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Codex — MCP Configs

File format
TOML
Syllago install method
JSON merge
Symlink support
No
Config file
.codex/config.toml
Transports
stdio

Features

How each feature converts to syllago's canonical format. See format conversion for what these statuses mean.

Fields

Native frontmatter or config fields this provider exposes. The first column is the provider's own field name; the canonical key column links to syllago's cross-provider equivalent.

Config keyConversionCanonical keySummary
enabled_toolsTranslatedConversion type: TranslatedActively mapped to the target provider’s equivalent field during conversion.Learn more →Per-server enabled_tools (allowlist) and disabled_tools (blocklist) arrays restrict which tools an MCP server exposes.
env_varsTranslatedConversion type: TranslatedActively mapped to the target provider’s equivalent field during conversion.Learn more →Per-server env_vars array of McpServerEnvVar entries; each is either a plain string (env var name to pass through) or a structured object {name, source} for named/sourced env var injection.
mcp_oauth_credentials_storeTranslatedConversion type: TranslatedActively mapped to the target provider’s equivalent field during conversion.Learn more →OAuth fields mcp_oauth_callback_port, mcp_oauth_callback_url, and mcp_oauth_credentials_store (keyring/file/auto), plus per-server oauth_resource and scopes.
mcp_serversTranslatedConversion type: TranslatedActively mapped to the target provider’s equivalent field during conversion.Learn more →MCP servers declared under mcp_servers in config.toml as RawMcpServerConfig entries (command/url, args, env, env_vars, http_headers, env_http_headers, OAuth, timeouts, enabled/disabled tools, bearer_token_env_var, supports_parallel_tool_calls).
tools.approval_modeTranslatedConversion type: TranslatedActively mapped to the target provider’s equivalent field during conversion.Learn more →Each MCP server can set per-tool approval_mode via the tools map, overriding session-level approval policy for individual tools.

Other features

Behaviors, conventions, and capabilities that aren't tied to a single named field — things like path-based activation, discovery rules, and lifecycle behavior.

FeatureConversionSummary
auto_approveTranslatedConversion type: TranslatedActively mapped to the target provider’s equivalent field during conversion.Learn more →mcp_per_tool_approval: Codex supports per-tool approval configuration to suppress confirmation prompts for trusted tools
env_var_expansionTranslatedConversion type: TranslatedActively mapped to the target provider’s equivalent field during conversion.Learn more →mcp_env_vars: Codex RawMcpServerConfig supports an env_vars array of McpServerEnvVar entries; each entry is either a plain string or a structured object with name and optional source fields enabling named environment variable sourcing
oauth_supportTranslatedConversion type: TranslatedActively mapped to the target provider’s equivalent field during conversion.Learn more →mcp_oauth_support: Codex supports OAuth 2.0 authentication for remote MCP servers
tool_filteringTranslatedConversion type: TranslatedActively mapped to the target provider’s equivalent field during conversion.Learn more →mcp_enabled_disabled_tools: Codex supports per-server tool enable/disable configuration controlling which tools are exposed to the agent
Codex MCP Server Interface (codex mcp-server)Not portableConversion type: Not portableUnique to this provider — can’t be carried across providers.Learn more →Codex exposes itself as an MCP server via `codex mcp-server` (JSON-RPC 2.0 over stdio). Primary v2 RPCs cover thread/turn/account/config/model/app/collaborationMode management. Approval requests (applyPatchApproval, execCommandApproval) flow server-to-client. Legacy v1 compatibility surface retained for existing clients. Experimental and subject to change.

Sources

Source
https://raw.githubusercontent.com/openai/codex/main/codex-rs/core/config.schema.json
https://raw.githubusercontent.com/openai/codex/main/codex-rs/docs/codex_mcp_interface.md