core/docs/workbench/api-contract-v1.md

CORE Workbench API Contract v1

Status: draft Scope: read-only local operator API

This contract defines the initial API surface for CORE Workbench v1.

The API exists to expose:

• runtime observability,
• replay evidence,
• proposal visibility,
• eval visibility,
• and trace inspection

without widening the mutation surface.

Transport

• HTTP JSON
• optional websocket stream later
• local-first (127.0.0.1) in v1

Response envelope

All responses MUST include generated_at as an ISO-8601 UTC timestamp. generated_at is wall-clock UTC and not part of replay state. Clients hashing or caching responses must exclude this field. Successful responses:

{
  "ok": true,
  "generated_at": "2026-05-26T00:00:00Z",
  "data": {}
}

Errors:

{
  "ok": false,
  "generated_at": "2026-05-26T00:00:00Z",
  "error": {
    "code": "not_found",
    "message": "artifact not found"
  }
}

W-026 error codes:

• bad_request
• not_found
• unsupported
• read_error
• eval_failed
• runtime_unavailable

unauthorized is reserved for a later auth ADR. W-026 remains unauthenticated and local-only by default.

Exception mapping:

Condition	HTTP status	Error code
malformed request, invalid path, unsafe traversal	400	bad_request
well-formed missing artifact/proposal/lane/trace	404	not_found
artifact exceeds the W-026 read size limit	413	read_error
deferred W-027+ route	501	unsupported
filesystem read failure	500	read_error
unexpected runtime failure	500	runtime_unavailable

W-026 execution model

The Workbench API is a single-operator local service. It emits a narrow local development CORS response for the Vite workbench origin http://127.0.0.1:5173; this supports W-028's documented split-server manual integration workflow without making the API a remote service. Eval execution is serialized per server instance so two /evals/run requests cannot race over shared runtime checkpoint files.

Side effects on engine_state/

W-026 is read-only with respect to teaching corpora and pack data. Two routes touch runtime checkpoint surfaces governed by existing ADRs:

• GET /runtime/status instantiates EngineStateStore and reads engine_state/manifest.json via load_manifest.
• POST /evals/run with lane="contemplation_quality" transitively invokes the ADR-0159 replay baseline. That path can create normal ChatRuntime checkpoints under engine_state/, governed by ADR-0146 and ADR-0150.

These checkpoint writes are runtime artifacts, not teaching/corpus/pack mutation. They are intentionally excluded from the W-026 read-only snapshot invariant.

---

Runtime

GET /health

Purpose:

Basic liveness/readiness.

Response:

{
  "ok": true,
  "data": {
    "status": "ok"
  }
}

---

GET /runtime/status

Purpose:

Expose runtime metadata.

Response:

{
  "ok": true,
  "data": {
    "backend": "rust",
    "git_revision": "abc123",
    "engine_state_present": true,
    "checkpoint_revision": "abc123",
    "revision_warning": false,
    "active_session_id": "session-001"
  }
}

---

Chat

POST /chat/turn

Purpose:

Execute a normal runtime turn and return the full UI evidence envelope.

This is the only Workbench POST route that touches the live chat runtime. Turns are serialized per server instance by a module-level lock, matching ADR-0160's single-operator-local v1 doctrine.

Request:

{
  "prompt": "What does alpha cause?"
}

Validation:

• prompt is required and must be a string.
• prompt.strip() must be non-empty.
• prompt must not exceed 4096 characters.
• request Content-Length must not exceed 64 KiB.

Invalid prompt shape returns 400 bad_request. Oversize request bodies return 413 read_error.

Response:

{
  "ok": true,
  "generated_at": "2026-05-26T00:00:00Z",
  "data": {
    "prompt": "What does alpha cause?",
    "surface": "alpha causes beta",
    "articulation_surface": "alpha causes beta",
    "walk_surface": "alpha -> beta",
    "grounding_source": "teaching",
    "epistemic_state": "decoded",
    "normative_clearance": "cleared",
    "normative_detail": "",
    "trace_hash": "sha256:...",
    "refusal_emitted": false,
    "hedge_injected": false,
    "mutation_mode": "runtime_turn",
    "identity_verdict": {
      "outcome": "cleared",
      "runtime_detail": ""
    },
    "safety_verdict": {
      "outcome": "cleared",
      "runtime_detail": ""
    },
    "ethics_verdict": {
      "outcome": "cleared",
      "runtime_detail": ""
    },
    "proposal_candidates": [
      {
        "candidate_id": "abc123",
        "source_kind": "discovery"
      }
    ],
    "turn_cost_ms": 17,
    "checkpoint_emitted": true
  }
}

Important:

This endpoint must use the existing runtime path. It must not introduce a parallel persistence layer.

Mutation boundary:

• A chat turn may write engine_state/ through the normal runtime checkpoint path governed by ADR-0146 and ADR-0150. checkpoint_emitted reports whether that occurred.
• A chat turn must not mutate teaching/, packs/, or language_packs/data/.
• A chat turn must not auto-accept proposals.
• proposal_candidates contains candidate identifiers only; it does not expose proposal acceptance/rejection affordances or candidate surfaces.
• surface, articulation_surface, and walk_surface remain distinct. The user-facing response is surface; walk_surface is telemetry/evidence.

---

Trace

GET /trace/{turn_id}

Purpose:

Inspect trace evidence for a turn.

W-026 status:

Trace storage is not implemented in W-026. Unknown turn ids MUST return 404 not_found. The API must never return a synthetic empty trace as a successful response.

Response:

{
  "ok": true,
  "data": {
    "turn_id": "turn-001",
    "surface": "...",
    "articulation_surface": "...",
    "walk_surface": "...",
    "trace_hash": "sha256:...",
    "grounding_source": "teaching",
    "replay_digest": "sha256:...",
    "proposal_refs": [],
    "admissibility": {
      "rejected_attempts": 0
    }
  }
}

---

Replay

GET /replay/{artifact_id}

Purpose:

Return replay comparison information.

Important:

The API must not claim "equivalent": true unless a real replay/compare path has run. Comparing an artifact digest to itself is not replay evidence. Until the replay theater is wired, this route should return unsupported or a non-equivalent comparison with explicit divergence evidence.

Response:

{
  "ok": true,
  "data": {
    "artifact_id": "artifact-001",
    "original_hash": "sha256:...",
    "replay_hash": null,
    "equivalent": false,
    "divergences": [
      {
        "path": "$",
        "original": "artifact digest",
        "replay": null,
        "severity": "info"
      }
    ]
  }
}

---

Proposals

GET /proposals

Purpose:

List proposal metadata.

Implementation rule:

Proposal reads MUST derive their current view by replaying teaching.proposals.ProposalLog.current_state(). The append-only JSONL file is an event log, not a table of proposal records.

Response:

{
  "ok": true,
  "data": {
    "items": [
      {
        "proposal_id": "proposal-001",
        "state": "pending",
        "source_kind": "contemplation",
        "replay_equivalent": true,
        "created_at": "2026-05-26T00:00:00Z"
      }
    ]
  }
}

---

GET /proposals/{proposal_id}

Purpose:

Detailed proposal inspection.

Response:

{
  "ok": true,
  "data": {
    "proposal_id": "proposal-001",
    "state": "pending",
    "source_kind": "contemplation",
    "replay_equivalent": true,
    "proposed_chain": {},
    "replay_evidence": {},
    "downstream_effect": {},
    "artifact_refs": []
  }
}

Forbidden:

• accept endpoint
• reject endpoint
• mutation endpoint

---

Evals

GET /evals

Purpose:

List eval lanes.

Response:

{
  "ok": true,
  "data": {
    "lanes": [
      "cognition",
      "learning-arc",
      "contemplation-quality"
    ]
  }
}

---

POST /evals/run

Purpose:

Run a read-only eval lane.

Request:

{
  "lane": "contemplation-quality"
}

Response:

{
  "ok": true,
  "data": {
    "lane": "contemplation-quality",
    "passed": true,
    "metrics": {}
  }
}

Constraints:

• only lanes explicitly marked safe/read-only may run through the API
• mutation-capable workflows are forbidden in v1

---

Artifacts

GET /artifacts

Purpose:

Enumerate readable runtime artifacts.

Response:

{
  "ok": true,
  "data": {
    "items": []
  }
}

---

GET /artifacts/{artifact_id}

Purpose:

Read structured artifact content.

Constraints:

• artifacts must be repo-root constrained
• no arbitrary path traversal
• no arbitrary shell execution

---

Security Constraints

Forbidden in v1

• proposal mutation
• corpus mutation
• workflow dispatch
• arbitrary file reads
• remote execution
• arbitrary command execution
• hidden background jobs

Required

• deterministic serialization
• stable artifact ids
• digest visibility
• explicit provenance where available
• read-only route tests