Warmplane

The local control plane that keeps MCP sessions warm.
v0.18.0 — Changelog · User Guide · Performance · Whitepaper · OpenAPI

Warmplane runs multiple upstream MCP servers behind one local process, keeps those sessions persistent, and exposes a compact, policy-aware surface for tools, resources, and prompts — accessible via HTTP, CLI, and MCP-native clients.

Quick Start

1. Build

cargo install --path .

# Optional: local ONNX vector embeddings (FastEmbed)
cargo install --path . --features semantic-search

2. Configure Upstream Servers

Manage servers interactively or import from existing tools:

# Interactive setup wizard
warmplane server add

# Or add non-interactively
warmplane server add filesystem --command npx --arg "-y" --arg "@modelcontextprotocol/server-filesystem" --arg "/tmp"
warmplane server add context7 --url "https://mcp.context7.ai/sse" --bearer-env "CONTEXT7_API_KEY"

# Or import directly from Claude Desktop / Cursor
warmplane config import

Or manually create mcp_servers.json:

{
  "port": 9090,
  "toolTimeoutMs": 15000,
  "capabilityAliases": { "sqlite.read_query": "db.query" },
  "resourceAliases":  { "filesystem.file:///tmp/readme.txt": "fs.readme" },
  "promptAliases":    { "github.code_review": "prompt.code-review" },
  "policy": {
    "allow": ["db.*", "fs.*", "prompt.*"],
    "deny":  ["fs.secret"],
    "redactKeys": ["token", "api_key", "password"]
  },
  "mcpServers": {
    "sqlite":     { "command": "npx", "args": ["-y", "@modelcontextprotocol/server-sqlite", "./test.db"] },
    "filesystem": { "command": "npx", "args": ["-y", "@modelcontextprotocol/server-filesystem", "/tmp"] }
  }
}

3. Validate, then start

warmplane server list
warmplane validate-config --config mcp_servers.json
warmplane daemon --config mcp_servers.json

Run Modes

All three modes share the same backend state, aliases, policy checks, and timeout behaviour.

HTTP Daemon

warmplane daemon --config mcp_servers.json
# Serves /v1/... on the configured port (default 9090)

Key endpoints:

MCP Server (stdio)

warmplane mcp-server --config mcp_servers.json

Point any MCP-native client at this process. It exposes lightweight facade tools (capabilities_list, capability_search, capability_describe, capability_call, capabilities_batch_call, resource_read, prompt_get, …) alongside native resources/* and prompts/* methods.

Claude Desktop / Cursor config:

{
  "mcpServers": {
    "warmplane": {
      "command": "warmplane",
      "args": ["mcp-server", "--config", "mcp_servers.json"]
    }
  }
}

CLI Configuration & Operations

# Interactive server setup wizard
warmplane server add

# Import settings from Claude Desktop or Cursor
warmplane config import

# Hot-reload in-memory workers from mcp_servers.json without restarting
warmplane reload

# Inspect & test servers
warmplane server list
warmplane server test github

# Ecosystem config import (Claude Desktop, Cursor, Zed)
warmplane config import

# Aliases and Policies
warmplane config alias set tool git-commit github.create_commit
warmplane config policy allow "github.*" "fetch.*"

# Capability and Execution CLI
warmplane list-capabilities
warmplane search-capabilities "triage logs" --limit 5
warmplane describe-capability db.query

warmplane call-capability db.query \
  --params '{"query":"SELECT 1"}' \
  --request-id req-101 --actor-id user-7 \
  --idempotency-key op-20-run-1

warmplane read-resource fs.readme
warmplane get-prompt prompt.code-review --arguments '{"code":"fn main() {}"}'

warmplane list-catalog-events --after evt_3
warmplane cancel-operation req-101

Performance Highlights

Warmplane is engineered with pure Rust zero-cost abstractions, keeping agent loops snappy:

• 50.4 ns ETag Cache Validation (If-None-Match $\rightarrow$ 304 Not Modified)
• 159.8 ns Idempotent Cache-Hit Deduplication
• 1.58 µs SHA-256 Incremental Catalog Version Hashing ($N=10$)
• 15.9 µs Filtered Hybrid Capability Search ($N=50$)
• 372.1 µs In-Memory Zero-Allocation Lexical Tag Search across 1,000 Tools

👉 See the complete benchmarks and profiling methodology in docs/PERFORMANCE.md.

Feature Overview

Changelog

v0.18.0 — Persistent State Subsystem, Graceful Teardown, CI UI Automation & E2E Test Suite

• Persistent State Subsystem: Added atomic, restart-resilient disk storage (AtomicFile<T> and StateDirectory) for Human-in-the-Loop pending approvals (approvals.json), idempotent execution records (idempotency.json), OAuth2 tokens (oauth_tokens.json), and catalog mutation events (catalog_events.json). Added state block in McpConfig and warmplane config state show/set CLI commands.
• Graceful Signal Handling & Subsystem Teardown: Added robust SIGINT (Ctrl+C) and SIGTERM signal capture on Unix and Windows, integrated graceful HTTP server draining, async audit worker flushes (AuditWorkerMsg::FlushAndShutdown), and clean stdio subprocess process termination on shutdown.
• Pragmatic Rust Compliance: Achieved 100% adherence across all 48 source files with standard compliance headers (// Rust guideline compliant YYYY-MM-DD).
• CI Automated Web UI Build & Drift Gate: Integrated Bun into GitHub Actions CI (ci.yml) and release pipelines (release-artifacts.yml), with automated build steps and strict git diff --exit-code ui/dist/index.html drift detection.
• Comprehensive End-to-End Integration Suite: Implemented dedicated E2E test harness (tests/e2e_tests.rs) exercising stdio MCP protocol handshakes, live TCP SSE streaming, config hot-reloading, mock OAuth2 RFC 8414 provider round-trips with silent 401 token refresh, and supervisor recovery.

v0.17.0 — 360° MCP Explorer, Visual Batch Pipeline Builder & WORM Audit Pagination

• WORM Audit Multi-Field Search & Pagination: Added case-insensitive substring search across 11 metadata fields, outcome status and server filters, offset/limit pagination slicing (/v1/audit/events), and context-aware CSV and JSONL export downloads (/v1/audit/export).
• MCP Resources Explorer & Live Content Reader: Added 360° resource discovery browser with protocol scheme badges (file://, postgres://, github://, memory://, sqlite://, etc.), metadata/MIME viewer, and live content reader supporting context distillation (_jsonpath, _limit_lines, _truncate_bytes).
• MCP Prompt Template Studio: Added dynamic prompt template browsing and argument form generation with REQUIRED validation badges, rendering resolved system/user prompt envelopes (/v1/prompts/get).
• In-Flight Operation Cancellation: Added interactive UI execution cancellation controls with live execution timers and instant cooperative abort (POST /v1/operations/:id/cancel).
• Visual Multi-Step Batch Pipeline Builder: Added interactive modal pipeline editor for chaining tools with parameter variable interpolation (${steps[0].result.id}) and per-node fault tolerance (POST /v1/tools/batch_call).
• Realtime SSE State Synchronization: Connected /v1/resources/updates SSE stream to automatically refresh resources, prompts, and catalog feeds on the Control Deck.

v0.16.0 — Enterprise Security Hardening, Audit Cryptographic Integrity & Lifecycle Resilience

• API Token Authentication & Middleware Guarding: Added --auth-token CLI parameter, McpConfig.auth_token configuration field, and WARMPLANE_AUTH_TOKEN environment variable support to securely protect daemon endpoints with Bearer/X-Warmplane-Key authentication.
• OAuth Proxy Security & Secret Masking: Hardened the OAuth proxy listener with Host validation and cross-origin browser blocking; masked state and PKCE code_challenge secrets in log output.
• Cryptographic WORM Audit Integrity & HMAC Signing: Included all 20 persisted metadata fields in hash chain digests (work_item_id, client_ip, resource_uri, execution_latency_us, error_message); added HMAC-SHA256 keyed digest calculations and checkpoint generation for external cryptographic anchoring.
• Secret Sanitization & Redaction: Enhanced case-insensitive redaction matching with built-in default sensitive key list (token, secret, password, key, authorization, etc.); restricted external HITL webhook events to only transmit sanitized_args; sanitized secrets before printing in CLI commands.
• Supervisor & Circuit Breaker Coordination: Automatically reset circuit breakers on successful supervisor reconnection; added single-flight probe limits in HalfOpen circuit breaker state; implemented 60-second sliding-window restart backoff; pruned removed items during catalog reconciliation; cleaned up circuit breakers on server unmount.
• Resource Caps & Safety Controls: Enforced MAX_BATCH_STEPS = 50 and DEFAULT_BATCH_TIMEOUT_MS = 60_000 execution budget; capped wildcard JSONPath output expansion to 10,000 items and search results to 100; returned POLICY_DENIED (HTTP 403) and 404 for unknown operation cancellation; sanitized CSV audit exports against formula injection.
• CI Quality Gates & Dependency Audits: Integrated native cargo-audit scanning in GitHub Actions CI; updated dependencies resolving all reported advisories.
• CLI Version Flag: Enabled standard --version and -V flags in the warmplane binary parser.

v0.15.0 — Fault Tolerance, Boot Resilience & Control Deck Feature Parity

• Boot Resilience & Degraded Startup: Graceful daemon boot when upstream servers (such as Docker, remote SSE endpoints, or unconfigured tools) fail or timeout. Failed servers are flagged as degraded without crashing the daemon or blocking other healthy upstreams.
• Process Supervisor & Circuit Breakers: Per-server and global circuit breakers (failureThreshold, cooldownMs, autoRestart, maxRestarts) with state tracking (CLOSED, OPEN, HALF-OPEN) and exponential backoff restart supervision.
• Full Web UI Feature Parity:
  • Server Hub: Server card edit workflow (✏️ Edit), live circuit breaker telemetry badges, and server resilience indicators.
  • Template Wizard: Fault tolerance and supervisor configuration accordion directly inside 1-click curated server setup.
  • Interactive Playground: Context distillation controls (_jsonpath, _limit_lines, _truncate_bytes) and execution latency measurements.
  • Responsive Bento-Grid overview cards with real-time health indicator dots (connected 🟢, degraded 🟡, error 🔴).
• CLI Resilience Configuration: warmplane config resilience set and warmplane config resilience show for headless circuit breaker management.

v0.14.0 — Agent Enrichment Suite: Facade Search, Context Distillation & Multi-Step Batching

• MCP Facade Hybrid Search: Exposed capability_search tool over MCP stdio facade with keyword, tag, server ID, and execution mode filters.
• Context Distillation & Truncation: Added _jsonpath, _limit_lines, and _truncate_bytes modifiers to /v1/tools/call and capability_call to protect LLM context windows from oversized outputs.
• Multi-Step Chained Batch Calls: Added POST /v1/tools/batch_call and capabilities_batch_call for single-roundtrip dependent tool executions with $step.field reference interpolation.

v0.13.0 — Human-in-the-Loop (HITL) Approval Engine & Signed Webhooks

• Approval Interceptor: Policy-driven suspension for sensitive capability calls (requireApproval).
• Operator REST API: Endpoints to list (/v1/approvals), inspect, approve with modified arguments (/v1/approvals/:id/approve), or reject (/v1/approvals/:id/reject).
• Signed HMAC Webhooks: Real-time webhook dispatch with SHA-256 HMAC signature headers on approval lifecycle events.
• Configurable TTL Expiration: Automatic timeout expiration (approvalTimeoutSecs) returning structured cancellation envelopes.

v0.12.0 — Cryptographic WORM Audit Log & SIEM Streaming

• Append-only linear SHA-256 hash chaining over tool execution and HITL decision events.
• Audit verification and export endpoints (/v1/audit/...), Splunk HEC and generic Webhook ingestion.

v0.11.0 — Control Deck Web UI & Dynamic Upstream Hot-Reloading

• Control Deck Web UI: Embedded zero-dependency web dashboard at /ui and / with live telemetry, server manager, interactive tool playground, policy/redaction manager, and alias registry.
• Zero-Downtime Dynamic Upstream Mounting: Dynamically mount and unmount stdio, HTTP, and OAuth2 upstream workers via REST/UI/CLI without restarting the daemon process.
• Dynamic Catalogs & ETags: Concurrency-safe state management with automatic SHA256 ETag recomputation and SSE resource notifications on server changes.
• Explicit Config Hot-Reload: Added warmplane reload CLI command and POST /v1/config/reload endpoint to cleanly reconcile in-memory workers against manual edits to mcp_servers.json.

v0.10.0 — CLI Configuration Management & Ecosystem Importers

• Added warmplane server (add, remove, list, get, test) commands with interactive inquire wizards and flag-driven headless automation.
• Added warmplane config (init, show, import, alias, policy) for safe, transactional configuration mutations.
• Added auto-discovery and import from Claude Desktop, Cursor, and Zed settings.
• Added atomic configuration file writes (fs::rename) preventing JSON corruption.

v0.9.0 — MCP 2026-07-28 Spec Compliance, MRTR & Subscriptions

• Upgraded to official MCP Rust SDK rmcp 3.1.2 and reqwest 0.13.
• Set default protocol version to "2026-07-28" with backward compatibility for "2025-11-25".
• Added Multi Round-Trip Requests (MRTR) support (input_responses and request_state) across HTTP REST, stdio facade, and upstream workers.
• Added cache hints (ttl_ms: 300000, cache_scope: "public") and deterministic alphabetical sorting on catalog listings.
• Added subscriptions_listen tool to stdio facade and /v1/resources/updates SSE stream for real-time notifications.
• Validated RFC 9207 / SEP-2468 iss callback verification for OAuth 2.0 flows.

v0.8.0 — Semantic Vector Embeddings & FastEmbed ONNX Pipeline

• Integrated FastEmbed ONNX embedding pipeline with dense cosine vector similarity under optional --features semantic-search.
• Hybrid reciprocal rank fusion combining BM25 keyword matching and dense vector search.

v0.7.0 — Pragmatic Rust Modernization & Builder Patterns

Full adoption of Microsoft's Pragmatic Rust Guidelines (AGENTS.md). Implemented Builder Pattern (M-INIT-BUILDER) for core state (AppStateBuilder), search filters (SearchFilterBuilder), and request context (RequestContextBuilder). Enhanced error safety (M-PANIC-IS-STOP), structured logging (M-LOG-STRUCTURED), canonical documentation (M-CANONICAL-DOCS), and flexible trait interop (M-IMPL-ASREF).

v0.6.0 — Idempotency, Cancellation & Retry Metadata

Pass Idempotency-Key / X-Idempotency-Key to deduplicate concurrent tool calls. Abort any in-flight request via cancel endpoint or CLI. Every response envelope now includes structured "retry" metadata (classification + state) for orchestrator-aware retry logic.

v0.5.0 — Request Context & Correlation

Structured RequestContext (operation_id, work_item_id, actor_id, grant_id) threaded through all execution envelopes and tracing spans. HTTP header fallback (X-Request-ID, X-Operation-ID, X-Actor-ID, X-Grant-ID).

v0.4.0 — Catalog Versioning & Cache Validation

SHA-256 catalog version. ETag headers on all catalog reads, If-None-Match conditional requests returning 304 Not Modified. GET /v1/catalog/events change feed with cursor-based pagination.

v0.3.0 — Hybrid Search

POST /v1/capabilities/search with BM25 scoring, optional FastEmbed vector embeddings, tag/server-ID filters, and ranked results. POST /v1/capabilities/search with BM25 scoring, optional FastEmbed vector embeddings, tag/server-ID filters, and ranked results.

Docs