Hermes

  • ID: hermes
  • Store: ~/.hermes/state.db (0.17+) or ~/.hermes/profiles/<profile>/state.db (older builds, one store per profile)
  • Home: HERMES_HOME, Hermes's own variable, is followed — profiles, plugins and config.yaml are read and written under it. DEJA_HERMES_HOME overrides it.
  • Read overrides: DEJA_HERMES_PROFILES_ROOT for the profiles directory, DEJA_HERMES_DB to pin a single store
  • Postgres: with sessiondb.provider: postgresql Hermes stops writing state.db; set DEJA_HERMES_PG_DSN and deja reads the same columns from the messages table through psql (#1018)
  • Format: SQLite relational store

A flat messages table, grouped by session_id: role, content, and timestamp

as REAL epoch seconds. An assistant row that calls tools has no content and an

OpenAI-style tool_calls array instead; the result lands on a tool row under the

same tool_call_id. Calls to terminal become commands: a non-zero exit_code from

the result rides on the command. -1, which Hermes returns for a command it never

ran (denied, blocked, waiting on approval), drops the command record; any other

negative code is a process killed by a signal after it started, so the command stays. read_file,

write_file and patch name the files, and patch and write_file give the edit and

written sides — patch in its V4A mode as Hermes' own parser reads it, Move File

included, with the lines after a move or delete belonging to no file. A tool row is

kept as tool output by its output, content, diff, matches_text or error, or,

when it has none of those keys, by every string in it (search_files in files mode,

web_search, delegate_task); keys starting with _ and a bare byte count are not

kept. Rows rewound away (active = 0, compacted = 0, or active = 0 on a store

without compacted) are skipped. Rows are read in insertion order, as Hermes reads them, on SQLite and Postgres alike.

In-place compaction archives the turns it summarises and writes the kept head, a

summary and the kept tail as one batch of live rows, in one transaction at the

summary's time or under each row's original timestamp. Head rows that repeat the start

of what was archived and tail rows that repeat its end, with such a timestamp, are that

batch's copies and are not read twice (#4296); every summary anchors one, so a second

compaction's archive of the first batch is read once too. The same request or run

later counts again, and so does a tool result that is neither the archived one nor a

stub. The summary ([CONTEXT COMPACTION … or the older [CONTEXT SUMMARY]:) is kept

under the summary role; when Hermes merged it into the first tail message, the text

after its end marker keeps that message's role. The placeholder compaction leaves for an

image it stripped is not text. The compressor's stubs are dropped. Multimodal content, stored as

\x00json: and a list of parts, keeps its text parts and not the image (#4242). The

Postgres path still reads prose only. A sessions table beside it carries id, cwd,

git_repo_root and title; the cwd is where the work happened and is what names

the project, the same way a Cline or Roo workspace does. A store without that table,

or a session whose row has no cwd, falls back to the profile name. The title is left

to the index rather than taken from the first row.

  • MCP: mcp_servers in ~/.hermes/config.yaml; deja install hermes-auto also drops a plugin (~/.hermes/plugins/deja, added to plugins.enabled) whose pre_llm_call hook injects recall and registers /deja, and whose transform_tool_result hook appends what was run after the same error before to a terminal result that did not exit 0, and a memory provider (deja-memory) that hermes memory setup lists next to mem0 and supermemory — the same recall in the memory.provider slot, with deja_recall, deja_fix and deja_blame as its tools. The provider is written against the interface Hermes has: RecallStatus arrived after MemoryProvider, so it is imported behind a guard and the status line is skipped where the class is missing — checked against Hermes 0.17.0, which has none. The hook stands aside for the provider only after loading it, so a provider that cannot import leaves the hook doing the recall rather than nobody.
  • Skill: ~/.hermes/skills/deja-history/SKILL.md, top-level rather than inside the plugin: a plugin-bundled skill is opt-in in Hermes and never reaches the system prompt.
  • Resume: hermes --resume <id>; Hermes takes the same session id deja indexes, so it reopens that conversation rather than the most recent one. A session from a profile's store gets -p <profile>, since resume looks only in the active profile, and a root-store session gets -p default when another profile is active or deja runs under a profile's HERMES_HOME. A profile directory Hermes does not take by name (a reserved one like default or tmp, or one outside its [a-z0-9_-] pattern) and a session deleted with hermes sessions delete are refused with a pointer to deja show.
  • Handoff: paste.

Requested in #355.

Last verified: 2026-07-28

deja reads this format and thirty-seven others, and turns what it finds into memory your agents can search. See the harness matrix for what is wired where, or install it and search your own history.

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