Reported issues for pmcp Desktop Extension by paiml

Pod holds 19 of 27 GitHub reports that passed its relevance review. This can include external user reports, maintainer-confirmed bugs, and concrete feature gaps. Treat them as evidence to inspect, not a count of distinct defects.

Back to pmcp Desktop Extension by paiml.

Most discussed

cargo pmcp deploy init --target-type google-cloud-run: scaffold .pmcp/deploy.toml with [target] + [gcp] + [server] + [environment] minimum-viable schema

Problem

cargo pmcp deploy init --target-type google-cloud-run (src/deployment/targets/google_cloud_run/mod.rs line ~99) currently scaffolds three files — Dockerfile, .dockerignore, and cloudbuild.yaml — but does not emit a .pmcp/deploy.toml. As a result, app-level configuration (environment variables, region, Cloud Run service name, memory/CPU sizing, ingress controls, allow-unauthenticated) has no declarative path. Operators who need to wire these values to a deployed serv

Read the thread · 2026-05-19 · open · 2 comments

cargo pmcp deploy --target-type google-cloud-run: switch default runtime base to gcr.io/distroless/cc-debian12 with opt-out [runtime] base knob

Problem

The generated Dockerfile produced by cargo pmcp deploy --target-type google-cloud-run (source: cargo-pmcp/src/deployment/targets/google_cloud_run/dockerfile.rs) uses FROM debian:bookworm-slim as the runtime stage and apt-installs ca-certificates and libssl3, producing runtime images on the order of ~80 MB. The runtime layer includes a full shell (bash/sh), apt, and a system package manager — none of which are required for a Rust HTTP server and all of which add to the a

Read the thread · 2026-05-19 · open · 2 comments

cargo pmcp deploy init --target-type google-cloud-run: support multi-crate isolated layouts via opt-in [layout] block in deploy.toml

Problem

cargo pmcp deploy init --target-type google-cloud-run emits one of two Dockerfile templates depending on detected layout, and both templates fail on multi-crate isolated layouts — for different reasons. The workspace template (cargo-pmcp/src/deployment/targets/google_cloud_run/dockerfile.rs line ~14) uses COPY . . followed by a cargo metadata regex-based step that excludes packages with "lambda" in their name. On a multi-crate isolated layout this over-bundles: every

Read the thread · 2026-05-19 · open · 2 comments

feat: Add OAuth client-side middleware with token injection and auto-refresh

Problem

The SDK has comprehensive server-side OAuth support (bearer token validation, scope middleware) but lacks client-side OAuth middleware for:

• Automatic token injection into outgoing requests
• 401/403 detection and automatic token refresh
• Retry logic after re-authentication
• Token lifecycle management (expiry tracking, proactive refresh)

This is critical for MCP clients connecting to OAuth-protected servers. The TypeScript SDK provides withOAuth for this use case.

Propo

Read the thread · 2025-10-08 · closed · 2 comments

feat: Add HttpMiddleware trait for transport-level HTTP concerns

Problem

The current middleware system operates at the Protocol/JSON-RPC layer, which misses HTTP-specific concerns like:

• Header injection (auth tokens, correlation IDs, custom headers)
• Request/response logging with header inclusion
• Status code-based conditionals (retry on 429, circuit break on 503)
• HTTP-specific transformations before reaching Protocol layer

The TypeScript SDK provides fetch-wrapping middleware for these concerns. We need equivalent ergonomics.

Proposed Solution

Read the thread · 2025-10-08 · closed · 2 comments

fix: .cargo/config.toml has local /mnt/zram/targets path — breaks CI

Bug

All CI jobs fail with:

error: failed to create directory /mnt/zram/targets — Permission denied (os error 13)

.cargo/config.toml has target-dir = "/mnt/zram/targets" committed, which only exists on a local dev machine.

Five-Whys

1. Why permission denied? /mnt/zram/targets doesn't exist on GitHub runners.
2. Why is Cargo using that path? .cargo/config.toml sets target-dir.
3. Why is a local path in the repo? Developer's zram ramdisk config was committed.

Read the thread · 2026-04-05 · closed · outside contributor · 1 comment

Stdio Transport Non-Compliance with MCP Specification

The stdio transport implementation uses HTTP-style Content-Length header framing instead of the newline-delimited JSON-RPC messages required by the MCP specification. This causes incompatibility with standard MCP clients.

The specification is exacting here:

Messages are individual JSON-RPC requests, notifications, or responses.
Messages are delimited by newlines, and MUST NOT contain embedded newlines.

The server MUST NOT write anything to its stdout that is not a valid MCP message.
The 

[Read the thread](https://github.com/paiml/rust-mcp-sdk/issues/158) · 2026-01-15 · closed · outside contributor · 1 comment

### feat: Add first-class middleware integration to Client/Protocol/Transport

## Summary

The middleware system (`Middleware`, `AdvancedMiddleware`, `MiddlewareChain`, `EnhancedMiddlewareChain`) is comprehensive and powerful, but there's no standard integration path to attach middleware to `Client`, `Protocol`, or `Transport`. Users must manually invoke middleware chains, which is error-prone and defeats the purpose of having middleware infrastructure.

## Current State

**What exists:**
- ✅ Comprehensive middleware traits (`Middleware`, `AdvancedMiddleware`)
- ✅ Chain im

[Read the thread](https://github.com/paiml/rust-mcp-sdk/issues/80) · 2025-10-08 · closed · 1 comment

## Most recent

### StdioTransport: stdin EOF disables stdout, dropping responses to already-accepted requests

# StdioTransport: stdin EOF disables stdout, dropping responses to already-accepted requests

## Summary

`StdioTransport` uses a single `closed` flag for two independent streams. Reaching EOF on
**stdin** sets it, and `send()` then refuses every **stdout** write. A client that pipes a
batch of requests and closes stdin — the normal shape of a one-shot MCP session — never
receives the responses to requests the server already accepted and answered.

## Where

`src/shared/stdio.rs` (v2.17.0):

Read the thread · 2026-07-31 · closed · outside contributor · 0 comments

pmcp-workbook-server: 2 stale golden-tool tests quarantined from workspace-test gate

Summary

Two tests in pmcp-workbook-server fail against the committed golden bundle and are quarantined from the workspace-test CI gate (--exclude pmcp-workbook-server) so unrelated PRs can merge. They need workbook-domain review.

Failing tests

crates/pmcp-workbook-server/src/assemble.rs:

• assemble::tests::build_server_from_golden_registers_five_tools (panics at :130)
• assemble::tests::matching_bundle_id_succeeds (panics at :142)

Both assert the server built from t

Read the thread · 2026-07-05 · open · 0 comments

wasm support for pmcp-macros

Love that this project supports webassembly though I notice that the WasmMcpServer uses WasmTool, WasmResource and WasmPrompt rather than ToolHandler, PromptHandler and ResourceHandler. I've not spent a ton of time digging into the macro generation

Read the thread · 2026-06-11 · open · external user · 0 comments

Phase 75 SATD: cargo-pmcp commands roadmap (landing build, dev watch, add scaffolding)

Outstanding SATDs from Phase 75 Plan 75-04 triage (D-04)

Filed as part of Phase 75 SATD triage. Replaces 4 // TODO: Implement ... comments in cargo-pmcp/src/commands/ with // See #NNN — references after this issue is filed.

Outstanding follow-ups

• cargo-pmcp/src/commands/landing/mod.rs:92 — Implement the landing build subcommand (currently prints "Build command coming in Phase 1!" and asks the user to fall back to npm run build).
• `cargo-pmcp/src/commands/landing/

Read the thread · 2026-04-25 · closed · 0 comments

Phase 75 SATD: wire aws-sdk-secretsmanager into AWS secrets provider

Outstanding SATDs from Phase 75 Plan 75-04 triage (D-04)

Filed as part of Phase 75 SATD triage. Replaces 4 // TODO: Implement with aws-sdk-secretsmanager comments in cargo-pmcp/src/secrets/providers/aws.rs with // See #NNN — references after this issue is filed.

Outstanding follow-ups

• cargo-pmcp/src/secrets/providers/aws.rs:96 — list(): integrate aws-sdk-secretsmanager list_secrets API; remove the Err(SecretError::ProviderError { ... "not yet implemented" }) stub.

Read the thread · 2026-04-25 · closed · 0 comments

Stdio example not working

Try example from README.md in the project root. Server started but not respond.

Read the thread · 2025-11-27 · open · external user · 0 comments

RFC: cargo-pmcp - Production-Grade MCP Server Development Toolkit

RFC: cargo-pmcp - Production-Grade MCP Server Development Toolkit

Type: RFC / Feature Request Labels: enhancement, RFC, tooling, cargo-pmcp, discussion

Summary

We propose cargo-pmcp - a batteries-included toolkit for building production-grade MCP servers in Rust. This RFC is based on real-world experience building 6 production MCP servers and incorporates proven patterns for security, scalability, and developer experience.

Goal: Make cargo-pmcp the

Read the thread · 2025-10-23 · closed · 0 comments

feat: Improve middleware developer ergonomics with macros, presets, and examples

Problem

Creating custom middleware currently requires significant boilerplate:

• Manual trait implementations with async-trait
• Verbose struct definitions
• Repetitive priority/should_execute implementations
• No guidance on typical middleware stacks per transport

The TypeScript SDK provides createMiddleware helper for concise middleware creation. We need equivalent Rust ergonomics plus:

• Macro for concise custom middleware
• Pre-configured middleware stacks per transport
• Concrete int

Read the thread · 2025-10-08 · closed · 0 comments

feat: Add Prometheus and OpenTelemetry exporters for middleware metrics

Problem

The existing MetricsMiddleware collects metrics but lacks integration with standard observability platforms:

• No Prometheus exporter for scraping
• No OpenTelemetry integration for distributed tracing
• No histogram/percentile metrics (only counters)
• Manual metrics retrieval required

Production deployments need:

• Automatic metrics export to monitoring systems
• Distributed tracing correlation
• Standard metric formats (Prometheus, OTLP)
• Histograms for latency distribution

Read the thread · 2025-10-08 · open · 0 comments

feat: Add CompressionMiddleware for HTTP/WebSocket payloads

Problem

Large JSON-RPC payloads (especially resource content, tool results, and prompt responses) can significantly impact:

• Network bandwidth usage
• Request/response latency
• Mobile/edge deployment performance

The TypeScript SDK doesn't have built-in compression, but this is a common production need for HTTP/WebSocket transports. Stdio transport should NOT use compression (breaks line-delimited framing).

Proposed Solution

Add CompressionMiddleware that operates at the HTTP transp

Read the thread · 2025-10-08 · open · 0 comments

feat: Enhance CircuitBreakerMiddleware and RateLimitMiddleware with scoping and metrics

Problem

Current CircuitBreakerMiddleware and RateLimitMiddleware implementations are global and lack production-grade features:

CircuitBreakerMiddleware limitations:

• Global state (no per-endpoint/method/session scoping)
• No persistence (resets on restart)
• No aggregated metrics/observability
• Fixed thresholds (no dynamic adjustment)

RateLimitMiddleware limitations:

• Global limits (no per-endpoint/method/session scoping)
• No persistence across restarts
• No distributed co

Read the thread · 2025-10-08 · closed · 0 comments

The remaining reports are on the project's issue tracker.