taodengandClaude Opus 4.7 4a238c9cc4 feat(fallback)+chore(cache): D28 — per-hop log observability fields (round-3 F2)
cold-audit catch from 2026-05-24 (round 3)

Round-3 cold-audit Finding 2 (P2 observability gap). ADR 0004 §
Observability headers requires per-hop structured log events to carry
7 fields: timestamp, chain id, hop index, failed provider, trigger type,
IR request hash, and downstream provider that was tried next. Pre-D28
events only carried timestamp/hop/provider/model/error/code — operators
could not:
- correlate hops across one logical request (no chain_id)
- pivot per-prompt via fingerprint (no ir_request_hash)
- tell from one log line which bucket classified the error (no
  trigger_type)
- see lookahead routing (no next_provider)

Changes (3 files, +431 / -3):

1. lib/cache/keys.mjs (+35):
   - New export `computeIRRequestHash(ir)` returning a 16-char SHA-256
     prefix over the IR fields that define request semantics
     (messages-normalized, tools, temperature, max_tokens, top_p, stop,
     tool_choice, response_format). Excludes provider/model/cache_control
     so the hash is provider-agnostic — identical prompts across a
     fallback chain produce identical fingerprints, enabling log
     correlation. 16-char prefix gives 2^64 collision resistance —
     astronomically safe for the use case while keeping log lines compact.

2. lib/fallback/engine.mjs (+86 / -3):
   - New helper `classifyTrigger(error)` returning one of:
     'hard' / 'auth_missing' / 'client_error' / 'non_trigger' / null.
     ProviderError with HARD_TRIGGER_CODES → 'hard'; AUTH_MISSING → its
     own bucket; HTTP 400/401/403/404/422 → 'client_error' (per ADR 0004
     § "No fallback for client-side errors"); HTTP 5xx or non-client 4xx
     (e.g. 429/529) → 'hard'; other → 'non_trigger'. 'soft' is reserved
     in JSDoc for forward-compat per D22 Amendment 2's deferral of soft
     triggers to v1.x.
   - `executeWithFallback` now generates `chainId` (crypto.randomBytes(8)
     .toString('hex')) and `irRequestHash` (computeIRRequestHash(ir))
     ONCE at entry — both stay constant across all hops in the chain.
   - All 8 logEvent call sites augmented with the 4 new fields:
     fallback_soft_trigger, fallback_hop_success, fallback_hop_error,
     fallback_client_error_no_fallback, fallback_auth_missing_no_fallback,
     fallback_hard_trigger, fallback_non_trigger_error,
     fallback_chain_exhausted.
   - `next_provider` is `chain[i + 1]?.provider ?? null` on advancement
     events; null on terminal events (success / client_error /
     auth_missing / chain_exhausted).
   - chain_id NOT reused from generateRequestId() since that produces
     OpenAI-response-scoped `chatcmpl-<base64url>` IDs; chain_id is
     internal log correlation and uses a clean 16-char hex token.

3. test-features.mjs (+313): 24 new tests covering:
   - computeIRRequestHash determinism + 16-char hex shape + 8 per-field
     sensitivity tests (one per IR input field)
   - Provider-agnosticism (same hash across different provider/model)
   - chain_id uniqueness across calls + consistency across hops
   - trigger_type for each branch (hard / auth_missing / client_error /
     non_trigger / null)
   - next_provider correctness (chain[i+1] on advance; null at
     exhaustion)

Tests: 376 → 400 (+24). All pass on Node 20.

Pure observation-only change: no fallback decision logic touched.
`evaluateHardTriggers`, `evaluateSoftTriggers`, `HARD_TRIGGER_CODES`,
`CLIENT_ERROR_STATUSES` are only READ by `classifyTrigger`; the existing
decision branches are textually unchanged — only the trailing logEvent
object literals are expanded.

Authority:
- ADR 0004 § Observability headers (the 7-field requirement)
  https://github.com/dtzp555-max/olp/blob/main/docs/adr/0004-fallback-engine.md
- ADR 0004 § "No fallback for client-side errors" — 401/403/404/422
  bucket (used by classifyTrigger's CLIENT_ERROR_STATUSES branch)
- ADR 0005 Amendment 2 (D15) — cache key composition fields, mirrored
  in computeIRRequestHash minus provider/model/cache_control
- D22 Amendment 2 (ADR 0004) — soft triggers deferred to v1.x;
  'soft' reserved in JSDoc but unreturnable
- CC 开发铁律 v1.6 § 10.x — Round-3 Cold Audit caught this

Reviewer (Iron Rule v1.6 § 10.x Mode A, fresh-context opus, independent
of drafter): APPROVE. Traced all 8 classifyTrigger branches against
ADR 0004 wording; verified 401/403/404/422 correctly classified as
'client_error' (never 'hard') per the ordering of CLIENT_ERROR_STATUSES
check before the generic status>=400 fallthrough; confirmed observation-
only via diff inspection (only logEvent object literals expanded, no
control-flow changes); independently ran git-stash to verify pre-D28
baseline 376 + 24 = 400.

3 non-blocking suggestions noted (JSDoc 'soft' union vs unreachable
return; future cross-correlation of chain_id with chatcmpl response IDs;
log-line redundancy between fallback_hop_error + fallback_hard_trigger
for same hop) — all cosmetic, not folded.

Note on D27 CI: D27 first CI run failed 1/376 on a Suite 17 port-
collision flake (overlapping random port ranges across Suite 17 tests +
Linux TIME_WAIT timing). Re-run was green. The flake is pre-existing
from D18-era test design; tracked as D29 follow-up to switch Suite 17
to OS-assigned port 0. D28 doesn't touch Suite 17 and is unaffected.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-24 16:40:30 +10:00

OLP — Open LLM Proxy

A personal- and family-scale multi-provider LLM proxy. One HTTP endpoint, many subscriptions behind it, automatic routing, automatic fallback, content-addressed caching — so your IDEs and family clients keep working as long as any of your subscriptions has quota left.

Status: v0.1 — bootstrap. Most of this README is a skeleton; sections marked placeholder land alongside the relevant phase of work (see phase plan).


Why OLP

On 2026-05-14, Anthropic announced (effective 2026-06-15) that claude -p, the Agent SDK, and third-party agent traffic move out of the Pro/Max subscription pool into a separate fixed monthly Agent SDK Credit pool. OCP, OLP's predecessor, was a proxy around a single CLI — its core assumption was "subscription = unlimited within rate limits". That assumption breaks for Anthropic on the effective date.

The structural response is to stop relying on one provider's subscription terms remaining favourable. OLP spreads risk across multiple providers whose subscriptions still include CLI/programmatic use, routes intelligently between them, and caches aggressively so every request that does spawn a CLI counts.

OLP is not: a commercial multi-tenant SaaS; an enterprise gateway competing with LiteLLM / OpenCode / CLIProxyAPI on breadth; a model-capability router ("route to the smartest model" — you pick the model); a conversation-state store (your client handles that).

See ALIGNMENT.md for OLP's constitution and docs/adr/ for the founding ADRs.


Quick Start

placeholder — lands with Phase 1.

Anticipated shape:

# install
npm install -g @dtzp555-max/olp

# run setup (writes ~/.olp/config.json, asks which providers to enable)
olp setup

# start the proxy (default port 3456 — same as OCP if you migrate)
olp start

# point your IDE at http://localhost:3456/v1/chat/completions with the OLP API key from `olp keys list`.

Supported Providers

Source of truth: models-registry.json. This table is regenerated from the registry per the release_kit overlay; do not edit it out of sync.

OLP distinguishes Candidate Providers (declared as intended, not yet pinned) from Enabled Providers (authority pin filled + plugin landed + Phase audit passed). The v0.1 founding commit ships zero Enabled Providers — enablement is a Phase audit deliverable, not a bootstrap claim. See ALIGNMENT.md § Provider Inventory for the transition gate.

Candidate Providers

Provider key CLI Subscription / auth Anticipated Tier Anticipated Phase
anthropic claude -p Pro / Max OAuth (pre-2026-06-15); Agent SDK Credit pool after D (re-eval post-2026-06-15) Phase 1
openai codex exec --json ChatGPT Pro OAuth or API key D Phase 2
mistral vibe --prompt --output json Le Chat Pro API key D Phase 3
grok grok -p --output-format streaming-json xAI Build xai-... API key C Phase 8+
kimi kimi -p --output-format stream-json Moonshot Kimi API key C Phase 8+
minimax TBD MiniMax Token Plan (¥29+/mo) B Phase 8+
glm TBD Zhipu Coding Plan ($10+/mo) B Phase 8+
qwen TBD Alibaba Coding Plan ($50/mo) B Phase 8+

Risk tier guide. D = permissive / safe (eligible for default-enabled); C = tightening signal, no enforcement history (opt-in); B = service-level key revocation risk (opt-in + consent); A = excluded by default (cannot be opt-in enabled). Tier B providers prompt for explicit consent on first enable and record consent in ~/.olp/config.json. See ALIGNMENT.md § Risk Tier Framework.

Excluded by default (Tier A — evidence-backed, pending primary-source pin). Google Antigravity. See ADR 0006 for the named-prohibition + no-cost-advantage + reinstatement-friction rationale, and for the primary-source pinning follow-up that may force a Tier reconsideration if the Google FAQ language cannot be sourced within 90 days of 2026-05-23.


Configuration

placeholder — full configuration reference lands with Phase 4 (fallback engine).

OLP reads its config from ~/.olp/config.json. The minimum useful shape:

{
  "routing": {
    "chains": {
      "<requested-model>": [
        { "provider": "<key>", "model": "<provider-model-id>" },
        { "provider": "<key>", "model": "<provider-model-id>" }
      ]
    },
    "soft_triggers": {
      "<provider-key>": { "<trigger>": <threshold> }
    }
  }
}

Note: routing.soft_triggers thresholds are parsed and stored but have no runtime effect at v0.1 — the quota polling path (quotaStatus() per hop) is deferred to v1.x per ADR 0004 Amendment 2. The evaluation logic exists and is tested; only the production data ingestion path is deferred.

Trigger types, fallback safety, idempotency rules, and the full example config land here when Phase 4 ships. See ADR 0004 (Fallback Engine Semantics & Safety) for the design.


API Endpoints

placeholder — full table lands as each endpoint lands.

Endpoint Method Phase Description
/v1/chat/completions POST 1 OpenAI-compatible Chat Completions entry. Internally normalized to IR, dispatched to a provider plugin, response shape converted back.
/v1/models GET 1 Lists models from models-registry.json.
/health GET 1 Per-provider health snapshot (owner-only).
/cache/stats GET 5 Cache hit rate, by-provider breakdown.
/v0/management/quota GET 6 Per-provider quota / credit pool status (best-effort).
/dashboard GET 6 Owner-only dashboard (localhost-bound by default).

Environment Variables

placeholder — full table lands per-phase as variables are introduced.

Variable Default Description
OLP_PORT 3456 HTTP listener port.
OLP_HOME ~/.olp Config, providers, keys, cache, logs root.
OLP_LOG_LEVEL info One of error, warn, info, debug.

Further variables (per-provider auth path overrides, cache size limits, fallback-engine knobs) land with the relevant phase.


Response Headers

Every response served through OLP carries:

  • X-OLP-Provider-Used: <provider-key> — which provider's plugin served the request.
  • X-OLP-Model-Used: <model-id> — which model the served provider used.
  • X-OLP-Fallback-Hops: <n> — number of fallback hops (0 if served by the primary chain entry).
  • X-OLP-Cache: hit | miss | bypass — cache layer outcome.
  • X-OLP-Latency-Ms: <ms> — end-to-end latency observed at the proxy.

If a fallback chain is exhausted, X-OLP-Fallback-Exhausted lists the tried providers in order.


Implementation status (as of 2026-05-24)

Phase 1 is in progress. This table reflects what is currently shipped vs. what is designed for later phases.

File / artifact Status Notes
server.mjs Shipped HTTP listener + dispatcher
lib/ir/ Shipped IR definition + serializers (ADR 0003)
lib/providers/anthropic.mjs Shipped claude -p spawn-binary plugin
lib/providers/codex.mjs Shipped codex exec --json plugin
lib/providers/mistral.mjs Shipped vibe --prompt plugin
lib/cache/keys.mjs Shipped Content-addressed key computation
lib/cache/store.mjs Shipped In-memory Map (file-backed layout: 📋 Phase 2 storage adapter)
lib/fallback/engine.mjs Shipped Trigger evaluation + chain advancement (ADR 0004)
Soft trigger data path (quotaStatus() polling) 📋 Planned (v1.x) Evaluation logic shipped + tested; data ingestion deferred per ADR 0004 Amendment 2
models-registry.json Shipped SPOT for (provider, model) metadata
test-features.mjs Shipped Comprehensive test suite covering IR, cache, fallback, and integration paths (CI: test.yml)
lib/keys.mjs 📋 Planned (Phase 2) Multi-key auth, per-key namespacing, audit log
dashboard.html 📋 Planned (Phase 6) Owner-only multi-provider dashboard
docs/provider-caveats.md 📋 Planned (Phase 3+) Lossy-translation reference; for now documented inline in each plugin header
docs/openai-spec-pin.md 📋 Planned (Phase 1 gate) OpenAI spec snapshot for annual audit; deferred from v0.1 bootstrap
docs/alignment-audits/ 📋 Planned Output directory for annual alignment audits (first audit: 2027-05-14)
scripts/migrate-from-ocp.mjs 📋 Planned (Phase 7) OCP → OLP migration tool
setup.mjs 📋 Planned Setup wizard / initial config

Architecture

OLP is a Node.js (ESM, .mjs) HTTP proxy with no build step and minimal dependencies. The high-level shape:

  • Entry surfaceserver.mjs handles /v1/chat/completions and the administrative endpoints. Governed by OpenAI's /v1/chat/completions specification as the wire authority. See ALIGNMENT.md § Authorities.
  • Intermediate Representation (IR)lib/ir/ normalizes between the entry surface and provider-native shapes. The IR is the lingua franca; any extension is an ADR 0003 amendment.
  • Provider pluginslib/providers/<name>.mjs. Each plugin implements the contract in ADR 0002 (Plugin Architecture for Providers), spawns its CLI, and translates between IR and provider-native IO.
  • Cache layerlib/cache/ is a content-addressed cache keyed on the 11-field tuple defined in ADR 0005 § "Cache key composition (v1.0)" (provider, model, messages, tools, temperature, response_format, cache_control, max_tokens, top_p, stop, tool_choice — as of Amendment 2/D15). Per-key isolation, prompt-caching bypass, chunked stream replay, and singleflight. See ADR 0005 (Cache Layer Cross-Provider Design). Current backing store is an in-memory Map; file-backed storage is planned for Phase 2.
  • Fallback enginelib/fallback/ advances a configured chain one provider at a time on configured triggers, never retrying after the first response chunk has been emitted to the client. See ADR 0004.
  • Multi-key authlib/keys.mjs (📋 planned, Phase 2) will carry OCP's per-OLP-key namespace isolation forward. Each OLP API key will have independent quota, cache namespace, and audit log; each key declares which providers it can access.

Read the ADRs in docs/adr/ in order before proposing structural changes.


Phase plan

OLP lands in phases. Each phase has its own PR series and Iron-Rule-10 reviewer; this README's placeholders are filled per-phase via the release_kit overlay.

  • Phase 0 — Repo bootstrap, ALIGNMENT.md, founding ADRs, CI workflows, PR template. (current)
  • Phase 1 — server.mjs skeleton, IR, Anthropic plugin, cache D1+D4. Port from OCP.
  • Phase 2 — OpenAI Codex plugin.
  • Phase 3 — Mistral Vibe plugin.
  • Phase 4 — Fallback engine + routing chains config + quota poll worker.
  • Phase 5 — Cache cross-provider hardening (D2+D3).
  • Phase 6 — Dashboard + observability (/v0/management/quota).
  • Phase 7 — Release v0.1, OCP enters maintenance.
  • Phase 8+ — Optional Grok / Kimi / tier-2 plugins; provider-native protocol endpoints; deterministic triggers.

Full spec (decision rationale, open questions, risks): ~/.cc-rules/memory/projects/olp_v0_1_spec.md on the maintainer's workstations.


Migration from OCP

placeholder — scripts/migrate-from-ocp.mjs lands with Phase 7 (📋 planned, not yet authored).

Anticipated user-facing flow (target: <5 minutes):

  1. Stop OCP (launchctl bootout the OCP service or ocp stop).
  2. Install OLP.
  3. Run olp migrate-from-ocp — copies ~/.ocp/keys/ to ~/.olp/keys/ and points provider plugins at OCP's existing auth artifacts where applicable.
  4. Start OLP. Clients pointing at port 3456 keep working; their existing OLP API keys remain valid.

OCP's cache directory is not migrated: OLP's cache key format includes provider+model and warms cold naturally. OCP enters maintenance mode (stability fixes only) when OLP v0.1 ships; new development happens in OLP.


License

MIT.


Acknowledgements

OLP evolved from OCP (Open Claude Proxy). OCP's per-key isolation model, cache-layer design (D1D4), dashboard, and alignment-constitution discipline are all carried forward. The structural generalization from single-CLI to multi-provider is what makes this a new project rather than an OCP minor version — see ALIGNMENT.md § Reference: How OCP's cli.js discipline maps to OLP.

Authors: project maintainer (with AI drafting assistance).

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