01
Define
Describe one existing application capability with an input schema, output schema, and behavioral annotations.
Build once, invoke by Code or AI.
A protocol-neutral runtime that keeps schema validation, ACL, approval, and execution evidence consistent across agent and code surfaces. One enforced capability contract, projected through the adapters you choose.
One schema →MCPA2ACLIHTTPOpenAI
summarize.binding.yaml◆ schema
module_id: "text.summarize"
description: "Reduce text to gist"
input_schema:
type: object
properties:
text: { type: string }
max_tokens: { type: integer, default: 200 }
required: [text]
output_schema:
type: object
properties:
summary: { type: string }
confidence: { type: number }
annotations:
readonly: true
cacheable: true
display:
mcp: { alias: "summarize" }
cli: { alias: "summarize" }
a2a: { alias: "Summarize text" }
One capability · One path
Start with the execution boundary.
Prove one governed capability end to end before adding more protocols, products, or infrastructure.
02
Govern
Apply identity, ACL, approval, validation, and middleware before the capability reaches business logic.
03
Expose
Project the same registered module through MCP, CLI, an HTTP integration, A2A, or direct code.
04
Operate
Inspect structured errors, trace context, events, and usage signals from every execution path.
Principles · 02
Why apcore
Keep capability contracts and runtime governance in application code, then project them through the protocol surfaces you actually need.
01Machine-readable contracts
Agent-Readable
Descriptions, input schemas, output schemas, and behavioral metadata give automated callers a structured contract. Model interpretation remains a caller responsibility.
02Apache 2.0, maintainer-led
Open Source
Licensed under Apache 2.0. The protocol, SDKs, conformance fixtures, and governance documents are public.
03Python · TypeScript · Rust
Cross-Language
Maintained Python, TypeScript, and Rust SDKs implement one normative protocol and shared conformance fixtures with language-idiomatic APIs.
04Predictable, validatable contracts
Schema-Driven
Strict input/output contracts on every interface. Predictable, validatable, and self-documenting.
05ACL · approval · middleware
Governed Execution
Identity, ACL, approval gates, call-chain guards, middleware, and validation run before and after application logic.
06MCP · A2A · CLI · HTTP
Protocol-Neutral
Use the native SDK directly or project registered modules through maintained MCP, A2A, CLI, and framework adapters.
Architecture · 06
One governed boundary, multiple surfaces
LAYER00
Application Layer (Frameworks)
Axum / FastAPI / NestJS / TipTap / Legacy Code
( Existing business logic and framework endpoints )
↓ 1. Decorator / YAML Binding
LAYER01
Governance Layer (apcore)
Schema · ACL · Approval · Middleware · Audit
( Enforced before and after execution )
↓ 2. Universal Exposure
LAYER02
Protocol Layer (Adaptation)
MCP <───> A2A <───> OpenAI Tools <───> CLI
( Independently versioned surface adapters )
↓ 3. Governed Execution
LAYER03
Caller Layer
Agents · Services · Operators
( Callers choose and interpret capabilities )
apcore Standard · 03
The apcore surface
Start with the core runtime, then add only the maintained adapter required by your caller.
Ecosystem · 05
Built with apcore
Adjacent experiments and framework integrations. Each project owns its own roadmap, compatibility, and maturity.
Contribute · 07
Help build the standard
apcore is open source and maintainer-led. Contributions should strengthen conformance, the supported adoption path, or verified documentation.
01SDK
Implement an SDK
Port apcore to a new language. The conformance fixtures are your spec — pass them and you have a compliant SDK.
Browse conformance fixtures02Adapter
Build an adapter
Expose apcore modules over a new surface — a web framework, a protocol, a runtime. One guide, one registry to read from.
Read the adapter guide03Code
Pick a good first issue
Small, scoped tasks across the SDKs and docs, labeled for newcomers and ready to claim.
Find an issue04Discuss
Join the discussion
Ask questions, propose spec changes, and shape the roadmap in the open on GitHub Discussions.
Open DiscussionsShip it · 06
Start with one governed capability.
Define and test one application operation in the native SDK. Add an MCP or CLI adapter only after its validation, ACL, approval, and evidence paths are clear.
apache-2.0 · open source · specification-driven