[Bug]: opencode-free: all free models fail with permission_denied from the Codex App

Client or integration

Codex App

Provider or upstream service

opencode-free (https://opencode.ai/zen/v1)

OpenCodex version

2.86.0 (npm global @bitkyc08/opencodex; OpenCodex desktop app on macOS)

Endpoint or capability

/v1/chat/completions via the opencode-free provider (every free model tried; failures captured for opencode-free/ll-alpha-free)

Current behaviour

Using OpenCodex as the provider proxy in front of the Codex App, every opencode-free model fails with permission_denied. The error appears on the first message, for every free model tried, so the entire free tier is unusable through OpenCodex. Proxy logs show 12 consecutive 403 permission_denied failures (headers-only / credential-rejected) on 2026-10-16; redacted evidence in the comments.

Expected behaviour

opencode-free models should return a normal completion (cost 0) from the Codex App through OpenCodex, as they did after the fix in #4136.

Minimal redacted request or reproduction

# Standard request shape sent by the Codex App through the local OpenCodex proxy.
# Exact outgoing request was not captured; this is the reproducible shape.
curl http://127.0.0.1:<port>/v1/chat/completions \
  -H "Authorization: Bearer <REDACTED>" \
  -H "Content-Type: application/json" \
  -d '{"model":"<any opencode-free model>","messages":[{"role":"user","content":"hi"}]}'

Reproduces on every free model, on the first message, with no special configuration.

Actual response or error

The Codex App surfaces exactly permission_denied for every opencode-free model; no response is generated. Proxy-side records confirm: upstream HTTP 403, error code permission_denied, failure stage headers-only, failure cause credential-rejected (see redacted log excerpt in the comments). The raw upstream response body was not logged. For reference, the same gate in #4121 returned MissingSessionID / "OpenCode's free tier can only be used in OpenCode", so this may be the same Zen free-tier check surfacing under a different client-side error string.

Upstream documentation

https://opencode.ai/docs/zen/

Suggested mapping or implementation notes

Possibly related to #4121 (Zen free-tier gate rejecting non-OpenCode clients, fixed by #4136). A comment there from 2026-09-14 (OpenCodex 2.54.0) reported the upstream gate still triggering on some free routes; this report suggests it now affects all free models from the Codex App. Control: opencode-go requests from the same proxy returned 200 on 2026-10-12, so the failure is specific to the opencode-free provider.

Checks

I searched existing provider and compatibility issues.
The request and response were redacted.
The expected behaviour is based on an upstream specification or a concrete client requirement.

Issue reopened

The report now contains the information required by the automated check. Thanks for updating it.

Redacted evidence from the local proxy logs (OpenCodex 2.86.0, macOS, npm global install). Nothing sensitive below: request/conversation ids are truncated, and no tokens or message contents are included.

All 12 failures occurred within a single session on 2026-10-16, 23:17:31-23:17:42 (+0800), immediately after selecting the model in the Codex App:

field	value (identical across all 12 attempts)
provider / requested model	`opencode-free` / `opencode-free/ll-alpha-free`
HTTP status	`403`
error code	`permission_denied`
failure stage	`headers-only`
failure cause	`credential-rejected`
inbound protocol	`responses` (Codex App), translated `responses -> chat` (`cross-wire-ir`)
adapter	`openai-chat`
reasoning effort	`xhigh` (`reasoning_effort`)
route decision	`explicit-provider-namespace` (model picked explicitly in the client)
retries	12 requests, ~1 s apart, `sendCount: 1` each, no recovery

Sample redacted attempt record (from the proxy usage log):

{
  "requestId": "ocx-ed30bf5b...(truncated)",
  "provider": "opencode-free",
  "model": "ll-alpha-free",
  "requestedModel": "opencode-free/ll-alpha-free",
  "inboundProtocol": "responses",
  "status": 403,
  "errorCode": "permission_denied",
  "attempts[0]": {
    "adapter": "openai-chat",
    "status": 403,
    "errorCode": "permission_denied",
    "failureStage": "headers-only",
    "failureCause": "credential-rejected",
    "sendCount": 1,
    "recoveryKinds": []
  }
}

Two observations that may help debugging:

headers-only / credential-rejected means the upstream Zen gate rejected the request from the headers alone, matching the opencode-free: Zen rejects requests without x-opencode-session (free tier lock-in) #4121 pattern (free-tier provenance check), even though this run is on 2.86.0, well after the docs(provider): explain the opencode-free Zen lock-in instead of leaking MissingSessionID #4136 fix.
Control group: requests through the opencode-go provider (opencode-go/deepseek-v4.1-flash) returned 200 on 2026-10-12 from the same proxy. Only opencode-free fails.

This is from Opencode logs.

{
  "event": {
    "id": "***",
    "requestID": "***",
    "workspaceID": "***",
    "startedAt": 1792267781376,
    "finishedAt": 1792267781486,
    "durationMs": 110,
    "outcome": "rejected",
    "category": "inference",
    "protocol": "openai-chat",
    "product": "standard",
    "path": "/inference/openai/v1/chat/completions",
    "method": "POST",
    "stream": true,
    "userAgent": "Bun/1.4.2",
    "userID": "***",
    "requestedModel": "deepseek-v4.1-flash-free",
    "model": "deepseek-v4.1-flash-free",
    "provider": "opencode",
    "statusCode": 403,
    "errorCode": "inference_failed",
    "errorMessage": "The inference request failed.",
    "reasoningMode": "effort",
    "reasoningEffort": "high",
    "country": "***",
    "region": "***",
    "city": "***",
    "requestHeaders": {
      "accept": "*/*",
      "content-length": "127458",
      "content-type": "application/json",
      "user-agent": "Bun/1.4.2"
    },
    "metadata": {},
    "attemptCount": 0,
    "attempts": []
  }
}

The added upstream log narrows this to rejection before provider dispatch (attemptCount: 0), but neither that nor the proxy's credential-rejected / headers-only classification establishes the upstream rejection reason by itself.

At dev 8640c2f30edb, the opencode-free registry note and opencode-zen-rate-limit.ts already document the keyless client gate; OpenCodex intentionally does not mint an OpenCode identity/session header to bypass it. Please retain the actual redacted upstream error type/message (especially whether it is MissingSessionID) and exact version/model before treating this as a new adapter regression. The public Console model docs describe keyed access by other coding agents; they do not by themselves authorize third-party keyless-tier impersonation. Keyed opencode-zen is a separate supported path, with separate quota/billing. Leaving this open for exact refusal evidence; no header-spoofing workaround is proposed.

opencode-free support is being removed in #7351 because all models now 403 under the upstream gate. Existing configs that reference opencode-free keep loading: the entries are skipped with a one-time warning that suggests alternatives such as opencode-go. Thanks for the detailed report and logs.

_{Automated translation bookkeeping — detected language: English.}

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[Bug]: opencode-free: all free models fail with permission_denied from the Codex App #7255

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[Bug]: opencode-free: all free models fail with permission_denied from the Codex App #7255

Description

Client or integration

Provider or upstream service

OpenCodex version

Endpoint or capability

Current behaviour

Expected behaviour

Minimal redacted request or reproduction

Actual response or error

Upstream documentation

Suggested mapping or implementation notes

Checks

Activity

github-actions commented on Oct 16, 2026

Issue reopened

Guns160 commented on Oct 16, 2026

fehmi commented on Oct 18, 2026

Ingwannu commented on Oct 18, 2026

lidge-jun commented on Oct 19, 2026

github-actions commented on Oct 19, 2026

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