLI input in src/cli/main.ts with commands registered via per-family modules (register-setup.ts, register-list-query.ts, register-mutation.ts, register-operations.ts).
2. Command modules normalize options and call domain services.
3. Domain services load settings, acquire locks when needed, mutate canonical item documents, and append history.
4. Renderers emit TOON by default, JSON when requested, and markdown for calendar views.
5. Extensions can add commands, schema, renderers, import/export handlers, search providers, lifecycle hooks, and selected service overrides.

Source Tree

src/
  cli.ts
  cli/
    main.ts
    register-setup.ts
    register-list-query.ts
    register-mutation.ts
    register-operations.ts
    registration-helpers.ts
    commands/
    help-content.ts
    error-guidance.ts
    extension-command-options.ts
  core/
    extensions/
    fs/
    history/
    item/
    lock/
    output/
    schema/
    search/
    store/
      item-metadata-cache.ts
    test/
    validate/
    shared/
  mcp/
    server.ts
  sdk/
    cli-contracts.ts
    index.ts
  types/
tests/
  unit/
  integration/
.agents/
  pm/
    extensions/
docs/
scripts/

Important public docs:

• Command Reference
• Configuration
• Testing
• Extensions
• SDK

Storage Layout

Project tracker root defaults to .agents/pm/.

.agents/pm/
  settings.json
  epics/
  features/
  tasks/
  chores/
  issues/
  decisions/
  events/
  reminders/
  milestones/
  meetings/
  plans/
  stories/
  history/
  locks/
  schema/
  checkpoints/
  runtime/
  search/
  extensions/

Type folders are created on demand: the listing above shows the built-in item types plus stories/, a representative folder created by a custom or preset type. schema/ holds config-driven customization (types.json, statuses.json, fields.json), checkpoints/ holds bulk-mutation rollback snapshots, and runtime/ holds non-canonical operational state (for example background-refresh coordination). The legacy required index/ directory was removed in 2026-05-31 (pm-yf31).

Required data:

• item documents under type folders
• history/<id>.jsonl
• settings.json

Optional rebuildable data:

• keyword and vector search cache files (search/)
• checkpoints/ and runtime/ operational state

Item Documents

Default format is TOON:

id: pm-a1b2
title: Implement restore replay
description: Restore should rebuild target item state from history.
type: Task
status: in_progress
priority: 1
tags[2]: history,restore
body: |
  Implementation notes.

Legacy JSON-front-matter markdown files are read only for one-way migration into TOON. Runtime internals use metadata as the item metadata model key.

Item metadata carries an explicit, monotonically increasing storage format version (pm_format_version). The baseline version (1) is the implicit default and is never serialized, so the field stays absent for the entire current corpus and adds no per-item token cost; it only materializes once an item advances past the baseline via a future breaking migration. Absence therefore always means the baseline. core/item/item-format-version.ts owns the constant and the classification helpers (effectiveItemFormatVersion, classifyItemFormatVersion, scanItemFormatVersions) that pm health (the integrity check) and pm validate (the format_version check) use to flag items that are outdated (a future migration would rewrite them) or ahead of the runtime (written by a newer pm). When a breaking item metadata change ships, bump CURRENT_ITEM_FORMAT_VERSION and add a migration that rewrites items below it — the version gate makes that a per-item decision instead of a full-corpus structural re-parse.

Built-in item types (11; confirm at runtime with pm schema list):

• Epic
• Feature
• Task
• Chore
• Issue
• Decision
• Event
• Reminder
• Milestone
• Meeting
• Plan

Runtime type resolution merges built-ins, persisted project schema in .agents/pm/schema/types.json (pm schema add-type / pm init --type-preset), settings.item_types.definitions, and extension registerItemTypes(...) registrations.

Mutation Contract

Every item mutation follows the same safety path:

1. Resolve project root and settings.
2. Acquire item lock when mutating existing item state.
3. Read and parse the current canonical item document.
4. Enforce ownership and policy gates.
5. Compute before_hash.
6. Apply mutation in memory.
7. Set updated_at.
8. Compute RFC6902 patch and after_hash.
9. Write item atomically through temp-file plus rename.
10. Append one history JSONL line.
11. Release lock.

If a write fails after state changes begin, mutation code attempts rollback before returning the error.

History and Restore

History entries are append-only JSONL records:

{
  "ts": "2026-05-01T12:00:00.000Z",
  "author": "codex-agent",
  "op": "update",
  "patch": [],
  "before_hash": "sha256...",
  "after_hash": "sha256...",
  "message": "Start implementation"
}

pm restore <id> <timestamp-or-version> replays history from create through the target record and appends a restore event. Restore does not rewrite prior history.

Useful diagnostics:

pm history <id> --full --diff --verify
pm activity --id <id> --limit 50
pm validate --check-history-drift

Command Contracts

Command/action metadata is centralized in src/sdk/cli-contracts.ts and used by:

• CLI option normalization
• help output
• completion generation
• provider-safe tool schemas
• pm contracts
• extension command/action contract exposure

Use runtime contracts instead of duplicating flag lists:

pm contracts --json
pm contracts --command create --flags-only --json
pm help create --json

Adding a Command or Flag (Wiring Checklist)

A new command or field-mutating flag touches several registries. Missing one produces a silently partial surface (for example a flag that parses on the CLI but is absent from pm contracts, MCP, or completions). Wire each site that applies:

1. Commander registration — register the command/flag in the relevant src/cli/register-*.ts family module (register-setup, register-list-query, register-mutation, register-operations).
2. Command module — implement the handler under src/cli/commands/ and add it to the src/cli/commands/index.ts barrel. The static orphan-modules gate fails on a command module that only the dynamic dispatcher imports, so the barrel export is mandatory.
3. Flag contracts — declare flags in src/sdk/cli-contracts.ts (the *_FLAG_CONTRACTS registries). Use list: true only for comma-list accumulation flags, never for Commander collect repeatable flags. Flags that should not appear in the public surface go through the NO_SURFACE set.
4. MCP exposure — if the command is agent-callable, add or extend its tool in src/mcp/tool-definitions.ts (tool definition plus parameter properties). Shared parameter names (fields, scope) are owned centrally — prefer a new boolean over overloading a shared enum.
5. Option policies — if the flag participates in command_option_policies (provided-set governance), wire it into the command's policy declaration.
6. Package policy scope — optional packages validate their policy-specific flags before mapping them onto the core's narrow internal ownership controls.
7. Docs and completions — document the command in Command Reference; completion output is generated from the contracts, so confirm pm completion reflects the new surface.
8. Contract snapshot — run pnpm contracts:update to regenerate tests/fixtures/contracts/full.json; the static gate compares against it.
9. Coverage — add focused tests so the new module keeps the corpus at 100/100/100/100 (see Testing Architecture).

Verify the end-to-end surface with pm contracts --command <name> --json, pm help <name> --json, and the matching MCP tool listing.

SDK-First Boundary

The target layering is: src/core remains private implementation detail, src/sdk is the public programmatic API, and src/cli plus src/mcp are presentation layers over SDK primitives. The migration is tracked under pm-usfg, with the current map in SDK Primitive Inventory.

The static quality gate now enforces the completed boundary without an allowance file:

• The hard gate counts type-only imports and re-exports too. A type-only src/core reference still couples the presentation layer to private core contracts, so it must be promoted behind src/sdk with the rest of the primitive surface.
• pnpm quality:static fails on every private edge or computed dynamic import() from a boundary source; the required edge count is always zero.
• Shared presentation-host services live in src/sdk/runtime-primitives.ts. Higher-level consumers should prefer typed SDK operations and PmClient.

Do not add new CLI/MCP behavior by deep-importing src/core. Add or extend an SDK primitive first, then consume that SDK surface from the presentation layer.

Telemetry Schema Negotiation

Telemetry preserves wire compatibility through an explicit client/server negotiation split:

• Event payloads keep event.schema_version as the event-document schema (currently v1).
• Queue envelopes include client_schema_version so client/runtime evolution can be tracked independently from event payload versioning.
• pm health --check-telemetry probes /healthz and records any advertised max-version header for observability/debugging.

This keeps v1 behavior stable while providing a forward path for future telemetry schema upgrades.

Output Pipeline

Core output formats:

• TOON for sparse, token-efficient default command output
• JSON for strict machine parsing
• markdown for calendar-oriented views

The renderer omits null, undefined, empty arrays, and empty objects from sparse TOON fallback output. JSON preserves the machine payload.

Search Architecture

Search supports:

• keyword mode, always available
• semantic mode, when an embedding provider and vector store are available
• hybrid mode, combining keyword and semantic results

Keyword scoring uses weighted fields such as title, description, tags, status, body, comments, notes, learnings, reminders, events, and dependencies. Semantic indexing uses the same core corpus so calendar-heavy work remains discoverable through normal search and reindex flows.

Runtime semantic components can come from built-ins or extensions:

• provider selection: settings.search.provider
• vector adapter selection: settings.vector_store.adapter
• extension registration: registerSearchProvider(...) and registerVectorStoreAdapter(...)

Useful commands:

pm search "restore history" --mode keyword --limit 10
pm reindex --mode hybrid --progress   # requires the search-advanced package
pm health --check-only

Performance and Startup Latency

pm-cli is optimized for the agent loop, where many short commands run back to back. The performance model has three layers (the absolute timings below are indicative order-of-magnitude figures at the time of writing — treat the relative behavior, not the exact milliseconds, as the durable contract):

• Per-command startup. After a command-family code split, each handler imports only its own command module rather than the full command barrel, so a read command does not pay for mutation/search modules. On a clean project the dominant remaining cost is Node ESM module resolution (~90ms); this is the last structural startup lever and is tracked under the observability epic.
• Reads. The item metadata cache splits item metadata from body text and skips re-reads of unchanged files, and on-read hooks are skipped when no extension registers one. pm health uses a drift-scan verification cache so repeated health checks do not re-hash every history stream.
• Mutations. Mutations are non-blocking: the semantic reindex runs in a detached background worker behind a reindex lock instead of inline embedding, and item-format migration skips already-migrated items rather than re-parsing the whole corpus on every write. This is what keeps create/update in the hundreds-of-milliseconds range instead of multi-second inline-embed latency.

What dominates latency in a given repository:

• a clean project is fast (~140ms); a large dev repo is slower mainly from many auto-loaded extensions and any inline embedding provider, not from item count.
• pm --version short-circuits before the main entrypoint, so it is not a valid probe for command startup cost.

Profiling startup cost:

node --cpu-prof --cpu-prof-dir=/tmp/pmprof dist/cli.js list >/dev/null
pm health --check-only          # drift-scan + telemetry timings

Reindex and embedding remain the heaviest background operations; keep them off the synchronous mutation path. See the observability epic (pm-5oj5) for tracked perf work.

Extension Host

Load order:

1. core commands
2. global extensions
3. project extensions

Project extensions take precedence over global extensions for matching command or renderer keys. Extension dispatch is extension-first when a registered handler matches a core command path.

Extension override planes:

• commands
• parser overrides
• preflight overrides
• service overrides
• renderers
• import/export handlers
• item fields and item types
• migrations
• search providers and vector adapters
• lifecycle hooks

See Extensions and SDK.

Testing Architecture

Tests live under:

tests/unit/
tests/integration/

All tests must run with sandboxed PM_PATH and PM_GLOBAL_PATH. Use:

node scripts/run-tests.mjs test
node scripts/run-tests.mjs coverage

Linked-test execution also creates sandbox roots and can seed settings/extensions for schema parity. See Testing.

Coverage governance is literal all-source, not a curated allowlist:

• vitest.config.ts coverage.include is the full ship surface: src/*.ts, src/**/*.ts, packages/**/*.ts, scripts/*.mjs, scripts/**/*.mjs, plugins/*.mjs, plugins/**/*.mjs, and the docs/examples/**/*.{ts,js,mjs} reference snippets. The only coverage.exclude entry is src/**/*.d.ts (type-only declarations have no executable lines).
• Global thresholds are 100/100/100/100 (lines/branches/functions/statements) for the whole measured corpus — there is no per-file ratchet and no per-file /* c8 ignore */ allowlist for production modules.
• Adding a new module under any included root automatically pulls it into the gate. There is no include-list to edit; if a new module is genuinely not shippable source (a throwaway script), it belongs outside these roots rather than in a hand-maintained exclude list.
• When authoring example snippets under docs/examples/, import the published SDK by its bare specifier (@unbrained/pm-cli/sdk); vitest.config.ts aliases that to src/sdk/index.ts so the example specs cover without the workspace self-link present in a clean CI install.
• When a module is hard to test end-to-end (for example CLI orchestration), extract pure logic helpers into small modules and cover those directly instead of weakening thresholds. Run node scripts/run-tests.mjs coverage locally to confirm 100/100/100/100 before pushing.

Terminal Compatibility

Runtime behavior should remain terminal-neutral:

• no required ANSI or custom terminal protocol
• deterministic TOON/JSON/markdown output
• graceful process.exitCode handling
• broken-pipe-safe output writes
• explicit TTY rejection for stdin token paths that require piped input
• non-interactive linked-test subprocess handling

Public Documentation Boundary

Architecture docs should describe source structure and public runtime behavior only. Ignored local operations material and host-specific runbooks must stay out of tracked docs.

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