ocas/packages/cli/prompts/usage.md

OCAS — Object Content Addressable Store

Overview

OCAS is a self-describing content-addressable store for typed JSON data. Every node has a type field (hash of a JSON Schema) and a payload. Hashes are 13-character Crockford Base32 strings (XXH64 over deterministic CBOR).

All commands output { type, value } JSON envelopes, making them composable via pipes.

Install: bun add -g @ocas/cli

Packages: @ocas/core (engine) · @ocas/fs (filesystem store) · @ocas/cli (CLI)

When to Use

• Storing structured, schema-validated JSON data with content addressing
• Building knowledge graphs or DAGs with typed nodes and cas_ref edges
• Agent memory, config versioning, or any use case needing immutable data + mutable pointers
• Don't use for: binary blobs, large files, or high-throughput streaming

Quick Start

# Register a schema (from stdin)
echo '{
  "type": "object",
  "properties": { "title": { "type": "string" }, "done": { "type": "boolean" } },
  "required": ["title", "done"],
  "additionalProperties": false
}' | ocas put @ocas/schema -p
# → { "type": "...", "value": "<schema-hash>" }

# Name it
ocas var set @todo/schema <schema-hash>

# Store data
echo '{ "title": "Buy milk", "done": false }' | ocas put @todo/schema -p

# Retrieve + verify
ocas get <hash>
ocas verify <hash>

Core Concepts

Hashes

13-char uppercase Crockford Base32 (e.g. 9S7JEYS3FKSDH). Deterministic: same content → same hash.

Envelope Format

Every command outputs { type, value }. type is the hash of the result schema. Pipe any envelope into render -p to render it human-readable.

Variables

Mutable pointers to immutable data (like git branches → commits). All names must follow @scope/name format:

• @myapp/config ✅
• @ocas/schema ✅ (builtin, read-only)
• config ❌ (no scope)

Templates

LiquidJS templates bound to a schema. render uses the template for the node's type, falling back to YAML.

CLI Reference

Store & Retrieve

ocas put <type> <file>          # store node → hash
ocas put <type> -p              # read payload from stdin
ocas get <hash>                 # retrieve node
ocas has <hash>                 # check existence
ocas hash <type> <file>         # compute hash without storing
ocas verify <hash>              # integrity + schema validation

Graph Traversal

ocas refs <hash>                # direct cas_ref edges
ocas walk <hash>                # recursive DAG traversal
ocas walk <hash> --format tree  # tree view

Listing & Querying

ocas list --type <hash|name>    # list nodes by type
ocas list-schema                # all schemas
ocas list-meta                  # meta-schema hashes

Sorting and pagination:

ocas list --type @todo/schema --sort updated --desc --limit 20
ocas list --type @todo/schema --offset 20 --limit 20   # page 2

Variables

ocas var set @myapp/config <hash>              # bind name → hash
ocas var set @myapp/config <hash> --tag env:prod --tag pinned
ocas var get @myapp/config                     # look up
ocas var delete @myapp/config                  # remove
ocas var list [prefix]                         # list (prefix filter)
ocas var list @myapp/ --tag env:prod           # filter by scope + tag
ocas var history @myapp/config                 # last 10 values (LRU)
ocas tag @myapp/config status:active           # add tag/label to a target
ocas untag @myapp/config status                # remove tag/label by key

Naming rules:

• Format: @scope/name — @[a-zA-Z][a-zA-Z0-9]*/segments
• @ocas/* reserved for builtins
• Any command accepting a hash also accepts a variable name

Templates & Rendering

ocas template set <schema-hash> --inline "{{ payload.title }}"
ocas template get <schema-hash>
ocas template list
ocas template delete <schema-hash>
ocas render <hash>                     # render with template (or YAML fallback)
ocas render --pipe/-p                  # render from piped envelope
ocas get <hash> -r                     # inline render shorthand

Render options: --resolution N (max depth), --decay N (depth decay), --epsilon N (cutoff).

Garbage Collection

ocas gc                    # collect unreachable nodes
ocas gc | ocas render -p   # human-readable stats

Global Flags

Flag	Description
--home <path>	Store directory (default: $OCAS_HOME or ~/.ocas)
--var-db <path>	Variable database path
--json	Compact JSON output
-p, --pipe	Read from stdin
-r, --render	Render output inline
--sort created|updated	Sort key (default: created)
--limit <n>	Max results (default: 100)
--offset <n>	Skip first N (default: 0)
--desc	Sort descending

Pipe Composition Patterns

# Store + render in one go
echo '{"title":"test","done":false}' | ocas put @todo/schema -p | ocas render -p

# Or use -r shorthand
ocas get <hash> -r

# List schemas, extract hashes with jq
ocas list --type @ocas/schema | jq -r '.value[].hash'

# Render GC stats
ocas gc | ocas render -p

Library Usage

import { bootstrap, createMemoryStore, putSchema } from "@ocas/core";

const store = createMemoryStore();
await bootstrap(store);

const typeHash = await putSchema(store, {
  type: "object",
  properties: { message: { type: "string" } },
  required: ["message"],
  additionalProperties: false,
});

const hash = await store.put(typeHash, { message: "hello" });

For filesystem persistence:

import { openStore } from "@ocas/fs";
const store = await openStore("/path/to/store");
// store.cas / store.var / store.tag

Common Pitfalls

1. Variable names without @scope/ — all names must be @scope/name format. config alone will be rejected.
2. Writing to @ocas/* namespace — reserved for builtins, CLI will reject.
3. Forgetting -p for stdin — ocas put <type> expects a file path; use -p to read from stdin.
4. Expecting list to return hashes — list commands return ListEntry[] with { hash, created, updated }, not bare hashes.
5. workspace:* in published packages — only on main branch; release branches must have fixed versions.