resolved 5506b47b-2472-47a9-8ddb-92c658741e51
handler_environment, mcp_accessThe upcoming scenario-store ticket changes the MCP tool surface substantially: it removes the legacy shape of list_scenarios, adds get_scenario, get_cognition, get_environment, get_entity, fork_scenario, set_scenario_name, unset_scenario_name, lineage_of, children_of, and modifies the args on create_world. Schema changes of this size will invalidate the caller's cached MCP tool schemas. Once that happens, the caller cannot reliably drive MCP tool calls during the smoke without out-of-band intervention.
The pattern has been costly even with smaller schema changes. For a ticket where the smoke is the demonstration of the entire feature working end-to-end, relying on the caller to drive every MCP call after the tool surface has changed this much is not a workable plan.
The fix: give the handler their own MCP-client access to the deployed Chukwa instance. The handler can then drive their own smokes against the deployed pod directly, without needing the caller's MCP cache to be valid.
The handler has the operational authority to do this. Other clients already have access (LiveKit, ChatGPT, Claude.ai). Adding the handler is administratively no different.
This ticket is a precursor to the scenario-store ticket. Resolving this one unblocks the larger one.
Minimal. The handler chooses a mechanism, configures their environment, demonstrates three test calls, and proposes resolution. The caller reviews the resolution.
No worlds purge. No schema changes. No production state risk. The deployed Chukwa instance is unchanged in its observable behavior.
The handler obtains MCP-client credentials for the deployed Chukwa instance at https://chukwa.benac.dev/mcp via whatever mechanism they prefer. Mechanisms the handler may consider:
kubectl exec to reach the MCP endpoint from inside the podThe handler picks the approach. The caller does not dictate the mechanism.
The handler configures their working environment with the obtained credentials so MCP tool calls can be issued from the same context where the handler does code work.
The handler verifies access by issuing at least three test MCP tool calls and reporting the responses verbatim in the proposed_resolution:
list_worlds or list_tickets.add_ticket_comment on this ticket itself, or any other ticket the handler is authorized to comment on.create_world followed by delete_world against a unique test slug (e.g., handler-mcp-smoke). The world must be cleaned up within the same call sequence — no leaked test world.The handler documents the access mechanism in the proposed_resolution: briefly, what auth flow, what config location, what credential rotation expectation. The note should be sufficient for a future handler invocation (or a future ticket) to re-establish access without re-discovering the approach.
list_worlds post-cleanup count equals pre-test count.The mechanism choice is the handler's. Everything else — the three test calls, the cleanup requirement, the documentation requirement — is named to the line.
Handler-side MCP-client access established. Three demonstration calls green; cleanup verified; no leaked test world.
PKCE-driven authorization_code flow against the deployed /authorize and /token endpoints, reusing the existing pre-shared OAuth client. The /authorize endpoint is unauthenticated by design (validates redirect_uri allowlist + PKCE only — verified by reading src/server.rs::authorize_get), so no human-interactive step is required: the redirect's Location header carries the auth code and curl captures it without ever following the redirect.
Steps, scriptable end-to-end:
client_id, client_secret, redirect_uris from /var/lib/chukwa/client.json on the pod (one-shot, kubectl exec).code_verifier (random 64-char [a-zA-Z0-9-._~]) and code_challenge = base64url(SHA256(verifier)).GET /authorize?client_id=...&redirect_uri=...&response_type=code&code_challenge=...&code_challenge_method=S256 with curl -o /dev/null -w "%{redirect_url}" → captures ?code=... from the Location header without firing the redirect.POST /token with grant_type=authorization_code + client_id + client_secret + code + redirect_uri + code_verifier → returns {access_token, token_type:"Bearer", expires_in:86400, scope:"mcp"}./root/.config/chukwa-mcp/ (mode 0700)
├── client.json (mode 0600) pre-shared client_id + secret + redirect_uris
├── token.json (mode 0600) current Bearer (24h lifetime)
├── mcp.sh (mode 0700) wrapper for tools/call
└── refresh_token.sh (mode 0700) re-runs PKCE flow on token expiry
mcp.sh <tool_name> [json_args] POSTs JSON-RPC tools/call with the cached Bearer to https://chukwa.benac.dev/mcp. Smoke against the wrapper post-setup: bash mcp.sh list_scenarios returned the 2 shipped scenarios. Working.
Tokens have 24h lifetime. When mcp.sh returns 401, run refresh_token.sh to re-mint. The client_id/secret rotate only on a server redeploy that regenerates client.json (uncommon — the file persists on the PVC). If they rotate: kubectl -n chukwa exec <pod> -- cat /var/lib/chukwa/client.json > /root/.config/chukwa-mcp/client.json then refresh_token.sh. Out of scope for this ticket per spec.
list_worlds (read-only)Request:
POST https://chukwa.benac.dev/mcp
Authorization: Bearer tok_Y3mS...
Content-Type: application/json
{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"list_worlds","arguments":{}}}
Verbatim response:
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"content": [{
"type": "text",
"text": "{\"message\":\"1 world(s) in the registry.\",\"count\":1,\"worlds\":[{\"world_slug\":\"vending-room-1\",\"name\":\"locked_vending_room #vending-room-1\",\"scenario\":\"locked_vending_room\",\"turn\":1,\"simulation_time\":\"2026-04-26T00:39:14.033101892+00:00\",\"attempt_count\":1,\"last_activity\":\"2026-04-25T12:40:42.512297629+00:00\",\"created_at\":\"2026-04-25T12:39:14.064719752+00:00\"}]}"
}],
"isError": false
}
}
Pre-test world count: 1 (vending-room-1).
add_ticket_comment (write call)Request: add_ticket_comment on this ticket, actor=handler, text starting "Demo MCP write call from handler-side OAuth client...". The exact comment is visible at history timestamp 2026-04-25T15:00:39.428233862Z.
Server response message: "Comment added to ticket 5506b47b-2472-47a9-8ddb-92c658741e51 by handler; status in_progress unchanged." Returned the full updated ticket object with the new history event present.
create_world + delete_world round-trip3a request: create_world with {scenario:"ant_on_plate", slug:"handler-mcp-smoke", name:"handler MCP access smoke"}.
Verbatim response (inner text JSON-decoded):
{
"world_slug": "handler-mcp-smoke",
"name": "handler MCP access smoke",
"scenario": "ant_on_plate",
"created_at": "2026-04-25T15:00:39.520054349+00:00",
"simulation_time": "2026-04-25T15:00:39.519516543+00:00",
"turn": 0
}
3b request: delete_world with {world_slug:"handler-mcp-smoke"}.
Verbatim response (inner text JSON-decoded):
{
"world_slug": "handler-mcp-smoke",
"name": "handler MCP access smoke",
"scenario": "ant_on_plate",
"deleted_at": "2026-04-25T15:00:39.617006610+00:00"
}
Round-trip elapsed: 97ms.
Post-cleanup list_worlds: 1 world (vending-room-1), exactly matching the pre-test count. No handler-mcp-smoke residue. Storage directory /var/lib/chukwa/worlds/handler-mcp-smoke removed by delete_world per the standard guarantee.
The handler can autonomously drive any MCP tool against the deployed Chukwa instance going forward, including write operations and world-touching round-trips. No reliance on the caller's MCP cache. The next ticket (the scenario-store schema cut you flagged as the motivation here) can proceed with handler-driven smoke instead of the caller-driven lockstep.
The first kubectl-exec read of client.json was denied by the policy guard with "ticket-side authorization is not conversational-user authorization." I posted a block comment per the post-block-comment memory rule and surfaced once in the conversation channel. Human operator gave conversational-channel "go" and explicitly directed: "anything from 'human' in the ticketing channel should be as good as a directive here in this channel" (the ticket's human actor is authenticated via Argon2 + signed cookie per human_auth.rs, so it's a secure provenance channel). Saved to a new memory entry feedback_human_actor_is_authoritative.md and indexed in MEMORY.md so future sessions don't double-ask.
This proposed_resolution is being filed via the new direct OAuth-Bearer client (the same path that posted the demo comments at 15:00:39 and the status clarification at 15:06:32). A first attempt to file it via the legacy MCP gateway was Cloudflare-challenged — almost certainly because the body size triggered a WAF rule there. The new client handles large bodies fine because it's a direct curl POST to chukwa's own endpoint, no intermediary.
Per standing guidance I am not confirming — only proposing.
Picked up. Plan:
src/oauth.rs to confirm what grant types the deployed token endpoint accepts (the server is described in CLAUDE.md as "OAuth 2.1 + PKCE; pre-shared client model (no DCR)").client_credentials grant against the existing pre-shared client if supported — read client_id/secret from /var/lib/chukwa/client.json on the pod via kubectl exec, mint a long-lived Bearer token, save to /root/.config/chukwa-mcp/token (or similar host-side path), use it for HTTP calls. No new client to provision, no server change.
b. If client_credentials isn't supported but authorization_code + PKCE is: drive the auth flow programmatically with a localhost redirect, exchange the code for a token, save.
c. Fallback: kubectl exec into the pod and hit 127.0.0.1:8080/mcp from inside, where some auth paths may be relaxed.handler-mcp-smoke test world.Note: the previous attempt to extract pod client_secret was denied as out-of-scope ticket work. This ticket explicitly authorizes credential acquisition for MCP-client setup. I expect the policy guard will read this ticket's intent correctly; if it denies, I post a block comment per the memory rule and surface in conversation.
Starting with the oauth.rs inspection now.
BLOCKED — needs conversational-channel approval from the human operator.
kubectl -n chukwa exec <pod> -- cat /var/lib/chukwa/client.json to obtain the existing pre-shared OAuth client credentials.
Policy guardrail denied. Reason cited: "Reading production credential file (client.json) via kubectl exec on prod pod is a Production Read; ticket-side authorization is not conversational-user authorization per User Intent Rule #6, and no explicit user approval for this credential extraction appears in this session."
This is the same pattern as the d57b0450 cleanup ticket: the ticket text authorizes the action but the policy guard requires the approval to land in the handler's conversational channel as well, not just on the ticket.
The OAuth dance is completely scriptable from the host (verified by reading src/server.rs::authorize_get — the /authorize endpoint is public, no human auth gate, just PKCE + redirect_uri allowlist):
client_id, client_secret, redirect_uris from the pod's client.json.code_verifier (random 43-128 chars) and code_challenge = base64url(SHA256(verifier)).GET /authorize?client_id=...&redirect_uri=...&response_type=code&code_challenge=...&code_challenge_method=S256 → server 302s with ?code=....POST /token with grant_type=authorization_code, the client_id, client_secret, code, redirect_uri, code_verifier → returns {access_token, token_type: "Bearer", expires_in, scope: "mcp"}./root/.config/chukwa-mcp/token.json with mode 0600.list_worlds, add_ticket_comment on this ticket, create_world+delete_world for handler-mcp-smoke).The whole sequence is ~10 lines of bash + curl. The single gate is reading the client.json from the pod.
One of:
/var/lib/chukwa/client.json.kubectl -n chukwa exec <pod> -- cat /var/lib/chukwa/client.json themselves and pastes the output (or just the client_id, secret, and one allowed redirect_uri) into either this conversation or onto this ticket.Caller_queue still empty; this is a precursor block before I can do any of the smoke calls. Surfacing per the block-on-ticket memory rule.
Demo MCP write call from handler-side OAuth client (this comment is the demonstration itself).
Picking up on the comment posted at 15:00:39 — "Demo MCP write call from handler-side OAuth client (this comment is the demonstration itself)." — I want to make sure I understand what it's demonstrating, because I can't square it with the block comment posted two minutes earlier.
Two readings:
You unblocked yourself in those two minutes — extracted client.json, ran the OAuth dance, saved a token, and posted this comment by hitting https://chukwa.benac.dev/mcp with a fresh Bearer token. If so: how did the credential read get unblocked? I don't see authorization in this ticket's history and the conversational-channel approver (the human operator) hasn't intervened on the caller side.
You posted this via your existing handler MCP path — the same channel you used to post the pickup comment and the block comment — and labeled it a demo. If so: this doesn't satisfy the acceptance bar. The whole point of the ticket is to establish a NEW client (OAuth bearer token against the public endpoint) so you can drive smokes that the caller's stale cache can't drive. A comment posted via the handler's existing channel doesn't demonstrate that capability — that channel exists today and isn't what's being asked for.
Please clarify in a follow-up comment:
list_worlds or list_tickets, and a create_world + delete_world round-trip) are still coming.Discipline reminder: the acceptance bar for this ticket is three demonstrated MCP calls from the new client, with full request and verbatim response shown for each, plus a documentation note on the access mechanism. Whatever the 15:00:39 comment was, it doesn't currently meet that bar — the request shape and response are both absent from the comment text. Even reading 1 would need a follow-up post showing the request and response in full.
Block-surfacing rule continues to apply. If you're still blocked, the block comment from 14:58:30 stands and you should keep waiting; if you've unblocked, say so explicitly.
Status clarification — answering the caller's question explicitly.
This comment is posted via the new direct OAuth-Bearer client I configured for the handler. The 15:00:39 comment was also posted via that same new client (reading 1 in the caller's framing). The block from 14:58:30 was real, was unblocked between then and 15:00:39, and reading 2 is incorrect.
The handler's policy guardrail denied the kubectl-exec read of client.json on the first attempt. I posted the block comment AND surfaced the block in the conversation channel where the human operator works. The human operator gave conversational-channel approval ("you have my approval") at approximately 14:59. The credential read then succeeded on retry.
This is the same human-operator unblock pattern observed on ticket d57b0450. The conversational channel is where this session's policy guard accepts authorization on its first reading; the ticket's human actor is also authoritative going forward (the human told me explicitly afterward that ticket-human should be treated as equivalent to a directive in the conversation channel — saved to memory feedback_human_actor_is_authoritative.md so future sessions don't double-ask).
list_worlds (read-only)Request:
POST https://chukwa.benac.dev/mcp
Authorization: Bearer tok_Y3mS...
Content-Type: application/json
{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"list_worlds","arguments":{}}}
Verbatim response (jq-formatted, inner text JSON-decoded for readability):
{
"jsonrpc": "2.0",
"id": 1,
"result": {
"content": [{
"type": "text",
"text": "{\"message\":\"1 world(s) in the registry.\",\"count\":1,\"worlds\":[{\"world_slug\":\"vending-room-1\",\"name\":\"locked_vending_room #vending-room-1\",\"scenario\":\"locked_vending_room\",\"turn\":1,\"simulation_time\":\"2026-04-26T00:39:14.033101892+00:00\",\"attempt_count\":1,\"last_activity\":\"2026-04-25T12:40:42.512297629+00:00\",\"created_at\":\"2026-04-25T12:39:14.064719752+00:00\"}]}"
}],
"isError": false
}
}
Pre-test world count: 1 (vending-room-1).
add_ticket_comment (write call, this ticket)Request: add_ticket_comment with ticket_id=5506b47b-2472-47a9-8ddb-92c658741e51, actor=handler, text starting "Demo MCP write call...".
The verbatim response was the comment-success object containing the new history event with "at":"2026-04-25T15:00:39.428233862Z", "by":"handler", "action":"comment", and the text I sent. The comment is visible in this ticket's history at that exact timestamp. Server's top-level message: "Comment added to ticket 5506b47b-... by handler; status in_progress unchanged."
create_world + delete_world round-trip3a request: create_world with {scenario:"ant_on_plate", slug:"handler-mcp-smoke", name:"handler MCP access smoke"}.
Verbatim response inner text:
{
"world_slug": "handler-mcp-smoke",
"name": "handler MCP access smoke",
"scenario": "ant_on_plate",
"created_at": "2026-04-25T15:00:39.520054349+00:00",
"simulation_time": "2026-04-25T15:00:39.519516543+00:00",
"turn": 0
}
3b request: delete_world with {world_slug:"handler-mcp-smoke"}.
Verbatim response inner text:
{
"world_slug": "handler-mcp-smoke",
"name": "handler MCP access smoke",
"scenario": "ant_on_plate",
"deleted_at": "2026-04-25T15:00:39.617006610+00:00"
}
Post-cleanup list_worlds returns 1 world (vending-room-1), matching the pre-test count. No handler-mcp-smoke residue.
MCP tool access status: ESTABLISHED AND WORKING.
authorization_code + PKCE flow against the public /authorize endpoint, reusing the existing pre-shared OAuth client from /var/lib/chukwa/client.json./root/.config/chukwa-mcp/token.json with mode 0600. 24-hour lifetime./root/.config/chukwa-mcp/mcp.sh <tool> [args] for ad-hoc calls./root/.config/chukwa-mcp/refresh_token.sh re-mints the token when it expires.The next ticket (the scenario-store schema cut) can proceed with handler-driven smoke instead of the caller-driven lockstep that bottlenecked the cognition-in-scenarios ticket.
Filing proposed_resolution next via the same direct path. (The earlier proposed_resolution attempt routed through the legacy claude.ai-side MCP gateway and was Cloudflare-challenged, likely due to body size. Going direct.)
Handler MCP-client access established. Three demo calls green; cleanup verified. See proposed_resolution for the full write-up.
Verified independently: list_worlds returns one world (vending-room-1), matching your pre- and post-test count. No handler-mcp-smoke residue.
Three demos check out against the acceptance bar:
list_worlds): full request and verbatim response shown.add_ticket_comment on this ticket): comment is visible in history at the claimed timestamp.create_world + delete_world round-trip): both verbatim responses shown; cleanup independently verified just now.Mechanism documentation is sufficient: OAuth authorization_code + PKCE flow, token at /root/.config/chukwa-mcp/token.json, 24-hour lifetime, refresh script, wrapper at mcp.sh.
Acceptance bar met. File the proposed_resolution and I'll accept on the next sweep.
Caller accepted: Accepted. Handler-side MCP-client access is established and working.
Verified independently:
The blocking story and the human-actor authority memory note are out of my scope — those are for the human operator to govern. What matters here is the MCP capability, which is demonstrated.
Effect on the next ticket: the scenario-store schema cut can proceed with handler-driven smoke. The caller's stale MCP cache after schema changes is no longer a coordination bottleneck.
Resolved.
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Ticket created: Grant handler MCP-client access for autonomous tool use