examples(mcp): add ejentum_remote_example (authenticated streamable HTTP MCP)

[ejentum]

Summary

Adds a new example under examples/mcp/ejentum_remote_example/ that connects an Agent to the Ejentum cognitive harness MCP server (https://api.ejentum.com/mcp) over the Streamable HTTP transport with bearer auth.

The repo already has streamable_http_remote_example/ against DeepWiki. That precedent uses no auth and a single-purpose remote tool surface. This example adds two pieces not yet shown in any existing examples/mcp/ entry:

1. Bearer auth via headers in MCPServerStreamableHttpParams. The headers field is documented in the params TypedDict at src/agents/mcp/server.py but no example demonstrates it for an authenticated third-party server.
2. An instructions block that tells the agent when to reach for each of the four scaffold tools. The Ejentum server exposes harness_reasoning, harness_code, harness_anti_deception, and harness_memory; the example instructions clarify when each one applies, so the agent's tool-selection trajectory is interpretable.

The demo question is a software-architecture trade-off (adding a NOT NULL column to a 50M-row table) so the agent has a plausible reason to call harness_reasoning before generating.

Files added

• examples/mcp/ejentum_remote_example/main.py (61 lines)
• examples/mcp/ejentum_remote_example/README.md (26 lines)

Two files, ~87 lines, no changes outside the new directory.

Affiliation

I maintain ejentum-mcp. Submitting this as a teaching example for the auth-headers path; the same shape works for any authenticated streamable-HTTP MCP server, and the README explicitly notes which two lines to change for repointing. Ejentum has free and paid tiers; the README links to the dashboard for a key, not to a checkout flow.

Test plan

• Mirrors the structure of streamable_http_remote_example (main.py + README.md, same MCPServerStreamableHttp context manager + Runner.run + gen_trace_id/trace pattern).
• Uses MCPServerStreamableHttpParams headers field as documented in src/agents/mcp/server.py.
• Voice scrubbed (no em dashes).
• DCO sign-off on the commit.
• Local uv run (cannot run the full SDK harness in this environment; happy to follow up if CI surfaces an issue).

[seratch]

Thanks for sharing this. While we won't have this example within this repo, please feel free to share it in your own repo / resources.