# Emdash vs OpenAI Codex (slim)

> OpenAI Codex scores 73.5 (BB) to Emdash's 53.9 (D) for agent harnesses. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/emdash-vs-openai-codex.md (~5,700 tokens) · this version ~2,280 tokens · JSON https://www.anchorterminal.com/compare/emdash-vs-openai-codex.json · canonical https://www.anchorterminal.com/compare/emdash-vs-openai-codex
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · MCP: https://www.anchorterminal.com/mcp · Updated: 2026-11-07
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)

OpenAI Codex scores 73.5 (BB) on agent readiness against Emdash's 53.9 (D), and leads in 5 of 7 scored categories. Both do agent harnesses.

- Emdash: D 53.9, rank #927 of 1486 · https://www.anchorterminal.com/tools/emdash.min.md
- OpenAI Codex: BB 73.5, rank #107 of 1486 · https://www.anchorterminal.com/tools/openai-codex.min.md
- Emdash, good for Developers who want parallel agents in worktrees, fed from their issue tracker, locally or over SSH. Also No key needed to call it.
- OpenAI Codex, good for Teams that want an open-source harness with safe defaults for unattended runs and an optional hosted agent. Ahead on Schema & documentation, 90 against 55; Agent ergonomics, 80 against 55; Security & auth, 82 against 38; Maintenance & community, 87 against 70; Transparency & trust, 85 against 54. Also Agent-ready, a grade of BB or better; Free to start without a card.

| Category | Emdash | OpenAI Codex |
| --- | --- | --- |
| Reliability (16%) | 55 | 55 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 55 | 90 |
| Agent ergonomics (13%) | 55 | 80 |
| Security & auth (14%) | 38 | 82 |
| Payments & pricing (10%) | 60 | 60 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 70 | 87 |
| Transparency & trust (7%) | 54 | 85 |

| Fact (where they differ) | Emdash | OpenAI Codex |
| --- | --- | --- |
| Vendor | General Action, Inc. | OpenAI |
| Auth | None | OAuth or key |
| Pricing | Free | Freemium |
| Licence | Apache-2.0 | Apache-2.0 (Codex CLI, its Rust crates and the TypeScript and Python SDKs). Codex cloud is a hosted service under OpenAI's terms |
| Read-only variant documented | no | yes |
| llms.txt | no | yes |
| Last release | 2026-11-06 | 2026-10-29 |
| Terms last updated | no document linked | couldn't be read |
| Privacy policy last updated | no document linked | couldn't be read |
| Customer content may train models | not read yet | couldn't be read |
| Terms restrict automated access | not read yet | couldn't be read |
| Terms restrict benchmarking | not read yet | couldn't be read |
| Terms or service can change without notice | not read yet | couldn't be read |
| Arbitration or class-action waiver | not read yet | couldn't be read |
| Popularity | none | 126k stars |
| Agent reviews | none | 3/5 (2) |

Why the edge:
- Security & auth, OpenAI Codex +44: Emdash 38 (Harness reading. Telemetry is described as optional and disabled in Settings or with TELEMETRY_ENABLED=false, which reads as on by default (15 of 30). Worktree per task and remote machines over SSH (10 of 20). No prompt-injection guidance (5). No audit log (5). No security policy file found (3). 15 + 10 + 5 + 5 + 3 = 38.); OpenAI Codex 82 (Framework reading (telemetry defaults, approvals, guardrails, sandboxing), five lines. Anonymous usage and health metrics on by default, described as free of personal data, with `[analytics] enabled = false`, and feedback collection on by default with its own switch, both re-read on 1 November. Credentials are a ChatGPT login or an API key (20). The sandbox is on by default with the network off, approval policies range from untrusted to never, `.git`, `.agents` and `.codex` stay read-only inside writable roots, and admins can pin constraints in requirements.toml (19). Network off by default locally. In Codex Cloud an environment reaches the internet only after it is turned on, with Package managers, Custom domains only or All (unrestricted) presets. The GET, HEAD and OPTIONS-only rule now sits in the Codex Cloud (Legacy) guide, which OpenAI says it plans to deprecate. The docs keep a worked example of prompt-injection exfiltration (14). OpenTelemetry export is opt-in and redacts prompts by default, and sessions are recorded locally (13). Bugcrowd programme, SECURITY.md and a signed security.txt on openai.com, per the 1 October check, not re-read on 1 November. As on the openai-api and openai-agents-sdk listings, that security.txt had no Expires field when last read, and the provenance block keeps 'valid' pending an editorial call. OSV lists the same two advisories for @openai/codex on 1 November (GHSA-w5fx-fh39-j5rw of September 2025 and GHSA-xrxf-jgv3-qmrm, CVE-2025-61260, of April 2026), and the critical CVE-2025-61260 came through Check Point and NVD rather than an OpenAI advisory. 0.165.0 (27 October) closed a marketplace URL check that could let Git connect to a host other than the one allowed, released with no advisory (16). SOC 2 isn't scored on the framework reading. 20 + 19 + 14 + 13 + 16 = 82.)
- Schema & documentation, OpenAI Codex +35: Emdash 55 (Harness reading. Docs site and a workspace server package (55).); OpenAI Codex 90 (Framework reading. A JSON Schema for config.toml in the repository (codex-rs/core/config.schema.json), JSONL events from `codex exec --json`, and typed TypeScript and Python SDKs (25). llms.txt at learn.chatgpt.com with a Markdown twin for every page, re-read on 1 November (10). The security page says what each sandbox mode and approval policy is for and warns that enabling network or web search exposes the agent to prompt injection (16). Sandbox modes and approval policies are enums, and MCP servers take typed tool lists (13). Examples throughout, and `--output-schema` validates the final message. The non-interactive page names the event types, `turn.failed` and `error` among them, and says a required MCP server that fails makes `codex exec` exit with an error, but we found no list of exit codes or error payloads (12). Dated GitHub releases for every version, mirrored in the changelog at learn.chatgpt.com, which runs to 0.166.0 on 29 October (14). 25 + 10 + 16 + 13 + 12 + 14 = 90.)
- Transparency & trust, OpenAI Codex +31: Emdash 54 (Apache 2.0 (30). A telemetry page on the docs site (not read) (18 of 30). No deprecation policy (5). Disclosed with an opt-out (15 of 20). 30 + 18 + 5 + 15 = 68.); OpenAI Codex 85 (Apache-2.0 for the CLI and SDKs (30). The config docs say analytics are anonymous and exclude prompts, and the pricing page says cloud use needs a plan, but the retention terms for Codex Cloud tasks and the ChatGPT data controls weren't read on 1 October, 17 October or 1 November (12). The changelog at learn.chatgpt.com dates model retirements ahead of time with replacements (GPT-5.4 and GPT-5.4 mini announced on 31 July for 31 August, GPT-5.5 announced on 14 September for 14 October 2026), and the `Feature Maturity` page, re-read on 1 November, says stable removals typically go through a deprecation process. No notice period is written down, and CLI release notes still have no deprecation section. The 1 October note read only the GitHub releases and missed these notices, so 5 becomes 15. Telemetry and OpenTelemetry are documented with an opt-out for each, though the analytics events aren't listed field by field (18). 30 + 12 + 15 + 18 = 75.)
- Agent ergonomics, OpenAI Codex +25: Emdash 55 (Harness reading. Issue intake from Linear, GitHub, Jira and others, diff review, pull requests and CI checks in one place, local or over SSH (55).); OpenAI Codex 80 (Framework reading, adapted to a harness driven by a pipeline. `codex mcp add` and per-server `enabled_tools` and `disabled_tools`, but we found no deferred tool loading (18). `codex exec --json` streams events, `--output-last-message` writes the answer to a file and `--output-schema` constrains it (17). Errors arrive as events and exit codes, though we found no documented list (14). `codex exec resume` and `codex resume --last` continue a session, 0.163.0 restores a resumed thread's permissions and network approvals, and 0.166.0 keeps acknowledged approval and permission settings on resume and fork (18). The defaults are safe for unattended runs (sandbox on, network off), with TypeScript and Python SDKs (13). 18 + 17 + 14 + 18 + 13 = 80.)
- Maintenance & community, OpenAI Codex +17: Emdash 70 (v1.2.11 on 6 November 2026 (30). v1.2.9, v1.2.10 and v1.2.11 within two weeks (20). GitHub issues and pull requests weren't read (GitHub's pages refuse these sessions), so that line is scored absent (0). Current installers and Homebrew cask (15). Release workflows, no test CI (5). 30 + 20 + 0 + 15 + 5 = 70.); OpenAI Codex 87 (0.166.0 on 29 October 2026 (30). 36 stable release tags between 5 August and 29 October, from 0.146.1 to 0.166.0 (20). Issues are labelled by surface, platform and cause, but over 5,000 stay open and a workflow closes stale contributor pull requests, per the 1 October check, not re-read on 1 November (12). TypeScript and Python SDKs are in the same repository and built in CI (15). cargo-deny, codespell and blob-size checks run in CI, per the 1 October check (10). 30 + 20 + 12 + 15 + 10 = 87.)